Lift installation

How does Lift installation work, step by step?

1. 1

   Step 1: Select the lift and procure it early

   The designer establishes what the building needs - how many lifts, what capacity, what speed and what arrangement - from the traffic the building will generate and the space the shafts can occupy. That produces a specification which the lift contractor prices and, once appointed, develops into manufacturing information. Because lifts are made to order with delivery commonly measured in months rather than weeks, the package is let very early. On many projects the lift order sits alongside the steel and the facade as one of the few procurement items whose lead time can move the completion date, so a late decision on lift selection is a late decision on handover.

2. 2

   Step 2: Agree the builder's work requirements

   The lift contractor issues a builder's work drawing that tells the main contractor exactly what the shaft has to provide: internal dimensions and the tolerance on them, pit depth, headroom, the position and load capacity of every fixing point and beam, the door opening sizes at each level, the pit drainage, the shaft ventilation and smoke arrangements, the lighting, and the electrical supply with its isolation. These are not preferences. They are the geometry the manufactured equipment was made to fit. Anything the structure cannot deliver has to be resolved on paper, well before the shaft is poured, because a shaft that is out of tolerance is corrected in concrete and not in the lift.

3. 3

   Step 3: Build, survey and hand over the shaft

   The shaft is constructed as part of the main works and then surveyed before the lift contractor accepts it. The survey checks the shaft for plumb and squareness over its full height, confirms the pit and headroom dimensions, checks the position of every opening and every fixing point, and confirms that the pit is dry and the shaft is clean, weathertight and secure. Handover is a formal step: the shaft becomes the lift contractor's working area, with its own access control, edge protection at every opening and its own permit arrangements. Shaft accuracy governs everything that follows - a shaft that is out of plumb over its height means guide rails that have to be packed and shimmed, and a lift that is never as quiet or as smooth as the one that was designed.

4. 4

   Step 4: Install the guide rails and the fixed equipment

   The first equipment into the shaft is the guiding system - the rails that the car and the counterweight run on, fixed back to the shaft at the bracket positions the builder's work drawing established. Alignment of those rails is the single most important quality item in the whole installation, because the ride quality, the noise and the wear of every component afterwards follow the straightness of the rails. Buffers, pit equipment and the counterweight frame go in with them. This is high-risk work at height inside a confined structure and is carried out only by the lift contractor's trained operatives under their own controlled system of work.

5. 5

   Step 5: Install the drive, ropes or ram, and the car

   The drive is installed - in the machine room for a traditional traction arrangement, at the head of the shaft or within it for a machine-room-less lift, or as a pump unit and ram for a hydraulic lift. Suspension ropes or belts are reeved over the sheave, or the ram and cylinder are set. The car frame is assembled and hung, the car enclosure is built out, and the safety gear, overspeed protection and travelling cables are fitted. Every one of these components is part of a life-safety system and is installed and adjusted by the manufacturer's trained engineers to the manufacturer's own procedures.

6. 6

   Step 6: Fit landing doors and complete the interfaces

   Landing door assemblies are installed at each floor and set against the finished floor levels and the finished wall line, which is why the lift contractor needs the surrounding finishes settled before final adjustment. Car doors, operators, interlocks, landing indicators and call stations follow. Interfaces with the rest of the building are completed at this stage: the fire alarm signal that sends the car to the designated floor, the emergency power arrangement, the intercom and autodialler for entrapment, the access control, and the building management system connection. Each interface is a separate item to be proved, and each one usually belongs to a different contractor.

7. 7

   Step 7: Commission, examine and hand over

   The lift contractor commissions the installation - setting the drive, adjusting the doors, proving the safety devices and running the lift through its operating modes and its emergency conditions. The installation is then subject to a statutory examination by an independent competent person before it is put into service, and the certification from that examination is what allows the lift to be used. Only then does handover take place, with the documentation package, the operating instructions, the emergency release arrangements and the maintenance contract. Entrapment release is a task for trained persons named in the building's procedures, and the arrangements for it are established at handover rather than improvised later.