66 BULLETIN 440, U. S. DEPARTMENT OF AGRICULTURE. 
flat, the pond is usually constructed by excavating the center and 
building earth dykes on the low sides. In some instances a ditch 
must be constructed for supplying water. 
For circular mills cutting from 30,000 to 40,000 daily, the usual 
size of the pond is frorn one-half to one acre. For single-band mills 
where storage is not an item, the ponds vary from 1 to 4 acres. The 
size of ponds at double-band mills depends upon the possibilities of 
each site and the desire of the operator to store logs for a rim of a 
month or more in the fall. Such ponds range from 4 to 14 acres. 
The usual capacity of a pond, excluding sinkers, is from two-thirds 
to three-fourths of a million feet of logs per surface acre. Where 
necessary, logs may be piled in a pond with an overhead trolley, 
thus about trebling the capacity. The cost is, however, very large. 
The work upon a log pond may begin with unloading the cars, 
and includes sorting, raising sinkers, and delivering logs to the haul- 
up. In the yellow pine of the eastern Sierras sinkers are practically 
•unknown, and the unloading is customarily done by the tram crew. 
The pond crew, therefore, consists of one man for a singls-band mill 
and two men for a double-band mill. One man is stationed at the 
lower end of the log slip to pole the logs into position for the hoisting 
chain. The other man poles the logs to within reach of the first 
and does sorting and general pond work. For a daily output of 
120,000 the cost is about 5 cents per 1,000, which may be considered 
the low figure for such work in good-sized plants. ■ 
Since both sugar-pine and white-fir butt logs sink on being placed 
in the water, provision must be made for raising sinkers from ponds 
where these two species are logged. The simplest scheme is one 
used at a double-band mill with a small pond. The log cars are 
unloaded by a stationary overhead boom at a point very near the 
log slip. A swinging boom with a steam winch and cable is located 
on a crib work in the pond. After each train is unloaded, the sinkers 
are picked up by tongs and swung around by the boom to within 
reach of the pikeman at the log slip. The crew consists of two 
pondmen delivering logs to the slip, one man in a flatboat attaching 
tongs to sinkers, and one winchman. One-third of the time of the 
winchman is devoted to unloading. The night crew contains only 
the two pondmen. The total daily cost is therefore SI 7, which, dis- 
tributed over 250,000 feet, is 7. cents per 1,000. 
At another operation, with a large number of sinkers, the cost of 
pond work is still greater. The pond crew does the unloading, 
using a winch located on a cribwork in the pond. The entire crew, 
except one man, works at unloading, and the average time required 
for an 18-car train is 20 minutes. The unloading is done at a point 
some distance from the log slip. When not unloading, the crew is 
at work raising sinkers, sorting logs, and shifting logs to the mill end 
