22 
BULLETIN. 300, U. S. DEPARTMENT OF AGRICULTURE. 
maximum width of ditch a machine of the above size can dig is 
50 feet and the greatest depth is 22 feet. It has excavated 500 
cubic yards in 10 hours. The machine is supported on 4 wheels, and 
is moved on the work in advance of the excavation by cable and 
"dead man." 
Another drag-line machine of the stationary type has been designed 
to meet the demand for a light excavator that can be economically 
and quickly moved across country from one job to another. The 
power consists simply of a steam or oil traction engine which forms the 
rear of the machine as shown in figure 1 . The front end is carried on 
two wide wheels. It is claimed that this excavator can be moved over 
ordinary country roads, or even across fields', at the speed of an ordi- 
nary large traction engine, and that it can be quickly taken apart and 
reassembled if shipment is desired. For work on soft ground a heavy 
timber pad is provided for each wheel. These are shifted by engine 
Fig. 1.— Drag-line scraper excavator of the stationary type. 
power; in doing this one side of the machine at a time is raised on 
power jacks. 
A drag-line machine with two buckets has been used to some 
extent in the excavation of drainage channels. This machine, illus- 
trated in Plate IV, figure 2, is mounted either on runners or on cater- 
pillar tractors. The two booms, which are separated at the foot 
according to the width of the ditch to be cut, swing from the center 
of the ditch outward. The operations are so timed that one bucket 
is being emptied while the other is being filled. This feature greatly 
increases the output of the machine. The excavator can be dis- 
mantled for shipping in about 2 weeks and can be assembled in about 
1 month by a crew of 5 men. Under favorable conditions this 
machine has excavated 1,500 cubic yards in 15 hours. Such a 
machine, equipped with 42-foot booms, can dig a ditch with a 46-foot 
top, 25-foot bottom, and 12-foot depth. 
