Anderton Boat Lift - Problems of Hydraulic Operation

Problems of Hydraulic Operation

For its first five years of its life the boat lift operated successfully, with the longest closures being during spells of cold weather when the canal froze over. However, in 1882 one of the cast iron hydraulic cylinders burst while the caisson that it supported was at canal level with a boat in it. The caisson descended rapidly, but fortunately the water escaping from the burst cylinder slowed the rate of descent, and the water-filled dock at the river level softened the impact. No-one was hurt and the superstructure of the lift was not damaged. During subsequent testing, the second cylinder failed too, and the boat lift was closed for six months while sections of both cylinders were replaced and the connecting pipework, which was thought to have contributed to the cylinders' failure, was redesigned.

Volumes of traffic through the lift grew steadily through the 1880s and 1890s, but the hydraulic cylinders continued to give problems. The gland of one cylinder (where the piston travelled through the cylinder wall) had to be temporarily repaired in 1887 and replaced in 1891, and the gland of the other cylinder was replaced in 1894. However, the main cause for concern was corrosion of the pistons. The use of canal water as a working fluid in the hydraulic system, and the immersion of the pistons in the wet dock at river level led to corrosion and "grooving" of the pistons. Attempts to repair these grooves with copper made matters worse, as this reacted electrolytically with the acidic canal water and hastened the corrosion of the surrounding iron. In 1897 the lift was converted to use distilled water as its working fluid. This slowed down the corrosion, but did not stop it completely. Over the next few years maintenance and repairs took place with increasing frequency, each occasion requiring either the complete closure of the lift for several weeks or a period of reduced and slower operation with a single caisson.