The Society of Automotive Engineers have made efforts to standardize dimensions of bed timbers for supporting power plant in an aeroplane. Owing to the great difference in length no standardization is thought possible in this regard. The dimensions recommended are as follows:
| Distance between timbers | 12 | in. | 14 | in. | 16 | in. | ||
| Width of bed timbers | 1 | 1⁄2 | in. | 1 | 3⁄4 | in. | 2 | in. |
| Distance between centers of bolts | 13 | 1⁄2 | in. | 15 | 3⁄4 | in. | 18 | in. |
It will be evident that if any standard of this nature were adopted by engine builders that the designers of fuselage could easily arrange their bed timbers to conform to these dimensions, whereas it would be difficult to have them adhere to any standard longitudinal dimensions which are much more easily varied in fuselages than the transverse dimensions are. It, however, should be possible to standardize the longitudinal positions of the holding down bolts as the engine designer would still be able to allow himself considerable space fore-and-aft of the bolts.
HALL-SCOTT ENGINE INSTALLATION
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Fig. 148.—End Elevation of Hall-Scott A-7 Four-Cylinder Motor, with Installation Dimensions.
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