The articulated design of some Budd-Michelin cars, with trucks shared between adjacent cars, presented another opportunity for weight saving with the new train. On conventional passenger cars, each carbody rode upon a pair of trucks (pivot-mounted wheel-axle assembly), with one truck at each end. The articulation not only reduced the number of trucks under the train, but it also dispensed with the need for couplers between each of the carbodies, further reducing the train's weight. The concept was used by Budd engineer Walter B. Dean to build a train consisting of three semi-permanently attached cars. It did, however, mean that train lengths could not be easily changed by switching out cars.