| Item. | Per Cu. Yd. |
| 1.45 bbls. Portland cement | $4.330 |
| 0.55 cu. yd. crushed stone | 0.604 |
| 0.252 cu. yd. pebbles | 0.328 |
| 0.465 cu. yd. sand | 0.419 |
| 40,000 ft. B. M. lumber (¼ cost of $16 per M.) | 0.348 |
| Carpenter work on forms | 0.780 |
| Mixing and placing concrete | 1.909 |
| 20 per cent. cost of plant | 0.090 |
| Miscellaneous | 0.182 |
| ——— | |
| Total | $8.99 |
Mixing Plant.—The concrete for all the lock work of 1893-4 was mixed by the plant shown by Figs. 72 and 73. The mixer plant proper consisted of a king truss carried by two A-frames of unequal height; under the higher end of the truss was a frame carrying a 4-ft. cubical mixer and under the lower end a pit for a charging box holding 40 cu. ft. This charging box was hoisted by ½-in. steel cable running through a pair of double blocks as shown; the slope of the lower chord of the truss was such that the cable hoisted the box and carried it forward without the use of any latching devices. On two sides of the pit were tracks from the sand and stone piles and on the other two sides were the cement platform and water tank. The charging box dumped into the hopper above the mixer and the mixer discharged into cars underneath. A 15-HP. engine operated the hoist by one pulley and the mixer by the other pulley. Nine revolutions of the mixer made a perfect mixture. The plant as illustrated was slightly changed as the result of experience in constructing the guard lock. The charging hopper was lowered 6 ins. and the space between the mixer and lower platform reduced by 9 ins.; diagonal braces were also inserted under the timbers carrying the mixer axles. This plant cost for framing and erection $300 and for machinery delivered $706. The crushing plant shown by Fig. 73 consisted of a No. 2 Gates crusher delivering to a bucket elevator.
Fig. 73.—Stone Crushing Plant for Lock Walls, Illinois & Mississippi Canal.
Fig. 74.—Forms for Guard Lock, Illinois & Mississippi Canal.
Guard Lock.—The forms employed in constructing the guard lock are shown by Fig. 74, and in this drawing the trestle and platform for the concrete cars are to be noted. The walls were concreted in sections. A batch of concrete consisted of 1 bbl. cement, 10 cu. ft. sand and 20 cu. ft. crushed stone. The average run per 8-hour day was 40 batches of facing and 60 batches concrete, representing 100 bbls. cement. The gang worked was as follows:
| Duty. | No. Men. | P. C. Cost. |
| Handling cement | 3 | 5.26 |
| Filling and pushing sand car | 5 | 8.77 |
| Filling and pushing stone car | 9 | 15.79 |
| Measuring water | 1 | 1.75 |
| Dumping bucket on top platform | 3 | 5.26 |
| Opening and closing door of mixer | 1 | 1.75 |
| Operating friction clutch | 1 | 1.76 |
| Attending concrete cars under mixer | 1 | 1.76 |
| Dumping cars at forms | 2 | 3.51 |
| Spreading concrete in forms | 3 | 5.26 |
| Tamping concrete in forms | 10 | 17.54 |
| Mixing mortar for facing | 6 | 10.53 |
| Finishing top of wall | 2 | 3.51 |
| Hauling concrete cars with 1 horse | 1 | 3.51 |
| Engineman operating hoist | 1 | 3.51 |
| Engineman operating engine | 1 | 3.51 |
| Foreman in charge of forms | 1 | 3.51 |
| General foreman | 1 | 3.51 |
| — | ——— | |
| Total | 52 | 100.00 |
The percentages of cost in this statement have been calculated by the authors upon the assumption that each laborer received one-half as much wages as each engineman, foreman and horse and driver per 8 hours, which would make the total daily wages equivalent to the wages of 57 men. Wages of common labor were $1.50 per day. Considering the size of the gang the output of 40 batches of mortar and 60 batches of concrete per day was very small. The total yardage of concrete in the guard lock was 3,762 cu. yds., 2,212 cu. yds. in the walls and 1,550 cu. yds. in foundations, culverts, etc. Its cost per cubic yard was made up as follows:
| Item. | Total. | Per Cu. Yd. |
| 5,246 bbls. Portland cement | $15,604} | $4.170 |
| 152 bbls. natural cement | 84} | |
| 2,910 cu. yds. stone | 2,901 | 0.771 |
| 126 cu. yds. pebbles | 113} | 0.401 |
| 1,970 cu. yds. sand | 1,398} | |
| 145,000 ft. B. M. lumber (¼th cost) | 659 | 0.175 |
| Iron for forms, trestles, etc. | 90 | 0.024 |
| Coal, oil, miscellaneous | 327 | 0.087 |
| Carpenter work | 2,726 | 0.724 |
| Mixing and placing concrete | 6,693 | 1.780 |
| Pumping, engineering, misc. | 742 | 0.197 |
| 20 per cent of plant | 550 | 0.146 |
| ——— | ——— | |
| Total | $31,887 | $8.475 |