Caloric Ship 'Ericsson'
Note: This is a sub-section of John Ericsson
John Ericsson built the 'caloric ship' Ericsson, powered by an enormous hot air engine. The builders were Perine, Patterson, and Stack, while the massive engine was constructed by Hogg and Delamater. It had a stroke of 6 ft., and four working cylinders of 168" (14 ft) diameter and four air compressing cylinders of 137" (11 ft 5") diameter. Ericsson had wanted 16 ft diameter working cylinders, but these were beyond the capacity of the makers. There were four "regenerators", each containing 50 discs of 1/16" wire netting, each disk measuring 6 ft by 4 ft. The ship was launched on 15 September 1852, just five months after laying the keel, and her first trial trip was on 4 January 1853. It is a remarkable illustration of his industry, energy, thoroughness, and skill in management, as well as his ability to persuade financial backers that this was the power source of the future.
The Ericsson's engine was said to be extremely frugal in its consumption of coal, but the engine's power output and the ship's speed (8 mph) were disappointing. Modifications were carried out to increase the furnace draught. 'A veil of secrecy was thrown around all activities concerning the ship, but the magnitude of the changes under way could not long be concealed. The news leaked out that the huge low pressure caloric engine was a complete failure in spite of the eulogies of the press. It could not drive the ship at more than five or six knots at sea and required such extensive repairs after the short voyage to Washington that it was being removed from the ship. In particular the bottoms of the working cylinders had been so badly burdened, buckled, and distorted by the heat of the furnaces that complete replacement was necessary, and furthermore a great deal of trouble had been experienced with lubrication when the engine became thoroughly warmed up by continuous operation for seventy hours or more. Only by the use of prodigious quantities of tallow had the engine been kept running on the return trip from Washington.'
Trial trips were undertaken on 15 March and 27 April 1854. It was claimed that a speed of 11 mph was acheived, but the fuel consumption was not determined, before the ship was struck by a tornado and quickly sank. Despite the fuel economy, it took up too much space, and too great an outlay of machinery to permit competition with the steam engine. The ship was rapidly salvaged, but the owners replaced the 'caloric' engine with a steam engine.
The above information is largely condensed from 'An inquiry into the hot air engines of the 19th century'[1].
From The Engineer, 29 March 1889: 'Ericsson was quite unable, from lack of consideration for detail, to see that it could not be made to answer on a large scale. Money was available, however, and on a large scale it was tried on board the Ericsson, a ship 260ft. long, built specially for the purpose. She was fitted with paddle-wheels driven by four cylinders, each 14ft. in diameter, with a stroke of 6ft. The number of revolutions made per minute was nine, and the indicated horse-power of this huge machine was only 300 horses, the effective pressure being, according to Rankine, only 2.12lb. per square inch. It is said that during the trial trip a man was kept in each cylinder - they were open-topped - and well supplied with buckets of melted tallow, with which he lubricated the sides of the cylinder. He stood on the piston and went up and down with it. It was only a detail that the use of hot air was incompatible with any efficient system of lubrication, and that the fires were lighted under the cylinder bottoms - a way of heating the air as inefficient as possible. The engine, however, notwithstanding its unwieldliness, might have achieved a certain measure of success if only the lubrication could have been managed. The ship was altogether too slow for commercial purposes, and Ericsson had the caloric engines taken out and replaced with steam.' See Leading article on John Ericsson.
Ericsson subsequently designed hot air engines of much smaller output, and these were a commercial success. He was awarded the Rumford Prize of the American Academy of Arts and Sciences in 1862 for his hot air engine developments.