The New Zealand Railways Magazine, Volume 2, Issue 12 (April 1, 1928.)
Interest continues in the performance of the oil-electric locomotives, a number of which have now been in service for a sufficient period to demonstrate the economies and other operating advantages of this type. Two 100-ton units are now in heavy switching service on the Erie Railroad and 60-ton units were completed for the Chicago and North-western Railway, the Union Carbide Company and the American Rolling Mills Company.
Work is proceeding on the oil-electric freight and passenger locomotives for the Putman Division of the New York Central Railroad, and a 300 h.p. oil-electric motor car is ready for service.
The New York Central Railroad is actively working on the electrification of its west side yards which will be operated from an overhead trolley north of 60th Street. Below this point self-propelled oil-electric and storage battery units will be used, one of which is already in service. This unit is a 120-ton locomotive equipped with a storage battery and a 300 h.p. oil engine generating set for battery charging. It will also operate from the third rail.