OASI: lift

The lift at Orwell Park Observatory is derelict and has for many decades been unused. At a meeting in early 1979, the committee of OASI agreed to investigate potential avenues for its repair or renovation. Members of OASI were encouraged to use any contacts that they might have with heritage organisations to explore potential restoration of the lift. Thus it was that David Baker, an architect with Ipswich Borough Council, Mr Jackson, a representative from lift engineers Marryat & Scott [1], and I visited Orwell Park Observatory on Tuesday afternoon, 27 March 1979, with the aim of examining the lift. David Baker is a member of OASI keen on exploring what can be done to renovate the lift.

Mr Jackson was much taken with the Observatory. He thought that the telescope and lift were ahead of their time, and we spent over one and a half hours examining the Observatory as far as possible - unfortunately, we did not have access to all the areas which may have been associated with the lift. During the visit I took four pictures which, when developed, may show the lift shaft, the car and its underside.

The lift provided access to all four levels within the Observatory Tower: the equatorial room, the belvedere; the first floor muniment room and the ground floor. The lift was hydraulic, powered by water pressure from a header tank in the water tower, situated at the other end of the mansion from the observatory tower. The weight of the lift car was offset by a counterbalance weight attached by a chain running over a large pulley at the top of the lift shaft. There was a single hydraulic cylinder directly beneath the lift shaft, connected through a seal-gland to the floor of the lift car. Ropes ran through holes in the floor and ceiling of the lift car and were anchored on hydraulic valves at the top of the lift shaft. Either each rope activated a valve which had a spring-return mechanism so that it was normally closed, and was opened only when the rope was held taut; or there were two ropes and a yoke-bar to open and close each valve, one rope to open the valve and the other to close it. It is likely that some of the valves were coupled together so as to minimise the number of ropes involved, making for easier operation of the system. Details of operation of the lift are uncertain, but the diagram below illustrates two possibilities.

Possibility One illustrates a single-stage, double-acting hydraulic piston. The piston would have been approximately 18 m long and relied on water pressure both to ascend and descend. (For ascent, valves V1 and V3 are open, V2 and V4 closed and for descent, V1 and V3 are closed, V2 and V4 open.) As the piston is double-acting, variations are possible depending on the mass of the counterweight. For example, if the counterweight were small, counterbalancing the lift car to a limited extent which did not offset its full weight, it would be possible to rely on gravity for descent, with hydraulic drain-away as regulation. Conversely, if the lift car were lighter than the counterweight, it would be possible to use gravity for ascent and rely on hydraulic pressure for descent.

Possibility Two illustrates an alternative approach, relying on a multi-stage, single-acting piston (the diagram illustrates a four-stage piston). The stages of the piston would be telescoped together to position the lift car at ground level and would be fully extended to position it at the level of the equatorial room. The main advantage of a multi-stage piston is the reduced depth of hole required to mount it. However, construction of an 18 m deep hole to house a single-stage piston was well within the capabilities of the Victorian builders who constructed the Observatory. The main disadvantage of a multi-stage piston is the extra weight and the additional seals. The single-acting piston relies on hydraulic pressure for ascent, and gravity for descent, thus the counterweight must have less mass than the lift car. It requires only two hydraulic valves: one for ascent and one for descent.

In fact, there is another possibility, Possibility Three, for operation of the lift (not shown in the diagram below). This is a variable-weight counterweight, with the weight changed by adding or removing water. However, the infrastructure in terms of pipes to add water and remove it from the counterweight without spillage could involve some complexity around management of extensive flexible hoses. This possibility appears remote.

The cross-sectional area of the piston raising/lowering the lift car must be about 130-160 cm². If the net load to be raised is 250 kg (allowing for the counterweight), a head of water would need to be maintained above 18 m in Possibility One. As the cylinder is entirely below ground, and any drain piping is not much above ground, this is quite in order. But this analysis rules out Possibility Two - a 40m tall tower would be required to provide sufficient head of water to raise the piston to its fully extended position. Note that in this regard, Possibility Three might allow an even lesser head of water than Possibility One, if the counterweight had an opportunity to descend lower than the lift car, and empty at the lowest level. The highest position of the counterweight would then not need to be at the top of the lift shaft, but could be some way down, thus not needing so much head of water.

If the lift were to ascend or descend its full travel of approximately 18 m in one minute, flow through a 1 cm diameter pipe supply system would need to be only about 1.5 m/s, which is quite reasonable.

There is no evidence of a nameplate on the lift. Mr Jackson was of the opinion that it was most likely to be a very early Waygood [2]. (Waygood lifts were commonplace around 1880.) Sometimes, in a lift like that at Orwell Park, the cylinder was capped extensively with concrete as there was no intention of ever raising it again, on the assumption that it would last for as long as necessary. However, new Board of Trade regulations require that cylinder and piston be examined and possibly re-annealed (or other maintenance performed) after 50 years and that chains (for counterbalance) are replaced by cables even on direct-acting lifts where the descent can never reasonably be excessive in speed. (The only exception is where the lift shaft is not very tall.) Many water-powered lifts in London had been updated to oil operation, and double cables installed.

Mr Jackson said that the counterweight of the lift at Orwell Park couldn't travel far in its current condition, and that the lift was safe. He said that it would be uneconomic, although not impossible, to refurbish the lift. However, refurbishment would likely be dependent upon the availability of heritage funding, which would be easier to arrange if the Observatory had an association with, for example, a museum. He promised to send a written report to David Baker, who had contacted him in the first place.

Meanwhile, we may be able to obtain further information by emptying the lift of its load of files and enormous filing cupboard, so that any nameplate now obscured may be made visible, and so that the lift car might be raised a little to see better what is underneath. Also, adjoining rooms might be opened to check for pipework associated with the lift. It would also be worthwhile inspecting the clock tower and any surviving plans of the building. It would be a good idea additionally to make contact with the successors of Waygoods, and to investigate industrial archaeology files on water-operated lifts.

Possible configurations for operation of the lift at Orwell Park Observatory.

Footnotes

[1]

Marryat & Scott was founded by Joseph Richmond in the 1860s as a small company called Richmond Lifts. In 1979 Kone took over the company, later changing its name to Kone.

[2]

Waygood & Co. was founded by Richard Waygood in 1830 and manufactured its first hydraulic elevator in 1868. It was renamed R Waygood & Co. in 1897 and was bought by Otis in the late 1800s, becaming Waygood Otis.