RWS E-Booklet

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Contractor :- Client :-

MMCEC-MMCOG-SEW JV SDN BHD CONTRACT : PD&T/PGB/2019/326

Open PETRONAS GAS BERHAD

TABLE OF CONTENT 16-11Da-t2e 0: 225 1October 2021

1. PROJECT BACKGROUND 2
2. CONSTRUCTION SEQUENCE
3. DEFINATION
4. JOB SCOPES
5. RESTRICTED WORKING SPACE REQUIREMENT
6. LESSON LEARNT
7. TYPE OF HAZARD FOR EXCAVATION/TRENCHES

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PROJECT BACKGROUND

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PETRONAS Gas Berhad (PGB) has awarded MMCJV to complete installation of
33km long NPS36 at Teluk Kalong (Graphite Project) in Kemaman, Terengganu.

The pipeline will commence
from Gas Processing Kerteh
(GPK) and then terminate at
tie-in point in M1 Station

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CONSTRUCTION SEQUENCE

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DEFINATION

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16-11-2021
Date : 25 October 2021

Industry Code of Practice (ICOP) for Safe Working in a Confined Space 2010
“Enclosed or partially enclosed space that is at atmospheric pressure during occupancy
and it is not intended or designed primarily as place of work..

Petronas Technical Standards – Confined Space Entry – PTS 18.52.08 - 2021

An enclosed or partially enclosed space that is at atmospheric pressure during occupancy and is
not intended or designed for continuous occupancy, could have restricted means for entry or exit
AND liable at any time to have any of the following conditions:

Liable at any time to – Restricted means for entry and exit.
Deficiencies or excess of oxygen

Potential harmful contaminants Can cause engulfment
at atmospheric

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CONFINED SPACE VS RESTRICTED WORKING SPACE

Deficiencies or
excess of oxygen

Potential harmful
contaminants

Can cause
engulfment

Restricted entry
and exit

Natural ventilation Low potential harmful
contaminants – Gas test,
Low risk for slope failure (slope Personal gas detector
design, tie-in box)
Easy Ingress & Egress
Continuous Ventilation (blower)

Jacking Pit Tie-in Box

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BASED ON INTERNAL RISK ASSESMENT,
TRENCHED WORKING SPACE AT

GRAPHITE PROJECT DOES NOT MEET
THE CRITERIA TO BE DEFINED AS A
CONFINED SPACE

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The proposed control measures to meet the intention of the Restricted Working Space implementation

Confined Space Restricted Working Space

• Required competent person to enter • Workers require to attend awareness training on
confined space area. Restricted Working Space
1. Registered AGT
2. Registered ES • OHD & AME Medical Check up
3. AE • Daily Health Declaration
4. SP
• Daily PTW revalidation (up to 7 days a week)
• OHD & AME Medical Check up (CSE) can be extended more than 12 hours up to
• Daily Health Declaration maximum 16 hours daily

• PTW only valid for 1 shift (8 Hours +4 Hours) • Gas Test can be conducted by Certified
Company Gas Tester (CCGT)
• Gas Test shall be conducted by AGT registered
with DOSH only

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TYPE OF RESTRICTED WORKING SPACE

WORKING SPACE TYPE 1 TYPE 2 TYPE 3
NORMAL SPACE CONGESTED SPACE SWAMPY/MUDDY

SLOPE SLOPE - LESS 60 DEGREES SLOPE OVER 60 DEGREES REFER CONDITION
SHORING NIL SHEET PILE & STEEL PLATE SHEET PILE & STEEL PLATE

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2m 3m 16-11Da-t2e 0: 225 1October 2021
3m 3m
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2m Angle slope
2m less than 600

1m <600
11mm

Note:

1. Trench slope must less than 60 degrees.
2. No shoring (sheet pile) required.
3. Tie-in box are compulsory. To be installed before tie-in.
4. 2 ladders either at both side of trench or can be installed in same side at deferent end. (inside the

protected area).
5. Ventilation. 2 blowers during hot works (1 blower In and 1 blower Out). 1 blower during cold works

(In).
6. Tie-in box shall be placed adjacent to the overlapping pipe section for temporary protection before

evacuate from the trench incase of emergency.
7. Condition/criteria:

i. Type of soil : All type (except swampy and muddy area).
ii. Width of ROW :
iii. Depth of trenches : 2m - 4m

Note: Angle Slope 16-11Da-t2e 0: 225 1October 2021
1. Trench slope at tie-in area must less than 60 degrees. more than 600
2. Sheet piles or beam and steel plate be installed: Angle Slope
>600 more less 600
i. At any tie-in area where only 1 slope cannot meet less than 60 degrees shoring
(sheet pile/beam and steel plate) are to be installed (at the slope location more than <600
60 degrees slope).
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ii. If both side of trench slope more than 60 degrees, shoring (sheet pile/beam and
steel plate) are to be installed at both sides.

iii. Sheet piles/beam and steel plate shall be installed if the distance of the tie-in
section less than 5 meters from existing pipeline to protect the existing pipeline
moving from its position.

1. Tie-in box must be installed before tie-in work.
2. 2 ladders either at both side of trench or can be installed in same side at deferent end.

(inside the protected area).
3. Ventilation. 2 blowers during hot works (1 blower In and 1 blower Out). 1 blower during

cold works (In).

TYPE 3 16-11Da-t2e 0: 225 1October 2021

3m Shoring using sheet pile
2m
1m 1m Steel plate
Angle slope

more than 600
>600

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SLOPE OVER 60 DEGREES

0.8m-1.0m Sheet pile Steel plate

Note:

1. Sheet piles vertically installed along tie-in
point.

2. Steel plate slot-in behind sheet piles to
avoid slope failure.

3. Ladder at both side of trench.

4. Continuous ventilation.

3m

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JOB SCOPE

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Entry Supervisor

Entry Supervisor who have a knowledge about Restricted Working Space and assigned to perform the Entry
Supervisor’s duties:

• Ensure AGT do gas test.
• Plan the work and prepare required documentation e.g. PTW and RWS checklist.
• Conduct toolbox talk at site.
• Confirm understanding and acceptance of conditions of the PTW.
• Ensure that all equipment have been maintained and have valid inspection tag and are safe for use.
• Identify all authorised entrants and the slope watcher.
• Verify that entry conditions remain safe.
• Verify control measures are in place e.g. ventilation, designated PPE, RPE, rescue equipment.
• ES are not required to be at the restricted working space throughout the work.

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• Authorised Gas Tester - Certified Company Gas Tester (CCGT)
• Carry out gas tests (oxygen content, toxic gas level & flammability)
• Ensure the reading are within acceptable limits at the frequency specified on the PTW and
supporting certificates.
• Gas test to be carry out prior the work commences and every interval 4 hours subjected to AA.
• AGT are not required to be at the restricted working space throughout the work.

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• Work Leader
Work Leader must have a knowledge about Restricted Working Space.
▪ Keep a log of names of all entrants.
▪ Record every entry and exit into/from the Restricted Working Space.
▪ Prohibit unauthorized entrants from entering.
▪ Ensure all entrants declared their health fitness prior entering Restricted Working Space.

• Fire Watcher – must a Competent Fire Watcher and attend awareness training on Restricted
Working Space.

• Authorised Entrant - attend awareness training on Restricted Working Space.

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RESTRICTED WORKING SPACE
REQUIREMENT

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RESTRICTED 16-11Da-t2e 0: 225 1October 2021
WORKING SPACE
TRAINING/AWARENESS
REQUIREMENT
• AA
TOOLS AND EQUIPMENT PROCEDURAL • RA
• WL
• BARRICADES AND SIGNAGE • RISK ASSESMENT • ES
• VENTILATION • PTW • AGT
• GAS DETECTOR • ERP • AE
• LOG IN AND LOG OUT • ISOLATION • FW
• HEALTH DECLARATION
• PPE (remove hazardous material - positive isolation, 23
draining, venting, cleaning & purging)

• GAS TEST
• DESIGN

a) Trench
b) Tie-inbox
c) Calculation

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LESSON LEARNT

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Overview 16-11Da-t2e 0: 225 1October 2021

Case 1 25

Slope slide direction
Incident location

Incident : Collapse of trench due to land slide during pipeline tie-in works

Location: SSGP Project, Batu Niah
Date/Time:
Impact: 9th February 2012 @ 1545 hour
Immediate Actions:
1 fatality and 1 injured (arm injury)

1. Evacuation of the deceased and injured person to Bintulu Hospital
2. Stop work order by PMT

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Leveling of ground for
side boom placement

and movement of
excavator at the
location had affected

soil stability

Steep Slope
(>3m)

without shoring,
bracing or hard

barriers

Slope slide direction

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Pipeline Mass of soil gave way and
moved downwards

Foreman went
inside trench to
assist on work

Asst. Fitter Fitter Foreman was
Rigger Rigger observing from top
of trench

Foreman

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Soil Profile at Incident Area

Clayey Soil layers Side
(Water accumulated) Boom

Dense Silt Clay
(low permeability)

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LOCATION OF DECEASED

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VIEW FROM HILLTOP

Incident location
Land slide direction

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LESSON LEARNT : FATALITY INCIDENT AT SSGP

FINDING & RECOMMENDATION

2 workers doing pipe fitting inside trench. The
shoring collapsed and buried 1 of the workers.
1 workers managed to escaped but injured.

• Poor soil condition – heavy rain overnight
• No risk assessment done before work start
• Require additional SHO at critical activity sites

• Provide cage for workers at high risk

locations

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Case 2

Case Study (Malaysia):
1. On 16 March 2018, 4 workers entered a trench to level sand bedding in trench.
2. The trench wall suddenly collapsed and 2 workers were trapped.
3. Rescue efforts managed to rescue only 1 of the workers while the other worker

was pronounced dead by doctors at site.

Impact;
Collapse of trench wall -trapping and burying worker.

Causes Illustration

:1.Ineffective enforcement and PTW implementation causing non-compliance

to the excavation procedure and requirement.

2. Stock pile soil (approx. 2m height) was placed at the edge of excavation

trench.

3. Minimum distance of stock pile was less than 1m.

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How HEAVY is 1m3of soil?

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TYPE OF HAZARD FOR
EXCAVATION/TRENCHES

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Hazards in relations with excavation/trenches activities are divided into
the following categories:

Ground FaGilruoruesnd Failures
Moving Objects
Underground Utilities

Health Hazard

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GROUND FAILURE

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Case Study (Japan): 16-11Da-t2e 0: 225 1October 2021
• Three (3) workers engaged in removing soil from an excavated trench that
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had a leaking pipe.
• A crack was later noticed at surface of the soil near the excavation site.
• Soil collapsed into trenches.
• The entire body of the victim was buried.

Impact;
The sides of an excavation trench collapse during work to remove soil
that had fallen into the trench at the construction site of an agricultural
drainage channel

Causes:
• Firm measures to protect against the collapse of the natural ground were not taken.
• Work was being carried out without a clear instructions.
• Appropriate operations plans were not formulated.
• The slope of the walls were too steep.

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Case Study (Japan):
• A trench (1.4 m deep, 24.5 m long and 1.6 m wide) was excavated for construction of a

sewer line.
• The ground in the area was very soft as the development was being built on reclaimed land.
• Victim was walking along the edge of trench, the edge of the trench at his feet collapsed
• He was buried in the trench.

Impact:
The edge of a trench suddenly collapses during work to inspect
an excavated sewage trench

Causes:
• Walking along the edge of the excavated trench.
• Installation of soil-retaining sheeting or other measures to moderate

the slope, etc., had not been taken.
• Safeguards such as prohibiting entry into the area, etc., had not been taken in advance.
• Additional earth was piled up on the edge of the excavated trench.
• An operations plan for the excavation was not prepared.

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Case Study (Japan):
• A drag shovel was used to dig the trench to install branch lines to an existing main sanitary sewer line.
• The victim entered the trench (about 3m length 2m width 2.7m depth) to remove soil from the main sewer by

shovel.
• The trench wall collapsed and buried the victim beneath a pile of soil.

Impact:
Fatality caused by landslide while digging a sewer trench

Causes:
• The trench wall was cut almost vertically.
• Measures to prevent landslides had not been taken.
• Pressure was applied to the top of the trench where the

excavated soil was piled.
• Vibration caused by using a drag shovel loosened the soil,

making it prone to collapse.
• No excavation operations leader was appointed.
• A work plan had not been prepared.

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Case Study (USA): 16-11Da-t2e 0: 225 1October 2021
• The walls of the excavation were not properly sloped,
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shored, benched or otherwise adequately protected
against collapse.

Impact:
Ground failure due to load/surcharge

Cause:
• Excessive weight near the surface
• Close distance from the edge of the trench
• The classification of the supporting soil with insufficient

strength to sustain loads

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This is a very dangerous situation Shear plane failure along the
requiring ground support. No worker seepage (slippage) plane
should be in a trench >1.5m deep unless
support has been installed.

Worker badly injured after being crushed Worker Trapped and crushed against
against the opposite wall by the the trench wall by the quick collapse.
collapsing ground weighing about 3
tonnes.

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How do Cave-Ins Occur?

1. Undisturbed soil stays in place because opposing horizontal and vertical forces are evenly balanced.
2. When an excavation is created, the horizontal support of soil is also removed.
3. Soil will eventually move downward into the excavation.
4. The longer face (side of excavation) remains unsupported and it could cave in the following

manners:

source: Oregon OSHA

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MOVING OBJECTS

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• Powered mobile machine should not operate or travel 16-11Da-t2e 0: 225 1October 2021
near the edge of an excavation unless the shoring can
support such loads. 44

• Mobile machine should approach end-on to excavations. If
this is not practicable, make sure workers in the
excavation get out when the mobile machine is within the
excavation’s zone of influence or move away and stand
further down the excavation.

• Workers should never stand under a load being lifted
over the excavation.

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A blind area/spot is the area around a vehicle that is not
visible to the operators, either by direct line-of-sight or
indirectly by use of internal and external mirrors.

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UNDERGROUND UTILITIES

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UG Scan is required prior to start of any excavation works in brownfield areas 16-11Da-t2e 0: 225 1October 2021
REFER UG DRAWING
Numbers Indicate
Distance From Ground/
Pavement Surface to Top
of Utility (top of pipe/cable
etc.)

SAMPLE OF UG SCAN

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