Page 256 - Industrial Process Plant Construction Estimating and Man Hour Analysis

234 Industrial Process Plant Construction Estimating and Man-Hour Analysis

11.9.3 Air cooled condenser installation decreased quantities
estimate

Description MH Qty Unit Qty Unit IW
Upper structure A-frame steelwork 267.0
Erect and temporarily bolt structural 2.50 7.25 Ton 7.25 Ton 18.1
steel
Seal plate 2.00 20.00 EA 20.00 EA 40.0
Access door frame 10.00 1.00 EA 1.00 EA 10.0
Cut sheeting to size 0.002 532.10 SF 532.10 SF 1.1
Place sheeting 0.23 357.00 SF 357.00 SF 80.5
Fix sheeting with flashing and caulk 0.05 532.10 SF 532.10 SF 26.6
Tack or screw sheeting 1.00 21.25 EA 21.25 EA 21.3
Install access door 10.00 1.00 EA 1.00 EA 10.0
Pipe hanger with turnbuckle and 10.00 2.00 EA 2.00 EA 20.0
clevis
Install steam saddles 10.00 3.00 EA 3.00 EA 30.0
Bolt connection 0.15 62.90 EA 62.90 EA 9.4

11.10 Comparison and graphic analysis of data

Comparison of estimated direct craft man-hours Man-hours
Equipment quantities are decreased; estimated man-hours are decreased 1 267
MHc ¼ field erection man-hours based on historical data 2 295
Equipment quantity is increased; estimated man-hours are increased 3 325

400
300
Man hours 200 y = 29.196x + 237.29 Series1

2
R = 0.9991
Linear (Series1)
100
0
0 1 2 3 4
FIG. 11.10.1 Comparison of estimate man-hours.

Estimate is based on historical data from field erection of A-frame structure
in a solar power plant (Fig. 11.10.1), and the scope and quantity differences can
be identified and the impacts estimated; therefore,
MHᵦ MH c MHₔ