8 
BULLETIN 300, U. S. DEPARTMENT OF AGRICULTURE. 
On dredges such as are ordinarily used in drainage work, the dipper 
or bucket varies in size from one-half cubic yard to 4 or 5 cubic yards. 
The dipper varies considerably in shape with the different manufac- 
turers. For work in ordinary material the cutting edge is made of a 
single steel plate, preferably of manganese steel, but if the material is 
hard large steel teeth are used to reinforce the cutting edge. The 
bottom of the dipper is a heavy steel plate which is hinged to the back 
and is held in place by a spring latch on the front of the dipper. The 
latch is operated by the craneman, who thus dumps the contents of 
the dipper. As the latter is lowered into the ditch the weight of the 
bottom causes it to close and latch automatically. 
The larger the dipper used, the larger must be the engine and boiler, 
and, in fact, all of the parts, including the hull. Thus the size of a 
dipper dredge is determined by the capacity of its dipper. 
COST. 
The cost of dredges advances rapidly as the size and capacity are 
increased. Dredges of the same rated capacity also vary somewhat 
in cost with the different manufacturers. All of the machinery is 
usually made at the shops of the manufacturer. The material 
for the hulls may also be supplied by the manufacturer, but usually 
the purchaser obtains lumber in the open market and builds the hull 
in the field. The cost of hauling the material and machinery from 
the railroad to the place of erection, the local price of labor, and the 
conveniences for housing and feeding the workmen are factors which 
will enter into the cost of a machine of any type. It requires at least 
two cars to transport the material for a small dipper dredge, while for 
a machine of large size from four to six cars are required. 
The following table gives the approximate costs of the various sizes 
of dredges ready for operation, though these would be largely 
affected by the difficulties and expense of transporting the material 
and assembling the machine: 
Approximate costs of dipper dredges. 
Size. 
f-yard. 
1-yard . 
li-yard 
1^-yard 
2 J -yard 
Cost of 
machin- 
ery. - 
S3, 700 
5,400 
6,100 
7,100 
14,000 
Cost of 
wood 
hull. 
81,800 
2,200 
2,250 
4,500 
9,000 
Total. 
$5, 500 
7,600 
S,350 
11,600 
23,000 
It requires practically a month for ten men to erect a 1-yard dredge, 
6 weeks to erect a 1 J-yard or If -yard dredge, and 8 weeks to construct 
a 2-yard or 2^-yard machine. It requires less than one-half the time 
given above to dismantle a machine. A 1-yard dredge whicn cost 
