COSTS 



The cost of cement pipe or of cement pipe lines cannot be stated 

 readily because of the variable local conditions. For example, the 

 cost of good, clean sand in the Casa Grande Valley is two or three 

 times the cost at a point situated close to a good supply. The loca- 

 tion with respect to the railway, living accommodations, the char- 

 acter of labor, and the size of the job all have a bearing on the cost. 



In Iowa and neighboring states the custom is to establish large 

 factories at central points and to ship the pipe by rail to the points 

 where it is needed. The pipe is used mainly by drainage districts, 

 and in large quantities. The manufacturers furnish pipe to the con- 

 tractors, or they take the full contract themselves. 



In the Pacific Coast states contracts are taken for the pipe line 

 laid complete, and the contractors make their own pipe. This has 

 been the custom in Arizona also. It has the advantage that there 

 is no divided responsibility. If the pipe line fails, the layer cannot 

 claim that the pipe was defective while the manufacturer claims that 

 the pipe was injured in handling, or the trench bed was not brought 

 to grade, or the joint mortar was not properly cured. 



The cost of making can be estimated in advance for a particular 

 case where conditions and prices are known. Some assumptions 

 must be made, such as for rate of work per day. Depreciation and 

 maintenance of the plant, taxes, and interest on the investment 

 should be computed. Maintenance of equipment is costly on ac- 

 count of the wear on packer-heads, rings, and other parts. A liberal 

 percentage should be added for contingencies, for the work may be 

 stopped, due to non-arrival of cement, severe storms or freezing 

 weather may cause delay or damage, and there are many other un- 

 foreseen difBculties that may arise. 



The following estimate of the cost of McCracken machine pipe 

 is presented as illustrative of the method to be used. It is based 

 on Tucson prices in 1918. The figures should not be quoted as 

 general or average costs. 



Table XXIII. ANNUAL FIXED CHARGES ON INVESTMENT OE $6,000 

 Item Percent I Amount 



Maintenance and depreciation. 



Interest 



Taxes 



Total 



25 

 8 

 1 



34 



$1500 



480 



60 



$2040 



