Tank Farm Field Construction Work Progress Measurement System- Sample Template for Practical Use

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Tank farm mechanical construction progress calculation sheet (system) would be an excellent resource for those who have never done field fabricated above ground tank construction work. The basis of an external floating roof type, t ype, tank farm construction progress calculation sheet/system is mainly depending on ex ternal floating roof type, single deck with internal pontoon (1) Scope : Mechanical work for an external type for oil and fuel storage above ground tank. Civil foundation, cathodic protection work, fire system, cabling works and instrumentation works are not included in this calculation sheet. Engineering details design is done by Owner or EPC Contractor.

(2) WBS (Work Breakdown Structure) : As described on Progress Calculation/Tracking System for Oil and Fuel Storage Tank Fabrication. (3) Work Steps and Weight Factor: Field Construction for Each Construction Steps

Method of progress calculation is the same as Progress Calculation/Tracking System for Fabrication.. The only difference is construction work steps and weight factors. The details are as Fabrication the following.

Tank Bottom and Floating Roof Plate Field Erection Work Steps and Weight Factors Field erection works steps for tank bottom (annular plate, sketch plate and rectangular plate) and floating roof (centre deck plates, pontoon p late and stiffeners) installation are 1) Position/lay plate, alignment and fit-up and tac k welding (short-seam) 2) Full Welding (long-seam) and NDT (e.g. LPT at center deck, pontoon deck, d eck, RT test, etc.) 3) Field Blasting/Primer at field weld joints/Final Coating (if carbon steel tank) 4) Final inspection as per API 650 or Owner’s specific requirements Tank material at erection area is added as part of construction progress calculation assuming that  prefabricated materials are delivered by Contractor. Once again, decision on whether it will be included or not depends on o n company specific requirement and client’s approval. Work steps weight factor needs to be adjusted so as to facilitate exclusion of that work step. Use the sample work steps and weight factor table below for starting point.

Work Steps Material at Erection Area Lay Plate/ Alignment & Fit up welding Full Weld/NDT Field Blasting/Final Coating Final Inspection

Weight Factor 5%

35% 45% 10% 5%

Tank Shell Side Field Construction Work Steps and Weight Factor Shell plate field erection work steps includes as minimum, 1) Position, alignment and fit-up and tack welding 2) Full Welding at both sides(Front & Back joints) and Inspection (DP Test/NDT) 3) Field Blasting/Primer at field weld joints/Final Coating (if carbon steel tank) 4) Final inspection as per API 650 or Owner’s specific requirements Then, they are listed in Work steps and % weight table for physical progress calculation. See a sample table below. Work Steps Material at Erection Area Position Plate/Alignment & Fit up Welding Full Welding both sides(Front & Back) /NDT Field Blasting/Final Coating Final Inspection

Weight Factor 5%

35%

45%

10% 5%

Tank Accessories and Fittings Field Construction Work Steps and Weight Factors for Physical Progress Calculation Two different work steps weight factor tables are made in this system as the construction method for tank external accessories is different from internal apparatus. This will help you to track the  progress closely without distorting overall construction progress.

(a) Construction work steps for tank external accessories installation at site includes (1) Member Assembly: -Lift the each section of prefabricated spiral stairway and welding onto tank body (Shell side), - Lift prefabricated platform and handrail materials on to tank roof, welding onto tank body and final bolt up - Lift prefabricated rolling ladder/rail tracks and handrails on to tank roof, welding on centre deck and final bolt-up with gauger platform (2) Final inspection as per API 650 or Owner’s specific requirements Then, the sample work steps and weight factor table can be used for tank external accessories conduction physical progress measurement. Work Steps Material at Erection Area Member Assembly Final Inspection

Weight Factor 5%

85% 10%

(b) Construction work steps for tank internal accessories and nozzle installation at site includes 1) (Marking & Cutting for Nozzle holes, Alignment & Fit -up Welding for all) includes - Marking/cutting on nozzle locations, install reinforcement pad and fit-up weld with prefabricated nozzle, Alignment & fit-up/tack welding of pontoon legs, center deck support legs and gauge poles 2) Full Welding/NDT

3) Field Blasting/Primer at field weld joints/Final Coating (if carbon steel tank) 4) Final inspection Then, the work steps and % weight table for physical construction progress can be defined as below Work Steps Material at Erection Area (Marking & Cutting for Nozzle holes, Alignment & Fit up Welding for all) Full Welding/NDT Field Blasting/Final Coating Final Inspection

Weight Factor 5%

35%

45% 10% 5%

Once you get construction work steps and weight factors above,....... Apply Construction Work Steps and Weight Factors in Quantity and Physical Progress Calculation Sheet As described in fabrication progress sheet, list the tank components, man hours, weights, etc. so as to track and monitor the status of each member to high level WBS which is in line with GA drawing. Firstly, find the quantity progress calculation sheet on “Field Installation Status-Qty ” tag. Spread sheet is filled with complete data so as to show progress calculation sheet work. Construction work step progress for each member can be tracked by entering each work step  progress status. See the below snapshots of field erection progress updating section for tank  bottom and roof plate erection work,

Secondly, you will find the construction progress summary b y quantity at the same tag “Field Installation Status-Qty ”. The progress summary for an individual GA d rawing is calculated so as to track the summary progress of all members for each work steps. See the snapshot below.

Finally, find the "Physical Prog Tracking Sheet " tag. The quantity wise progress data is used to enter into the physical progress calculation sheet so as to measure an individual physical progress to overall progress. An individual physical progress calculation method is u sed in the following table. E.g. Individual physical progress (Tank platform/Handrail) = Material at Erection Area (5%) x quantity wise progress + Member Assembly (85%) x quantity wise progress + Final Inspection (10%) x quantity wise progress

For your project reference, simply download the sample progress measurement sheet/system for tank farm mechanical construction work . You can modify and prepare your own tank farm construction progress measurement sheet/system using the same methodology to suite your p roject requirements. You might just need to work either one or all of the following items, (1) Change scope of work (tank components and materials) (2) Add or remove field construction works steps (3) Change work steps weight factor percentage (4) Work Breakdown Structure for the level of d etail of progress reporting