Description

A model of a flexible “ball & socket” water main designed by James Watt in 1809.

In the late 18th century Glasgow’s supply of water was from a well and tunnel formed in sand on the left (south) bank of the Clyde, which provided a natural filter for the river water. The city at that time was located on the right (north) bank and this presented a problem in taking the water to the city.

Now in his 70’s in 1809, James Watt was approached by the Glasgow Water Company to assist them in devising a method of pumping water across the river from south to north. From the germ of an idea based on the structure of the lobster’s tail, he formed the concept of a flexible main, comprising ball and socket joints made in cast iron. The idea was accepted and in 1810 the main was drawn on timber “sleds” across a trench formed under water in the bed of the river (see drawing below). The sleds were constructed as timber frames with planks as “runners”. Water was thus distributed to Glasgow.

This main continued in use until 1859 when the scheme to use fresh water from Loch Katrine was completed.

In its advertising the Austrian company Röhren- und Pumpenwerk Bauer GmbH states that “in 1947 the Bauer lever closure coupling was born. Even then, the system was unique and a sensation.” It also claims that ”One thing is certain: no one can match the original.” The Bauer coupling is essentially the same as the flexible ball & socket main joint devised by James Watt some 140 years earlier.

The model was made by Tom Stenhouse who was until retirement in 2021 a senior member of the technical staff at EGIS (Department of Energy, Geoscience, Infrastructure and Society) at Heriot-Watt University.

The museum holds digital copies of the original design drawings for the water main.