After grading has been done or estimated, wooden trestles as follows: 10 to 12 ft. B. M. per sq. ft. of opening spanned, i.e., between ground surface and base of rail, estimate $15 to $18 per M. ft. B. M. for erection. Wooden Howe truss bridges - say 32 M. ft. B. M. for an 80-ft. span, to 60 M. ft. B. M. for a 140ft. span, and allow $20 to $25 per M. ft. B, M. for erection. Abutments extra.

Steel bridges, deck girder.............

50-ft. span

35,000 lb.

E45 loading, deck girder..............

75-ft. span

74,000 lb.

Deck girder.............

100-ft. span

125,000 lb.

Through riveted truss..........................

130-ft. span

204,000 lb.

Through riveted truss..............

175-ft. span

342,000 lb.

Any of the above erected at 4 1/2 cents to 5 cents per lb.; abutments extra.

For prices of lumber, ties, rails, fastenings, bolts, see current material prices in technical papers.

Equipment, freight locomotive,

60 ton weight about...........

.....$11,000

100 ton weight about..............

............16,000

140 ton weight about..............

.............22,000

Box cars.........

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

$400 to 600

Flat cars...

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

200 to 400

For actual cost of construction, equipment, and two years operation of an industrial railroad see page 128.

Cableway 2 1/4-in. lock strand including a 75-h.p. engine, and all lines, sheaves, and accessories, not including towers, may be assumed for a preliminary estimate as ranging from $10,000 for 700-ft. span to $15,000 for 2000-ft. span. In the case of fixed towers, the cost of the anchorage may vary widely according to the material anchored in, say from $100 to $400 per anchorage.

Towers may be estimated about on the following basis:

A frame 75 ft. high

4 Post 75 ft. high

4 Post extra heavy 75 ft. high

4 Post 100 ft. high

Traveling 57 ft. high

Traveling 90 ft. high

Intermediate 23c ft. high for two cables 1

Timber (so. pine)......

12 in. X 12 in. posts

10 in. X 10 in. posts

12 in. X 12 in. posts

12 in. X 12 in. posts

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

12 in. X 12 in. posts

12 in. X 12 in. posts

3 ft. X 12 in. bracing

3 in. X 12 in. bracing

4 in. X 12 in. bracing

4 in. X 12 in. bracing

4 in. X 12 in. bracing

4 in. X 12 in. bracing

Iron work.....

4,000 ft. B.M.

Including truss rods, $100

10,000 ft. B.M. $75

13,000 ft. B.M. $75

19,500 ft. B.M. $100

25,000 ft. B.M. $250

50,000 ft. B.M. $450

101,000 ft. B.M.

Largest tower ever built

Labor, framing, and erecting.

$50 to $100

About $20 per M.ft. of lumber

About $20 per M.ft. of lumber

$15 to $20 per M.ft. of lumber

$15 to $18 per M.ft. of lumber

$15 or $16 per M. ft. of lumber

Second-hand railroad axles.

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

....

....

....

14 at $15 to $20

20 at $15 to $20

Boxes...............

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

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

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

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

28 at $7

40 at $7

For traveling towers add for grading, ties, and rails. Estimate 75-lb. rail, say five times the length of travel for 57-ft. tower, and seven times the length of travel for 90-ft. tower.

1 Later raised 60 ft., making a total height of 290 ft.

At the Kensico dam the 1861-ft. span, 2 1/2-in. lock strand, 10-ton cableways, with 400-h.p. electric engines giving a hoisting speed of 300 ft. and a conveying speed of 1200 ft. per minute, on 125-ft. high traveling towers, base of tower 50 ft. X 100 ft., with fifty-eight wheels under each tower. Cost above the rails, in place about $25,000 each.

Cableway engine:

75 h.p., steam (not including boiler) or compressed air, with drum to move the towers,about....

.... $3,300

Same with electric motors.....

$3,700 to 4,000

Water wheels:

3800 h.p. at 250 ft. head, at 500 r.p.m., weight 83,000 lb..

....... 7,500

Lombard governor for above.....................

....1,600

1800 h.p. at 46-ft. head, at 200 r.p.m., vertical type, single runner including oil governor, thrust bearing, penstock, and draft tube..

12,000

180 h.p. at 46-ft head, at 425 r.p.m., including mechanical governor about....

....... 3,200

500 h.p. at 20-ft. head, including governor, 26,000 lb. to 32,000 lb.

according to speed....

$3,400 to 3,800

500 h.p. at 30-ft. head, including governor, 16,000 lb. to 17,000 lb. according to speed...............................

$2,300 to $2,500

Generators:

D.c., 500 kw., 150 r.p.m., weight 39,000 lb...

....... 4,500

A.c, 400 kw., 225 r.p.m., three-phase, sixty-cycle, 6,600 volts,

36,000 lb...

A.c, 320 kw., 257 r.p.m., three-phase, sixty-cycle, 2,300 volts,

23,300 lb...

4,000

A.c, 320 kw., 450 r.p.m., three-phase, sixty-cycle, 2,300 volts,

17,600 lb...

3,100

A.c, vertical type, 300 kw., 164 r.p.m., three-phase, sixty-cycle,

2,300 volts, 28,000 lb.....

4,600

Exciter for either of the four above 14 k.w., 125 volts, including sliding base, pulley and field rheostat, 1,600 lb........

400

A.c, vertical type, revolving field, 1400 kv-a., three-phase, 60-cycle,

200 r.p.m., 2300 volt....

$9,500 to $10,000

Parsons type steam turbine, electric generating unit 500 kw three-phase, sixty-cycle,2300 volts about....

...... 14,000

Boilers:

Per h.p 250 h.p. weighs 20 tons.

$10 to $12

Transmission line:

For 1000 kw. at 45,000 volts, wooden poles, single three phase circuit erected per mile.......

$1,800 to $2,000

Power Plant At Elephant Butte Dam

Three 500 kw. turbogenerator sets, furnishing 2200-volt sixty-cycle current.

Two small turbine driven exciters each of sufficient capacity to handle the three main units.

Four Erie vertical water-tube type boilers.

Steel storage bins, automatic chain grate stokers, coal and ash handling appliances, water purifying and cooling systems.

Cost erected, with house, including overhead charges...........

...... $136,500

See Engineering Record, Oct. 4, 1913.

Distribution system (see Eleventh Annual Report U. S.

Reclamation Service), about.........

.........$22,000

Motors:

D.c., 35 h.p., 750 r.p.m., 3,200 lb............

....... 575

50 h.p., 750 r.p.m., 3,700 lb......................

....... 75o

80 h.p., 750 r.p.m., 6,600 lb................

....... 1,050

Induction, 15-h.p., three-phase, sixty-cycle, 440 volts, about............

..............250

Hoisting engines:

Double drum, electric, 75-h.p., a.-c. motor with another 11-h.p. motor for swinging gear, two speeds by shifting gears, rope speeds on drum 250 ft. and 500 ft. per minute. Weight about

37,000 lb. As installed at Kensico, cost................

......3,200

Double drum, electric, 35-h.p.,d.-c. motor with swinging attach-ment; prices obtained from four makers in 1908.....

$1,400 to $1,600

Pile driver, weight 8,000 lb, steam hammer..........

....... $700

hoist..........

........1,200

leads..............

............300

Steam shovel, 70 tons..................

$10,000 to 11,000

Compressors:

537 cu. ft. free air per minute, weight 17,000 lb., requires 100 h.p., price..............

....... 1700

957 cu. ft. free air per minute, weight 22,000 lb., requires 175 h.p.

to 200 h.p., price..............

....... 2,500

Temple electric-pneumatic (see page 156).....

............1,200

Drills:

Tripod, 3 1/4 in., with tripod, 25 ft. of hose, and one set of steel to 16 ft....

.... 310

Hammer, largest size, with hose and one set of steel to 6 ft..

.... 115

Electric locomotive, 10 ton, 36-in. gage, 500 volt, 10 miles per hour on level track, 50-ton load, about.....

.........2,200

Electric mine locomotive, 24-in. gage, 250 volt, drawbar pull 900 lb., at

10 miles per hour, about....

..............1,800

Crushers:

Gates No. 7 1/2, weight 63,000 lb., 350 r.p.m., h.p. required 50 to 75, price.....

$3,100 to 3,200

Gates No. 5, 33,000 lb., 375 r.p.m., h.p. required

25 to 30, price...

$1,500 to 1,600

Blake jaw crusher, 9 in. X 15 in., 250 r.p.m., crushes 15 tons per hour, weight 16,000 lb., about....

750

Pulverator (for sand) No. 2, 7 tons per hr., h.p. required

40, weight 5000 lb.,..........

...... 825

Pulverator No. 4, 20 tons per hour, h.p. required 75, weight

12,000 lb...............................................

12,000

Davis Standard crushing rolls, 36-in. diameter by 16-in.

face weight 27,000 lb....

$1,800 to 1,000

Bucket elevator, 30 ft. centers, belt or chain, for capacity of 35 tons crushed rock per hour, complete, about......

...... 400

For each additional foot between centers add about....

...... 6

Tromel, 40-in. diameter by 12 ft. long, five spiders, punches steel screen countershaft and drive pulleys, weight 4,500 lb, about..

...... 400

Concrete mixer:

1 cu. yd. capacity, batch mixer, at 6,000 lb., about....

600

Dump buckets, 2 cu. yd...........

... $150 to 200

Skips. 4 cu. yd.....

... $125 to 150

Hopper bottom dump cars, 4 1/2 cu. yd. of 3/16 -in. steel plate, 36-in gage, with brakes....

250

Centrifugal pumps:

10-in, 3,000 gal. per min. at 50-ft. head, h.p. required

65,865 r.p.m., weight 2,500 lb....

260

6-in., 1,000 gal. per min. at 50-ft. head, h.p. required

25,1,300 r.p.m., weight 1,000 lb.....

...... 150

The erection and maintenance of plant, expenditure for supplies, etc., are very variable items. Experience upon one piece of work could only with caution be taken as even an approximate indication of what those items might amount to on other work. It is believed however that even qualified as above the following notes regarding plant and expendible material may be of some interest.

At the Roosevelt dam the main items of plant were as follows:

Air compressor, 700 cu. ft. of free air per minute.

One receiver.

Seven tripod drills.

Twelve plug drills.

Cable ways - Three 1,200 ft. long 2 1/4-in. lock strand.

One 1,000 ft long 2-in. lock strand.

Two 100 h.p. electric engines.

All lines, sheaves, and accessories.

Anchorages in rock, towers quite small. Crusher, one No. 7 1/2 o gates. Fifteen derricks.

Sixteen electric engines Three air engines 35 h.p. and 40 h.p.

One motor-generator set, three motors, wiring, transformers, arc lights.

One 1 1/2-cu. yd. and one 3/4-cu. yd. mixer.

Two pile drivers, 30 ft. leads, steam hammers.

Two 11 -in. Campbell hydraulic elevators.

Four 4-in. auxiliary hydraulic ejectors (pumps).

Three giant nozzles.

Four 4-in., one 6-in., one 8-in., centrifugal pumps.

Two small triplex pumps.

Leschen tramway 1,700 ft. long, two terminals, two short intermediate towers, one intermediate loading station, seventeen 10-cu. ft. buckets, one extra traveling line.

Miscellaneous:

Thirty 4-cu. yd., four 2-cu. yd., four 1-cu. yd. iron skips, chain, rail, pipe, five flat cars, value about...

$7,200

Hose, small tools, rope, jacks, blocks, etc., about................

13,000

Blacksmiths' shop and tools about....

750

Eight mules, wagons, harness....

4,500

The total cost of the plant, including freight at say an average of $1.50 per 100 lb., in Globe was about....

$180,000

Wagon haul to dam site, 40 miles....

7,650

Used in erection, lumber, $7,000, cement $700....

7,700

$195,35

Labor of erection, including moving and re-erection during five years,

104,580 hours labor....

$34,745

Repairs on equipment during five years (could not always be distinctly separated from re-erection), 67,600 hours labor.....

28,575

Supplies, oil, iron, steel, repair parts, small hardware, including freight, and about $900 wagon haul....

66,800

Blacksmith's coal about 140 tons,including freight and haul....

3,570

Explosives, including freight and haul....

20,000

Above does not include erection or maintenance of camp, office, or commissary. For magnitude and nature of work see pages 38, 81,

89, 139, 206 to 210, 243 to 246.

Material entering into the work.

The items have been suggested, and the procedure for estimating them has been sufficiently discussed on page 203, obviously prices cannot be given.

Labor Cost

For a general discussion of the subject see pages 203 to 210 and elsewhere throughout the book.

In the specific illustrative labor costs given (see index) it has been attempted so to describe conditions, rates of wages, etc., that they may be of some assistance in forming an estimate.

Cost Of Steam Power

The following is taken from tables prepared by the Canadian Hydro-Electric Power Commission (see their Fifth Report) from data published in technical journals and also from data collected by their own engineers regarding existing plants in the district.

Steam Power Plants. Capital And Annual Costs

Sice of plant, h.p.

Capital cost of plant per horse-power installed

Annual cost of 10-hour power per brake horsepower

Annual cost of 24-hour power per brake horsepower

Engines: Cora pound, Corliss, condensing. Boilers: Return tubular with reserve capacity.

100

$91.40

$33.18

$60.05

200

70.I0

28.14

51.72

300

63.90

26.27

48.83

400

59 55

24.84

46.12

500

55.25

23.73

44.21

750

53.30

23.56

4402

1000

51.00

23.26

43.71

Engines: Com pound, Corliss, con densing. Boilers: Water tube with reserve capacity.

300

73.20

25.77

46.32

400

6750

24.18

43.61

500

63.40

23.19

42.03

750

59.70

22.88

41.56

1000

56.80

22.47

41.11

Capital cost includes engines, boilers, etc., installed and buildings. Annual costs include interest at 5 per cent., depreciation and repairs on plant, oil, waste, labor, and fuel (coal at $4 per ton). Brake horse-power = mechanical horse-power at engine shaft. Effect on the cost of steam-power (in previous table) of a variation in the price of coal of $0.50 per ton.

Size of plant, h.p.

10 Hour

24 Hour

200

Compound condensing...

$1.69

$3.71

300

Compound condensing....

I.62

3 60

400

Compound condensing....

1.56

344

500

Compound condensing, water-tube boilers...

1.39

3.05

750

Compound condensing, water-tube boilers...

1.39

3.05

1000

Compound condensing, water-tube boilers...

1.39

3.05

It may be noted that while another authority agrees closely with the foregoing figures, two others set the annual cost of 10-hour power in a 300 h.p. plant 50 per cent, higher. It is probable that as usually installed upon construction work the capital cost might be somewhat less owing to the more temporary character of buildings, chimneys, etc.; also that the annual cost might be somewhat higher.