hydraulic crane

The power of water can be harnessed to do all sorts of things. Waterwheels were invented thousands of years ago to turn mill wheels to grind wheat into flour and to power pumps to raise water for crop irrigation and to supply cities with fresh water.

When water is contained within a pipe we can use it to create motion in a straight line by using a cylinder and piston. The piston is a tight sliding fit in the cylinder and when the water enters the cylinder it pushes the piston along. This method of applying a FORCE and causing motion is called Hydraulics. Here is a video showing how water in syringes connected by tubes can be made to move a crane. The syringes are the cylinders and pistons.

The hydraulic crane was invented in Newcastle by William Armstrong in about 1845 to help load coal into barges at the Quayside. It was a great success and the cranes were sold all over the world. The hydraulic crane helped the North East of England to grow and prosper, and Newcastle became one of the most important cities in the world as a result. The cranes on the quayside were water powered. Using water in cylinders to create a force to move things is called ‘hydraulics’ and today a special oil called ‘hydraulic fluid’ is used instead of water. All sorts of machines use hydraulics: car brakes; aeroplane wing and tail actuators; JCB diggers etc.

This is an old drawing of one of the quayside hydraulic cranes. The cylinders are hidden away under the deck of the crane. The ends of the pistons are attached to steel cables and pulleys so that they can cause the main cable to wind up and the main tower to rotate.

This is William Armstrong as a young man in his early twenties, the age at which he invented the hydraulic crane.

	There is an amazing model of the hydraulic crane in the Discovery Museum in Newcastle upon Tyne. One of Armstrong’s biggest hydraulic cranes is being restored and an attempt may be made to bring it back to Tyneside from its current home in Venice. The crane was built in 1885 and continued in use until 1950 after having been damaged by bombing in the second world war.