A Dp:cexxiai- Recokd 49 



the conipiiratively small supply of dry stock available, and left the 

 alternatives of either using green stock or resorting to artificial dry- 

 ing. The former was of course out of the question and many were 

 convinced that the latter also was not feasible. The shortage of 

 northern-grown oak complicated the matter still more since the 

 southern oaks are admittedly much more difficult to dry, and the sea- 

 soning losses, even with the most careful air drying, are very large. 

 'J'lie problem here was to get the wood dry, even if considerable de- 

 grade occurred, the development of the last ounce of strength being 

 out of the question and not essential. In this it differed, of course, 

 from the aircraft wood-drying problem. 



The laboratory's experience in the experimental drying of vehicle 

 stock and in the design and operation of kilns indicated clearly that 

 successful drying of this class of stock would require very careful con- 

 trol of kiln conditions — an accuracy of control which could not be 

 secured in kilns of the common ventilated types, even with well- 

 trained and skilled operators. The only type of kiln which, in the 

 laboratory's experience up to that time, was susceptible of sufficiently 

 close control was the water-spray type, and therefore this type was 

 recommended for this piu-pose, and suitable drying schedules were 

 prepared. 



This heavy drying divided itself naturally into two groups: the 

 army wagons for the Quartermaster C'orps. and the artillery wheels 

 for the Ordnance Department. Assistance was given at both gov- 

 ernment-owned plants and arsenals and at contract plants in the 

 design and erection and the eventual operation of numerous kilns 

 handling lieavy stock, a corps of experts being maintained in the field 

 for that purpose. One man was stationed at the Rock Island Arsenal 

 almost continuously for seven months, while the kilns were being 

 erected and the operators trained. The knowledge and experience 

 of the laboratory staff and the help which they were able to render 

 made possible, since it enabled the dry material to be secured jn-omptly, 

 the carrying on of tlie various i)r()grams dependent upon heavy hard- 

 wood stock. 



An important problem involving wheel stock was the steam- 

 bending of the felloes. Tliere was but little standardization of prac- 

 tice in the industry, and the losses which were occurring at many of 

 the plants were very large. A field study of this problem was under- 



