| 5 men on driver at $1.75 | $ 8.75 |
| 2 men handling shells at $1.75 | 3.50 |
| 1 engineman | 3.00 |
| 6 men mixing and placing concrete | 10.50 |
| 1 foreman | 5.00 |
| Coal and oil | 2.50 |
| ——— | |
| Total, 13 piles, at $2.55 | $33.25 |
Deducting the cost of placing the concrete we get a cost of $1.75 for driving the cores. The pile, 25 ft. long, 6 ins. at the point and 18 ins. at the head, contains 21¼ cu. ft., or 0.8 cu. yd., of concrete, and has a surface area of 77 ft. As No. 20 steel weighs 1.3 lbs. per sq. ft., each shell weighed approximately 100 lbs. The cost per pile may then be summarized as follows:
| 1.2 bbls. cement in 0.8 cu. yd., at $1.75 | $2.10 |
| 0.8 cu. yd. stone at $1.25 | 1.00 |
| ⅓ cu. yd. sand at $1.05 | 0.35 |
| 100 lbs. steel in shell at 3½ cts. | 3.50 |
| Labor and fuel as above | 2.55 |
| —— | |
| Total per pile (38 cts. per lin. ft.) | $9.50 |
This cost, it should be carefully noted, does not include cost of moving plant to and from work or general expenses.
Example II.—In constructing a building at Salem, Mass., 172 foundation piles, 14 to 37 ft. long, 6 ins. diameter at the point and 20 ins. diameter at the top, were constructed by the Raymond process. The general contractor made the necessary excavations and provided clear and level space for the pile driver, braced all trenches and pier holes, set stakes for the piles and gave all lines and levels. The piles were driven by a No. 2 Vulcan steam hammer with a 3,000-lb. plunger having a drop of 3 ft., delivering 60 blows per minute. Figure 49 shows the driver at work. Sixteen working days were occupied in driving the piles after the driver was in position. The greatest number driven in one day was 20, and the average was 11 piles per day. When in position for driving, the average time required to complete driving was 12 minutes. The total number of blows varied from about 310 to 360, the average being about 350. The piles were driven until the penetration produced by 8 to 10 blows equaled 1 in. When in full operation, a crew of 5 men operated the pile driver. Seven men were engaged in making the concrete and 5 men working upon the metal shells.
Assuming the ordinary organization and the wages given below, we have the following labor cost per day:
| 1 foreman at $5 | $ 5.00 |
| 1 engineman at $3 | 3.00 |
| 4 laborers on driver at $1.75 | 7.00 |
| 6 laborers making concrete at $1.75 | 10.50 |
| 5 laborers handling shells at $1.75 | 8.75 |
| ——— | |
| Total | $34.25 |
As 172 piles averaging 20 ft. in length were driven in 16 days, the total labor cost of driving, given by the figures above, is 16 × $34.25 = $548, or practically 16 cts. per lineal foot of pile driven.
The concrete used in the piles was a 1-3-5 Portland cement, sand and 1½-in. broken stone mixture. A 20-ft. pile of the section described above contains about 20 cu. ft. of concrete, or say 0.75 cu. yd. We can then figure the cost of concrete materials per pile as follows: