Letters to the Editor

摘要

I have just received Observer 351 - great content as usual. I had seen some of the material in David Berry's article on earlier electrification schemes before, but quite fascinating - especially the various power struggles among the staff. On the actual (electrical) power there is a technical error/ typo.The last paragraph on page 144 has,'... the reason for low frequency being that commutator series traction motors were possible.' This should be'... commutator free traction motors.'AC motors are com mutator free at any frequency, but for higher starting torque the lower frequency is preferable.