Fig. 77.—Cross Section of Marquette Breakwater.
Footing Placed under Water with Buckets.—Besides the material track which was constructed along the old wooden structure the plant consisted of a mixing scow and a derrick scow, which were moored alongside the work. The sand, stone and cement were brought out in cars between working hours and stored on the mixing scow, enough for one day's work at a time. The derrick handled a 40-cu. ft. bottom dump bucket, which sat in a well on the mixing scow with its top flush with the deck. The concrete was mixed by hand on the deck and shoveled into the bucket; the bucket was then handled by the derrick to the crib and lowered and dumped under water. The gang consisted of 24 men, 1 foreman, 1 master laborer, 14 men shoveling and mixing, 3 men wheeling materials, 1 derrick man and 3 men placing and depositing concrete. No record of output of this gang is available. The cost of the concrete in place with wages $1.25 to $1.40 per day for common labor is given as follows:
| Materials. | Per cu. yd. |
| 1.21 bbls. (459 lbs.) cement at $2.20 | $2.657 |
| 1 cu. yd. stone at $1.58 | 1.580 |
| 0.5 cu. yd. sand at $0.50 | 0.250 |
| 2.02 lbs. burlap at $0.037 | 0.075 |
| Twine and needles | 0.005 |
| ——— | |
| Total materials | $4.567 |
| Labor. | |
| Loading scow with materials | $0.4114 |
| Mixing concrete | 0.8459 |
| Depositing concrete | 0.5242 |
| ——— | |
| Total labor | $1.7815 |
| Grand total | $6.348 |
These figures are based on some 757 cu. yds. of concrete footing. In explanation of the items of burlap, etc., it should be said that the cribs were carpeted with burlap to prevent waste of concrete into the stone fill.
Fig. 78.—Cross Section of Marquette Breakwater Showing Manner of Constructing Footing with Bags of Concrete.
Leveling Off Cribs with Concrete in Bags.—The sketch, Fig. 78, shows the method of leveling off the cribs with concrete in bags. The concrete was mixed by hand on shore and filled into 8-oz. burlap bags, 6 ft. long and 80 ins. around, holding 2,000 lbs. The bags were filled while lying in position in a skip holding one bag. A skip was lifted by gallows frame and tackle onto a car and run out to the work where the derrick scow handled the skip to the crib, lowered it into the water and dumped the bag. The cost of making and placing some 375 cu. yds. of concrete in bags is given as follows:
| Materials. | Total. | Per cu. yd. |
| 453 bbls. cement at $2.627 | $1,190.03 | $3.173 |
| 375 cu. yds. stone at $1.619 | 607.13 | 1.619 |
| 180 cu. yds. sand at $0.392 | 70.56 | 0.188 |
| 3,220 yds. burlap at $0.03304 | 106.39 | 0.283 |
| Twine and needles | 6.36 | 0.017 |
| ———— | ——— | |
| Total materials | $1,980.47 | $5.280 |
| Labor Mixing. | ||
| 108 hrs. master laborer at $0.21⅞ | $23.42 | $0.062 |
| 1,750 hrs. labor at $0.175 | 306.25 | 0.816 |
| Superintendence | 12.55 | 0.033 |
| ———— | ——— | |
| Total labor mixing | $ 342.22 | $0.911 |
| Labor transporting. | ||
| 306 hrs. labor at $0.175 | $53.55 | $0.142 |
| Superintendence | 5.25 | 0.014 |
| ———— | ——— | |
| Total labor transporting. | $58.80 | $0.156 |
| Labor Depositing. | ||
| 108 hrs. engineman at $0.25 | $27.00 | $0.072 |
| 108 hrs. master laborer at $0.21⅞ | 23.42 | 0.062 |
| 510 hrs. labor at $0.175 | 89.25 | 0.238 |
| Superintendence | 13.25 | 0.035 |
| ———— | ——— | |
| Total labor depositing | $ 152.92 | $0.407 |
| Grand total labor | $ 553.94 | $1.477 |
| Grand total materials and labor | $2,534.41 | $6.757 |
Molding Footing Blocks.—The blocks used at the toe of the prism were of the form and dimensions shown by Fig. 79. They were molded in a temporary shed heated to 50° to 65° F., and provided with a 2×8-in. dressed plank floor on 12×12-in. sills. The floor formed the bottoms of the block molds. Four molds were used, each consisting of four sides. Three laborers molded one block, 2.22 cu. yds. per day, wheeling, mixing, erecting and removing forms, placing concrete and doing all other work. The cost of making 40 blocks was recorded as follows: