Jacket Weighing Procedure
Jacket Weighing Procedure
Jacket Weighing Procedure
(PHASE I)
ITUT AND ABANG JACKET WEIGHING PROCEDURE
MOBIL
P RODUCING
NIGERIA
Description
Gordon Dunthorne
NIGERDOCK Engineer
Manager
Prepared
by
Melchor Yaun
NIGERDOCK Lead Engineer
Checked
by
Jagba Smart
NIGERDOCK QA/QC
Engineer
Edward York
NIGERDOCK Project
Manager
Endorsed
by
MPN Representative
NGTA-NK-NPZZZ-00-XXXXXXX Rev. A
Signature
Approved
by
Approved
by
ii
Date
MOBIL
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Revision
Section
Rev. A
ALL
ACTION
Description
Initial Document
NGTA-NK-NPZZZ-00-XXXXXXX Rev. A
iii
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TABLE OF CONTENTS
1.0
SCOPE OF WORK
2.0
INTRODUCTION
3.0
CONCLUSION
4.0
SAFETY
5.0
EQUIPMENT
6.0
ORGANIZATIONAL CHART
7.0
PERSONNEL
8.0
COMMUNICATION
9.0
METHOD
10.0
ANALYSIS
10
11.0
DATA ANALYSIS
13
12.0
REFERENCES
13
APPENDIX A
APPENDIX B
NGTA-NK-NPZZZ-00-XXXXXXX Rev. A
iv
1.0
MOBIL
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SCOPE OF WORK
This procedure describes the method that will be utilized for the weighing of
SFDP Jackets pertaining to NDs Scope of work for Mobil Producing Nigeria.
This procedure is based on SFDP Jackets, SFDP Jacket Weight is 258.2 Mt
(as of estimate 27-01-).
2.0
INTRODUCTION
This document describes the weighing of ITUT Jacket Structural Analysis of the
Jacking point currently being fabricated at Nigerdock Nigeria FZE, located at
Snake Island Apapa Lagos.
The method of weighing will be firstly place sheets of 30mm thick steel plate
under the jacket grillage points, then insert jacking stool frames in position
directly under the centre of each platform support leg and to place the enerpac
load cells immediately on top of this jacking stool support frame (shimmed to
suit) This will enable 4 enerpac load cells wires to be run and utilized along with
the enerpac control panel ensuring accurate recording of the weighing exercise.
Drawing ND-ITT-710-GA-200-A1 Below clearly shows enerpac locations and
wiring connected to the main control panel
The structural analysis on the jacking stool was carried out using Staad Pro
2004, the design and checking is in accordance with AISC ASD 9th Edition and
API RP2A All Dimensions used in this procedure are based on SI units and
weight calculation in Mtons.
3.0
CONCLUSION:
The analysis performed on the jacking stool satisfies the structural integrity to
withstand the stresses and that the deflection is within the allowable limits
Maximum stress ratios for weighing are listed below:
-
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4.0 SAFETY
The Gantry side where the intended structure for Weighing will be temporarily
positioned must be cordoned off from unauthorized persons and visitors. Barrier
control will be strictly enforced. No personnel will be allowed in the vicinity of
suspended loads.
ND shall ensure all procedures are understood and workers are briefed as to any
potential worksite hazards. All identified hazards or potential hazards shall be
promptly eliminated or controlled.
ND shall ensure all works related to the Weighing are carried out in a safe and
efficient manner and that safe systems of work are prepared and implemented.
ND shall ensure all equipment are safe, suitable for the operation, kept in good
condition and that defects are identified and follow up action initiated to repair
defective equipment or withdraw it from site.
All Weighing Equipment shall be inspected prior to use and will have an up to date
certification.
A pre-weighing checklist shall be used to verify safe systems of work are in place,
the check list shall be endorsed by MPN Heavy Lift Advisor.
ND shall ensure all places of work, including work at heights, etc are safe and
where necessary adequate control measures shall be implemented through JSA,
Risk Assessment or Toolbox talks.
Risk assessment will be carried out by ND and Company and will be developed by
the Risk Charter Group as per required procedures.
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EQUIPMENT:
This section describes the minimum equipment needed to perform this
operation. All Equipment to be used in this procedure shall be checked and
certified by a recognized certifying authority. Equipments required for the
Weighing operation are not limited to the following list:
ENERPAC
4 off ENERPAC 500t LOAD CELLS complete with central control panel
JACKING STOOL
As fabricated by Nigerdock
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6.0
Construction Support
Mgr James Cunningham
7.0
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Stand-by Team
plus
Maintenance
Group:
Scaffolders
Welders
Electrician
Helpers
Fitters
Forklift
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7.1.5
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8.0
COMMUNICATION
A communication exercise between the involving personnel will be established
prior to Weighing Operation. A minimum of two (2) days is expected for this
exercise before the final Weighing operation and one (1) day prior to Pre-Weigh
meeting.
During the operation the Hand Signaling, Verbal and Radio will be the means of
communication. Spare radio equipment will be made available.
All the Instructions will come from the Construction Support Manager; he gives
the instructions and receives the information from his subordinates. This
coordination will come from Load Cell Operators and Safety In charge.
The communication between the involved personnel will be by means of one
radio channel in order to ensure clear communication.
The Load Cell Operators and any assistant will communicate to the
Construction Support Manager whenever the event or situation of the Load Cell
is in dangerous position. The instruction will be three STOPS, ex. STOP!
STOP!! STOP!!!.
The four (4) Load Cells used in the operation will be named and identified as
follows:
Load Cell C1
Load Cell C2
Load Cell C3
Load Cell C4
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METHOD
9.1
PREPARATION:
All Rigging and Weighing Appliances should have all certifications checked
prior to use.
Remove all obstructions that will hinder the operations.
During operation the area shall be limited to nominated yard personnel only.
All other personnel shall observe operation from outside the taped area.
Load Cells shall be positioned as specified in the drawings.
Any Required Rigging equipment shall be positioned in accordance to the
specified drawings.
All radio communication shall be checked if working properly.
The Over all control of the operation shall be Construction Support Manager
who will be in touch with the personnel as defined by Communication
sections of the procedures.
During Weighing Operation, all client communicate shall be addressed
through Project Manager or his deputy.
A pre-weighing meeting shall be held between ND Team and Company to
discuss the procedure and issues concerned. All procedure shall be clear to
both parties and pass JSA (Job Safety Analyses) prepared by the
Construction Support Manager with support from the Safety Department.
9.2
9.3
During weighing a 50% load shall be tested on each load cell as
specified on the above theoretical value of each load point, and measurement
shall be taken and recorded. All loads in the load cells will be measured. When
the 50% load is achieved, the structure will be lifted gradually until a full 100%
load is achieved at a height of 100mm from the support and this operation is to
be repeated a minimum of 3 times and readings recorded for each lift
operation.
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9.4
Acceptance criteria of the final recorded value of the 3 weighing
operations shall be the average of the 3 recorded values and this value should
not differ from the maximum of any of the 3 values by more than 0.7%. The
tolerance of the enerpac load cell should be equal to or less than 1%.
9.5 The maximum load on any one load cell shall between 20-80% of their
total load capacity.
9.6
10.0
If the weighing is achieved and satisfies the operation, the structure will
be put back in original position otherwise the weighing operation will be
repeated again.
ANALYSIS:
This section explains the procedure performed for the analysis of the ITUT
jacking stool.
The data for the model was taken from the weight control and CofG report
produced by Nigerdock and analysis was performed on Staad-pro
See attachements in Appendix A
REFERENCES:
Nigerdock Shop Drawings Reference:
1. ND-ITT-710-GA-200-A1
2. ND-ITT-710-GA-201-A1
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