Cross River Dam

(Fig. 46).

In addition to the dam, the contract included a spur track connection with a railroad and 5 1/2 miles of highways. The prices bid for the principal items were as follows:

Earth excavation, 65,000 cu. yd., class A at....

..... $0.80

Earth excavation, 3000 cu. yd., class B at......

..... 1.50

Earth excavation, 120,000 cu. yd., class C at....

..... 0.45

Rock excavation, 25,000 cu. yd., class A at....

..... 1.75

Rock excavation, 5,000 cu. yd., class B at....

..... 5.00

Rock excavation, 25,000 cu. yd., class C at.................

..... 1.75

Rock excavation, 4000 cu. yd., class D at..................

..... 1.75

Refill and embankment, two classes at....................

$0. 20 and $0.40

Portland cement, 135,000 barrels at....

...................1.30

Concrete face blocks, 17500 cu. yd. at.....

..................12.00

Monolithic concrete, 6000 cu. yd. at.......................

..... 6.50

Cyclopean concrete, 132,000 cu. yd. at...............

........................2.90

River control works (lump sum).................

................30,000.00

Superstructure of gate house (lump sum)..............

...............8,000.00

Macadam highway surfacing (12 ft. wide), 8000 lin. ft at...

.................1.40

Gravel highway surfacing, 20,000 lin. ft. at.................

..... 0.25

Fence and guard rail, 47,000 lin. ft. at...............

..... 0.25

Stone boundary wall, 90,000 lin. ft. at..............

.....0.08

Miscellaneous smaller items such as granolithic, face dressing, paving, rip-rap, special castings, valves, sluice gates, screen and stop-plank guides, railing, drain pipe, grassing, clearing reservoir, etc., made a total for the bid of $1,246,212.

The actual total cost, owing to various departures from the estimated quantities, was $1,389,210.94. Cost of engineering was $81,78749. Cost of inspection was $45,031.25.

Maximum quantity of masonry laid, 18,430 cu. yd. per month = 864 cu. yd. per day.

Maximum quantity of cyclopean masonry per day 823 cu. yd. by six gangs of eleven men each.

Fig. 46. Section of Cross River dam. New York; built 1905 to 1907; cyclopean masonry; concrete block face; length of top 986.5 ft.; max. height above foundation 170 ft.; contains 158,467 cu. yd.; masonry all kinds.

Average quantity of cyclopean masonry for entire work laid by gang of eleven men = 105 cu. yd. per ten-hour day.

The distribution of the cost between the features of dam, spur track, and highways is indicated by the following division of principal items.

Dam

Spur Track

Highways

7480 lin. ft. standard gage, length of trestle 642 lin. ft., average height of trestle 21 ft., max. cut 40 ft., max. fill 40 ft.

1.43 miles of 12-ft. macadam cost $40,225 per mile, including one 40-ft. arch bridge, one 8-ft. arch, small culverts, catch basins, paved slopes, etc. The 40-ft. arch cost $8985.83. Dirt roads (4.06 miles) cost $28,031 per mile, including one 18-ft. and one 8-ft. arch, small culverts, catch basins, paved slopes, etc.

Earth excavation, 89,403 cu. yd.....

69,052 cu. yd.

126,795 cu. yd.

Rock excavation, 40,016 cu. yd...

954 cu. yd.

23,287 cu. yd.

Refill and embankment, 71,138 cu. yd.

...

715 cu. yd.

Cyclopean masonry, 132,254 cu. yd..

...

...

Concrete blocks 17,655 cu. yd...

............... . .

...

Monolithic concrete, 7294 cu. yd..

...

2,354 cu. yd.

Portland cement, barrels, 134,630....

...

2,840

Fence and guard rail...............

...

40,145 lin. ft.

Stone boundary wall.....

...

88,268 lin. ft.

Croton Falls Dam

(Fig. 47).

The entire contract included the construction of the main dam; a diverting dam on another stream; an open channel 3522 ft. long connecting the reservoirs formed by the two dams; 2 1/2 miles of standard gage railroad, 14 1/2 miles of new highways; fourteen large concrete highway bridges; 21 miles of stone wall boundary fencing; 21 1/2 miles of wooden guard rail fencing; clearing 1600 acres of reservoir; 2 miles of 15-in. twin-tile pipe sewer.

Following are the principal items of the contract, and the prices at the accepted bid. Total amount of bid $3,028,853.

River control works, lump sum.................................

$90,000.00

Earth excavation, class A, 490,180 cu. yd. at.....................

0.75

Earth excavation, class B, 11,675 cu. yd. at......................

1.65

Earth excavation, class C, 130,000 cu. yd. at.....................

0.35

Rock excavation, class A, 202,025 cu. yd. at.....................

1.50

Rock excavation, class B, 13,800 cu. yd. at......

4.00

Rock excavation, class C, 35,850 cu. yd. at......................

1.25

Refill and embankment, A, 20,5,500 cu. yd. at...................

0.40

Refill and embankment, B, 87,620 cu. yd. at....................

0.02

Portland cement, 370,000 barrels, at............................

1.75

Cyclopean masonry, 262,000 cu. yd. at..........................

3.65

Concrete face blocks, 38,100 cu. yd. at...........................

8.50

Monolithic concrete masonry, A, 3000 cu yd. at .................

7.00

Fig. 47. Section of Croton Falls dam. New York; built 1906 to 1911; cyclopcan masonry; concrete block faces; 1100 ft. long; max. height 173 ft.; contains 390,540 cu. yd: masonry all kinds.

Monolithic concrete masonary, B, 13,600 cu. yd. at..

5.59

Block stone, masonary, 3000 cu. yd. at..

30.00

Dimension stone masonry, 1500 cu. yd. at......................

55.00

Various items: Granolithic, grouting, face dressing paving, rip-rap, total value...

86,873.00

Various items of metal work: Valves, gates, cast iron-pipe, special castings, railings, guides, etc., total value...

60,340.00

Gate house superstructures, stop planks, gratings,etc....

13,000.00

Highway surfacing, sewers, fencing, wall, etc.....................

136,843.00

As constructed, the principal items were distributed among the various features as follows:

Main dam:

Earth excavation....

280,000 cu. yd.

Rock excavation.............

95,000 cu. yd.

Refill............................................

180,000 cu. yd.

Cyclopean masonry..........

245,000 cu. yd.

Concrete face blocks...........

30,000 cu. yd.

Monolithic concrete............

15,000 cu. yd.

Dimension stone...........

540 cu. yd.

Reinforcing steel...........

575 tons

Portland cement.............

230,000 barrels

The temporary channel for handling the water took out of the stream 600 ft. above the dam and returned to it 800 ft. below. Of this 1400 ft. total length, 800 ft. was timber flume 24 ft. wide X 8 ft. 2 in. deep.

Diverting dam, 1185 ft. long

Earth with core wall

Earth excavation....

.. 108,090 cu. yd.

Rock excavation.............

56,234 cu. yd.

Refill and embankment....

.. 252,000 cu. yd.

Cyclopean masonry..........

.. 37,053 cu. yd.

Portland cement....

..48,384 barrels

Dimension stone.......

..776 cu. yd.

Paving..............

..21,904 cu. yd.

Connecting channel, 3522 ft. long

In rock, 24 ft. wide, 1/2 to 1 slope.

In earth 15 ft. wide, 1 1/2 to 1 slope.

Earth excavation................................

• • 306,392 cu. yd.

Rock excavation................................

.. 43,093 cu. yd.

Refill..........................................

23,246 cu. yd.

Concrete masonry..............

4,164 cu. yd.

Dry paving..................

27,717 cu. yd.

Portland cement.................

4,403 barrels

Highways 14 1/2 miles

In cut, 22 ft. roadway

On fill 28 ft. roadway

Earth excavation............

.. 798,000 cu. yd.

Rock excavation................................

..69,000 cu. yd.

Concrete and rubble masonry.........

..20,000 cu. yd.

Dry paving

....35,600 cu. yd.

Portland cement................................

..22,000 barrels

Surfacing......................................

..80,000 lin. ft.

Post and rail fencing...............

.. 110,000 lin. ft.

Total plant cost including installation and renewals, minus salvage, about...................................................

$425,000

Total value of work done under the contract, about..............

4,250,000

Maximum progress on masonry in October, 1008.

27 eight-hour days, eight gangs of twelve men (less four gangs off one-half day), laid 24,266 cu. yd. cyclopean masonry. 30 eight-hour days, two gangs of six men, laid 720 face blocks = 1666 cu. yd.

Common labor was paid, $1.50, $1.75 and $ 2.

Masons and carpenters were paid, $2.50 to $4.

Foremen and engineers were paid, $3 and $3.50.

Eight-hour day rigidly enforced.

From paper by Frederick S. Cook in the Proceedings of the Municipal Engineers of the City of New York.