50 

 Cost of Excavation for Cement Pipe Lines (In cents), per Lineal Foot. 



Laying the pipe. (Fig. 39). 



The pipes are placed in the trench standing on end with the bell end or 

 grooved end up. To lower the large pipes more easily they may be slid on 

 a chute or skid made of timber. The pipe sections are joined with a mix- 

 ture of 1 part of cement to 2 of fine sand. The taper end of the pipe which 

 has already been laid, and the bell end of the pipe to which it is to be 

 joined, are brushed clean and well wetted with a fiber brush. About an 

 inch thick of the soil under the bottom of the joint to be made is removed 

 and a trowel full of mortar is spread in its place to form a bed of mortar. 

 The bell end of the pipe which is standing on end is filled with cement 

 mortar and is jammed against the taper end of the previously laid pipe. 

 The mortar which is squeezed out on the inside of the joint is wiped with a 

 wet brush to form a smooth joint. To complete the joint a band of mortar 

 from 2 to 3 inches wide and *4 to % inch' thick is formed on the outside 

 of the pipe. 



It is always preferable to lay the pipe uphill to avoid the shrinkage at the 

 joints due to the pipe pulling away. It is well to protect the bands from 

 the action of the sun for about 30 minutes before backfilling by using wet 

 burlap or placing a board over them. To raise a pipe and hold it on grade 

 do not use clods but shovel in dirt and compact it by tamping. The bands 

 should be wetted before backfilling; this must be done carefully by shovel- 

 ing the earth, free from rocks, around the pipe and tamping it until the 

 pipe is well covered. With loose sandy soil which packs easily, very little 

 tamping is necessary. The pipe should not be used for at least 2 to 3 days, 

 especially if under pressure, to give sufficient time for the bands to harden. 



In the accompanying table is given information regarding the laying 

 and hauling of cement pipe, based on the wages and cost of material given 

 above. Ten per cent, has been allowed for supervision, organization, break- 

 ing of pipe and miscellaneous. 



