History of Hydraulics - William George Armstrong
William George Armstrong (26 November 1810 – 27 December 1900) was an industrialist from Tyneside who founded the Armstrong Whitworth manufacturing empire.
Armstrong was born in Newcastle upon Tyne, England. His father was determined that he should follow a career in law, and so he was articled to Armorer Donkin, a solicitor friend of his father’s. Armstrong spent five years in London studying law and returned to Newcastle in 1833. He worked for eleven years as a solicitor, but during his spare time he showed great interest in engineering.
A very keen angler, and while fishing on the River Dee at Dentdale in the Pennines, Armstrong saw a waterwheel in action, supplying power to a marble quarry. It struck Armstrong that much of the available power was being wasted. When he returned to Newcastle, he designed a rotary engine powered by water, and this was built in the High Bridge works of his friend Henry Watson. Unfortunately, little interest was shown in the engine. Armstrong subsequently developed a piston engine instead of a rotary one and decided that it might be suitable for driving a hydraulic crane. In 1846 his work as an amateur scientist was recognized when he was elected a Fellow of the Royal Society.
In 1845 a scheme was started to provide piped water from distant reservoirs to the households of Newcastle; Armstrong was involved and he proposed to Newcastle Corporation that the excess water pressure in the lower part of town could be used to power a Quayside crane specially adapted by himself. He claimed that his hydraulic crane could unload ships faster and more cheaply than conventional cranes. The Corporation agreed to his suggestion, and the experiment proved so successful that three more hydraulic cranes were installed on the Quayside.
The success of his hydraulic crane led Armstrong to consider setting up a business to manufacture cranes and other hydraulic equipment. He therefore resigned from his legal practice. In 1847 the new firm of W.G. Armstrong & Company built its first factory and received orders for hydraulic cranes from Edinburgh and Northern Railways and from Liverpool Docks, as well as for hydraulic machinery for dock gates in Grimsby. The company soon began to expand. In 1850 the company produced 45 cranes and two years later, 75. It averaged 100 cranes per year for the rest of the century. In 1850 over 300 men were employed at the works, but by 1863 this had risen to 3,800. The company soon branched out into bridge building, one of the first orders being for the Inverness Bridge, completed in 1855.
Armstrong was responsible for developing the hydraulic accumulator. Where water pressure was not available on site for the use of hydraulic cranes, Armstrong often built high water towers to provide a supply of water at pressure. However, when supplying cranes for use at New Holland on the Humber Estuary, he was unable to do this because the foundations consisted of sand. After much careful thought he produced the hydraulic accumulator, a cast-iron cylinder fitted with a plunger supporting a very heavy weight. The plunger would slowly be raised, drawing in water, until the downward force of the weight was sufficient to force the water below it into pipes at great pressure. The accumulator was a very significant, if unspectacular, invention, which found many applications in the following years.