| 1 foreman, at 30 cts. per hour | $ 2.70 |
| 1 crabman, at 27 cts. per hour | 2.43 |
| 1 topman, at 27 cts. per hour | 2.43 |
| 2 bottom men, at 23 cts. per hour | 4.14 |
| ——— | |
| Total per 9-hour day | $11.70 |
Fig. 232.—Derrick for Stripping Wall Column Forms Shown by Fig. 230.
This gang of five men stripped 4 columns containing 18.52 cu. yds. of concrete each day, so that the cost of stripping was $11.70 ÷ 18.52 = 62.7 cts. per cu. yd.
Concrete.—The concrete was mixed in a No. 2 Ransome mixer and delivered to the work in Ransome concrete carts. These carts were pushed along a runway which terminated in a slight incline under the derrick so that their contents could be emptied into the derrick buckets.
The concrete was hoisted in an 8-ft. bottom dump bucket, using the derrick described above. It was necessary to stir up the concrete thoroughly with long-handled slicers as it was being deposited in order to prevent segregation. This expedient combined with a wet mixture and tight molds was found to overcome this difficulty very effectually.
The gang mixing and wheeling concrete was made up as follows:
| 1 mixer foreman and engineer at 27 cts. per hour | $ 2.43 |
| 4 laborers charging mixer at 18 cts per hour | 6.48 |
| 4 laborers wheeling concrete at 18 cts. per hour | 6.48 |
| ——— | |
| Total per 9-hour day | $15.39 |
This gang mixed and wheeled concrete for four columns, or 18.52 cu. yds., hence the cost per cubic yard was 82.6 cts.
With cement at $1.60 per bbl., sand at $1 per cu. yd. and slag at $1.10 per cu. yd. the cost of materials per cubic yard of concrete was $3.