The Anderton Boat Lift - IELTS Reading Answers & Explanations

You should spend about 20 minutes on Questions 15–27, which are based on Reading Passage 2.

The Anderton Boat Lift

Section I

When the Trent and Mersey Canal opened in 1777, the Cheshire town of Anderton was the obvious place to transfer goods to and from the nearby River Weaver. There was just one problem: the canal was fifteen metres above the river.

Pathways, inclined planes, and chutes were constructed to ease the task of moving cargo by hand. Primitive railways were laid to move cargoes, cranes were built, and steam engines were later installed to power lifting. In the early 1870s, however, the Weaver Navigation Trustees decided to eliminate the cost, effort, and wastage involved in hand transportation when the engineers Edward Leader Williams and Edwin Clarke suggested a 'boat carrying lift'.

Section II

Their design was a unique and magnificent example of the Victorians' mastery of cast iron and hydraulics. Completed in 1875, graceful in appearance, simple in use, and above all efficient, the lift was hailed as a marvel of the era, and became a prototype for larger versions on the waterways of France and Belgium.

The operating mechanism consisted of two vertical sets of interconnected hydraulic cylinders and pistons set into the bed of the river and each piston supported a boat-carrying tank 22.86 metres long and 4.72 metres wide. At rest, one tank was level with the canal and the other level with the river and to move the tanks, a small amount of water was removed from the bottom tank making it lighter than the top tank.

Because the two hydraulic cylinders were connected, the heavier top tank moved down and forced hydraulic liquid through the connecting pipe into the other cylinder pushing that piston and the lighter tank upwards. Watertight gates both on the tanks and at the entrance to the canal contained the water while the tanks were moving. A hydraulic pump driven by steam supplied the small amount of additional energy required to effect a reasonably rapid movement and to enable the tanks to be precisely levelled at the end of their journey.

Section III

All went well for the first ten years, then pitting and grooving of the cylinders and pistons occurred. Investigations showed that the canal water used as the hydraulic liquid was contaminated by chemicals and was corrosive, therefore causing the damage.

It was immediately changed to distilled water from the steam engine powering the hydraulic pump. Corrosion was dramatically reduced but the damage had been done.

In addition, the boiler for the steam engine needed renewing, so in 1906 the Trustees ordered the construction of a new lift, to a design by their engineer J A Saner.

Section IV

The new lift was built over the top of the Victorian structure, utilizing the Victorian front and rear columns. The main structure had strong A-frames at either side of the new lift to support the enormous weight of the platform that now formed the top of the framework: on it was located the new operating mechanism, which included seventy-two pulleys weighing up to 35 tonnes each.

Each of the boat-carrying tanks was now suspended on wire ropes which ran from the tank to the top of the lift, around pulleys, and down to cast-iron weights at the side of the structure. These were equal to the weight of the water-filled tank. Turning the pulleys one way or the other moved the ropes, so that one tank was raised or lowered independently of the other tank. Because the tanks were counterbalanced by the weights, only a small electrical motor was required to turn the pulleys and so move the tanks up or down.

Completed in 1908 the lift was reliable, cheap and easy to operate. Unlike the Victorian lift it was not the least bit elegant, but it was functional and it worked.

Section V

Both the 1875 the 1908 versions carried large volumes of commercial traffic and the principal cargoes transported were coal, china clay, salt, manufactured goods, including china ware, and agricultural produce.

Sadly, trade on inland waterways in Britain declined dramatically in the 1950s, and goods traffic via the lift effectively ended in the 1960s. The 1970s increase in pleasure boating briefly prolonged its active life, but in 1982 the 'Cathedral of the Canals' was finally closed.

Section VI

Demolition seemed inevitable, but, after a long campaign by concerned groups, British Waterways agreed, in 1999, to save the lift.

Some wanted it 'conserved as found', but that would entail replacing much of the existing structure, virtually creating a replica lift. The steel of the 1908 structure had been badly corroded by pollutants from the local chemical industries and would need replacing if it were to support the overhead machinery and 500-tonne counterweights. In addition, safety considerations would require the installation of a back-up braking system.

It was decided, therefore, to revert to the 1875 hydraulically-operated system, using the original cast-iron structure. Although the counterweights had to be removed, the 1908 framework and pulleys would be retained as a static monument.

It was a huge and expensive project, and not without difficulties. Eventually, in 2002, the Anderton Boat Lift was officially reopened. Boat owners and visitors alike can once again ride 'the world's first boat lift'.