RESERVOIR FLOOR, PITTSBURG, PA.—The following methods and costs of laying a reservoir floor are given by Mr. Emile Low, M. Am. Soc. C. E., for the Hiland Reservoir constructed at Pittsburg, Pa., in 1884, by contract. There were 7,681 cu. yds. of concrete in the floor which was 5 ins. thick and laid on a clay puddle foundation.
Natural cement costing $1.35 per barrel was used. The broken stone varied in weight from 147 to 152 lbs. per cu. ft.; it was quarried and hauled 20 miles by rail and then unloaded into small cars and hauled ½ mile to the reservoir. The cost of the stone per cubic yard delivered was:
| Quarrying, per cu. yd. | $0.45 |
| Breaking, per cu. yd. | 0.35 |
| Transporting, per cu. yd. | 0.50 |
| Total | $1.30 |
The sand was obtained on the site at the cost of excavation, or 1¼ cts. per bushel.
The method of proportioning and mixing the concrete was as follows: Platforms 10×16 ft. of 2-in. plank were laid on the puddle foundation and by these were set 5×4×1½-ft. boxes on legs. Into these boxes 1 bbl. of cement and 2 bbls. of sand were emptied and thoroughly mixed dry, then mixed with water to a thin grout. Five barrels of stone were placed on the platform and thoroughly wetted; the grout was then emptied over the stone and the two turned over three times with shovels. The concrete was rammed until the mortar flushed to the surface. The following costs cover various periods as follows:
| Two Days Work (101 cu. yds.): | Total. | Per cu. yd. |
| 27 laborers, 2 days, at $1.25 | $72.90 | $0.7217 |
| 1 foreman, 2 days, at $2.50 | 5.00 | 0.0495 |
| ——— | ——— | |
| Total | $77.90 | $0.7712 |
| One Month's Work (1,302 cu. yds.): | ||
| 642 days, laborers, at $1.35 | $ 866.70 | $0.6649 |
| 17 days, water boy, at $0.60 | 10.20 | 0.0078 |
| 22 days, foreman, at $2.50 | 55.00 | 0.0421 |
| ——— | ——— | |
| Total | $931.90 | $0.7148 |
| Two Days Work (101 cu. yds.): | Total. | Per cu. yd. |
| 27 laborers, 2 days, at $1.25 | $72.90 | $0.7217 |
| 1 foreman, 2 days, at $2.50 | 5.00 | 0.0495 |
| ——— | ——— | |
| Total | $77.90 | $0.7712 |
| One Month's Work (1,302 cu. yds.): | ||
| 642 days, laborers, at $1.35 | $ 866.70 | $0.6649 |
| 17 days, water boy, at $0.60 | 10.20 | 0.0078 |
| 22 days, foreman, at $2.50 | 55.00 | 0.0421 |
| ——— | ——— | |
| Total | $931.90 | $0.7148 |
| Total Work (7,861 cu. yds.): | ||
| Quarrying stone | $0.45 | |
| Transporting stone | 0.50 | |
| Breaking stone | 0.35 | |
| 1⅓ bbl. natural cement | 1.80 | |
| 8 bu. sand | 0.10 | |
| Water | 0.05 | |
| Labor mixing and laying at $1.25 | 0.75 | |
| Incidentals | 0.05 | |
| —— | ||
| Total | $4.05 |
The contract price was $6 per cu. yd.
