30 BULLETIN 155, U. S. DEPARTMENT OF AGRICULTURE. 
bands five-eighths of an inch in diameter, while the failure of a sec- 
tion of machine-banded pipe due to the wire being cut in this way 
is not uncommon. 
Small leaks at the joints or seams of wood pipe are usually stopped 
with wooden wedges. In the case of leaks around the wooden cou- 
plings of machine-banded pipe, the wedges are driven into the staves 
of the coupling sleeve, and not between them and the pipe. If a 
section of machine-banded pipe or a collar fails on account of the 
cutting of the wire, individual bands with coupling shoes similar to 
those used for the large continuous stave pipe can be obtained for 
making repairs. An assortment of these might well be kept on hand 
where likely to be needed. 
The repairs of a large pipe may call for considerable ingenuity 
and unique methods. When several five-eighths-inch bands of the 
48-inch Mabton (Wash.) siphon were cut by a leak, allowing the 
ends of two staves to spring out and break off, a diver was em- 
ployed to make the repairs. At the bottom of the Yakima River, 
15 to 20 feet under water, steel plates with gaskets, one on the inside 
and one on the outside of the pipe, were clamped together with bolts 
so as to stop the leak. 
Under ordinary circumstances the repair of continuous stave pipe 
is not difficult. The removal and replacement of staves or portions 
of them is a matter of frequent occurrence. It is only necessary to 
remove a few bands, take out the defective stave, spring another into 
place, and reband. If the pipe has been buried and the threads on 
the bands have become badly rusted, as they frequently do, any 
change in the position of the nut may necessitate the use of a new 
band, though if the body of the band is fit to be used again a new 
thread may be welded on. This has been done by the Butte 
Water Co. 
Where a pipe is above ground any landslides coming in contact 
with it should be cleared away as a precaution against decay, par- 
ticularly if it is at a point where the pipe is under lght pressure. 
If supported in cradles, mudsills or footings should be renewed 
as decay progresses, in order to avoid injury to the pipe from set- 
tling. Weeds permitted to grow along an exposed pipe may, when 
dry, be a source of danger from fire, and on this account if for no 
other reason they should be kept down so far as conditions will 
warrant. | 
On many irrigation systems it is necessary to empty the wood 
pipes in the fall, as a precaution against damage from freezing. 
Where this is the case they should be kept full as late as possible, 
and be filled again in the spring just as soon as conditions will per- 
mit. In some instances irrigation managers close the inlets and out- 
lets of wood pipes when emptied in the fall, so as to prevent the 
