A Car-Builder's Dictionary

Creamer's Automatic Ventilator

Monitor roofs with their elevated clerestory were designed for two purposes: to provide light and to provide ventilation. Open car windows provided a breezy effect but seldom provided passenger with any real fresh air. And the fresh air they did provide was likely to be dusty and filled with smoke and cinders.

One of the first improvements was to pivot the windows in the middle so that one end swung in when the other swung out. When swiveled partially open so the projecting portion was away from the direction of travel, the air blowing past the opening created a slight vacuum, pulling out stale air and presumably allowing fresh air to enter through vents or a transom in the end of the car. (Same principle as the “wing” windows in 1940-57 cars [before wrap-around windshields].)

The idea worked well enough if the brakemen positioned the windows correctly. But he did not, and the projecting end was into the direction of travel, it acted as an air-scoop, bringing in dust and dirt, rain, snow, cold air, and the ever-present cinders and smoke. But brakemen generally had other, more pressing duties such as tending the stoves, trimming the lamps, reversing seats, etc. not to mention manning the brakes, and often the clerestory windows did not get set properly.

( Car-Builder’s Dictionary, 1879 edition)

A railway supplier named William G. Creamer sought to solve the problem with a ventilator that set itself automatically to the direction of travel. He designed an open-ended sheet metal box that could be fastened to the deck side with the openings positioned in the directions of travel (see photo above). Inside was a “Y”-shaped flapper valve (see illustration below) that set itself in the proper direction.

Outside view of Creamer's Automatic Ventilator. In this view, A represents the side of the ventilator against the deck side. B is the outside of the ventilator. The car is moving to the right, pushing the vane C to the left. The air moving past the ventilator on the outside (from right to left) creates a slight vacuum, pulling air out of the car through the opening D.

This is a cross section of the ventilator looking down. A is the deck side. B is the outside of the ventilator. C is the vane being pushed from its “normal” position E. D is the opening into the car through which air is sucked out as in the illustration above.

Creamer's Automatic Vents on clerestory roof of a passenger car

Creamers Automatic Ventilators on the deck of a clerestory-roofed passenger car about 1876. Either the deck windows have been replaced with solid panels or simply appear opaque because of the sun's reflection.

The ventilator wasn’t Creamers first or only invention. He had also created an “emergency brake” for railway cars. See it HERE.

For more information on passenger car ventilation and/or brakes --

White, John H. The American Railroad Passenger Car.  Baltimore, MA: Johns Hopkins University Press, 1978.

11 April 2006

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