28 BULLETIN 1037, U. S. DEPARTMENT OF AGRICULTURE. 
STEAMING GREEN STOCK AS A CONTROL MEASURE. 
METHODS COMMERCIALLY EMPLOYED. 
Steaming certain kinds of stock (green gum lumber, birch hubs, 
spokes, and sawed felloes of red or white oak) is sometimes resorted 
to as a means of reducing shipping weight by hastening drying or 
to even up the color and reveal defects in the wood. 
In the steaming of green gum lumber a large steel tank, or pre- 
parator, is employed. The lumber loaded upon trucks is run into 
this preparator and steamed for perhaps 15 to 30 minutes at pres¬ 
sures of 20 to 30 pounds (figs. 13 and 14). Provided this lumber is 
then carefully open 
piled, it remains clean. 
When close piled or 
when exposed to ad¬ 
verse weather condi¬ 
tions, however, it may 
mold almost as readily 
as untreated green 
lumber. 
Hubs, sawed felloes, 
and turned spokes 
green from the saw are 
sometimes steamed at 
atmospheric pressure. 
At one plant visited, 
green birch hubs were 
stacked in large cement 
boxes and subjected to 
exhaust steam for 24 
to 36 hours, depending 
upon the size of the 
hub. At the end of that time the steam was shut off and the hubs 
were allowed to cool for perhaps 10 hours. The hubs were then 
carried to a ventilated warehouse and stacked, zigzag fashion, to 
provide for ample circulation of the air through the inside as w^ell 
as around them. In this manner an even drying was secured. Two 
to three weeks was considered a sufficient length of time for the 
necessary air drying previous to shipping. During the warmer 
months, stock cars were used as means of transportation. 
The steaming of gum and birch is a comparatively simple process. 
But in the case of woods that check readily, such as oak, this treat¬ 
ment requires considerable care. 
Fig. 9.—A box car loaded with split billets upon its 
arrival at the spoke mill. The method of loosely 
boarding the doorway, as shown in figure 8. is prefer¬ 
able in that there is less danger of the stock working 
out while in transit. When, however, the masses of 
billets are held in position by supports, or when ver¬ 
tical boards are nailed a few inches back of the cleats, 
this method may be used. Both provide for the venti¬ 
lation of the stock. 
