Part 26 (1/2)

[Ill.u.s.tration: Fig. 110.--End View of Forms for Retaining Wall, New York Central Terminal Work.]

~WALL FOR RAILWAY YARD.~--For building a retaining wall 7 ft. high, forms were made and placed by a carpenter and helper at $8 per M., wages being 35 cts. and 20 cts. an hour, respectively. Concrete materials were dumped from wagons alongside the mixing board. Ramming was unusually thorough. Foreman expense was high, due to small number in gang; 2 cu.

yds. were laid per hour by the gang.

[Ill.u.s.tration: Fig. 111.--Corner Detail of Retaining Wall Forms, New York Central Terminal Work.]

Per day. Per cu. yd.

7 mixers, 15 cts. per hour $10.50 $0.53 2 rammers, 15 cts. per hour 3.00 0.15 1 foreman 30 cts. per hr., 1 waterboy 5 cts. 3.50 0.17 ------- ------ Total labor $17.00 $0.85

The total cost was as follows per cubic yard:

Per cu. yd.

0.8 bbls. Portland cement, at $2 $1.60 Sand 0.30 Gravel 0.70 Labor mixing and placing 0.85 Lumber for forms, at $16 per M. 0.56 Labor on forms, at $8 per M. 0.28 ------ Total, per cubic yard $4.29

The sheathing plank for the forms was 2-in. hemlock.

~CONCRETE FOOTING FOR RUBBLE MASONRY RETAINING WALL.~--In constructing a footing for a retaining wall at Grand Rapids, Mich., a 1-2-5 natural cement concrete was used. It was found that 1 cu. yd. of concrete was equivalent to 29.8 cu. ft. of material composed of 3.6 cu. ft. or 1.1 bbls. of cement, 8.4 cu. ft. or 2.7 bbls. of sand and 17.8 cu. ft. or 5.5 bbl. of broken stone. The labor cost of 15.5 cu. yds. of concrete was as follows:

Item. Total. Per cu. yd.

Foreman, 14 hours at 40 cts. $ 5.60 $0.3613 Foreman, 20 hours at 22.5 cts. 4.50 0.2903 Laborers, 49 hours at 12.5 cts. 6.11 0.3942 Mason, 2 hours at 35 cts. 0.70 0.0451 ------ -------- Total labor $16.91 $1.0909

All material was furnished by the railway company, the contractor furnis.h.i.+ng labor only; his contract price for this was $1 per cu. yd.

~TRACK ELEVATION, ALLEGHENY, PA.~--The wall was 6,100 ft. long and 75 per cent. was on curves. The first wall built had a top width of 2 ft. and a bottom width of 0.4 the height with the back on a smooth batter. Later the back was stepped and last the wall was proportioned as follows: Calling the height from top of foundation to under coping, then width of base was 0.45 (h + 3), the top measuring 2 ft. The back was arranged in steps 24 ins., 30 ins. and 36 ins. high, and the thickness of wall at each step was, calling h equal to height of step from base, 0.45 (h + 3).

Several forms of expansion joints were tried. The first was tarred paper extending through the wall every 50 ft.; the second was -in.

boards running through the wall every 50 ft.; the third was -in. board extending 2 ft. into the wall, with a -in. cove at the angles, every 25 ft. The third construction gave perfect satisfaction.

A 1-2-5 natural cement and a 1-3-6 Portland cement concrete mixed fairly wet were used. The concrete was laid in 8-in. courses and faced with a 1-2 mortar. The forms were 2-in. white pine faced and jack planed on the edges; upon removal of the forms board marks and other defects were removed and a wash of neat cement was applied. One contractor used hand mixing. The sand and gravel were measured in wheelbarrows and wheeled onto the platform; the sand and cement were spread in thin layers, one over the other, and thoroughly mixed dry; the gravel was then spread over the mixture, the whole was shoveled into barrows or the pit again shoveled into place and rammed. The other contractor used a cubical mixer. A charging box holding 1 cu. yds. and graduated to show the correct proportions of sand and gravel was filled by shoveling; cement was placed on top and the box hoisted and dumped into the mixer. A barrel holding the correct amount of water was emptied into the mixer which was turned 10 or 15 times and discharged into cars. The costs of mixing by hand and by machine were as follows:

Hand mixing. Total. Per cu. yd.

foreman at $3 $ 1.50 $0.025 3 men wheeling barrows at $1.50 4.50 0.075 10 men wheeling materials at $1.50 15.00 0.250 3 men mixing sand and gravel at $1.50 4.50 0.075 6 men mixing concrete at $1.50 9.00 0.150 1 man sprinkling at $1.50 1.50 0.025 ------ ------ Total $36.00 $0.600

The output of the hand mixing gang was 60 cu. yds. per day.

Machine mixing. Total. Per cu. yd.

1 foreman at $3.50 $ 3.50 $0.035 1 stationary engineer at $3 3.00 0.030 foreman at $1.75 0.87 0.009 15 men loading charging bucket at $1.50 22.50 0.225 2 men dumping charging bucket at $1.75 3.50 0.035 2 tagmen at $2, time 2.00 0.020 1 man at trap at $2, time 1.00 0.010 ------ ------ Total $36.37 $0.364

The output of the cubical mixer was 100 cu. yds. per day.

The costs of placing concrete in the forms above the foundation by hand below 12 ft., and by cars and derricks any height, were as follows:

By hand (barrows) below 12 ft. Total. Per cu. yd.

4 men loading concrete at $1.50 $ 6.00 $0.100 1 foreman time at $3 1.50 0.025 10 men wheeling at $1.50 15.00 0.250 1 man sc.r.a.ping barrows at $1.50 1.50 0.025 2 men placing concrete at $1.50 3.00 0.050 1 man placing mortar face at $1.50 1.50 0.025 2 men mixing and carrying mortar at $1.50 3.00 0.050 ------ ------ Total $31.50 $0.525

By cars and derricks-- 1 horse and driver at $3 $ 3.00 $0.030 2 men dumping concrete time at $1.50 1.50 0.015 1 fireman time at $1.75 0.88 0.009 3 tagmen at $1.50 4.50 0.045 8 men placing and ramming conc. at $1.50 12.00 0.120 2 men mixing mortar at $1.50 3.00 0.030 2 men placing mortar at $1.50 3.00 0.030 2 men carrying mortar at $1.50 3.00 0.030 1 foreman at $3 3.00 0.030 1 stationary engineer at $3 3.00 0.030 2 men attending hook at $1.50 3.00 0.030 ------ ------ Total $39.88 $0.399

The costs of placing concrete in the foundations were as follows: