112 BULLETIN 111, U. S. DEPARTMENT OF AGRICULTURE. 
size of the engine, the character of the country, and the amount of 
work done. Under ordinary conditions the amount consumed comes 
to about 20 feet per thousand feet of output. Figuring stump age at 
$1.50 per thousand feet, the fuel cost of wood per thousand feet of 
output amounts to $0.03; stumpage at $2 per thousand feet, $0.04; 
stumpage at $2.50 per thousand feet, $0.05 ; stumpage at $3 per thou- 
sand feet, $0.06. 
The amount of fuel oil consumed in a yarding engine ranges from 
6 to 8 barrels per day. Under ordinary conditions the amount con- 
sumed amounts to about 5 gallons per thousand feet of output. On 
this basis, with the delivery cost of oil at $1 per barrel, the fuel cost 
of oil per thousand feet amounts to $0.12 ; with the delivery cost at 
$1.10 per barrel, $0.132 ; with the delivery cost at $1.20 per barrel, 
$0,144; with the delivery cost at $1.30 per barrel, $0,156. 
A yarding engine consumes about 1J tons of coal per day. On this 
basis, with a delivery cost of coal at $4.50 per ton, the cost of fuel per 
thousand feet amounts to about $0,135. 
Lubricants, waste, and packing. — Few companies segregate the cost 
of lubricants, waste, and packing, and possibly no operator is in a 
position to say confidently what their cost amounts to per thousand 
feet yarded. The amount is small, about $0.01 per thousand feet. 
The fixed investment in the supplies is about $50 per yarding engine. 
Maintenance of yarding engines. — Regardless of the care given 
ground engines, there will be breakdowns through wear, latent de- 
fects, or accidents. It is impossible to do more than approximate 
the maintenance cost per year on this class of equipment. 
Seldom is the total cost of repairs on yarding engines, consisting 
in a general way of shop and miscellaneous labor, new parts, and 
repair materials, etc., segregated in such a way as to enable one to 
speak confidently of it. Besides, the maintenance cost varies with 
the size of the timber, character of ground, stability of sled, kind 
of settings, the speed at which the machines are driven, etc. 
At one camp the cost of repairs on three yarding engines for one 
year amounted to $1,836, or $612 per engine. During the year some 
improvements were made on the engines, the cost of which is included 
in the above figures. The engines handled about 27,000,000 feet of 
timber. At another camp the repairs on two yarding engines for 
one year cost $422, or $211 per engine. The engines handled about 
18,000,000 feet of timber. A year's upkeep of another yarding 
engine which handled 11,000,000 feet of timber amounted to $682. 
The year's repairs on two other yarding engines which handled 
21,000,000 feet of timber averaged $357 per engine. A year's repairs 
on a yarding engine that handled 9,000,000 feet of timber amounted 
to $180. The above figures represent total costs, including labor, 
repair parts, material, etc. 
