Part IV.—Cost of Steam Shovel Work.

The cost of steam shovel work varies greatly with the different conditions affecting each piece of work. It depends mainly upon the nature of the material, its location, the capacity and efficiency of the steam shovel, and the supply of empty cars or wagons. The efficiency of a steam shovel is not necessarily proportional to its capacity, but to the amount of work done compared to its cost; and while the amount of work done is generally larger in the machines of larger capacities, this advantage may be more than balanced by the greater cost of operation, including the cost of labor, fuel, supplies and repairs, etc. Machines of the largest capacity, with dipper of 2½ cu. yds. capacity, are employed mostly in excavating soft materials, especially in loading gravel for ballasting. Machines of medium capacity are usually the most efficient for general construction work.

The average daily operating expenses of a steam shovel of medium capacity are about as follows:

One engineman$4.00 
One cranesman3.50 
One fireman2.00 
Four pitmen at $1.506.00 
 —— 
Wages of crew $15.50——
  $15.50
One ton coal$3.00 
Oil and waste.75 
Water.50 
 —— 
Fuel and supplies$4.25——
  $19.75
Interest on capital, $6,000, at 6%$1.00 
Depreciation at 10%2.00 
Repairs1.00 
 —— 
 $4.00——
Total daily expense with regular crew $23.75

This will suffice for loading loose gravel; in the harder materials ordinarily occurring on construction work the following daily expenses must be met:

Expenses of regular crew  $23.75
Foreman$5.00 
Two pole (or bank) men at $1.503.00 
Two extra men at $1.503.00 
One night watchman1.50 
Powder and dynamite1.00 
 —— 
 $13.50——
Daily expenses on average construction work $37.25

To the above must be added the expense of transporting the machine to the work, and returning.

The cost of hauling is also a variable item; it depends mostly upon the length of the haul, and on railways very largely upon the delays met with in going to and from the dumping place. On construction work it is seldom less than 3 cts. per cu. yd., and sometimes reaches 10 cts. On railways it is not often below 4 cts. for hauls up to 10 miles in length, and may reach 50 cts. or more for hauls of 75 miles or farther.

Fig. 97.
Fig. 98.

Dumping is a very small item where small dump cars are used on construction work, and does not exceed ½ ct. per cu. yd. When wagons are used it will average about 1½ cts. On railways the cost of unloading with the plow varies somewhat, depending upon the kind of material; it averages about ½ ct. per cu. yd. Unloading by hand averages 6 cts.

On railway work, where the spreader is used, the average cost of leveling the material for widening embankments is only 0.1 ct. per cu. yd.; spreading it by hand will range from 5 to 20 cts. per cu. yd. for widths of 5 to 15 ft. from the unloading track.

The total cost per cu. yd. of excavating and loading, hauling and dumping different kinds of materials with the most usual length of haul averages about as follows:

  Loading. Hauling. Dumping. Total.
  Cents. Cents. Cent. Cents.
Sand and loose gravel 34 to 10 ½ 7½ to 13½
Loam " " 8 to 14
Dry clay 4 " " 8½ to 14½
Damp clay 6 " " 10½ to 16½
Stiff blue clay 8 " " 12½ to 18½
Cemented gravel, hardpan, etc.,
materials loosened by explosives
10 to 16 " " 14½ to 26½

The steam shovel will do the work of 60 to 120 men, saving from 5 to 25 cts. per cu. yd. of material excavated and loaded. The gain is proportionally much greater in the harder, and particularly in the more tenacious materials. The machine is not adapted to small jobs, and is seldom worked in cuts of less than 8 ft. in depth; nor is it cheaper than hand and team labor on such small jobs, but on nearly all large work it is much cheaper and faster; and last, though not least, its use largely reduces the number of laborers required, and hence the probability of strikes and other labor troubles.