Frames. As has been previously stated, the frames of a locomotive are very difficult to design because of the many .unknown factors which affect the stresses in them. The following method of proportioning wrought-iron and cast-steel frames will give safe values for size of parts although the results thus found will be greater than usually found in practice.
P = the thrust on the piston or the area of the piston in square inches multiplied by the boiler pressure in pounds per inch
A = the area in square inches of the section of the frame at the top of the pedestal
B = the area in square inches of the section of the frame at the rail between the pedestals
C = the area in square inches of the section of the lower frame between the pedestals
Table of Contents; Page 129; Page 131; Index