Tuesday, December 11, 2007

Revival of the Use of Compressed Air as a Motive Power -- December 11, 2007

This blog is named after a series of articles written by Doctor P. H. Van der Weyde and published in Manufacturer and Builder Magazine in 1889 and 1890. The more I learn about Doctor P. H. Van der Weyde -- I'll share more about him in future posts -- the more I like him. Here is an article he wrote about attempts to use compressed air to drive transit vehicles. In this period, people know that horse-powered railways were inefficient, but cable traction was expensive, steam power was not suitable for urban areas, and electric traction was still being developed.

Revival of the Use of Compressed Air as a Motive Power

By Dr. P. H. Van Der Weyde

From Manufacturer and Builder / Volume 26, Issue 12,
December 1894

Lately an important problem has again been brought to public notice -- namely, the propulsion of street cars by means of compressed air, carried on the car itself.

The solution of the problem requires the execution of two kinds of contrivances -- first, a reservoir strong enough to withstand considerable pressure, and, secondly, a motor machine to be put in operation by this pressure. The reservoir is by preference made in the form of cylinders, of say one or two feet in diameter, so that they can be placed under the seats of the car, and of a length sufficient to utilize all the space afforded. The motor is best placed under the floor of the car, now a common method in the electric trolley cars, while the regulating devices are on both platforms where the motorman performs his duty.

It is evident that this system offers peculiar advantages, especially by reason of its apparent simplicity. The cylinders containing the compressed air -- the motive power -- are charged at the station and need no further attention, as is the case with locomotive boilers, where the chances of safety depend on the engineer and stoker. All the heavy machinery used for the production of the primary power is stationary, and no power is wasted to move it about as in the case of the locomotive, the only weight to be transported is the motor and the cylinders containing the compressed air. Summing up the advantages, they are:

1. No dead weight of coal or fuel on board.

2. No dead weight of water, boiler, furnace, and other material which has to he stabled, the real primary motor, which is a stationary structure of large dimensions, and therefore economical, as the economy increases at a very large ratio as the engines are increased in size.

3. The compression of air is going on continually in the reservoirs, and is always connected with the gauges, so as to insure safety.

The first application of this principle was seen some six or eight years ago at the Harlem station of the Second Avenue Railroad. It was intended for the propulsion of trains, and the compressed air reservoirs consisted of two huge cylinders placed horizontally, with a space between, through which the engineer could see the forward track while standing on the motor, and having the train of cars behind.

A few years later I saw some interesting experiments of thie same character at the Delamater works, where pipes were laid to quite a distance from the works, and at which pipes the cylinders could take up new supplies of compressed air without going back to the supply station.

A syndicate has been formed to introduce this system of street transportation, so that we will have another additional method in practice.

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