» WOOD PIPE FOR CONVEYING IRRIGATION WATER. 17 
metal, thus leaving it subject to decay. It is considered better prac- 
tice to insert the wood pipe into the metal pipe and calk with lead 
and oakum. ‘To do this usually requires a special coupling either of 
cast iron or steel. An example of a cast fitting illustrating this 
method of joining wood pipe and cast-iron pipe is shown by figure 
5, and another of steel for uniting wood pipe and steel pipe by figure 
6. Animportant fea- 
ture in both of these 
designs is the thim- 
ble or flange which 
fits inside the wood 
staves to prevent 
them from _ being 





forced in by the i 
ealking. ji 
CRADLES. a 
If continuous 2 
stave pipes are built 3 
above ground it is = 
usually best to sup- = x 
port them in “cra- * : 
mies or “chairs.” : 
In the design and 3 | 
spacing of supports @ 
of this kindtheideas 2 | 
and judgment of en- ® ear 
gineers differ andas yw Fees | 
yet there isnostand- ¢ —~ & _ gp a 3g 
ard practice. 2 = 
Cradles of the = | NI : 
general type shown = | 
by figure 7, A, were © 7 
used on several large __.v__-_ WLLL ae 77 Sy 
pipe lines of the A@@IFQ 2 -/ Se i 
Kings Hill irriga- — Aad Blt Circle 43"! 
tion system in Idaho, ee 
and they appear to : ages 
be well designed. 
On some pipe lines the 2 by 12 inch mudsills are continuous; on 
others, blocks 18 inches long are used. The use of short blocks in 
this way is more economical of material, and requires less grading. 
The cradles of the type shown by Plate IV, figure 1, were spaced 6 
feet center to center under a 54-inch pipe, and to support a pipe 100 
inches in diameter cradles of the same type of 8 by 8 inch material 
61133°—Bull. 155—14—_3 


