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Discussion Starter #1 (Edited)
The principles of the turbine have been known for centuries, but after many failures, engineers considered it was a toy of no practical utility. It was not until 1884 that the young Hon. Charles Parsons designed and built a turbine which ran at 18,000 rpm and drove a dynamo.
Parsons was immediately interested in marine applications for turbines, as the steam reciprocating engine had passed its zenith for high speed vessels. Obviously the speed of the turbine needed to be considerably reduced if it were to drive a propeller.
As is often the case with a genius, Parsons appears to have been difficult to work with and he fell out with his partners. He left the partnership and established a small factory of his own. His problem was that the patents for his inventions were in the name of the partnership. Parsons entered into a long, expensive, but ultimately successful legal case to recover his patents. This law case resulted in a shortage of funds for technical development but inspired a remarkable series of improvised tests.
In 1892 Parsons made his first radial flow turbine, developing 200hp at 4,800 rpm. Its success decided Parsons to investigate propeller problems and then build an experimental turbine driven vessel. A series of 2 ft long models were made to test different hull forms by towing them across a pond at his home using a fishing rod and line. A flat stern produced the best characteristics and was adopted for vessel design.
Another model 6 ft long was built that was driven by twisted rubber cord with a single reduction gear on a shaft. Torque was determined by substituting for the propeller a light fan surrounded by a cardboard box with internal vanes – a primitive torsion meter. Resistance was found by towing the model across the pond with an apparatus consisting of a wheel and axle driven by weights. The efficiency of the propeller was thus calculated and the slip ratio estimated by observing the times between double and treble knotting of the rubber.
Parsons felt that the results of these crude experiments justified the formation of a small company to build Turbinia. She was 100 ft long, 9 ft beam, a displacement of 44.5 tons with a single compound radial flow turbine.
The initial trials in November 1894 were disappointing, only 19.5 knots being achieved. Clearly the vessel had severe propeller cavitation.
Parsons recovered the use of his patents and the machinery was replaced with parallel flow turbines with HP, IP and LP coupled to three shafts, thereby reducing the power to the propellers. The Admiralty became involved and their scientists at the elaborate Admiralty Tank at Haslar checked the garden pond tests and came up with answers that were only 2 or 3% different. Tests were made on various propeller shapes in tanks with glass observation windows and sea trials were resumed early in 1897 with 3 propellers on each of 3 shafts. 29.6 knots were obtained. The propellers were changed to an alternative design and 32 knots were achieved. The Admiralty was delighted and conspired with Parsons to publicise Turbinia at the Naval Review that year, to justify further experiments with a full size destroyer.

Fred
 

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What a great piece of history Fred, thank you for sharing it.
 

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Hi Fred, I was on a ship in Swan, Hunters dry dock in 1969 and on a Sunday afternoon a few of us went to the Hancock museum. The "Turbinia" was housed in a hall with all sorts of information and various propeller designs. The centre section was removed and covered with Perspex showing the controls ect. The space looked to be between two to three feet wide, stoking the boiler must have been hell. We reckoned he must have to shuffle between his legs, the space was that tight. A better day out that the usual visit to the pub!
Regards Bill Morrison
 
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