40 BULLETIN 300, U. S. DEPARTMENT OF AGRICULTURE. 
into place. A 45-horsepower, 2-cylinder, opposed-type oil engine is 
used for power. The bucket has a capacity of five-eighths cubic yard 
and is 43 inches wide. One man is required to operate the machine 
and one man to handle the track in soft ground. About 30 gallons 
of gasoline or 40 gallons of kerosene are required per 10-hour day. 
The machine is moyed ahead by means of a cable attached to a dead- 
man or to stakes. The large wheels will travel over fairly firm ground 
without track; no trackman is therefore needed, except in quite soft 
ground or swamp. The machine, complete, weighs 12 tons. When 
dismantled it can be loaded on one flat car or if transported by team 
will make 12 wagonloads. The heaviest load is the engine, which 
weighs 5,640 pounds. 
To assemble the machine takes five men four or five days. The same 
number can dismantle it in two days. The hoisting line is one-half 
inch cable 125 to 140 feet long. The loading line is three-fourths 
inch cable 60 feet long. In single-shift operation a loading cable will 
ordinarily last 10 days and a hoisting cable two weeks. The machine 
will excavate about 300 cubie yards per shift or about 15,000 cubic 
yards per month with double shift. The maximum ditch which it 
will dig at a single cut has a 42-foot top, 12-foot base, and 8-foot 
depth. The machine may be had in widths of 36 or 40 feet and costs 
approximately $5,500. 
In enlarging an old ditch averaging 6 feet deep so as to have a 
channel 13 feet deep with a 10-foot base, a five-eighths yard non- 
rotating excavator, with a 40-foot boom, was used. The material re- 
moved averaged 10 cubic yards per linear foot. The angle of swing 
was 75 degrees, and the boom was suspended at an angle of 35°. A 
direct-line swing was used, the swinging cables being attached di- 
rectly to the boom instead of running through sheaves on the boom 
and then back to the corner of the cross-frame. This kind of hitch 
gave a much quicker swing. A time study made of 75 dips gave the 
following information: To load the bucket took 8 seconds; to hoist, 
swing, and dump, 8 seconds; to return the bucket to the ditch. 8 see- 
onds; the entire time to complete one dip was, therefore, 2+ seconds. 
To move the machine ahead a distance of 9 feet required 9 seconds. 
Another type of nonrotating excavator has been developed which 
has a double boom with bull-wheel swing instead of pivot swing. 
The machine is made in two sizes, five-eighths yard and 1 yard. 
The smaller size can be furnished with either the caterpillar mount- 
ing or the regular sliding-track mounting, while the larger size is 
furnished only in the sliding-track mounting. 
The smaller machine has a five-eighths-yard bucket, 24-foot boom, 
and a 32-horsepower oil machine; the machine, complete, weighs 32 
tons. The track shoes are each 30 feet long and 30 inches wide, and 
