The Stirling Engine malfunction


By James Guthrie, worker at the Dundee Foundry, Scientific American, Boston, Mass. Nov. 30, 1860.

In reading the discussion on hot air engines, published in the present volume of the Scientific American, I noticed the question was asked : "Why its use (Stirling engine) was discontinued in the Dundee Foundry?".

I was working there for the greater part of the time that the second hot air engine was running. A common beam engine had been transformed into the hot air engine by the addition of the heating air pump and other requisites.

The great trouble with the air engine was the cracking of the heaters and their expense. They weighed about four tons each. They had to be molded in loam, the same as the cylinder of en engine faced up in the lathe, and everything done that was required for fitting a cylinder head.

Some would last for two months, others a year; and the time required to take one out and making another was from a week to tem days.

Stirling left the Dundee Foundry at the time it was discountinued, and it passed into the hands of Gourlay, Mudie & Co., who were not interested in it.

The great expense entailed for new heaters was the cause of its discontinuance in the Dundee Foundry. The same cause led to its discontinuance in the factory at DUndee, viz., the expense of replacing the heaters and the stoppage of the factory so often for repairs.

The hot air engine in the foundry had a very unsteady motion; so much so, that it was necessary to put new couplings on all the shafting when they put in the steam engine.

Saying from M. Stirling

At the meeting of the session of the Institution of Civil Engineers in Scotland, 26th December, 1860. Mr. D. Rowan asked if the economy of this engine was so great why does it not continue to work?

Mr. Stirling explained that they could not get the vessels to stand any length of time. The thickness of the vessels was about four inches. Possibly thinner metal would have stood, and they would have lost less heat from the outside. The vessel is the one difficulty of the engine.


The Scientific American adds the following.

The unsteady motion of the air engine in the Dundee Foundry referred to by our correspondant has also been experienced woth the air engines on this side of the Atlantic.

We have never heard of a large hot air engine which did not experience great difficulty and expense from the cracking of the marge heaters necessary to warm the air; but on a small scale, such as a two or five horse power engine, this difficulty may be overcome to a certain extend.