Applying Cement Mortar Lining to Existing Mains in England

It was the writer's good fortune to spend about a month in England during the past summer for the principal purpose of observing the work being done for the Manchester Corporation in cleaning existing mains and lining them with cement mortar. This work was done in accordance with a process invented by Mr. William T. Tate of Sidney, Australia, and used there and in New Zealand for a number of years prior to its introduction last year into England. The contract under which the work was being done covered the lining of about 10 miles of 3-, 4-, and 5-inch pipe, some of which was about 70 years old. This pipe in Manchester was in highly tuberculated condition. After lining, the bottom of the lining was slightly flattened, making the section somewhat of a horseshoe shape, due to the running down in the bottom of soft material squeezed out of the mortar by the mandrel. The mandrel used in the lining of bends has a hemispherical container attached to its rear end, and the soft mortar squeezed out by the mandrel is caught in this container and removed so that the lining in bends is truly circular. The bend machine will go around any ordinary 90° bend and make a perfect lining of circular section and of uniform thickness. The lining of bends is done in the yard before the bends are laid. At the writer's request the bend machine was used experimentally in the yard of the Manchester Corporation to observe its action in going around offsets formed by pairs of 45° bends with straight pipes between. This was a condition which had not been previously tested underground. The bend machine was found perfectly successful in making uniform lining around the reverse bands. The quality of the work was proved by subsequently separating the pipe and observing the condition and thickness of the lining in each of the fittings and pipes.