Electrokinetica The Electro-mechanical Museum

St. Pancras Chambers - Waygood Otis DC passenger lifts

Overview

The Midland Grand Hotel (later St. Pancras Chambers) was one of the first buildings in the UK to be equipped with lifts. Originally called 'Ascending Rooms' and propelled by hydraulic power, they were later modernised and fitted with Otis electric traction equipment. No motor room was present at the head of the shaft, therefore the machinery was located in a room in the basement, which survived largely unchanged until the building was stripped for refurbishment in 2006. The motor room also housed the machine for an adjacent baggage lift built by Etchells, Congdon and Muir, although this had long since become derelict. The Otis machines and their magnificent car-switch operated controllers had apparently withstood the passage of time in the damp motor room more or less intact, so when the time came for the room to be cleared, the more complete machine of the two, both controllers and some spares from the other machine were removed to ElectroKinetica. The cars were also dismantled and packed for conservation, possibly within the building or potentially on display with the working machinery.

Recovery

The plant was first spotted by Lucien back in 2004 during a visit to the building on business, where by the light of a handlamp the big old controllers had looked imposing and resplendent in their authentic period surroundings. Two years later, the opportunity to salvage them necessitated a detailed and impartial feasibility study, which revealed a slightly less attractive reality but one worth conservation nonetheless. Dave Cope and Lucien made a study of the connections and a photographic record of the installation, including the electrical equipment of the shaft and car. There were some difficulties with tracing the wiring out of the motor room as some connections had already been severed by the time the shaft was accessible. The actual removal of the plant to the loading bay was undertaken by Lift-Out, a specialist lift removal contractor engaged by the principal contractors Laing O'Rourke to decommission all the lifts in the building. The recovery of these heavy lumps can be awkward at the best of times, but in this case Lift-Out had to contend with uneven floors, lack of manoeuvring room, limited access through the building and wet, dark, dingy conditions. In spite of this, they dismantled the machine and got everything to the surface in good condition, where in the daylight its rather bedraggled appearance made it much less photogenic than the goods lift from the first floor.

The traction machine

Edward and Lucien cleaned the masonry debris off the machine and attempted to put it back together on arrival at the workshop, but some of the shims had been damaged and mixed up in the removal and it was not immediately possible to align the shafts. This will probably take the best part of a day, allowing for the cutting of new shims and proper attention to the bearings. The motor will benefit from a good bakeout to drive moisture from the windings before full voltage is applied, as leakage on a 240 volt DC machine can soon lead to insulation failure.

The Controllers

Although the machine saved was from the South lift, the controller from the North lift was found to be in better condition and received the first attention in the workshop. Remarkably, it required only the minimum of maintenance before firing up. All contacts were wiped clean, all moving parts lubricated, the dashpot was filled with oil and an open-circuit resistor temporarily patched. The insulation resistance of the coils was checked and found to be excellent, and on application of the DC supply all functions operated perfectly first time. Some contacts will require attention or replacement before being put into service, and a careful cleanup will make the unit look much more appealing, but nothing needs to be done beyond what would have been routine service work in its heyday.

How it works

Many early electric lifts used manual control; a driver in the car decided where to go next, and operated the lift with a handle controlling speed and direction. Usually only two speeds are required; full speed for driving and very slow for levelling the car floor with the landing. Thus the 'controller' is really a glorified motor starter, but the special requirements of lift installations mandate a rather complex arrangement of switchgear to achieve acceptable results. In particular, passengers do not like jerky movement, so the controller must accelerate and retard the car as smoothly as possible.

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