William Froude and the Haslar ship testing tank
William Froude was born on 28 November1810 in Dartington Parsonage in Devon, the eighth child of Archdeacon Robert Hurrell Froude. He was educated at Westminster School and then Oriel College Cambridge. In 1832 he obtained a first class degree in mathematics and a third in classics. He remained in Oxford and was already researching the problem of ship resistance. He was a brilliant engineer, mathematician, hydrodynamicist, naval architect and surveyor, amongst other talents. In 1833 he became a pupil of Henry Robinson Palmer who was resident engineer at London Docks. They created scaled model boats to test why water resistance affected barges. Froude was then employed on early surveys of the South-Eastern Railway and he became assistant engineer to Isambard Kingdom Brunel on the Bristol to Exeter line. He continued as a railway engineer until 1846 when he began his work on ship hydrodynamics.
After serving on a committee to study naval design in 1868, William Froude proposed that a covered tank be built to aid in calculating the resistance of a ship’s hull rather than using the previous method of calculating using the Admiralty Coefficient. He proposed to the Admiralty that a series of experiments be carried out using models to determine the physical laws governing full scale ships. His proposals were accepted in 1870 and a model test tank was built at Froude’s home in his attic. Here he pulled models along using a rope, which passed through a whole in the wall and had a weight attached.
|The civil engineer and naval architect, William Froude (left) and one of his staff with the first naval test tank.
WILLIAM FROUDE AND THE ADMIRALTY’S FIRST NAVAL TEST TANK AT TORQUAY, DEVON, C 1872 © IWM (HU 82581)
|View of the trolley used to propel ship models across the first naval test tank constructed by William Froude.
WILLIAM FROUDE AND THE ADMIRALTY’S FIRST NAVAL TEST TANK AT TORQUAY, DEVON, C 1872 © IWM (HU 82583)
|View of the first naval test tank constructed by the civil engineer and naval architect, William Froude.
WILLIAM FROUDE AND THE ADMIRALTY’S FIRST NAVAL TEST TANK AT TORQUAY, DEVON, C 1872 © IWM (HU 82582)
His experiments soon required a much larger tank. He estimated the cost of building the tank and running it for two years at £2,000 and offered his own services for free during that period. The huge tank became operational at Chelston Cross,Torquay by May 1872. This tank became the world’s first official Admiralty testing tank which was later replicated in 300 countries. The works – The AEW (Admiralty Experimental Works) remained in Torquay for seven years while William and son Robert undertook tests on every Naval ship launched using models 12 feet in length.
Froude extended the use of his tank to testing the performance of propellers. His use of wax models to test hull form meant that one could be ready to test in a two days. He discovered that the chief components of resistance to motion are skin friction and wave formation. From 1873 the tank was used to match hull form and power with the requirements of the whole ship. It was the work of Froude on developing a hull form, that would give 8.5 knots under its own power and 15knots when towed in the open sea, that convinced the Admiralty that there was a role for the gunboat as coast defence. William Froude died 4th May 1879 at Simon’s Town, South Africa whilst on holiday, and was succeeded by his third son Edmund, who had joined him in the Works at the age of twenty five.
On the 27th May, 1879, the Lords Commissioners of the Admiralty wrote to Robert Edmund Froude on the death of his father: ‘My Lords desire to convey to you and all members of your family their most sincere sympathy at the irreparable loss you have sustained – a loss which cannot be looked upon as other than a national one. They feel that Mr Froude rendered great service to the Navy and the country in making his great abilities, knowledge and powers of observation available for the improvement of the designs of ships, without reward or any other acknowledgement other than the grateful thanks of successive Boards of the Admiralty’.
On 3rd February 1886 Robert Edmund Froude supervised the transfer of the Admiralty Experiment Works from Torquay to a new site at Haslar adjacent to the gunboat yard and within its protective wall. Froude preferred this site to others at Chiswick, Deptford and Portsmouth Dockyard because of its privacy and remoteness. It required a building 520ft long and 10ft high with a width of 27ft at an estimated cost of £7,230. It had a concrete floor, brick walls and a iron roof covered with slate. On the completion of the construction, the tank needed to be filled with nearly half a million gallons of water, with the permission of Mr Horatio Compigne, clerk of the Gosport Water Company. The tank itself was 300ft long; for 250ft it was 33ft broad and 10ft deep containing 1,500 tons of water. The remaining 50ft of length consisted of two shallow docks, one at each end, constructed for convenience in ballasting, trimming and other such operations. Over the water supported on suitable beams and girders was a double line of rails, the distance between the rails being 3feet 4inches. On these rails ran a dynamometer track and screw truck, which were drawn along by an endless wire rope and an ordinary two-cylinder engine. About the engine there was nothing peculiar; but as constant speed was absolutely necessary, and it was desirable to produce any definite speed at will, the governor, designed by Mr. R.E.Froude, was extremely sensitive. The essential part of the dynamometer was the spring and the whole object of the remainder of the gear was to connect the model to this spring and to measure its extension. A triangular lever was suspended, connected to the model by a rod, which in its turn was attached to a wooden frame fastened rigidly to the model. The model was free to move either longitudinally of vertically, but was prevented from moving transversely by guiders. The dynamometer truck then gave the means of ascertaining the resistance of a model and from the screw truck, thrust, revolutions, slip and turning forces necessary to drive the screw or screws was obtained. The principle uopon which the tank results were used in predicting speeeds and power depended, so far as the resistance of the ship was concerned, upon the law of comparison which was discovered and proved by the late William Froude.
Here Professor Froude, Superintendant of the Admiralty Experimental Works, as it had become by 1905, supervised the testing of new designs for stability and correctness before they were handed to the constructors. The dynamometer, beneath which was suspended the model ship, allowed the experiments to record the speed, performance and resistance of the model in still water as well as motion in waves artificially induced by a wavemaking machine. The earlier models were constructed from paraffin wax, which was economical in use as it could be melted down and the wax reused. In later years fibreglass replaced the wax. The experiments allowed the great improvement of ship’s hull design, resulting in enormous savings in fuel to propel ships. There is no doubt that they also became safer. Once the tank opened in 1886 Froude realised that he needed to keep the tank free from algae, so he acquired fresh water eels from the lake at Gilkicker. An eel-keeper fed them with cat’s food.
|The first Admiralty Experimental Works tank at Haslar||25 June 1945,
Admiralty Experimental Works Haslar
© IWM (A 29387)
|Map showing the
Haslar Experimental Works 1898
A newer tank was added to the site in 1930. During WWII both tanks were designated as emergency water supplies for Gosport town.
Upon moving to Gosport Froude lived at No.1 Little Anglesey Road but later moved to North Lodge at the junction of Green Road and the Avenue (now The Old Lodge Hotel) Dr. Robert Froude resigned from active work in 1919. Robert Froude, like his father, was elected a Fellow of the Royal Society, but also held the LL.D. degree of Glasgow University. He was elected a Vice-President of the Institution of Naval Architects in 1905 and was gazetted G.B. in 1911. He died at Croft Cottage, Cambridge, in his seventy-eighth year, on Wednesday, March 19 1924.
Model Experiments and Merchant Ship design: Lloyd’s List – Thursday 27 May 1897
Haslar’s Historic Ship Tank: Lesley Burton. Gosport records No.3 Page 18 Gosport Historic Records and Museum Society
Admiralty Experimental Works Haslar