Snorkel in the US Navy - 1945 Onwards
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Transcript of Snorkel in the US Navy - 1945 Onwards
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Snorkel in the US Navy - 1945 onwards
by Peter D Hulme
This article makes no claim to any direct knowledge of the systems of the US Navy,
the author having served in the Submarine Branch of the Royal Navy in the early days
of snorting. What follows is brief descrition of the US Navy snorkel conversion
garnered from the documents listed below and is intended to be comlementary to the
article Snorting in the Royal Navy ! "#$% &nward and as an ad'unct to the article US
Navy (uy Submarine )onversions "#$*!"#%$
The rimary sources are a detailed descrition of the +ngine nduction and +-haust
system of the leet Submarine rior to the /tting of snorkel system in )hater *,
0entilation System, 1T2+ 3++T T45+ SUB67RN+1 8une "#$9 Nav5ers "9"9:, and 1T2+
SUB67RN+1, art "%, The Snorkel System, revised "#%%, Nav5ers "9"9:!71. Both
being training manuals of the US Navy. The coy of the latter document was kindly
rovided by ;eith 7llen of the US7.
7ttached as aendices is a comlete descrition of the US Navy leet Submarine
snorkel system and oeration made available by Bob +mery of the Submariners
7ssociation of )anada West. The Royal )anadian Navy had at one time oerated two
former US Navy leet Submarines.
n this article have focused on snorting the US Navy, however there is a
comlimentary article Snorting in the Royal Navy ! "#$% &nward
USS Irex (SS 482). First US Navy snorkel as !er"e#te$ in t%is US submarine in &'4.
Not a u!!y. In later years s%e a!!eare$ in a more streamline$ "orm it% *uns et#
remove$ an$ a !lasti# sail (+SS 482)
Historical Outline
The /rst US Navy submarine laced in oerational service with snorkel was the USS
re- <SS =>?@ in "#$*, a leet Submarine of the Tench class originally comleted in
"#$%.
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See 7endi- 7 for details of the history of US Navy snorkel develoment leading u
to the conversion of the USS re-.
This successful conversion design was alied to the arallel (uy conversion
rogram, the /rst conversion comleted in "#$*.
3ater when the (uy conversions roved too e-ensive, a rogram was initiated to
add snorkel to "? leet Submarines of the similar Balao and Tench classes. n general
aart from snorkel, they remained as /rst built but to accommodate the snorkel masts,
the older style conning towers were converted to a steed /n as seen in the early
(uy conversions. This class of "? submarines were known as leet Snorkels. The
/tting of snorkel usually took lace as art of regular shiyard overhauls.
t should be noted that aart from the more formal rogram of "? submarines, others
were also /tted with snorkel throughout the US Navy Submarine leet.
7ll leet Submarines conversions of any tye were rogressively hased out as the USNavy Submarine Service moved to become entirely nuclear roelled. 7 signi/cant
number were handed over for service with foreign navies.
This information was taken from T2+ 3++T SUB67RN+ N T2+ U.S. N704 by
)ommander 8ohn A 7lden. US Navy <ret@.
+-tract from 7dmiral (alantin1s SUB67RN+ 7A6R73 5age "=9
USS Pi#kerel (SS ,24) as one o" t%e u!!y II. Un$er %er innovative- $arin* ski!!er-
omman$er Paul / S#%rat0- s%e $emonstrate$ t%e ultimate !er"orman#e o" t%e
snorkel. S%e as t%e 1rst u!!y to be $e!loye$ to t%e Far ast- an$ in returnin* toPearl Harbour "rom Hon* 3on* s%e snorkelle$ all t%e ay- ,&'4 miles in ,, %ours. It
re5uire$ #are"ul !lannin*- su!erb en*ine o!eration an$ maintenan#e- an$ *reat
!%ysi#al stamina an$ $etermination. Her tenty6one $ays #ontinuously submer*e$ in
&', remaine$ a re#or$ until &',8- %en nu#lear !oere$ Seaol" ma$e %er sixty
$ay test.
Note. 5resumably the 7dmiral means a record for the US Navy as 26S 7lliance was
submerged for =: days continuously during her snort cruise in "#$*. 2owever she only
covered ="#= miles. The 5ickerel aarently achieving the remarkable average
submerged snorkel seed of ":.>? knots er day.
While the detail in 7endi- tem " aears to reeat much of what has been stated
in 7endi- B, 7endi- ), 7endi- A and 7endi- about the leet Submarine
conversions, it should be areciated the US Navy submarine veteran who contributed
this anecdote is describing the snorkel system on the new diesel submarine Blueback,
one of three Barbel class constructed for US Navy after the war, with snorkel
integrated into the design.
The Barbel class were the only US Navy diesel submarines with the revolutionary hull
shaed develoed in the trial submarine USS 7lbacore <7(SS %9#@, launched in "#%>.
ncidentally this shae became the basis of the hulls of US Navy SSN submarines
starting with the Ski'ack class of "#%?. The USS Barbel <USS %?:@ was commission in
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"#%#, more than a decade after the /rst snorkel submarine, USS re- <USS $?>@, "#$*,
yet in rincile little had changed.
t is of interest that he con/rms other sources that suggest that the Barbel class had a
similar snorkel system to that of the much earlier ost war Tang class.
The lead submarine, USS Tang <SS %9=@ was launched in "#%", and from these dates
we can seculate that the both the snorkel systems for the conversions and the new
submarines were being develoed at the same time. The only signi/cant dierence
aears to have been the use of a dry induction mast in the new submarines that also
only had one engine room. There the US Navy diesel snorkel story stos.
Documents
7 full descrition of develoment and alication will be found in these attached
documents.
• 7endi- 7 Submarine Snorkel System Aeveloment in the US Navy.
• 7endi- B 7ir nduction C Snorkel nduction Systems.
• 7endi- ) Snorkel +-haust System.
• 7endi- A Snorkel +lectrical C +ngine Safety )ircuit Systems.
• 7endi- + leet Submarine Snorkel &erating 5rocedure.
• 7endi- 7necdotes.
• 7endi- ( U!Boat 2istory, Aeveloment C +Duiment, "#"$ to "#$% by Aavid
6iller.
A SUA!" O# $H% &ON'%!S(ON
Before roceeding it should made clear that all the main iing is outside the ressure
hull under the outer shell. n the simle diagrams mentioned below, eDuiment within
the ressure hull is so indicated.
Basically the systems used in the US Navy leet Submarines were similar to those
described in the comanion article Snorting in the Royal Navy ! "#$% &nward . That is
a single air induction mast and a single e-haust mast, but all rather more comlicated
in alication.
There were two engine rooms each with two diesel!generators. These big submarines
were not direct drive, with at all times the screws being driven by electric motors
sulied from the batteries alone when submerged and the diesel!generators when
surfaced. The four diesel!generators could be arranged for 1all roulsion1 for
ma-imum surface seed <"# knots@ or both roulsion and charging the batteries.
0arious sources suggest that this roulsion arrangement was more suitable or
snorkelling than direct drive, in that no forward way was lost when snorkelling wasshut down due to a temorary loss of trim, the battery continuing to suly the motors
without any break in suly.
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This roulsion arrangement also brought about a rather dierent crew organisation
for snorkelling than the early Royal Navy direct drive, where the engines were directly
roelling the submarine, see 7endi- +. n the ost war scene, the Royal Navy
adoted this method of 1all!electric1 roulsion in the converted T )lass and the
5arthian )lass C &beron )lass. The later Royal Navy Uholder )lass, like all modern
multi!engine single screw submarines, had the single screw driven e-clusively by onelarge electric motor.
There has been a suggestion that the four stroke Royal Navy engines were more
tolerant of being occasionally Eooded through the oen e-haust than the US Navy two
stroke. 7endi- 7necdote $ gives a clue about this asect of snorkelling. t is known
the US Navy engine iston heads were modi/ed for snorkel.
)re-Snorkel (nduction
&n the surface the main engine air inlet was through a =9 inch ventilation stack and
valve <also described as the main induction valve@ in a comartment in the lower afterart of the bridge, oen to the sea when dived.
The stack was mounted on the outside of the ressure hull, raised by mounting legs.
The stack distributed air to the two engine rooms and shis ventilation through >> inch
ies installed on the outside of the ressure hull.
The outut air of the iing was admitted through the ressure hull into each engine
room by a manually oerated induction hull valve. 7 detailed drawing of this hull valve
is shown in 7endi- B.
7lso connected to the =9 inch ventilation stack was an additional outlet ie feeding
the aft air inlet for the ventilation system with a similar but smaller hull valve.
To reca, on the surface air was taken in through the bridge structure and fed into
each to the two engine room comartments, with additional air fed into the vessel for
ventilation. +ach oint of entry into the ressure hull could be sealed for diving by an
ad'acent hand oerated valve. 7 simle line diagram has been rovided to assist the
reader of this section of the summary,
Fig 1. Snort Induction Line Diagram
7%is is a mu#% sim!li1e$ $ia*ram o" t%e snorkel #onversion o" a US Navy eetsubmarine. It is in#lu$e$ to *ive t%e rea$er some i$ea o" t%e 9!lumbin*9 $es#ribe$ in
$etail in t%e a!!en$i#es. 7%e bla#k is !re #onversion. 7%e blue an$ re$ s%o t%e
a$$itions.
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Inset on t%e 1*ure are t%umbnail si0e !%oto*ra!%s o" t%e :; in#% ventilation sta#k an$
an in$u#tion %ull valve.
)re Snorkel %*haust
+ach engine had inboard and outboard e-haust valves, in much the same
arrangement as the Royal Navy. 2owever the individual outboard valves to each of the
four surface muFers were hydraulically oerated.
t is interesting to note that the inboard valve aears to be a sluice tye as /tted in
"#9? to Royal )anadian Navy 1&1 class.
Both inboard and outboard e-haust valves were water cooled, the inboard by water
from the engine fresh water system, the outboard by water from the engine salt water
system.
So to reca, the original engine e-haust set!u was Duite straightforward with each of
the four engines having searate valves and muFers.
Snorkel (nduction &onversion
The conversion to snorkel involved the relacement of the former conning tower
structure with a modern style steed 1Sail1 suorting the eriscoes and the various
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masts including the telescoic snorkel induction mast and the single telescoic snorkel
e-haust mast.
The induction air from the snorkel mast was taken through a large water searator and
a hydraulically oerated shut o induction valve to a new inlet in the structure of the
=9 inch ventilation stack still in its former osition but now enclosed by the after artof the sail as shown inset in ig ".
The distribution of air from the =9 inch ventilation stack remained as before aart from
a change in the shi1s ventilation system that aears to have been simli/ed.
5reviously there had been a artial bye!ass from >> inch ie feeding the main
induction to the aft engine room. This bye!ass sulied air to the single ventilation
hull valve aft in the manoeuvring room, while the "9 inch ie from the =9 inch
ventilation stack fed a ventilation hull valve in the forward engine room. 2ence there
were two smaller tye ventilation hull valves.
n the snort conversion the hull valve in the forward engine room and the artial bye!
ass were aarently removed. The shi1s "9 inch ventilation ie then simly ran
from the =9 inch ventilation stack to the e-isting ventilation hull valve aft. No te-t
e-lanation of this asect of the conversion is available but this is the arrangement
shown in all the drawings associated with this article and aendices. 7lso there is
nothing in the te-t to indicate ma'or changes in the battery ventilation as was the case
with the (uy conversions.
Snorkel %*haust &onversion
Turning to the engine e-haust, obviously the reviously four Duite searate enginee-haust systems had to be 'oined together to form a single ie to the snorkel e-haust
mast.
t was also considered desirable to isolate the iing etc, of the unused engines from
that of the snorkelling engines. The result was a relatively comlicated set of valves
and iing. 7 comlete descrition is rovided in 7endi- ), but a simle line
diagram has been rovided to assist the reader.
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Fig 2. Fleet Submarine Snorkel Exhaust System
t should be noted most of the e-haust iing is ressure tight and not Eooded at any
time. )heck drains were /tted.
(nduction ast Head 'alve
The induction mast had a head valve that closed to revent the ingress of sea water if
the submarine lost trim and went below snorkel deth. Unlike the British who
develoed their own version of the widely used U!Boat Eoat oerated valve, the US
Navy adoted a design where the head valve was oened and closed by high ressure
air, controlled by electrically oerated valves.
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7endi- 7 suggests this alternative to the U!Boat Eoat valve, was another (erman
develoment and this is con/rmed by 7endi- (. Though this reference also states
the develoment was not comleted before WW ended.
t is Duite clear from a hotograh of the snorkel head valve from U!=%:=, that Eoat
valves were being used on at least one of the latest (erman tye GG submarines ofWW. The scuttled U!=%:= was raised by the Swedish Navy and dismantled. 6ore
hotograhs can be seen here
t is reasonable to assume that the Tye GG U!Boats ut into trials service by the US
Navy had similar Eoat valves, but that the US Navy chose to roceed and comlete the
develoment of the (erman electro!neumatic snorkel head valve and this became
standard in the US Navy.
The celandic owned website UBoat.net that e-tensively records the history of the
(erman U!boat Service, shows a ost WW drawing of three dierent U!Boat snorkel
head valves with little background te-t. ncluded are the Eoat and the electro!neumatic versions. No original (erman source is given for these drawings.
Regardless of the origin of the design, the US Navy e-clusively used an electro!
neumatic electrical head valve control system automatically oerated by salt water
sensitive electrodes mounted on the snort head.
Thus if the electrodes were Eooded, the head valve was closed. The closing of the
head valve was assisted by srings and should the air ressure fail the srings would
close the head valve. When the electrodes were clear of sea water, the head valve
would again be oened by 25 air.
%*haust ast
Unlike Royal Navy conversions with a simle oen outlet to the sea , the US Navy
snorkel e-haust mast had a fairly comle- diuser head that added a venturi!like
action to aid in the e-haust rocess. t was of course still oen to mast Eooding if the
engine back ressure droed too much.
The e-haust mast raising mechanism was driven by the same hydraulic motor that
raised the induction mast, but the gearing was such that the reDuired relative
dierence in heights when raised was achieved by using a dierent gear ratio for each
mast, hence the induction mast and e-haust masts were raised as one unit, described
in 7endi- ). and the relative heights can be seen in the hotograhs below. This
arrangement has similarities to the (erman Tye GG U!Boat in that both masts were
raised by the same mechanism, but in the GG the two tubes were 'oined at the to
with the inlets and outlets Duite close together however further discussion of the Tye
GG is beyond the scoe of this article.
The main Snorkel +-haust 0alve <7ble@ was Duite sohisticated in its oeration. When
the hydraulic ressure was alied to oen the valve, it would not oen until assisted
by the increasing engine back ressure. The valve was designed to shut hydraulically
against the engine e-haust ressure should the mast Eood.
Automation
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t should be noted that unlike Royal Navy submarines, there were automatic engine
shut down facilities triggered by low vacuum, low engine back ressure and low
engine rm. 7endi- 7necdote No. ", gives detail of the later Barbel class system
that was basically similar to the original leet Boat conversion
Note+ t is understood from various US Navy Sub0et sources that only one engineroom <two AH(@ was used for snorkelling, usually the two forward AH(. 2owever in the
(uy (7 conversions, one diesel!generator was removed to make eDuiment sace,
detail of the lay!out and oeration is not known.
ast )hoto,rahs
Provi$e$ by <ob mery o" Submariner9s +sso#iation o" ana$a =est.
USS Dio$on SS:4' (+ II u!!y) =est!a# &';. SN>/3? INDU7I>N @ AH+US7
B+S7S /+ISD
7%is !%oto*ra!%- t%ou*%t to be USS %o!!er SS:42 (a &+ u!!y #onversion ) isin#lu$e$ be#ause o" its novelty an$ t%at it *ives anot%er vie an*le. 7%e to men are
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sat on t%e ex%aust %ea$- t%e in$u#tion mast is imme$iately "orar$ o" t%em. 7%ey
a!!ear to be takin* !%oto*ra!%s.
A$$A&. SU/A!(N%
The "#%% US Navy training document includes a reference to the ost!war submarines
with snorkel /tted as art of the overall design, as 7TT7); SUB67RN+S. They were in
fact the twin screw Tang class, the last numerically signi/cant diesel class in the US
Navy built in ost WW. The 5arthian )lass C &beron )lass of the Royal Navy
submarines may reasonably said to be comarable. Both classes being the roduct of
the early ost!war thinking of both navies. There is some discussion in the (uy
conversions article.
&ne of the key changes was that unlike the US Navy conversions and British ractice,
the snorkel induction mast remained dry, that is not Eooded when not in use. The
induction mast head valve was aarently caable of keeing the mast watertight at
any oerating deth.
&ne drawing shows the induction being formed by two smaller ies rather that one
single but larger tube.
t is assumed the main reason for this dry mast was that it avoided dealing with ?:::
lbs of sea water that in the conversions had to be either Eooded into the induction
mast when not in use or drained into the submarine when rearing snorkel. 7ll these
actions eect the management of the trim of the boat. 5resumably the lesser amount
of water in the e-haust mast of about =::: lbs, was tolerable. &ne can seculate that
this dry snort mast allowed a faster transit from snorkelling to a safe deth if in danger
of attack.
7nother signi/cant change was the use of the snorkel induction mast head valve as
the engine induction when running on the surface. This induction method seems to
have been the attern for most new ost war submarines.
f the snorkel induction mast was still e-tended at "?% feet, it was automatically
ressed down to the lowered osition.
6uch the same systems aear to have been used in the advanced class of three
submarines, the Barbel class of "#%#. 7s reviously mentioned, there is Duite a lot of
detail in 7endi- 7necdote No. "
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Aendi* A
Su0marine Snorkel System Develoment in the US Navy
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USS /6; snorkel mast. Bast is !ermanently 1xe$ to t%e Starboar$ si$e o" t%e
teles#o!in* ra$io mast. 7%e stran*e C%ookC is t%e en*ine ex%aust. 7%e /6; as t%e
test !lat"orm "or !er"e#tin* t%e US version o" t%e Dut#% invention o" t%e snorkel. =%en
t%e ermans inva$e$ Hollan$ t%ey took t%e te#%nolo*y an$ in#or!orate$ it in to t%e U6
<oat. P%oto taken +u*ust &'4, in Ft. ?au$er$ale- Flori$a Durin* snorkel testin*
o!erations.
P%oto !rovi$e$ by /ay ar*an %ose "at%er serve$ on t%e /;.
Several snorkel systems or snorkel!like systems were installed on board US
submarines. Simon 3ake used an engine e-haust system that utiliIed a ie e-tending
above the main deck aft. The 7lligator <"?9>@ had an 1air tube1 to allow air to be drawn
into the boat while it was submerged at a shallow deth. The )SS 2unley had a similar
air tube system. 8ohn 2olland1s 5lunger <"?#?@ was to have a coiled hose system which
had a Eoat to ermit air to be drawn in from a deeer deth than either the 7lligator or
2unley.
The snorkel system design and testing rogram for what can be called the 1standard
submarine snorkel1 is summarised belowJ
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5ortsmouth Naval Shiyard <;ittery, 6+@ erformed the design work on a snorkel
system as an indeendent design using catured bluerints and a snorkel mast
system catured in Toulon, rance. )N& directed, on >: 8anuary "#$%, that an
accelerated design and build rogram be instituted and an R!)lass submarine be
selected for e-erimentation <this is eDuivalent to the +ngineering Aeveloment 6odel
in today1s language@. K)N& letter of >9 8anuary "#$%L.
The R9 was selected and the snorkel was /tted in 5ortsmouth during the eriod ":
7ril to >: 6ay "#$%. The system was tested and rovided information on the eects
of the snorkel on ersonnel and eDuiment. 5iing was installed on the main deck for
simlicity and the snorkel mast was /-ed in an uright osition. R9 took the system to
lorida in 7ugust "#$% for testing in an 7SW setting. The boat oerated for three days
in southern waters <out of t. 3auderdale@ during the eriod = to >% 7ugust "#$% and
three ma'or engine casualties were reorted. 2owever it is unknown whether these
were due to the snorkel or were due to other factors such as age and maintenance.
The system1s comonents were removed rior to the decommissioning of the boat inSetember "#$%.
USS /62 SS' Provi$e$ by /i#k ?arsen BBB (SSS) (ret)
The ne-t testing hase was held aboard the USS Sirago <SS!$?%@ KNoteJ this is not the&da- <SS!$?$@L immediately after her commissioning <)ommissioning was on ":
Setember "#$%@. 5reliminary tests took lace at 5ortsmouth during the eriod "" to
"= Setember "#$%. The tests were to determine if the design was adeDuate and the
eect of snorkelling on diesel engines and ersonnel.
MSirago had four airbanks 6orse ": cylinder A=? ?!"H? engines numbered ?$?%?*
through ?$?%#:. &nly one engine was /tted with the e-haust ducting for testing,
number ?$?%??. The tests on "" Setember tested the machinery, calibration of the
measurement eDuiment and ersonnel orientation. +ngine standardiIation runs were
carried out on the ">th. These included runs at snorkel deth <alongside@ to determine
the eect of the varying back ressure on engine seed and loading. &n the "=th runswere made which simulated wave action on the <Eoat tye@ head valve cycling. The
system was dismantled starting on "* Setember.
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+lectric Boat )omany had been designing their own snorkel system. They asked the
Navy to rovide the data that had been comiled during the testing of R9 and Sirago.
The comany roosed on "> 8une "#$% that a system be ut aboard either
)lamagore <SS!=$=@ or )obbler <SS!=$$@. The Navy nsector of Shibuilding selected
)lamagore. 2owever, in +lectric Boat1s oinion the )lamagore was too close to
comletion and ushed for the )obbler in a test lan dated "# 8une "#$%. BuShisaroved the lan on $ 8uly "#$%. The test was not a full snorkel system but a
ressure variation test using 'ust the ower oerated head valve. The head valve was
to be fastened to a late which was then mounted on the after engine room hatch.
2owever, in the builder1s underway trials <rior to the head valve testing@ the lube oil
systems of the four main engines had roblems and the testing was delayed. +lectric
Boat withdrew from further snorkel design for Eeet submarines.
The re- <SS!$?>@ received the /rst 1full u1 snorkel system in 5ortsmouth Naval
Shiyard starting in Aecember "#$9. The system was evaluated in e-tensive testing
during the eriod 8uly "#$* to ebruary "#$?. She was then the /rst US submarine tobecome oerational with a snorkel.
+-tracted from Warshi nternational 0olume $" Numbers " and $. ONow 2ear ThisO
column by 6r. ). Wright. 5rimary research done by 6r. 6ark ) 8ones and 6r ) Wright.
+dited for content by 6r 8im )hristley
5rimary source material can be found in BuShis (eneral )orresondence iles )!
SSHS$"!%, )!SSHS9?, )SS?= and SS?= in the National 7rchives.
Aendi* /
Air (nduction 2 Snorkel (nduction Systems
Ba$e available by <ob mery o" t%e Submariners +sso#iation o" ana$a =est
A(N (NDU&$(ON
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While on the surface air is introduced into the submarine through the main induction
valve, the largest valve on the submarine. The main induction is =9 inches in diameter
and is located in the after art of the sail aro-. >? feet above the keel. t is of the
oet mushroom tye with an umbrella tye hood. 7ir entering through the valve
must /rst ass under this hood, which hels reduce water or sray during heavier
seas. The main induction valve oerating mechanism is located in the forward end ofthe after battery comartment and is normally oerated hydraulically from the
hydraulic manifold in the control room.
(NDU&$(ON HU33 'A3'%S
)onnected to the main induction are three air induction lines, along with a line to the
snorkel induction system. The shi1s ventilation line is "9 inches in diameter and runs
aft to a oint above the forward end of the forward engine room. 2ere it accesses the
ressure hull via the shi1s ventilation hull valve and into the ventilation suly
system. Two larger induction lines, >> inches in diameter, also run aft from the main
induction. The ort line accesses the ressure hull via the forward engine room
induction hull valve and sulies the forward engines. The starboard line accesses the
ressure hull via the after engine room induction hull valve and sulies the after
engines. 7n inboard hood surrounds the engine induction hull oenings, with a sheet
metal iing leading to the lower Eats to revent water carry!overs to machinery and
crew. 7ll outboard induction lines, valves and /ttings are designed for ma-imum
submergence ressure. There are drain lines installed to indicate Eooded iing and
the induction iing will hold aro-. "? tons of seawater if Eooded during a casualty.
The three induction hull valves are of the Eaer tye and their oerating gear
consists of a lever with a Duick release mechanism. They are manually oerated by a
hand lever with a cam locking device held oen by a Duick release locking device.
When the Duick release gri is deressed, the locking device is withdrawn and the
valves seat with their own weight. 7 gagging screw is rovided so the valves can be
gagged shut internally for ressure tests or other damage control uroses.
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INDU7I>N HU?? E+?E
SNO!.%3 (NDU&$(ON AS$
The snorkel induction mast is made u of a vertical, /-ed base ie and a telescoingsection. The telescoing section may be comletely retracted into the base ie or
ositioned above it at various redetermined oerating ositions. The telescoing
section is raised and lowered by hydraulically driven gears and shafting. The e-haust
mast and induction mast are geared together and are raised and lowered
simultaneously. The /-ed base ie forms a watertight tube for an air intake between
its uermost e-tremity and the iing leading to the branch lines of the main
induction valve.
When the telescoing section is in one of its oerating ositions, the watertight tube is
e-tended to the height of the head valve. n the housed osition, or any osition other
than an oerating osition, the mast will Eood at the 'uncture of the two iing
sections. Watertight seals are formed between the two sections of iing when the
mast is in the oerating ositions. The seals consist of built u circular steel bands
around the lower outer surface of the telescoing section and circular neorene
<rubber@ insert gaskets that are imbedded in the inner surface of the /-ed base ie.
The neorene gaskets are installed at seci/ed ntervals in the ie to rovide for
multi height snorkel oeration.
When the snorkel induction mast is Eooded, it contains aro-imately ?,::: ounds of
seawater. 5rior to snorkelling, the water must be removed from the snorkel induction
mast. The water is drained or blown to negative tank.
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7s noted above, the snorkel induction mast is constructed to ermit snorkelling at
various deths. t can be oerated in con'unction with radar antennas and eriscoes
in such a way that all are e-osed to the roer amount for ma-imum ePciency and
minimum e-osure.
Snorkelling can be conducted at either the No. " eriscoe deth or the search radardeth, with the actual snorkelling deth being usually controlled by the sea state.
When there is an increased risk of Eooding through the main induction when surfaced
during articularly heavy weather, the main induction valve can be shut and the
snorkel induction mast utiliIed to introduce oerating air into the submarine.
SNO!.%3 H%AD 'A3'%
The snorkel head valve, together with its housing, is a unit caing the snorkel
induction mast. The snorkel head valve is a >"O oet tye, Duick shutting valve
designed to minimiIe the amount of water taken into the induction system duringsnorkel oerations. When snorkelling, the head valve housing is normally the only art
of the submarine e-osed above the water1s surface, with the e-cetion of antennas
and masts which may be in use.
The head valve is automatically oerated by an electro neumatic control system,
which is installed as a art of the head valve safety circuit. When the head valve
electrodes, which are e-ternally mounted on the head valve housing below the level of
the valve seat, are above the water1s surface, service air is admitted by the head
valve control valve to hold the head valve oen against sring ressure. f the
electrodes are immersed, the head valve control valve vents o. the oening air and
sulies service air to the other side of the ower cylinder, causing the head valve to
shut by air ressure, sring ressure, and the weight of the valve. Thus the head valve
is oened by air ressure alone and shut by sring ressure, air ressure, and the
weight of the valve.
The head valve control system is designed to 1fail safe1. The head valve will shut if air
ressure andHor electric ower fail.
7n electro neumatic control valve located in the control room controls the snorkel
head valve. The control valve is normally oerated automatically by a solenoid
installed as a art of the head valve safety circuit. nstalled on the control valve is ahand oerated latch, which is used to hold the head valve oen <if desired@ while
oerating under normal surface conditions. The head valve may be held oen during
submerged oerations if desired. 7n emergency shut control valve is also rovided in
the air suly system.
A$%! S%)A!A$O!
7 water searator is installed in the snorkel induction iing between the snorkel
induction mast and the snorkel induction valve. The water searator is cylindrical in
shae. This water searator works on the rincile that the inertia force of a column of
air can be utiliIed to direct the air in a swirling motion inside the circular chamber.
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When snorkelling, the engine scavenging air blower creates a vacuum in the shi,
resulting in a constant intake of air through the snorkel induction mast and attached
iing. The incoming air is assed through the water searator in a swirling motion.
This action carries the heavier dros of water to the outer edge of the revolving air
column where they are collected on a saw tooth edge baFe late and allowed to run
down the baFe late into the drain rovided in the base of the water searator.
Water collected there is drained to negative tank or to the um room bilges <the
water is usually drained to negative tank@.
SNO!.%3 (NDU&$(ON 'A3'%
The air asses from the water searator through induction iing to the main
induction stack. The snorkel induction valve is located in this line between the water
searator and the trunk of the main induction valve.
The snorkel induction valve is aro-imately "% inches in diameter, is of the Eaertye and seats with air ressure. t is hydraulically oerated from the snorkel control
manifold located in the control room and may be manually oerated from the crew1s
galley if hydraulic ower is lost.
Aendi* &
Snorkel %*haust System
Ba$e available by <ob mery o" t%e Submariners +sso#iation o" ana$a =est
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The snorkel e-haust mast is a vertical telescoing mast housed in the conning tower
sail and mounted abaft the snorkel induction mast.
7 central snorkel e-haust line e-tends from the base of the snorkel e-haust mast
within the suerstructure to the vicinity of the forward engine room. 7t this oint the
line divides into two branch lines, one line going toward the forward main engines " C
>, and the other line going toward the after main engines = C $. +ach branch line
further divides into two more lines with each division going to an engine e-haust
system. These lines connect to the engine e-haust lines between the inboard and
outboard e-haust valves. The connection is made in the forward, vertical face of the
outboard e-haust valve housing.
3ocated in the horiIontal iing near the base of the e-haust mast is the main snorkel
e-haust valve <7ble 0alve@ which serves as the sea valve in the Snorkel +-haust
System.
)aing the e-haust mast is an e-haust gas diuser late that aids in reducing a
telltale lume of water while snorkelling.
The Snorkel +-haust System consists of the following ieces of eDuimentJ
". the snorkel e-haust mast.
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>. the snorkel e-haust diuser late.
=. the main snorkel e-haust valve <7ble 0alve@.
$. the forward engine room snorkel e-haust valve <Baker 0alve@.
%. the after engine room snorkel e-haust valve <)harlie 0alve@.
9. the e-haust iing.
%HAUS$ AS$
The snorkel e-haust mast is made u of a /-ed base ie structure designed to
receive a second telescoing section of ie. This mast is designed for snorkel
oerations at induction mast oerating deth. The lower li of the fully e-tended
telescoing section of the e-haust mast forms a metal to metal bevel seat with a built
u li surrounding the to of the /-ed base ie. 7t the lower osition a close /t
between the base ie and the telescoing section e-ists. No seal is formed, but thero-imity of the two ies recludes raid Eooding. The water that does enter the
mast is raidly vaoriIed and blown out by the engine e-haust gases.
The snorkel e-haust mast is geared to the induction mast and raises and lowers with
it.
The e-haust mast does not raise as high as the induction mast, thereby ermitting the
e-haust to be e'ected below the surface of the sea. Such an arrangement reduces the
amount of snorkel engine e-haust and sray that may be visible to a searching shi or
aircraft.
7t the start of snorkelling all the water in the snorkel e-haust mast <aro-. =::: lbs@
is blown to sea by engine e-haust ressure.
%HAUS$ D(##US%! )3A$%
The diuser is designed to break u the e-haust gas stream and radially e'ect the
gases into the surrounding water. t consists of a cylindrical framework with vertical
vanes mounted around the erihery of this framework. The forward side of the
framework is shielded by a circular iece of sheet metal. This shield revents dynamic
water ressure, due to own shis1 motion, from imeding e-haust in'ection. 7 large
deEector late is mounted on to of the diuser, and e-haust gasses e'ected from the
snorkel e-haust mast are radially discharged through the vanes and forced to bubble
to the surface around the erihery of the deEector late.
A(N SNO!.%3 %HAUS$ 'A3'% 6A/3% 'A3'%7
The main snorkel e-haust valve is located in the snorkel e-haust iing near the base
of the snorkel e-haust mast.
This valve seals the after Snorkel +-haust Systems from the free Eooding e-haust
mast, acting as the snorkel eDuivalent of an engine outboard e-haust valve.
This valve is a "% inch hinged Eaer tye unit housed in a cylindrical metal structure.
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The main snorkel e-haust valve is designed for hydraulic or manual oerations, the
oerating gear being located in the overhead of the shi1s galley.
The main snorkel e-haust valve is also known as 7ble 0alve and is designed so that a
combination of hydraulic ressure and engine back!ressure is reDuired to oen it.
t is oened hydraulically by concurrence of all of the following conditionsJ
". 7ble 0alve in the 15ower 5osition1 and hydraulic ower available.
>. control room lever in 1)ontrol in +ngine Room1 osition.
=. engine safety circuit energiIed.
$. e-haust back ressure "* si or above.
%. 7ble 0alve control lever in engine room is oened.
7ble 0alve may also be oerated by hand from the after battery comartment.
#O!A!D %N8(N% !OO SNO!.%3 %HAUS$ 'A3'% 6/A.%! 'A3'%7
The forward engine room snorkel e-haust valve is located in the snorkel e-haust
iing above the forward engine room. t can be oerated hydraulically from the
snorkel hydraulic manifold located in the forward engine room, or manually at the
valve oerating gear in the forward engine room. This valve receives the e-haust
gases from " C > main engines. The forward engine room snorkel e-haust valve is shut
when surface cruising. f the valve was oened, or was not installed, engine noises
would be magni/ed by the resonance of the e-haust iing and carried as far as themain snorkel e-haust valve. Saces such as the bridge area and the radio room would
be diPcult to work in under these circumstances. The valve also serves as an
additional safety factor in the Snorkel +-haust System. The forward engine room
snorkel e-haust valve is also known as Baker 0alve.
A#$%! %N8(N% !OO SNO!.%3 %HAUS$ 'A3'% 6&HA!3(% 'A3'%7
The after engine room snorkel e-haust valve is located in the snorkel e-haust iing
above the after engine room. t is designed for hydraulic or manual oeration, the
oerating gear being located in the after engine room. This valve receives the e-haust
gases from = C $ main engines. t serves the same urose as the forward engineroom snorkel e-haust valve and it is shut when not snorkelling. The after engine room
snorkel e-haust valve is also known as )harlie 0alve.
SNO!.%3 AS$ HO(S$(N8 %&HAN(S
The snorkel hoist mechanism is designed to raise the snorkel induction and e-haust
masts simultaneously. When the masts are in either of the two oerating ositions, the
e-haust mast is at a reset distance below the snorkel head valve. This laces the
snorkel head valve above water and the to of the snorkel e-haust mast beneath the
surface of the water.
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2oisting ower is sulied by main hydraulic ressure, driving a modi/ed % 7 +nd
hydraulic motor, which in turn drives gears meshing with rack gearing on the induction
and e-haust masts.
By using a dierent gear ratio, the induction mast travels a greater distance than the
e-haust mast for the same number of turns of the hydraulic motor. This ermits thetwo masts to be in the roer relative height ositions although starting from the
same initial level.
SNO!.%3 %HAUS$ )()(N8
The snorkel e-haust iing, valves and /ttings between the main snorkel e-haust
valve <7ble 0alve@ and the four main engine outboard e-haust valves are designed for
ma-imum submergence ressure, with drain lines installed to indicate Eooded iing.
Aendi* D
Snorkel %lectrical 2 %n,ine Saety &ircuit Systems
Ba$e available by <ob mery o" t%e Submariners +sso#iation o" ana$a =est
SNO!.%3 %3%&$!(&A3 S"S$%
The snorkel electrical system rovides the electrical controls which oerate the snorkel
system1s hydraulic and neumatic control devices, indicating lights and horns. 5ower
for this system is normally sulied from the ">: volt, 9: cycle single hase, a c bus
on the ) switchboard.
The snorkel system is so designed that the loss of all a!c ower or ower to the diesel
engine safety circuit will cause a shutdown of snorkelling.
AS$ 3%'%3 (ND(&A$(N8 &(!&U($
This circuit indicates the osition of the snorkel mast in any of three ositionsJ 67ST
U5, 67ST N 3&W+R &5+R7TN( 5&ST&N, and 67ST A&WN. Three lights on the
control room snorkel anel indicate the aroriate osition.
H%AD 'A3'% (ND(&A$(N8 &(!&U($
This circuit rovides indication of the osition of the head valve, either &5+N or S2UT.
H%AD 'A3'% O)%!A$(N8 &(!&U($
This circuit controls the oeration of the head valve so that water will not be taken in
through the induction mast while snorkelling. Three electrodes located in the head
valve housing normally control the head valve. The head valve may also be oened or
shut manually by the head valve control switch located in the control room. The three
electrodes are mounted at ">: degree intervals around the erihery of the head
valve housing, slightly below the valve seat. The electrodes are designated 5&RT,
ST7RB&7RA and 7T. The electrodes are connected into the control circuit by switches
located on the control room snorkel anel. The switches are designatedJ 7T, 5&RT,
and ST7RB&7RA.
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When the head valve oerating circuit is energiIed, a wave washing over one of the
electrodes will cause it to be shorted out. This action will de energiIe the head valve
control solenoid and the head valve will be forced shut by shis service air ressure
and sring ressure. 7s soon as the electrode short is removed, the head valve control
solenoid is energiIed and shis service air forces the head valve oen.
3ocated on the control room snorkel anel is a test switch to simulate shorting out an
electrode. 7lso located in the control room is a diving oPcerQs switch with which the
diving oPcer can cause the head valve to oen or shut at any time.
(NDU&$(ON AS$ #3OOD%D (ND(&A$(N8 &(!&U($
To rovide indication of a Eooded snorkel induction mast, there is an electrode located
in the snorkel air induction ie between the water searator and the snorkel
nduction valve. f water collects in this section of the induction iing, the electrode is
shorted and a Easher unit warns ersonnel in the control room. There is a test switch
that is used to test the circuit by hand for roer oeration. The switch is sringloaded so it is normally in the oen osition.
SNO!.%3 O!D%! &(!&U($
The snorkel order circuit rovides a means of transmitting signals from the control
room to the engine rooms and the manoeuvring room. The snorkel order switch is
located on the snorkel control anel in the control room. 5ositions on the switch are
labelled SN&R;+3, S+)UR+ SN&R;+3 and &.
When the order switch is turned to SN&R;+3, green indicating lights are lighted on all
four control anels <control room, forward engine room, after engine room, andmanoeuvring room@.
When the order switch is turned to S+)UR+ SN&R;+3, red indicating lights are lighted
on all four control anels and horns sound in the engine rooms and the manoeuvring
room.
When the switch is turned to &., the system is comletely de energised and no
indication shows on any of the anels.
A(N SNO!.%3 %HAUS$ 'A3'% H"D!AU3(& &ON$!O3 'A3'%S
The main snorkel e-haust valve, referred to as 7ble 0alve, can be shut, but N&T
oened from the control room at any time. The control valve is of the sool tye, four
way and manually oerated. The two oerating ositions areJ )&NTR&3 N +N(N+
R&&6 and +6+R(+N)4 S2UT.
or normal snorkel oerations, the control room 7ble 0alve control valve is laced in
the )&NTR&3 N +N(N+ R&&6 osition.
The 7ble 0alve remote control valve is located in an engine room and is solenoid
oerated during normal oerations, but there is a rovision for manually overriding the
solenoid.
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When the control room control valve is laced in the +6+R(+N)4 S2UT osition, the
hydraulic lines from the 7ble 0alve remote control valve are locked and the control
room control valve sends shutting oil to the 7ble 0alve ower iston.
The 7ble 0alve remote control valve has three ositionsJ &5+N, N+UTR73, and S2UT.
The remote control valve is ket in the N+UTR73 osition rior to snorkelling by aremovable in. When the in is removed, 7ble 0alve remote control valve solenoid
when energised can move the control valve to the &5+N osition against sring
ressure. With the in out and the solenoid de energiIed, the control <sool@ valve will
be moved to the S2UT osition by sring ressure.
7t the commencement of a snorkel start, the snorkel engine discharges e-haust gas
into the snorkel e-haust line. 7ble 0alve is shut, therefore, e-haust back ressure will
build u in the e-haust line. 7 bellows oerated back ressure switch, located in the
snorkel e-haust ie above the crew1s mess, e-ands as e-haust ressure builds u.
When the back ressure reaches "* si, the back ressure switch shuts and energiIes
7ble 0alve remote control valve solenoid. The energiIed solenoid moves 7ble 0alve
control valve to the &5+N osition. This seDuence of events allows ressure from the
hydraulic system to oen 7ble 0alve.
7s the e-haust mast blows dry and back ressure dros to about =!9 si, the back!
ressure byass switch is shut. The back ressure by ass switch kees 7ble 0alve
remote control valve and the engine shutdown solenoids energiIed when the back
ressure switch oens.
f at any time the circuit is interruted by either 2(2 B7); 5R+SSUR+, 3&W R56,
2(2 07)UU6, or 3&SS & 7) 5&W+R, 7ble 0alve remote control valve is de!energiIedand sring ressure forces the remote control valve sool valve to the S2UT osition,
thus sending shutting oil to 7ble 0alve.
A(N %N8(N% SHU$DON SO3%NO(D
3ocated in the manoeuvring room this solenoid holds the main engine shutdown valve
in the shut osition when energiIed. When de!energiIed, sring ressure will oen the
main engine shutdown valve allowing shis service air to shut down all running
engines. This solenoid has three lams in arallel with it to indicate to both engine
rooms and the manoeuvring room when this solenoid is energiIed.
D(%S%3 %N8(N% SA#%$" &(!&U($
The safety cut!out circuit oerates automatically to shut down the engine1s air
ressure under certain conditions. The safety devices are installed in the circuit in
such a manner that the oeration of any of the devices will cause the engines to shut
down and the main snorkel e-haust valve <7ble 0alve@ to shut.
The safety devices areJ 07)UU6 36T )UT!&UT, 2(2 B7); 5R+SSUR+ )UT!&UT, and
3&W R56 )UT!&UT.
". 07)UU6 36T )UT!&UTJ There are two vacuum limit cut!outs, one located in
each engine room. They are normally shut, bellows!oerated switches, designedto function when the vacuum in either engine room increases to si- inches. This
vacuum will result when the head valve or the induction hull valve is shut for
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any length of time while an engine is running. +ither of the two cut!outs may
function to sto the engines.
>. 2(2 B7); 5R+SSUR+ )UT!&UTJ There are two high back!ressure cut!out
switches. &ne located in the snorkel e-haust line of each engine room. The high
back!ressure cut!out switches are installed to revent damage to an engineresulting from e-cessive e-haust back ressure. The switches are normally shut,
bellows oerated tye, designed to oen at "% si. When the back ressure on
any switch e-ceeds "% si the switch oens and the engines are shut down. This
switch is byassed when blowing the e-haust mast and is laced in the circuit
after the engine is running.
=. 3&W R56 )UT!&UTJ There are four low rm cut!outs, one located on each
engine. +ach cut!out controls only the engine to which it is connected and is
oerated by engine fresh water ressure. The low rm cut!out functions to shut
down the engine when the engine seed dros below $:: rm. f more than one
engine is on the line and only one dros below $:: rm the remainder
continues to oerate and the main snorkel e-haust valve remains oen. The
main snorkel e-haust valve will remain oen until all low rm cut!outs have
functioned.
The snorkel safety circuit, when oened by any of the above causes, actuates the
engine air shut down tri and also shuts 7ble 0alve.
n addition to the safety features described, the oerating limit circuit is eDuied with
a SN&R;+3 S2UT!A&WN SWT)2 in each engine room. Aeressing a ushbutton on
this circuit will cause the main engines to shut down.
Byass switches are rovided to allow the engines to be started regardless of the
osition of the back!ressure or low rm cutout switches. This feature is necessary in
order to byass those safety devices when the engines are started at the
commencement of snorkelling.
%N8(N% A(! $%)%!A$U!% A3A! &(!&U($
This circuit is installed to revent e-cessive blower temeratures while snorkelling and
rovides indication of dierence in temerature of the air intake and outlet of each
main engine scavenging air blower. When the temerature dierential reaches "9:degrees, a warning light and warning bell are energiIed. The warning light remains
lighted as long as the temerature dierential is "9: degrees, however, a contact
maker in the engine throttle may secure ower to the warning bell when the throttle is
in the sto osition. 7 switch located on each of the warning anels may also secure
the warning bell. This alarm merely warns the engine room watch, it does not shut
down the engine. This circuit is installed on each main engine blower and failure to
shut down the engine may result in a wied blower caused by metal to metal contact
as the blower arts e-and with heat.
Aendi* %
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#leet Su0marine Snorkel Oeratin, )rocedure
Ba$e available by <ob mery o" t%e Submariners +sso#iation o" ana$a =est
F?7 SU<B+/IN SN>/3? PIPIN
SN>/3? INDU7I>N (<?U) SN>/3? AH+US7 (/D)
The order for secure snorkelling given by either the )ommanding &Pcer or )onning
&Pcer, deending uon the circumstances. The submarine1s transition from a normal
submerged routine to that of snorkelling was accomlished by the regular watch
section. Snorkelling could be conducted with a ma-imum of two engines and, to
reserve watertight integrity, normally carried out in one engine room.
%'O3U$(ON ON )!%)A!(N8 $O SNO!.%3
The order was relayed on the "6) by the helmsman. i.e. 15reare to Snorkel, Two 6ain
+ngines 5roulsion )harge.1
ANO%U'!(N8 !OO
7cknowledged on the *6). 15reare to Snorkel, Two 6ain +ngines 5roulsion )harge,
6anoeuvring 7ye.1
Signalled the +ngine 5riority to the Snorkelling +ngine Room by either the engine roomwith the lowest hours or, if there were rior snorkels during the dived time, by utilising
the coldest engines.
&ON$!O3 !OO
Raised the Snorkel nduction C +-haust 6asts.
+nergiIed the Snorkel )ontrol )ircuits.
Arained the Snorkel nduction 6ast to Negative Tank.
5laced control of the 6ain Snorkel +-haust 0alve <7ble 0alve@ to the Snorkelling +ngineRoom.
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A#$%! /A$$%!" &O)A!$%N$
5laced the Snorkel nduction 0alve &erating (ear into 5ower.
5laced the 6ain Snorkel +-haust 0alve &erating (ear into 5ower.
SNO!.%33(N8 %N8(N% !OO
3ined u the engine room C engines for snorkel oeration.
5laced the +ngine Room Snorkel +-haust 0alve <Baker or )harlie@ oerating gear in
5ower.
%'O3U$(ON ON &O%N&(N8 $O SNO!.%3
7t the order 1)ommence Snorkelling1 on the "6) the Snorkel nduction 0alve was
oened from the Snorkel 2ydraulic 6anifold in the control room on orders from the
Aiving &Pcer.
Uon the Snorkel nduction 0alve being oened the Snorkelling +ngine Room watch
keeers oened their +ngine 7ir nduction 2ull 0alve. The Snorkelling +ngine Room
Throttleman then commenced rolling one engine with starting air whilst the &iler
oened the aro-. == "H= turns hand cranked nboard +-haust 0alve.
7t engine start the Throttleman oened his +ngine Room Snorkel +-haust 0alve <Baker
or )harlie@, shut his engine e-haust dum <e-haust dumed into the engine room bilge
during engine roll and initial start@ and, uon the engine building suPcient e-haust
back ressure to blow the Snorkel +-haust 6ast dry, oened the 6ain Snorkel +-haust
0alve <7ble 0alve@.
When rigging for snorkelling, the nduction 6ast was drained to negative tank to
maintain the submarine1s trim, amounting to aro-imately ?,::: ounds. n addition,
when the +-haust 6ast was blown dry, the Aiving &Pcer Eooded =,::: ounds of
water from sea to negative tank to comensate for the water blown from the e-haust
mast, for a total of aro-imately "",::: ounds.
S%&U!% SNO!.%33(N8
When the order 1Secure Snorkelling1 was assed on the "6), or terminated by any of
the Snorkel +lectrical or +ngine Safety )ircuits, immediately C simultaneously theengines were stoed, all +-haust 0alves and Snorkel nduction 0alves were shut, and
the Snorkel 6asts lowered and housed. When the masts were lowered they Eooded
from sea, thus making the submarine heavier by aro-imately "",::: ounds. This
e-tra weight is immediately comensated for by the raid blowing of "",::: ounds of
sea water from negative tank thus maintaining the trim of the submarine.
Aendi* #
US Navy Su0vets Anecdotes
Anecdote No 1
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:ames ;)at; )atterson< US Navy Su0 'et< Docent< USS /lue0ack e*hi0it at the
Ore,on useum o Science and (ndustry Deceased =>>?
&ver Duite a long eriod 5at graciously rovided detailed notes about snorkelling
aboard the USS Blueback <SS%?"@, a Otear droO Barbel class submarine,
commissioned "#%# and was in service for =" years. These were the last diesel!electricsubmarines in the US Navy, but the design was taken over by the Autch and
develoed into the modern submarines of today. t is believed the ost war 8aanese
designs were also develoed from the Barbel class.
Before rearing, at my reDuest, a full descrition of the snorkelling aboard Blueback,
5at had already answered my various messages with seci/c Duestions about Oshut
downO if the snorkel head submerged and the boat could not recover before
unaccetable conditions arose in the boat. have included his several atient answers
as a comilation, but the date order is not always clear as the original +!mails were
lost in a comuter crash. ortunately the main content had been saved in a te-t /le to
disc and here it is. trust readers will /nd much of interest.
SNO!.%3 )!O&%DU!%S A/OA!D $H% USS /3U%/A&.
When the word is assed to reare to snorkel the submarine will come to eriscoe
deth. n each comartment watch standers will rig the comartments. This for most
art means the right line u of ventilation and to line u the engines to run and if a
battery charge is to be done the boat will rigged for that also.
n manoeuvring room the engine consul oerator will ut the snorkel safety switch in
the byass osition and the 'unior controller will ut the snorkelHsurface switch in the
snorkel osition, this switch has four ositions, snorkel, surface, and two tri ositions.
&nce the boat is rigged for snorkel the &&A <&Pcer of the deck@ will order the snorkel
mast raised by the )&W <)hief of the watch@. 7fter the mast is raised the &&A will
have the )&W test the head valve while he checks the mechanical indicator thru the
eriscoe. 7fter the head valve is tested the word is assed to commence snorkelling.
The )&W will then oen the main induction valve. This valve is located at the bottom
of the snorkel mast. The valve allows air to ass from the mast to the main induction
ie to the engine room. 7fter the main induction valve is oened the engine oerator
will oen the hull induction valve. This allows air into the engine room from the maininduction ie. The engine oerator then starts the engine and oens the engine hull
e-haust and the snorkel e-haust valves.
7t "*si of back ressure the main snorkel e-haust valve will oen automatically. The
high back ressure will blow the water from the free Eooding snorkel e-haust mast.
When they have all the engines started the engine oerator will ut the snorkel safety
switch in the on osition.
&nce the boat is snorkelling and the order to secure snorkelling is given the 'unior
controller will ut the surfaceHsnorkel switch to the tried osition. This will kick out
the fuel racks it also kicks o all generators and it shuts the main snorkel e-haustvalve.
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The engine oerator shuts the engine hull e-haust and the snorkel e-haust valves and
the hull induction valve. The )&W shuts the main induction and the head valve and
lowers the snorkel mast. This has been a normal light o and secure snorkel.
f there is over a ">si back ressure or 9 inches of vacuum or the rm of the fastest
running engine goes below $:: rm the snorkel safety circuit will shut the mainsnorkel e-haust valve and kick out the fuel racks and tri o the generators.
SNO!.%3 SHU$ DON DU% $O UN(N$%N$(ONA3 SU/%!8%N&% O# $H%
SNO!.%3 H%AD - USS /lue0ack .
The snorkel head valve would shut when too much salt water would short out some
electrodes and that would cause "::si air to oerate a valve we called the 1Duick as a
wink1 valve. That valve would send >>%si air to the shut side of the head valve iston,
this was all done automatically and was really Duick as a wink. When the water
washed o the head valve the Duick as a wink valve would then aly the >>%si air to
the oen side of the head valve. Then the head valve would oen automatically.
We could run all three engines while we were snorkelling. f the dive lost the bubble
and the head valve shut the engines would suck the air out of the boat until we
reached a 9 inch vacuum and then the main snorkel e-haust valve would shut
automatically. 7t ">si of engine back ressure the engines would shut down
automatically.
With three engines running it only takes about one minute to get to si- inches of
vacuum. With only one engine running it takes about si- or seven minutes. f you are
on one engine and the dive lost the bubble and went to dee the engine back ressure
would build u and the engine would shut down at ">si.
7lso if the rm of the fastest engine droed below $:: rm, the engines
automatically shut down. They /gured that an engine running only at $:: rm would
not have enough back ressure to kee water out of the engine.
7ll the engines were automatically shut down on high back ressure because the /rst
thing to haen would be the main snorkel e-haust valve would automatically shut
and this would always kee water out of the engines.
The main snorkel e-haust valve was always shut automatically by the snorkel safety
circuits. The engine inboard and engine snorkel valves were shut by the crew. When
say the crew that means they Eied a switch. 7ll the sea valves were electro!
hydraulic.
QUESI!" Does t%e 7an* #lass %ave t%e same snorkel set6u! as t%e <arbel #lass
Ges it $oes. 7%e 7an* #lass as t%e 1rst #lass to %ave only %ave t%e sin*le in$u#tion
!i!e. 7%e u!!y subs %a$ t%e same sa"ety #ir#uits- ; in#%es va#uum lo r!m an$
ba#k !ressure #ut out. 7%ey %a$ a main in$u#tion valve "or t%e en*ines. It as in t%e
sail ust above t%e main $e#k. 7%e snorkel air oul$ #ome into t%e snorkel %ea$ valve
an$ t%en $on t%e mast to t%e snorkel in$u#tion valve.
+"ter !assin* t%ru t%e valve air oul$ $um! into t%e main in$u#tion !i!e.
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7%ere as a #%an*e valve in t%e #ontrol room t%at t%e >= oul$ *ive #ontrol o" t%e
main snorkel ex%aust valve (also #alle$ +<? valve) to t%e en*ine room- %e #oul$ not
o!en t%e valve but %e #oul$ take #ontrol o" t%e valve an$ t%en s%ut it.
=%en t%ey starte$ to snorkel t%e !riority en*ine room oul$ take #ontrol o" able
valve. 7%ey oul$ o!en it %en t%e en*ine starte$ to run an$ t%ey %a$ enou*% ba#k !ressure to blo t%e mast.
>n#e t%e en*ine as runnin* ok t%ey oul$ !ut able valve on t%e lat#%. 7%is as a
relay t%at oul$ %ol$ able valve o!en until t%e sa"ety #ir#uit as tri!!e$ an$ t%en t%e
relay oul$ s%ut t%e valve an$ t%e en*ines ere also s%ut $on.
I %o!e t%is %el!s you.
Pat
2i 5eter
I also as on a u!!y sub. It as t%e USS Sea ?eo!ar$ SS 48: in &';'6&'2.
>n t%e u!!y boats you #an snorkel it% all en*ines. I t%ank t%e 4 en*ine as
remove$ on some u!!y boats.. 7%at as t%e ay it as on t%e to u!!y boats t%at
I as on.
2i 5eter < re"errin* to <arbel #lass@
7%e snorkel in$u#tion mast is a $ry mast. Hoever t%e I man o" at#% oul$ o!en a
$rain to ne*ative tank in t%e #ontrol room. 7%ere is a si*%t *lass so %e #oul$ #%e#k
an$ make sure t%e mast %a$ not oo$e$. 7%e $rain oul$ $um! into ne*ative tank
an$ i" you ere snorkellin* in ba$ eat%er a lot o" ater oul$ as% $on t%e mast
an$ t%en into ne*ative tank. ver so o"ten t%e >= oul$ %ave to !um! t%e tank
ba#k to t%e snorkel mark. He oul$ !um! t%e tank to sea.
Still lookin* "or t%e $rain*s- I kno I still %ave t%em.
I like t%e 5uestions be#ause it kee!s me s%ar! an$ makes me t%ink
Pat
2i 5eter
7%e Sea ?eo!ar$ an$ t%e <lueba#k %a$ a Prairie Basker an$ t%ey orke$ *oo$. >ne o"
t%e !roblems o" usin* a Prairie Basker %en snorkellin* t%e boat oul$ a#t very li*%t
a"t an$ you %a$ to oo$ in a lot o" ei*%t- I t%ink e oul$ %ave to oo$ in about &,k
a"t an$ in t%e #enter to snorkel more t%an about ' knots.
Pat
2i 5eter
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It as aroun$ t%e %ole a"t !art o" t%e boat an$ on t%e s#res. No t%at I t%ink ba#k it
may %ave been 2 en*ine t%at as remove$. >l$ a*e is sittin* in. Never %ear$ about
any valve !roblems but t%at $oesn9t mean t%ere asn9t any ( re"errin* to en*ine
valves) I $o kno t%ey %a$ to s%ut $on t%e #om!ressor be#ause o" %i*% tem! a lot o"
tines- but t%e system oul$ %i$e t%e noise "rom t%e en*ines very *oo$.
=e snorkelle$ about & yar$s "rom a tin #an an$ t%ey sai$ t%e boat soun$e$ like
rain ater. =e %a$ all t%ree en*ines on line. 7%e system orke$ but as %ar$ to kee!
on line.
Pat
Authors Note+
understand one engine was removed from some of the ( (uy conversions to
allow the 5rairie 6asker comressor to be installed. This was Duite some time after the
original (uy conversion.
5rairie 6asker was a system where the hull was covered in a skin of bubbles and
bubbles were used to reduce screw cavitation noise ! the web has several useful
references. The British e-erimental version was known as N(2TS2RT and as far as
is known only the only British submarine so /tted was the trials submarine Scotsman.
Several destroyers had trial sets.
7nswer to +!mail re erformance legend late.
7%e term 8J' means 8K en*ine out!ut an$ 'K *en out!ut. 7%e max r!m o" t%e
en*ines on snorkel as 2,- t%is as set be#ause t%ey #oul$ not *et enou*% air $ont%e snorkel mast it% t%e ba#k !ressure t%e en*ines run it% on snorkel. 7%is #lass o"
boat as to %ave $iLerent ty!e o" en*ines %oever t%ey ere "oun$ to be unsuite$ "or
sub servi#e. 7%e "Jm en*ines ere installe$ an$ it as "oun$ t%at t%e in$u#tion !i!e
as to small a"ter losin* some bloers.
think 5at is referring to the comact vertical 1ancake1 engines that were /tted in the
Tang class but were so troublesome they had to be removed and the hull lengthened
to allow the /tting of conventional engines. This situation may well have imacted on
the design of the Barbel class.
Anecdote No =
rom Rik Nilsson US Navy Sub 0et in answer to +!mail Duestion. < His eb site is %ere@
very time I reminis#e snorkellin*- I #an remember t%e rat% o" t%e en*inemen
a*ainst us !lanesmen %o alloe$ t%e boat to $ri"t $on #ausin* t%e en*ine #ylin$er
relie" valves to !o! an$ 1ll t%e #om!artment it% noxious "umes. I #an almost smell
t%em to t%is $ay.
In seas o" lon*- %eavy sells- it as sometimes %ar$ seaty ork #rankin* t%e !lanes
%eels (even in !oer mo$eM)- kee!in* $e!t% so t%e intake valve as as lo as
!ossible in t%e aves- yet not #y#lin* #lose$ "re5uently
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Unlike t%e ori*inal Dut#% an$ erman im!lementations- %i#% I believe ere sin*6u!
!i!es it% a oat valve %ea$- t%e 1nal US Navy version #onsiste$ o" %y$rauli#ally
o!erate$ tan$em verti#al teles#o!in* masts installe$ in t%e a"t o" t%e sail. 7%e "orar$
!i!e as t%e intake an$ exten$e$ sli*%tly more t%an ,; "eet above t%e keel. 7%e %ea$
valve as ele#tro6%y$rauli#- #losin* automati#ally %en $ouse$ it% seaater. 7%e
ex%aust sto!!e$ ust s%ort o" t%e sur"a#e at snorkellin* $e!t% (,2 to ,4 "eet keel$e!t%)- an$ en$e$ in a !er"orate$ %ea$ un$er a !late to $is!erse t%e *ases as a #lou$
o" bubbles. 7%is %el!e$ %i$e t%e $iesel smoke- an$ re$u#e$ t%e noise si*nature.
7%e loer en$ o" t%e intake mast #onne#te$ to t%e existin* main in$u#tion trunk
t%rou*% a ater se!aratin* #%amber. 7%e en*ine intakes alays $re t%eir air $ire#tly
"rom t%e interior o" t%e boat- %i#% as "e$ "rom t%e main in$u#tion in t%e "orar$
en*ine room. For t%is reason- an$ $ue to t%e #on$ition o" #om!artment $oors bein*
#lose$ %ile submer*e$- only t%e "orar$ en*ines- en*ines one an$ to- ere use$
"or snorkellin*.
a#% en*ine ex%aust #onne#te$ to a snorkel ex%aust %ea$er outsi$e t%e %ull t%rou*%
a sin* #%e#k valve outboar$ o" t%e en*ine ex%aust #oolin* system. 7%e ex%aust mast
as not test6$e!t% rate$- an$ "ree6oo$e$ %en $ivin*. +ny ater in t%e intake mast
as $raine$ into one o" t%e inboar$ tanks (!ossibly t%e ne*ative tank)- %ile t%e
ex%aust as !ur*e$ u!ar$s by t%e en*ine ex%aust !ressure. Snorkel start6u!
#onsiste$ o" "ully raisin* t%e masts- an$ %en t%e %ea$ valve o!ene$- t%e intake as
$raine$ to ne*ative tank. 7%e ne*ative tank inboar$ vent as s%ut an$ t%e tank as
!um!e$ to sea. 7%e inboar$ en*ine ex%aust valves ere release$- $rainin* any ater
to t%e bil*e- an$ an attem!t as ma$e to start an en*ine to #lear t%e snorkel ex%aust.
=%en ex%aust !ressure rose above sea !ressure- about to atmos!%eres at snorkel
$e!t%- t%e snorkel #%e#k valve o!ene$ to !ur*e t%e mast. n*ine #ylin$er %ea$s %a$
ba#k6!ressure release valves to !revent en*ine $ama*e i" t%e $e!t% as too *reat- or
ater as in*este$.
7%e rus% o" "res% air a"ter a lon* submer*en#e as *reatly a!!re#iate$- even t%ou*%
e kne e ere less Cstealt%yC %ile snorkellin*. 7%e $onsi$e as t%at %en e
sto!!e$ snorkellin*- our !ur*e$ ol"a#tory senses %a$ to rea$ust to t%e normal stinky
submarine atmos!%ere a*ain. +lso- most o"ten in t%e +tlanti#- t%e air at ni*%t is #%illy.
I" you orke$ or sle!t next to an air #on$itionin* vent- you mi*%t %ave to !ut on a
a#ket.
7%e o#eans- even on C#almC $ays- are not !er"e#tly still. ?on*6!erio$ sells as ell as
sea #%o! "rom in$ #an make snorkellin* an un!leasant ex!erien#e. =%en t%e
automati# snorkel %ea$ valve #loses- it9s like someone a!!lie$ a va#uum atta#%ment
to your "a#e. Gour ears !o!- your tear $u#ts an$ sinuses $rain- et#. It #an be messy i"
you9re aslee!.
In me$ium to rou*% seas- t%e !lanesmen %a$ to ork %ar$ to kee! t%e %ea$ valve
"rom #losin* too lon*. 7%ere as a va#uum sa"ety sensor in t%e system t%at #ut oL
"uel %en t%e !ressure in t%e boat $ro!!e$ somet%in* like J&t% o" an in#% o"
mer#ury ($oes t%at soun$ reasonable). I seem to re#all t%at i" it staye$ #lose$ more
t%an &, or 2 se#on$s- t%e en*ines oul$ s%ut $on- bot% "rom la#k o" air an$ ex#essex%aust !ressure. I9ve been in t%e en*ine rooms %en t%is %a!!ens an$ remember
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t%e #ylin$er relie"9s 1llin* t%e #om!artment it% $ark- #%okin*- eye6burnin* "umes in a
matter o" se#on$s.
I" t%e boat as steamin* $onin$ at less t%an sur"a#e in$ s!ee$- it oul$ be 5uite
!ossible to su#k en*ine ex%aust into t%e snorkel intake. I #an9t remember t%at bein*
an o"ten o##urren#e- but t%en- I as only aboar$ ubera "or to years. It #oul$ be t%at e alays #%an*e$ #ourses %en !ossible un$er t%e #ir#umstan#es- so as to stay
%ea$in* into t%e in$ %ile #%ar*in* batteries submer*e$.
I $o re#all t%at in t%e loer +tlanti# latitu$es- e %a$ ater va!our CmistC "orm in t%e
boat at times- $ue to arm in$u#te$ air #on$ensin* in our ot%erise #ool submer*e$
atmos!%ere at t%e onset o" snorkellin*. Baybe t%at9s %at t%e Darter !%oto*ra!%er
#au*%t on 1lm ( No.: belo). 7%e %ea$y- oxy*enate$ "res% air oul$ tem!orarily
!ur*e our nostrils an$ make us more #ons#ious o" t%e ever6!ervasive $iesel (an$ ot%er
smells) in t%e boat.
Anecdote No @
This icture came from the web. The comment recorded with the ictures wasJ I %a$
t%e lu#k to !ull USS Darter "rom early &'84 to early &'8,. Darter as one o" "our
$iesel boats at t%e time. 7%ey %ave all *one no. Gou #an see %o t%i#k t%e $iesel
smoke *ot %en you 9snorkel it% a tailin$.
The Aarter was a class of one submarine, a derivative of the Tang class.
&bviously e-haust gases in the atmoshere of a snorkelling submarines can only be
seen as an undesirable health haIard and worthy of some comment, so Rik Nilsson
being a US Navy Sub0et was asked about this hotograh, see his comments above in
his anecdote No.>
There have been unsubstantiated web reorts of Soviet submarine crews suering
serious illness due to snorkelling.
The author with service on Royal Navy 7 )lass and T )lass submarines has no
recollections of e-haust gases being drawn from the surface into the submarine, down
the induction mast along with air and so checked with members of the BarrowSubmariners orum. n their resonses most also wrote that they also had no
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recollection of e-haust gas in the submarine due to snorting. There were a number of
comments on SSN similar that included in the anecdote reroduced below.
#rom a ormer !oyal Navy watch keein, su0marine ocer on SS. and SSN
in the late si*tiesBseventies (t is in act a comosite o a num0er o orum
ostin,s 0y the same erson and 0rou,ht to,ether with the ermission
ertainly I remember it- you nee$e$ 5uite s!e#i1# #on$itions- snortin* $on in$ at
t%e ri*%t s!ee$ so t%at your ex%aust as *ently blon "orar$ to t%e in$u#tion mast.
It as not a !leasant ex!erien#e anyay- so most likely avoi$e$ %enever !ossible-
%en#e t%e limite$ ex!erien#e by ot%er members o" t%e Forum o" *ettin* 9one9s on9
ba#k.
7%e reality is t%at any boat is at risk o" 9*ettin* it9s on ex%aust "umes ba#k9 i" t%e
#on$itions are ri*%t- an$ t%at is t%e boat *oin* exa#tly $on in$- at a s!ee$ sli*%tly
less t%an t%e in$ s!ee$- t%en t%e ex%aust %i#% is $is#%ar*e$ but a "e "eet aay
"rom t%e in$u#tion mast must *et su#ke$ ba#k. <oats it% en*ines t%at %ave a %i*%erba#k !ressure #a!ability an$ t%us maintain a ell submer*e$ snort ex%aust may $o
better as t%e ex%aust is some%at #leane$ an$ $iLuse$ by bubblin* t%rou*% sea
ater. 7%ose it% !oor ba#k !ressure !er"orman#e %i#% %a$ non or sli*%tly
submer*e$ ex%austs (most soviet boats "or exam!le) oul$ ten$ to suLer more.
It as also a !roblem on t%e sur"a#e even it% t%e sur"a#e muers %en *oin* $on
in$ at about in$ s!ee$ %ere t%e ex%aust oul$ sirl aroun$ t%e 1n. /emember
t%e se#on$ary !ur!ose o" snortin* a"ter #%ar*in* t%e batteries as to re!lenis% t%e
oxy*en in t%e boat. I am sure t%e ventilation system also $re "rom t%e area o" t%e
in$u#tion system an$ ex%auste$ ba#k into t%e en*ine room.
It as orst runnin* on t%e sur"a#e on $iesels on an SSN in t%ose #on$itions be#ause
as t%ey %a$ no sur"a#e muer you use$ t%e snort ex%aust mast- an$ it nee$e$
#oolin* ater ine#te$ into t%e ex%aust- so *oin* $onin$ you %a$ a ni#e $ieselly
s!ray onto t%e bri$*e- $i$ a %ole at#% like t%at a"ter e %as a S/+B an$ sur"a#e
a"ter a main t%rottle steam leak- not ni#e.
By earlier #omments on t%e !oor ba#k !ressure !er"orman#e o" Soviet boats are a
$im re#olle#tion "rom my $ays in t%e Navy- an$ a!!lie$ to t%e =%iskyJ/omeo !erio$
boats- t%eir more mo$ern ones may %ave over#ome t%e !roblem. ertainly ba#k
!ressure as alays re!orte$ as t%e reason e #%ose me#%ani#al s#reamers(su!er#%ar*ers) on t%e P@> boats $es!ite t%eir noise. Bore re#ently I $o believe t%e
ermans %ave ma$e turbo #%ar*ers ork at %i*%er ba#k !ressures.
)OS$S&!()$
&n the 1getting your own back1 roblem, it has occurred to me that the ideal conditions
for ingesting ones own e-haust are a wind seed similar to the boats and that the sea
will be relatively calm so control roblems would be minor. n general though it is
highly unlikely any boat would ersist in a course that was likely to ashy-iate the
crew.
Anecdote No 4
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7%is little ane#$ote ori*inally #ame "rom %ere
>n most <oats- t%e en*ine use$ to blo t%e sta#k- ere t%e one9s it% t%e most
runnin* %ours on t%em. /eason bein*- t%at i" somet%in* ent ron* an$ s%e oo$e$-
%at t%e %ell- e %ave to over%aul %er in 4 %ours anyay.
7s did this little ditty that follows. The e-letive substitutes can make reading a little
diPcult for eole not used to US swear words, but the substance of the te-t gives a
deal of technical and oerational information.
Thanks to 6yron 2oward +N"<SS@ USS Bream SS>$=
# ty$ical con%ersation &rom the 'honoured' Engine (oom )ent something
like this
hrottleman C+= OOOOO- not a*ain- >3- lets line it u!- li*%t er oL an$ !ray it $on9t
oo$C
!iler u%- u%- u%- u%- ( t%at9s t%e soun$ %e ma$e o!enin* t%e inboar$ ex%aust valve
9#ause t%e stem as all #arbone$ u!)- UH- UH- UH- UH- ( a total o" :: &J: turns later)
OOOOOOOO- t%ou*%t I9as never *onna *it t%e OOOOOOOO o!en)
hrottleman C%ol$ t%at OOOOOO by6!ass t%is time- till I kno#k your OOOOOOO %an$ oL o"
it- >/ G>U9?? < ?IEIN IN 7H OOOOOOOOO <I?SC.
n*ine rolls : or 8 times- ($e!en$in* on %o #ute t%e t%rottle as tryin* to be-
s%oin* oL to t%e ot%er n*ine /oom).
hrottleman C>3- t%ey 1nally *ave me t%e OOOOOOOO or$ to li*%t oL- *rab t%atOOOOOOOO by6!ass sit#%- an$ remember- $on9t let *o on your on.
n*ine starts rattlin* an$ rollin*- %a#ks- #ou*%s- bel#%es an$ starts 1rin*- 2 or :
#ylin$ers at a time. Finally- it roars into li"e- t%e t%rottleman yanks t%e snorkel ex%aust
valve o!en- t%e oiler- tryin* to be #ute yells C#an I le**o- #an I le**o- %u%C but
remembers t%e !revious t%reat an$ %ol$s a $eat% *ri! on it. +bout t%at time t%e
n*ine $ies an$ starts rollin* to a %alt. 7%e t%rottleman- in one smoot% #ontinuous
motion s%oves t%e snorkel ex%aust valve lever ba#k to t%e #lose !osition an$ kno#ks
t%e oilers %an$ oL ust in time to kee! it "rom oo$in*- but t%e airbox $oor s!rin*s are
all s%ot an$ eak so t%ey blo o!en an$ 1ll t%e en*ine room it% t%at $eli*%t"ul- lun*6searin*- eye6aterin* bla#k smoke e all love$ so $early.
hrottleman COOOOOOO t%at as "un %y in t%e OOOO $on9t t%ey let me blo t%e sta#k
it% t%at ot%er OOOOOO o" OOOOO. Seems like t%e &st in #%ar*e o" t%e en*ine room alays
mana*e$ to be on t%e 8 to &2- an$ e never- never ever snorkelle$ on %is at#%-
ex#e!t $urin* eet o!ts an$ t%en it asn9t every OOOOOOO ni*%t- no as it.
I %ear tell t%at t%e events "or snorkellin* on a FB (Fairbanks Borse) boat ere a ta$
$iLerent.
!iler C>% s%oot- %y #oul$n9t t%ey %ave aite$ until e 1nis%e$ our #ookies an$
milkC.
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hrottleman C=ell ust %urry u!- %en e s%ut $on- you #an *o u! to t%e res
Dinette an$ *et us some i#e #ream it% %i!!e$ #ream an$ #%erries on to!- >3
!iler C>%- I *uess so. I ust is% t%ey oul$n9t $o t%is so o"ten. It %urts my ears %en
t%ose silly ol$ !lanesmen $i! t%e %ea$ valve.
hrottleman C =ell it %urts mine too but ya ust %ave to learn to *rit your teet% an$
!ut u! it% it. /emember- you #oul$ %ave been sent to one o" t%ose nasty < boats
it% t%eir $irty ol$ immy en*inesC.
!iler >%- I kno an$ I am so t%ank"ul t%at $i$n9t %a!!en.
Anecdote No 5
7dmiral (alantin <US Navy ret @ in his book SUB67RN+ 7A6R73, tells us more about
the snorkel voyage of the USS 5ickerel <SS %>$@ mentioned in the oening of the main
article.
In*enuity an$ %umour- to attributes o" su##ess"ul submariners- ere not la#kin* on
Pi#kerel. In %is re!ort- Paul S#%rat0 ( a!tain) sai$ C7%e most a##urate an$ reliable
in$i#ator va#uum in$i#ator aboar$ is almost too %omely "or mention in an oQ#ial
re!ort. 7o alert t%e manoeuvrin* room #ontrollerman to stan$ by to !ull #lear %en
t%e %ea$ valve is #y#le$- t%e ele#tri#ians !la#e$ a re$6!ainte$ #on$om over a mout%
o" a bottle. +s soon as t%e va#uum in#rease$- t%e #on$om stan$s u! ri*i$- !ointin* a
luri$ 1n*er o" #aution at t%e #ontrollerman.
Anecdote No C
Some years ago had an +!mail e-change with a retired US Navy submarine oPcer.
Unfortunately due to a comuter crash and my failure to back u +!mails, lost all the
messages, however one item stayed in my mind so here is the gist.
7%e !arti#ular u!!y submarine- relatively late in its servi#e li"e- %a$ a small $iesel6
*enerator 1tte$ $on t%e #entreline on soun$ re$u#in* mounts. +!!arently its
!ur!ose as to a !rovi$e a 5uieter means o" snorkellin* at slo s!ee$s %ile
su!!lyin* t%e s%i!9s ele#tri#al loa$. It as not a *reat su##ess as t%e oQ#er re!orte$ it
s!ent more time in bits bein* re!aire$ t%an in servi#e. Hoever it as an interestin*
i$ea t%at mi*%t %ave been !ursue$ i" t%e US Navy %a$ !ersiste$ it% $iesel
submarines.
Anecdote No ?
rom ! 3)AR ritI Steiner US Navy <ret.@
I serve$ in to snorkel boats- /a0orba#k (n*ineer >Q#er in &';&6;2). S%e as a
u!!y II+. <lue*ill as a "ormer SS3 it% a <R/64 !assive array sonar t%at ra!!e$
aroun$ t%e bo. It as an ama0in* !ie#e o" *ear. =e #oul$ $ete#t- #lassi"y an$ tra#k
s%i!s an$ ot%er submarines at astonis%in*ly *reat ran*es. <ot% ere :6en*ine boats.
=e #oul$ snorkel at 68 knots. +nyt%in* "aster t%an t%at an$ t%e masts an$ !eris#o!es
oul$ oul$9ve vibrate$ so ba$ly t%ey9$ !robably %ave broken in t%e Cu!C !osition
(not a $esirable event). =e #oul$ only snorkel on to en*ines any%o 6 t%ree oul$
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%ave !ulle$ su#% a va#uum in t%e boat t%at e9$ %ave s%ut $on anytime t%e %ea$
valve s%ut. =e use$ stan$ar$ air#ra"t altimeters to kee! visual tra#k o" %at Caltitu$eC
e ere at. It9s been a lon* time sin#e I $i$ any snorkellin*- but as I remember it- on
to en*ines at 8J' e9$ CyC at &-8 "eet. =%en t%e %ea$ valve s%ut e9$ C#limbC
"aster t%an an F64. It as 5uite a si*%t at#%in* t%e altimeter %an$s *o aroun$. Not to
mention %avin* your ear$rums !o!!in* (i" you ere lu#ky) an$ your sinuses su#ke$$ry (very messy). +s best I #an re#all "rom nearly , years a*o- t%e en*ines oul$
s%ut $on automati#ally at ;-, "eet.
>ne o" t%e t%in*s t%at snorkellin* "or#e$ as an in#rease in t%e lobe6to6lobe #learan#e
in t%e en*ine s#aven*in* bloers to #om!ensate "or t%eir %avin* to run in a !artial
va#uum. =it%out t%e in#rease- t%ey9$ %ave %eate$ u! an$ i!e$ (t%ereby ruinin* your
%ole !atrol).
I #an9t t%ink o" a *oo$ reason "or %avin* to snorkel at %i*% s!ee$s anyay. Gou9re
noisy as %ell %en you snorkel 6 at any s!ee$. Gou essentially ren$er yoursel" $ea"-
!assive sonar6ise. In an environment %ere ot%er- un"rien$ly submarines mi*%t lurk-
t%at9s not a *oo$ ay to be.
7%e orst kin$ o" snorkellin* as in a #%o!!y sea an$ a %eavy seaay. =%en t%e sea
as%e$ over t%e %ea$ valve ele#tro$es- it oul$ s%ut. 7%e en*ines #ontinue$ to su#k
air out o" t%e boat- so e9$ C#limb.C It as a stran*e sensation as t%e air oul$
su$$enly #%ill in t%e boat. 7%en ust as "ast as it s%ut t%e sea oul$ !ass an$ %ea$
valve oul$ o!en. CDonC in 9altitu$eC e oul$ *o as t%e atmos!%eri# air rus%e$
ba#k in t%rou*% t%e snorkel in$u#tion. +n$ t%e #y#le oul$ re!eat itsel" over an$ over-
=e #alle$ it a C#%atterin* %ea$ valve.C
Pretty soon everybo$y oul$ be annoye$. Peo!le slee!in* oul$ be ake$ u! by t%eir
!o!!in* ears an$ $rainin* sinuses. Peo!le alrea$y aake- oul$ ust bit#% about it
an$ en$ure it. Usually- be#ause submariners ?>E to a*itate t%eir s%i!mates- several
o" t%em oul$ alk t%rou*% t%e ontrol /oom (one6at6a time) an$ ask t%e Divin*
>Q#er i" %e #oul$n9t #ontrol t%e $e!t% a little better.
I ma$e my very 1rst $ive as $ivin* oQ#er aboar$ Irex %ile an >Q#er Stu$ent in
Submarine S#%ool in &',8. 7%e year be"ore- s%e %a$ been 1tte$ it% t%e rein"or#e$
1bre*lass- so6#alle$ CNort% +tlanti#C sail.
I soun$e$ t%e $ivin* alarm an$ s%oute$ Clear t%e bri$*eMC 7%e lookouts vanis%e$. I"oun$ mysel" in a very lonely !osition %i*% ato! t%e sail o" a s%i! t%at as sinkin*
beneat% my "eet. 7%e C#lear t%e bri$*eC $rill involve$ turnin* a"t an$ *oin* $on a
la$$er to a !lat"orm $e#k %al"ay to t%e u!!er #onnin* toer %at#%. 7%en a"ter a '
$e*ree turn to t%e ri*%t you9$ *o $on anot%er la$$er- turn &8 an$ you9$ be at t%e
u!!er %at#%- %i#% be"ore #onversion oul$9ve been at your "eet.
7%e la$$ers %a$ stainless steel verti#al %an$ rails. =e %a$ been a$vise$ by s%i!9s
#om!any t%at t%e ay $on as s!ee$e$ u! by loosely *ri!!in* t%ese rails an$
$ro!!in* $on. Folloin* t%eir su**estion I $i$ t%at an$ $arne$ near oun$ u! a
#asualty at t%e !lat"orm $e#k. + 1lm o" ater unevenly $istribute$ on ea#% rail %a$
be#ome a lubri#ant beteen my %an$ an$ t%e rail- resultin* in t%at %an$9s sli!!in*
%ile t%e ot%er one %el$ "ast. I believe you #an ima*ine %o t%at tor5ue$ my bo$y. I
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as lu#ky to lan$ on bot% "eet it%out breakin* an ankle or se!aratin* a s%oul$er. I
#oul$ easily %ave !ani#ke$- but I $i$n9t. I turne$ an$ !atiently $es#en$e$ t%e se#on$
la$$er ste!6by6ste!. I $ro!!e$ into t%e #onnin* toer an$ yanke$ t%e %at#% s%ut it%
!lenty o" time to s!are 7%e $ive ent ell a"ter t%at.
In &';& as /a0orba#k9s n*ineer >Q#er in t%e s%i!yar$ I oversa t%e installation o"%er Nort% +tlanti# sail- t%e 1rst in t%e Pa#i1# Fleet. <y t%en I9$ be#ome a mu#%
CsaltierC submariner an$ asn9t #on#erne$ about %urryin* $on t%e la$$ers. >n sea
trials t%e n*ineer >Q#er alays makes t%e 1rst $ive. <ase$ on my Irex ex!erien#e I
sim!ly took my time. +"ter all t%e boat $i$n9t submer*e any "aster t%an it $i$ be"ore.
=%ile I9m at it- it as ama0in* %at #oul$ be $one to #on1*ure t%e Snorkel x%aust
System in ays t%at t%e ori*inal $esi*ners never ima*ine$. +s a submariner I9m sure
you9re ell aare o" t%e in*enuity t%at #%ara#teri0es t%is uni5ue bree$.
CHmmm look at t%is. Su!!ose e #onne#te$ t%is to t%at an$ s%ut t%is valve. 7%en e
#oul$ $o t%is. ?et9s try it.C
For exam!le- %ile visitin* Hon* 3on*- <lue*ill as neste$ starboar$ si$e to a US
$estroyer t%at as moore$ to a buoy. 7%e DD as !re!arin* to $e!art H3 an$ %a$ all
%an$s at 5uarters in t%eir ni#e- #lean %ite uni"orms. +s soon as it as rea$y to *o- e
ere *oin* #ast oL an$ to move to our bert% at HBS 7amar.
=e %a$ statione$ t%e manoeuvrin* at#% but %a$n9t yet arme$ u! t%e en*ines. I
as stan$in* to!si$e a"t %en one o" my lea$in* en*inemen !o!!e$ %is %ea$ u! out
o" t%e a"ter en*ine room %at#%. =it% an evil *rin %e sai$- CBr. Steiner- let9s *et t%em
9skimmers9.C I aske$ %im %o. He sai$- C?et9s #ross #onne#t 4 to t%e outboar$
ex%austs "or & an$ 2 t%rou*% t%e Snorkel x%aust System an$ roll t%e en*ines to
make sure t%ere9s !lenty o" ra "uel in 9em. =%en e *et t%e si*nal "rom manoeuvrin*
e9ll start all t%ree to*et%er. =%en t%ey9re runnin* e9ll !o! o!en t%e outboar$
ex%austs "or & an$ 2 an$ let t%e 9skimmers9 %ave it.C I tol$ %im t%at as 1ne it% me.
7%e $estroyer as to leear$.
I staye$ to!si$e an$ at#%e$ it% $eli*%t as our en*ines blaste$ a broa$si$e o" $ense
bla#k smoke onto t%e DD. It as soon invisible. =%en t%e smoke 1nally #leare$ t%ere
asn9t a %ite6uni"orme$ CskimmerC any%ere to be "oun$ on t%e DD9s !ort si$e.
7%is as a #lassi# $is!lay o" t%e submariner9s9 in*enuity #ombine$ it% %is innate- !u#kis% instin#t to a*itate. 7%e CskimmersC no $oubt ere ma$ as %ell- but t%e $eli*%t
e took "rom t%is as t%at t%ey %a$ no i$ea e9$ $eliberately ruine$ t%eir $ay an$
t%ere as not%in* t%ey #oul$ $o about it.
Ho!e t%is %el!s
Frit0
5eter, here1s another ersonal anecdote you may /nd interestingJ
7%e year be"ore I be#ame n*ineer >Q#er in /a0orba#k %er %ie" n*ineman #ame u!
it% a brilliant i$ea.
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+ll o" our snorkel6#a!able submarines %a$ retaine$ t%eir ori*inal #on1*uration it%
res!e#t to t%e muers t%at t%ey %a$ $urin* ==II. 7%ese ere a $rone$6ty!e it%
!ressuri0e$ sea ater !ourin* into t%em to $am!en t%e $iesels9 roar 6 it oul$9ve
been extremely ba$ "orm to be #au*%t on t%e sur"a#e- by bein* %ear$.
7%ese $evi#es ere ei*%teen "eet lon*- an*e6to6an*e. 7%ey ere #onne#te$ to t%ein$ivi$ual en*ines9 outboar$ ex%aust risers at one en$ an$ to t%e overboar$ ex%aust
!i!e on t%e ot%er. <e#ause o" t%e $oubly #orrosive eLe#t o" sea ater an$ $iesel
ex%aust *asses- t%ey %a$ to be re!la#e$ on avera*e every tenty6"our mont%s. +s
time !asse$ t%e su!!ly o" re!la#ement muers %a$ $in$le$. .
7%e %ie" %a$ a solution. He #orre#tly re#kone$ t%at %enever e ere $oin* CSneaky
PeteC o!erations- e snorkelle$ to #%ar*e t%e batteries- so t%e ori*inal !ur!ose "or t%e
muers as moot. He su**este$ re!la#in* t%e muers it% a strai*%t !i!e t%rou*%
%i#% t%e same C$ronin*C ater oul$ be "or#e$.
>BSU<P+ a!!rove$ t%e i$ea on a trial basis- an$ aut%ori0e$ t%e re!la#ement o"one o" /a0orba#k9s muer it% a strai*%t !i!e "or evaluation !ur!oses. 7%e boat as
in t%e San Fran#is#o Naval S%i!yar$ at Hunters Point. 7%e s%i!yar$ manu"a#ture$ an
ei*%teen "oot6lon*- #ir#ular strai*%t !i!e it% a!!ro!riate an*es "rom :J46in#% Cbla#k
ironC an$ installe$ it beteen t%e outboar$ ex%aust riser an$ tail!i!e "or t%e :
en*ine. It asn9t a!!re#iably lou$er t%an t%e muer. >BSU<P+ bou*%t it %olesale
an$ re#ommen$e$ to t%e %ie" o" <USHIPS t%at strai*%t !i!es be#ome a stan$ar$
SHIP+?7 to be a##om!lis%e$ Fleet i$e at ea#% submarine9s next overall. It as so
or$ere$ it% t%e !roviso t%at t%ey be ma$e o" :J46in#% #orrosion resistant steel- i.e.-
stainless steel t%at oul$ never %ave to be re!la#e$. 7%e era o" submarine muLers
as %istory.
Fast "orar$ to &';&. /a0orba#k as at Hunters !oint "or a mu#%6nee$e$ #om!lete
over%aul. =e ere to re#eive t%e rein"or#e$ 1bre*lass Nort% +tlanti# sail. =e also
ere to re!la#e all o" t%e su!erstru#ture aba"t t%e "orar$ en$ o" t%e sail it%
rein"or#e$ 1bre*lass C#lam s%ellC se#tions. Naturally- e ere also *oin* to *et t%ree
ne stainless steel strai*%t !i!es.
nter Frit0- t%e ever #urious- C=%y is it like t%atC n*ineer >Q#er. I aske$ t%e
s%i!yar$ man (one al =oolley) %o as res!onsible "or installin* t%e strai*%t !i!es
%y t%ey %a$ to be so lon*. =as t%ere some a#ousti# reason No- t%ere as no reason
"or it ot%er t%an to 1t beteen t%e an*es so t%e ex%aust #oul$ !ass t%rou*% t%e
tail!i!e %i#% itsel" !asse$ t%rou*% t%e %ole in t%e s%eet metal su!erstru#ture t%at
%a$ been t%ere sin#e #onversion. (7%is as a mani"estation o" t%e C=e9ve alays $one
it t%is ayC syn$rome.)
I sai$. Cal- e9re *ettin* an entire ne su!erstru#ture- so t%e yar$9s *oin* to %ave to
#ut %oles in it "or t%e ex%austs- ri*%tC
C/i*%t.C
C>kay- $esi*n a !i!e "or me t%at atta#%es to t%e outboar$ ex%aust an*e an$ t%en
sim!ly turns in t%e s%ortest !ossible ra$ius to !ass t%rou*% t%e %ole in t%esu!erstru#ture. I9ll take it to my > an$ i" %e a*rees e9ll mar#% it u! t%e %ill.C
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He a*ree$. 7%e s%i!yar$ #oul$n9t %ave #are$ less. >BSU<P+ love$ it an$ tol$
<USHIPS %o also bou*%t it an$ issue$ a ne SHIP+?7 re!la#in* t%e !revious one.
/a0orba#k *ot t%e 1rst t%ree ne s%ort !i!es. very ot%er $iesel boat in t%e Fleet t%at
$i$n9t alrea$y %ave t%e lon* strai*%t !i!es by t%en *ot t%em- too.
7%e s%ort !i!es #onsiste$ o" a an*e el$e$ to a :J46in#% transition se#tion about a"oot lon* on its s%ortest $imension an$ about t%ree "eet on its lon*est #reatin* a "orty6
1ve $e*ree an*le. 7%is as el$e$ to anot%er se#tion %i#% turne$ t%e $ire#tion o"
o anot%er "orty61ve $e*rees. i.e. $ire#tly to starboar$ or !ort- %ere a 1nal strai*%t
se#tion a #ou!le o" "eet lon* ent t%rou*% t%e su!erstru#ture.
+ resi$ual bene1t "or /a0orba#k as t%at >BSU<P+ alloe$ us to kee! t%e
substantial savin*s "rom t%e "un$s t%at %a$ alrea$y been allo#ate$ "or a lon* !i!e
re!la#ement. =e a!!lie$ t%ese savin*s to lots o" $esirable !roe#ts t%at e ot%erise
oul$ %ave never a##om!lis%e$
<est-Frit0
#OO$NO$%
ritI, after reading the comleted article added to his already very informative
anecdote and made a review comment that is most welcome from an e-erienced US
Navy submarine oPcer.
It meets it% my a!!roval an$ +/NS BG !raise. =?? D>NM >ne minor item #au*%t
my attention
C Hoever in t%e u!!y II+ #onversions- one $iesel6*enerator as remove$ to make
e5ui!ment s!a#e- $etail o" t%e lay6out an$ o!eration is not knon.C
/a0orba#k (SS:'4) as a u!!y II+. /e*ar$in* t%e above un#ertainty- I believe t%at
t%is s%oul$ #lear t%in* u!. 7%e 2 n*ine (Port) as remove$ "rom t%e Forar$ n*ine
/oom. 7%e air #om!ressors- trim an$ $rain !um!s- va#uum !um!- IB> !um!- an$
Hy$rauli# +##umulator- air #on$itioners- /e"ri*eration unit- an$ IBs ere move$
"rom t%e Pum! /oom (un$er t%e ontrol /oom $e#k) into t%e s!a#e va#ate$ by t%e
en*ine- bot% above an$ belo t%e $e#k !lates. 7%e IBs ere relo#ate$ to t%e
Banoeuvrin* /oom. 7%e va#ate$ s!a#e in t%e "ormer Pum! /oom be#ame t%e Sonar
/oom.
+s %as been state$ else%ere in t%e arti#le- e #oul$ snorkel on to en*ines only. +
t%ir$ en*ine oul$ %ave #reate$ too *reat a va#uum in t%e boat- %i#% in turn-
oul$9ve le"t too little mar*in be"ore rea#%in* Cameout altitu$e.C No !re"eren#e as
*iven to runnin* only t%e +"ter n*ine /oom9s en*ines %ile snorkellin*. 3ee!in* t%e
en*ines9 a##umulate$ runnin* times more or less e5ual as more o" a $e#i$in* "a#tor
in $eterminin* %i#% to oul$ be run at any *iven time.
USS <lue*ill (SS6242) "ormerly (SS36242) as a +7> #lass #onversion t%at also
remove$ t%e 2 en*ine. S%e as one o" about a $o0en +7>9s t%at *ot #onverte$. I
as C>le <lue9sC n*ineer >Q#er "or &, mont%s- t%en be#ame %er >!erations >Q#er
an$ Navi*ator.
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In &'; $urin* my Submarine >Q#er Ruali1#ation 1nal exam- I ent to sea in USS
+IB+N (SS6:2:)- S%e $emonstrate$ t%e *reat- albeit uninten$e$- versatility o" t%e
snorkel system by- are your rea$y "or t%is- $ivin* on t%e snorkel.
Durin* t%is evolution s%e submer*e$ in t%e usual "as%ion- s%uttin* t%e main in$u#tion
valve %ile raisin* t%e snorkel mast- s%uttin* t%e main en*ine overboar$ ex%austvalves- an$ o!enin* t%e snorkel ex%aust valves. <y t%e time t%e boat rea#%e$
!eris#o!e $e!t% t%e snorkel mast as "ully raise$- t%e %ea$ valve as o!en an$ air
in$u#tion as bein* taken t%rou*% it. 7%e en*ines never sto!!e$ runnin*. 7%e main
snorkel ex%aust o!ene$ easily sin#e t%e snorkel ex%aust mast as never #om!letely
oo$e$. +IB+N $i$ t%is routinely.
I as $a00le$- to say t%e least. 7%is !rove$ t%at it #oul$ be $one- but not t%at it s%oul$
be $one. >n#e as enou*% "or me.
<est re*ar$s-
Frit0
Aendi* 8
U-/oat History< Develoment 2 %uiment< 1914 to 1945
by Davi$ Biller
!%3%'AN$ %$!A&$S
7ll four Stroke, two stroke considered but not alied in WW
The diesels had to be modi/ed to run with the SchnorchelJ the 67N 6#0 in the G)!$:,
for e-amle was /tted with secial camshafts with a 1normal1 osition giving an
e-haust ressure of :." atmosheres and a Schnorchel osition ,with a ressure :.$!
:.$% atmosheres.
+arly e-eriments on two tye U!%*!U%? involved removing a eriscoe and relacing
it with the Schnorchel tubes. This was followed by modi/ed tubes in Tye 0 U!>=%!
U>=9 in Set "#$=.
(erman e-haust discharge techniDues were dierent to the simle underwater outletadoted by the Royal Navy. British 7SW e-erience had showed that the submarine
could be detected by observation of the e-haust gases, while the (ermans ersisted
in thinking this was not so.
The (ermans develoed two versions of the all imortant air induction tube head
valve, the /rst a simle ball Eoat and later a ring Eoat. Both these methods were
adoted by the Royal Navy, /rst the ball and later the ring Eoat. 6iller reorts that an
electro!neumatic head valve was roduced but then adds a footnote that this tye of
valve was still under develoment when the war ended.
7s in the Royal Navy, the induction Eoat valve fell oen when lowered allowing the
mast tube to Eood. 7arently the ring Eoat had a vent valve that oened at =: m
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