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 o& 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 necessary, the number and size of culverts required, the cost of 



