CD 2055083 E&MP10.001
October 20, 1946
The Firestone Tire and Rubber Company’s air spring mounted on a railroad passenger car truck. The white tire-like objects on either side of the journal box suspension are the bellows which are connected to a compressed air reservoir containing a specially constructed valve.
This valve acts as a shock absorber and cushions the ride of passengers. The white square at the right is a scratch plate which recorded the vertical motion of the car.
Scientific instruments recorded the difference between the rail shock transferred to the passengers by both air springs and steel springs in a special run of the Pullman-Standard Company’s laboratory car over the Chicago South Shore and South Bend lines in the Michigan City area.
Original Caption by Science Service
©Firestone Tire and Rubber Company