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SPDC - HSEGbaran Ubie Oil & Gas ProjectBayelsa StateNigeria

15/02/09

This preliminary information bulletin is to outline the contributing factors

that occurred during the lead up to the polyester webbing sling failure at

Saipem Pipeline ROW.

DESCRIPTION POLYESTER DUPLEX WEBBING SLINGSWL 8 METRIC TONDATE MANUFACTURED MAY 2007SAFETY FACTOR 6/1STANDARD No: BS 3481 BS 3481 1993EFFECTIVE WORKING LENGTH 6 MTR (8 DIA)MANUFACTURER ALLSAFE

SERIAL NUMBER 2891

Incident Summary:

Mr.Guiza Edga was preparing tie in joint of 20 concrete coated duplex steel

pipe, which was already lowered inside the trench at Zarama (Z1) ROW

access.

In this process he lifted first section of welded pipe joints around 1 feet

height inside the trench in order to reposition to align with second section

of pipe elbow joint end.

Two side booms (A&B) lift the section of pipe by positioning between 4 no:

welded joint pipes.

After visual alignment of two sections by foreman, side boom (A) lowered

the pipe inside the trench, while side boom (B) start lowering the pipe, web

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sling attached to it snapped immediately and pipe drop back from 1 foot

height inside the trench.

No personnel has been injured.

(Twelve pipes welded together in section one.) Four pipes been lifted for

repositioning where the rest of the pipes remain stationary inside trench

surface.

1 x 20 diameter concrete coated duplex pipe is 12 meters long and weighsapproximately 4.75Ton.

Second section with elbow end laid inside the trench though not lifted

throughout the operation.

The web slings used in this operation is 8 width X 6 mts length, rated SWL

8 Ton for straight single loop lift.(As detailed above)

FINDINGS:

Webbing sling,

Under examination the sling has damage at various points along the EWL

(effective working length)

The damage was in the form of:

Deep cuts to the side of the sling

Abrasion

Broken stitching at the eyes (this indicates over loading)

Tears Total failure point

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Broken stitching

I.D Tag With info

Deep cuts to the side of the sling could severely compromise the slings

performance and would lead to catastrophic failure before the Working Load

Limit (WLL) could be reached.

The sign of the busted stitches in the eyes of the slings is another clear

indication that the sling has been over loaded.

Abrasion to the slings is concurrent with lifting and turning pipe.

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Sling standard,

Semec Agencies Nigeria (agent to Allsafe) sold this sling to Saipem

The standard they made the sling to is now OBSOLETE and was replaced in2000 by BS EN 1492 Part 1& Part 2.

The standard they used was introduced in 1983 and the standard has been

outdated for 9 years!

Sling inspection examination documentation:

This was investigated and it was found that the manufactures test

certificate was available on file and also that the 2009 six monthlyexamination was conducted by Nitram Land LTD on the 08-01-09,

I ask the question could this sling have been damaged at the time of

inspection and could inspector have missed the damage post 08-01-09

inspection campaign?

What are the qualifications of the inspector that inspected the sling and

what are his competence levels as a lifting equipment inspector!!!!

Daily and pre use inspection:

It is obvious that the daily and pre use before and after each time used was

not conducted as the defects would have been picked up and the sling

removed from service,

No daily inspection check sheets for slings are available for the

rigger/supervisors etc for guidance,

No daily record of inspections of slings was available,

There are control measures for signing slings and lifting equipment in and

out of the rigging store, however sling serial numbers or tag numbers are notrecorded.

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Awareness and training:

Although Saipem had records of training for their personal we are yet to

see the curriculum of the training that is being delivered to Saipem. The

Plan now is to organise a training sessions for Saipem that cover webbing

sling and safe sling in detail.

Application of slings:

Slings were not used in line with manufactures specification- used beyond

recommended SWL.

Section being lifting weighs 18.8Ton (4 lengths) while the overall dead

weight is 57 Ton (12 lengths) at 4.75Ton per 12m lengths.

1 x 8 ton slings at zero degree x 2 slings for the overall length= 16Ton. Thus

minus 20% for choke hitch=12.8Ton for the two slings.

Besides, slings with integrity were compromised by cuts/ abrasion andbroken stiching.

Dynamic force during this operation will also contribute to the existing

excess static loading.

Force Moment Diagram

Take moment about point O (Turning)

Cog X 72=F1 X 132 + F2? X 84

O

COG

72 MTR

48 MTR

72 MTR

12 MTR127MTR

F1

R1

F2?

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But F1=6.4Ton, Cog= 4.75 X12 (12 welded pipes)=57Ton

Substituting, 57X 72= 6.4 X 132 + F2? X 84

4104=844.8 + 84F2?

3259.2/84= F2?

38.79Ton= F2

F2?=F2= Static force.

Cog Total load of 12 length of pipe (Dead weight) 57Ton

F1 Max SWL of web sling that didnt fail (with choke) 6.4Ton

F2? Calculated load on sling prior to failure 38.79Ton

Web sling was subjected 6 times more than the Rated Load.

Graphical View of incident layout

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In conclusion, incident occurs due to:

Over loaded web sling at approximately 6 times its Rated Load and

catastrophically failed.

Sling damaged prior to use (compromising SWL)

Lack of awareness of safe slinging & rigging practice. Non-routine lift-was not categorised accordingly.

No lift planning.

No pre use and after use inspection (No record keeping or daily

checklist for slings)

HSE GBARAN UBIE

Idada/Paul