440 
LOGGING 
loading stations. They may be made from 2- by 4-inch joists or 
from goHd 4-inch blocks (Fig. 158 A and B). 
A practical type of trestle'^ for a lumber flume under 75 feet 
Fig. 161. — A Five-leg Trestle for Heights Greater than 75 feet. 
in height has two legs made from 2- by 6-inch joists, doubled 
and braced CFig. 160). For heights greater than 75 feet a 
trestle with five legs is used (Fig. 161). 
^ Designed by F. M. Kettenring, C. E., Vancouver, Washington. 
