Balancing of Locomotive Reciprocating Parts

Since the British Bridge Stress Committee's report† of 1928, an increase has occurred in the speed capacity of locomotives. After showing how the recommendations of that Committee have been met in modern British locomotive design, the effects of higher rotational speeds are discussed, and tests with the lifting of coupled wheels off the track at maximum speeds and with various proportions of reciprocating balance are described.Since the necessity may arise for reducing hammer blow values still further to meet civil engineers' requirements, the possibility of reducing or eliminating the amount of reciprocating balance becomes important. The effect of this factor on the locomotive itself is discussed theoretically, expressions being given for the amplitude of the resulting horizontal and lateral oscillations.Available practical evidence in support of the theoretical considerations is described, and conclusions are reached regarding the conditions under which it is still necessary for locomotive reciprocatin...