| 1 crusher, No. 7 Gates | $12,000 |
| Use of locomotive | 2,200 |
| Car and track | 5,300 |
| 3 mixers | 3,000 |
| Lumber | 1,200 |
| Pipe | 720 |
| Small tools | 1,000 |
| ——— | |
| Total | $25,420 |
This $25,420 distributed over the 44,811 cu. yds. of concrete amounts to 57 cts. per cu. yd.
It will be noted that 2 mixers were kept busy. Their average output was 100 cu. yds. each per day, which is the same as for the mixers on Section 14.
The total cost of concrete on Section 15 was as follows:
| Per cu. yd. | |
| Labor quarrying, crushing and mixing | $0.991 |
| Explosives | 0.083 |
| Utica cement, at $0.60 per bbl. | 0.930 |
| Portland cement, at $2.25 per bbl. | 0.180 |
| Sand, at $1.35 per cu. yd. | 0.476 |
| ——— | |
| Total | $2,660 |
| First cost of plant | $0.567 |
It is not strictly correct to charge the full first cost of the plant to the work as it possessed considerable salvage value at the end.
Comparison.—For the purpose of comparing Sections 14 and 15 the following summary is given of the cost per cubic yard of concrete:
| Sec. 14. | Sec. 15. | |
| General force | $0.078 | $0.082 |
| Wall force | 0.108 | 0.116 |
| Mixing force | 0.121 | 0.250 |
| Timbering force | 0.150 | 0.140 |
| Hauling force | 0.142 | 0.081 |
| Crushing force | 0.073 | 0.128 |
| Quarry force | 0.303 | 0.275 |
| Cement, natural | 0.863 | 0.930 |
| Cement, Portland | 0.305 | 0.180 |
| Sand | 0.465 | 0.476 |
| Plant (full cost) | 0.407 | 0.567 |
| ——— | ——— | |
| Total | $3.015 | $3.225 |
It should be remembered that on Section 14 there was no drilling and blasting of the rock, but that the "quarry force" not only loaded but hauled the stone to the crusher. The cost of mixing on Section 15 is higher than on Section 14 because the materials were dumped on platforms and shoveled into the mixer, instead of being discharged from bins into the mixer as on Section 14.