16. CHAPTER - 16 Working at Height and Depth

8/19/2019 16. CHAPTER - 16 Working at Height and Depth

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CHAPTER - 16

Working at Heights and Depths

1 Incidence, Types and Causes of Fall Accidents

2 Statutory Provisions3 Indian Standards4 Safety while worin! on the Sa"e

#evel$ Safety while worin! at %ei!ht &

$'1 Stairways$'2 (uns, (a"ps and )an!ways$'3 Floors and Platfor"s$'4 #adders

$'$ Sca*oldin! &$'$'1 )eneral (e+uire"ents$'$'2 Types of Sca*old

$' Safety -elts and %arness &

$''1 )eneral (e+uire"ents$''2 Types of Safety -elts

$'. Fall Arrester /Anti fall0 evices$' Safety ets$' 5orin! on (oofs$'16 5or Per"it Syste"$'11 )eneral Precautions while

worin! at %ei!ht Safety a!ainst Fallin! -odies. Safety while worin! in epths and

Con7ned Spaces

.'1 8eanin! and %a9ards of Con7nedspace

.'2 :essel ;ntry Per"it

.'3 5orin!


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T'pe o( "a))

+an(a$tring

PriateIndstr

'

Constr$tion

To samelevel

. ''.+ .

To lower

level

*.' 5.' ''.(

3lips 0 Trips

#. #.( #.$

All deaths 1occupational plus non"occupational2 due to falls in 83A arereported as under :

T'pe o( "a)) 1../

1..0

1..

;n or from stairs or

steps

''$* '+) ''(

;n or from ladders orscaolding

*# *+' #()

4rom or out of building or structure

5+( 5'*

&nto holes or ooropening

(* '+ ((

;ther fall from onelevel to another

'+$$ ''5$ ()

4all on same levelfrom slipping,tripping or stumbling

$++ 5#+

4all on same levelfrom collision,pushing or shoving

( $

4racture, causeunspeciillie ?ammer,

are '$.% due to falls and #5% due tostruc by or against objects.

All these data of India,


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safety belt, safety shoes, unsafe use of vehicles, poor supervision, poor lightingetc.

+ain Cases o( "a))s andPreentie +easres%

Co&&on Cases o( "a))s are %

'. >ater, oil or grease not cleaned up.#. Doose, defective or broen oor or toe

board.*. 3crap, chipping, swat and obstructions

lying on the way.. 9usty, steamy or smoy atmosphere

restricting vision.5. !arrying too much load maing it

diEcult to see over the load.

$. >arn out or unsuitable footwear.. Poor lighting, glare or shadows.). Fushing instead of waling.(. 9efective or wea scaolds.'+. Dadders, ramps, plans and platforms

not rigid or safe for the job.''. /o or inadeuate handrails.'#. !limbing oddly instead of using

ladder.'*. Throwing instead of lowering tools or

materials while woring aloft.'. /ot using spectacles for clear vision.

'5. /ot using crawling board on fragileroof.

'$. /ot using a safety belt or using in awrong way, e.g. not tying its free"endor tying it with a wea support.

'. /ot closing the manhole cover oroor"opening etc.

'). Allowing roof wor and oor wor at atime in the same vertical plane.

'(. Touching of crane boom, hoo etc. towea or unfastened structure.

#+. /on"compliance of statutoryprovisions.

3ee Fule ' for overhead protectionand Fule # for slipping, tripping, cutting,drowning and falling ha@ards, of Building0 !onstruction >orers !entral Fules,'(().

3ee Part #.5+ of !hapter"#).

+ain Preentie +easres are %

'. 3afe, sound and dry 1non"slippery2surfaces for waling and woring.4encing, guarding and toe boards.

#. 3afe helmet, safety belt, foot"wear,etc.

*. 3afe practice in waling and woring./o ecessive load lifting.

. 3afe means of access while woring atheight or depth.

5. 8se of crawling board, cat ladder, fallarrester net etc. while woring onfragile roof.

$. 8se of 3afety wor permit for woringat height or depth.

. 3afe and sound stairs, ladders, scaoldetc. and safe use thereof.

). -ood lighting and supervision, cuttingo power supply in overhead electriclines.

(. 3afety cordon to disallow persons inthe area where any object may fallfrom height.

'+. Femoval of #+ causes mentionedabove. ;ther details are given below.

8ost of the falls fro" hei!ht provefatal or result in serious fracture' Asreported in )uiness -oo of 5orld(ecordsD, &. C. !hissov of Fussia fell##+++ ft from a damaged 6&lyushin 7

without a parachute and survived. ?estruc the edge of a snow"covered ravineand then slid to its bottom. ?is pelvis andspinal were damaged but he lived.

"a)) Energ' %

Gnergy reuired for sull fracture is *+to 5 foot"pound. >hite and Brownindicated that ') mph 1# ftHsec2 is avelocity 1of fall or impact2 which may ill5+% of all persons against a hard surface.

This is euivalent to a free fall of '' ft.>illie ?ammer has given following


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4eet 0Anles

'# "'*

) " ( #5 " *+

Dumber 03pine

) $ '#

Courtesy : >illie ?ammer, Feference /o. at the end of this !hapter.

Ability of a human body to sustaineect of fall depends on 1'2 velocity of aninitial impact 1#2 magnitude of thedeceleration and 1*2 orientation of thebody on impact.

The inetic energy of a body fallingon a hard surface can be given by aformula :

G I

where w is the weight in pounds, ν

isftHsec, g is gravity constant i.e. *#.#ftHsecHsec, and G in ft"pound. &f G and ware nown, falling 1fatal2 speed 1velocity2can be nown by the same formula.9eceleration 6d7 is given by d I ν2H#hwhere h is the falling height or stoppingdistance.

STATT!RY PR!9ISI!NS

Se$tion 0 and 00 of the 4actoriesAct, '() provide precautions regardingoors, stairs, means of access, pits,sumps, openings in oor etc. Accordinglyall oors, steps, stairs, passages andgangways should be of soundconstruction, properly maintained andept free from obstructions andsubstances liely to cause persons to slip.3teps, stairs, passages, gangways withsubstantial handrails, fencing and safemeans of access to every wor place,

shall be provided to prevent a fall andensure safety.

Gvery ors uHr '+#, -4F, de


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ll

l


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top and bottom ventilation and se)(-$)osing orers !entral Fules, '(() arepertaining to runways and ramps.

2*0 ")oors and P)at(or&s%

The design should consider all typesof load in the form of materials, personsand other forces acting on the oor. Acidproof brics laid in acid resistant plastershould be the choice of ooring for aworroom in which acids are handled.8nprotected oor edges situated atheights and openings, sumps, pits etc., inplatforms or oors should be protected byrailings, toe"boards or guards. The heightof the railings from the base should benot less than (+ cm or more than '#+ cm.

&t should have intermediate members toshorten the gap less than cm. The toe"board should not be less than '5 cm inheight.

4loors should be of suEcient strengthand shall never be overloaded. Theyshould be non"slippery, free from holes,openings, pinch points, uneven surfaces,irregularities, accumulation of oil, water,waste, dust etc. /ear wet processes andwater showers, proper drainage should be

provided.

;pen gutters, erbs and ooropenings 1holes, chutes, inspectionplates2 must be fenced or guarded toprotect unwary persons or preventmaterial falling through it to the oorbelow.

/on"conductive oor in eplosive

atmosphere pose special [email protected] of static electricity generatesspar which can ignite the eplosivemiture near the oor. Therefore steeltipped or nailed boots or dropping of steeltools on such oor is ha@ardous. 3uchoors must be earthed properly.

&n industry, criteria for oor selectionare many. &n addition to strength, comfortand cost, resistance to 1a2 wear andabrasion 1b2 chemicals 1c2


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Dadders should rest on


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construction, maintenance, repair anddemolition wor.

The scaold serves two purposes.;ne is to provide a convenient platformfor persons to wor at height and theother is to provide a safe means of accessto all places where any person may be

reuired to wor at any time. Accidents atscaolds are generally caused either dueto direct collapse of the scaold or as aresult of persons or material falling o thescaold.

The scaolds should be of soundmaterial, suEcient strength 1 times theepected load2 and properly designed.

Their erection, alteration and dismantlingshould be done under the supervision of acompetent person. They should besecurely supported or suspended andshould be properly strutted or braced toensure stability. /ormal si@e is cm thic #* cm wide *" m long.

3teel components of tubular1normally 5 cm dia2 scaolds shouldconform to &3:#5+ and +' for 3teel3caoldings. >ood and bamboo shouldmeet the speci


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ecess of the woring load for which theyare designed. >ood scaolds are notgenerally painted. ?owever, in case of ladders and certain permanent types of scaolds such as the mobile scaold,protection is generally provided byperiodically treating them with a coating

of linseed oil.Cain ha@ards with scaolding are:

'. 8nsuitable or faulty material of construction.

#. &nadeuately supported scaoldboards.

*. &mproper platform width and thicness.. /on"securing or bracing scaold to the

structure. 9amaged or wrong couplers.5. 8nsecured ladders slipping.$. ;mission of guard rails or toeboards.. ;verloading the scaold.). Grected on uneven ground.

3caold foundation should be veriorers !entralFules, '(() gives provisions regardingscaold.

2*2* T'pes o( S$a8o)d %

3ome common types of scaold areas follows :

1 Po)e t'pe s$a8o)ds %

&t may be an independent structure or

the putlog type erected and supportednear wall or another structure.

The uprights 1vertical poles2 shouldrest on strong foundation to support loadwithout settlement. They should not beept more than * mt apart. Tubularuprights have steel base plates placed onwooden sole plates. 3oft ground should bewell rammed and levelled.

4iings lie steel bolts, nails or


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&t is a balcony type cantilever scaoldresting on wall. &f other types of scaoldare possible, this type should not be used.

The outriggers should be passed rightthrough the wall and be secured on theinner side. 3upporting hoo between bric

joints is dangerous.

Platform should not project beyond #mt from the wall. -uard rail and toe boardshould be provided.

/ Singing BHanging S$a8o)ds %

?ere the platform is hanging by twochain pulley bloes, ropes and hoos onsupporting beam. 3uspended platformcan be raised or lowered as per need.Covement of both the ends should besimultaneously. The anchorage and thesuspension gear should be strong enoughto withstand the load with good factor of safety. 3uspension ropes should withstand$ times the intended load. Fope diametershall be more than +.5 inch.

A safety rope shall be provided inaddition to the suspension ropes.

The width of the platform should bemore than 5+ cm and less than (+ cm.-uard rails and toe boards necessary onall the three sides open. The platform

should be lashed or secured while in use,to prevent swaying.

Gach person woring on swingingscaold should wear safety belt withlifeline attached to an anchorage otherthan the scaold itself.

2 Sspended S$a8o)ds %

Two or more platforms are suspendedby ropes from overhead outriggersanchored to the building.

3uch scaolds are designed with afactor of safety and shall never beoverloaded. Anchor plates should be tiedwith 8 bolts. !ounter weights are used toprevent overturning. >ire ropes 143 $2 areused to support scaold. ?oisting drum1lie winch2 is used with at least # deadturns. -ap between handrail and toeboard should be covered by a wire meshof *) mm and '$ gauge wire. ;verheadprotection should be provided if ris of

falling objects is possible.

6 Foatsain=s Chair %

-oatswainDs chair is used forsupporting and hoisting single person insitting position. -eneral chair 1seat2 si@eis $+ cm *+ cm, with #5 mm thictimber. !leats etending in front to at

least #* cm should be securely


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woring since the worer is to be pulledout when he gives indication of anydiEculty to him or when it is observed bythe person holding the rope, standingoutside and watching the person woringinside.

>orers should be trained,

encouraged and supervised to wearsafety belt properly because it can savetheir precious lives.

All safety euipment are to be freelysupplied by the employer and it should beseen that worers use them. This is astatutory reuirement.

3afety belts are reuired for worersworing on towers, masts, windows andbuilding projects and also in conrapping of free end 1rope2on waist is a wrong practice. &ncreasinglength of the rope without permission canalso lead to ha@ard. Anchorage pointshould be at such height so that there

shall be minimum slacness in the line. &tshall never be lower than the beltattachment to the restraining line.

Sa(et' )o$k 1lie chain pulley blocor hoisting drum bloc2 is used to connectthe wire rope with the safety belt to allowmore freedom of movement. A suddenpull operates loc or brae to stop therope. Because of a friction brae on therope drum, jolt is avoided and the fallingperson is stopped smoothly. &n anotherdesign, a centrifugal brae is applied on

the drum so that the person descendsslowly to reach the ground.

Tensile tests and drop tests arecarried out on safety belts and apparatusused with them.

3afety belts should be ept in a cool,dry and well ventilated place. Fegularcleaning, visual inspection for defects andrepair only by a competent person arenecessary for good maintenance.

3ee Part 5.$ of !hapter"#5 for further

details of fall protection.

3ee !hapter"KJ& 1F.'5 to ')+2 of Building and other !onstruction >orers1!entral2 Fules, '(() for catch platforms,safety belts, nets etc.

2*6* T'pes o( Sa(et' Fe)ts%

Cainly four types of safety belts arein practice :

1 @enera) prpose Sa(et' Fe)t :

&t consists of a waist belt, arestraining line 1lifeline2 and the metalcomponents. 3traps covering shoulders,chest, waist and hips are preferable as bywearing it the forces during fall will beabsorbed not only by the trun but alsoby the legs. !hoice of model depends onworing method, time of wor,environmental factors etc. Fope 1normally# m2 is attached to 9 ring secured to thewaist belt.

4or window cleaning, straps are longenough to


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de


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pollution and corrosion spoil the roof condition. ?idden cracs in a roof increase the ha@ard.

The shape of the roof"at or slopingwith a straight, polygonal or curvedpro


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"or&at 1 % Work Per&it (or o at High E)eation

Per&it No* Date %

/ame of the !ompany

Plant 0 DocationGlevation H ?eight

ob 9escription

Jalidity period

Please answer the following after checing at site. &f answer is 6/o7, justify with yourremars :

Sr* Che$k Points Yes>No Re&arks, i( an'

1* >hether the job reuires erection of scaoldingfor maing a temporary wor platform at highelevationQ

#. A standard scaolding has been erected to

mae a temporary wor platform at reuiredheightQ

*. Proper ladder has been provided for access toand egress from the wor place at heightQ

. >or platforms are provided with hand railsQ5. 3tatic lines provided for hand hold to facilitate

safe movement of worersQ$. 3afety net1s2 provided 1>here erection of

scaold or wor platform is not feasible orotherwise ris is high2Q

. Proper use of safety belt by all wormen is

ensuredQ The safety belts are of standard maeand inspectedQ

). 8se of safety helmet and safety shoes by allwormen is ensuredQ

(. !rawling boardsHduc ladders are used for worover slopping roofHfragile roofQ

'+. Area below has been cordoned oQ&ssuing Authority 1Gngineer in"charge2 Permittee 13ite 3upervisor2

3ignature of the 3ite Gngineer

/ame RRRRRRRRRRRRRRRRRRRRRRRRRR !ompany RRRRRRRRRRRRRRRRRRRRRRRRRR 9ate RRRRRRRRRRRRRRRRRRRRRRRRRR

3ignature of the 3ite 3upervisor

/ame RRRRRRRRRRRRRRRRRRRRRRRRRR !ompany RRRRRRRRRRRRRRRRRRRRRRRRRR 9ate RRRRRRRRRRRRRRRRRRRRRRRRRR

>or completed and this permit epired 19ate 0 Time2 :

14


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"or&at % Work Per&it to ork at Height or Digging

/ame 0 Address of the !ompany :

W!R? PER+IT to ork at Height or Digging PER+ITN&er Date

9ate and Time of >oring

Jalidity of Permit Docation of >or &nitiating 9ept.

4rom To 4rom To

Detai)s o( ork to e $arried ot

@enera) de$)aration ' $ontra$tor=s sperisor ho i)) e aai)a)e

at site*

& hereby declare that the wor detailed above will be carried out strictly as per safetyprecautions 1&nstructions A or B2 mentioned overleaf. & ensure that only those personswho are instructed by me about the safety precautions to be observed and who aretrained in such wor will do the said wor.

& will be available at site throughout the period of wor.

9ate 3ignature of !ontractor 0/ame

!ontractor :

Please read carefully and follow instructions 1A or B2 mentioned overleaf.

Per&ission @ranted (or BTi$k :

>oring on 4ragile FoofH>oring at ?eight BRe(er Instr$tion A

9igging >or BRe(er Instr$tion F

&ssuing 9epartment Feceiving 9epartment

/ame : /ame :3ignature : 3ignature :>or completed and this permit epired 19ate 0 Time2 :

Cop' distrition : 'st !opy " &ssuing 9ept, #nd !opy " 3afety 9ept, *rd !opy " 8ser9ept, th !opy " !ontractor

15


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$. Doose ecavated material shall beremoved by person using rubbergloves.

. /o tools shall be left after each day7swor is over.

). The 3upervisor must be available atsite during the period of wor.

2*11@enera) Pre$ations hi)eorking at height %

They are as under "

'. !ut o power in nearby electric lines toavoid shoc and fall.

#. 9o not lift or carry ecessive load so asto loose balance and fall.

*. Tools should be attached by lanyard tothe belt or garment to prevent theirfall on others.

. 3afety helmet, shoes, safety belt,respirator and other PPG should beworn as per need.

5. =eep the wor oor always dry, cleanand well protected. The oor should becheced for fragility, crac and itssoundness to carry load. /on fragilemetal sheets or reinforced A! sheetsare preferable.

$. =now safe means of access,emergency staircase,


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Con


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*. 3ump pumps with ameproof electricor pneumatic motors and air etractionfans 1sparproof2 and ehaust ductingto remove heavy vapours arenecessary.

. !omplete isolation of the vessel,cleaning, purging and ventilation of the

vessel, inspection and testing, safetypermit and all rescue arrangementsmust be done before such wor andonly a trained worer will wor underconstant help and supervision.

5. Datest safety and rescue systemsshould be used. >inch arrangementconnected with the worer7s harness isuseful to lower and pull out uicly.?andfree communication system isavailable to eep the worer in thetan in constant touch with thesupervisor outside. ?and operatedclutch, cord and chair assembly can beused to lower the person while woringat height or depth.

$. Bottom drain valve and other no@@lesshould be ept open to allow goodventilation and fresh air in a vessel ortan.

Fefer Part ') of !hapter"') for moredetails of safe entry into con


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1* Ep)ain, State, +ention orDis$ss -

'. Types of fall accidents.#. Cain causes of fall accidents

and their preventive measures.*. The inetic energy of a falling

body.. 3tatutory provisions to prevent

fall accidents.5. >hich are the areas where a

worer has to wor at heightand what precautions arenecessary to wor safelyQ

$. 8sefulness of Building and other!onstruction >orers Act andFules for safety while woring atheight or prevention of accidents due to falls of personsand materials.

. Types of misuse of ladder andsafety precautions to avoidthem.

). -eneral reuirements of scaolding

(. ?a@ards and safety measureswhile woring with scaolds.

'+. -eneral reuirements of asafety belt.

''. Types of safety belt.

'#. ?a@ards and safety precautionswhile woring on a slopping orfragile roof.

'*. /eed and chec points of asafety wor permit for woringat height ;F in 9epth.

'. -eneral precautions whileworing at height.

'5. The meaning and ha@ards of acon


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*. -uard rail and toe board are notnecessary on scaold.

. >hile woring at height safetybelt is fully suEcient, no otherarrangement is necessary.

5. Boiler is a con

16. CHAPTER - 16 Working at Height and Depth

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Transcript of 16. CHAPTER - 16 Working at Height and Depth