PORTLAND CEMENT CONCRETE ROADS. 55 
finishing machine, road roller, water pump, pipe, forms, and all 
other miscellaneous equipment, will cost approximately $18,000, ex- 
clusive of the grading, unloading, and hauling equipment. An in- 
dustrial railway outfit, consisting of a four-sack mixer, unloading 
crane and clamshell bucket, 4 miles of industrial track, 60 industrial 
cars, 120 batch boxes, 4 gasoline locomotives, road rollers, subgrade 
planer, water pump, pipe, forms, and all other miscellaneous equip- 
ment, will cost approximately $75,000, exclusive of the grading equip- 
ment. The magnitude of this expenditure makes it imperative that 
considerable thought should be given to the selection of equipment 
and that a well-balanced outfit be secured. 
CAPITAL REQUIRED. 
The amount of capital required to carry on concrete-pavement 
construction depends almost wholly on the size of the project. As a 
general rule, the amount of working capital required after the 
equipment has been secured will vary from 5 to 10 per cent of the 
total amount of the contract. A small project will require a larger 
percentage of working capital than a large one; so that while a 
working capital of 10 per cent or over might be required on a com- 
paratively small project, a relatively large project can often be 
handled with a working capital as low as 5 per cent of the contract 
total. The usual method of paying for the work provides for 
semimonthly or monthly estimates to the contractor based upon 
the amount of work done, from which a nominal percentage is with- 
held until the completion of the work. Ordinarily this method 
should enable the contractor to meet most of his bills for labor and 
materials after the first two or three estimates are paid. The amount 
of working capital required also depends to a considerable extent 
upon the quantities of materials maintained in storage. Some 
storage of materials is nearly always necessary and it is especially 
desirable that these materials be stored during the off season. The 
storage of a large quantity of materials usually requires an outlay 
of capital greater than the average pavement contractor can afford 
to make. The buyers of the pavement, however, whether State or 
local subdivision, can relieve the contractor of the burden of carry- 
ing stored materials by paying for materials delivered and placed 
in storage. This policy enables the contractor to secure storage of 
materials at the cost of unloading, and by encouraging such storage 
the time of completion of the work is generally hastened, benefiting 
both the State and the contractor. This policy is recommended. 
COST OF CONCRETE PAVEMENTS. 
The cost of concrete pavements depends upon the amount of grad- 
ing necessarv, the number and size of culverts required, the cost of 
