South Transept Lift Installation

The project comprised the installation of a new, bespoke architect designed 10 person all-glass passenger lift to provide access to the new exhibition halls on three levels within the South Transept of Winchester Cathedral. The new lift was constructed within the centre of an existing 17th century oak wrap around staircase and passes through a 12th Century vaulted ceiling of an Ancient Monument, an engineering feat which has never been achieved before.

The works involved the construction of a new lift pit founded on 8no, 15m mini CFA piles, the erection of a structural steel frame that supported the lift car and decorative glazing, and the installation of a new lift car providing ‘Access for All’ to the new mezzanine level and Triforium.

Our scope of works increased post contract award to include the replacement flooring in the Triforium and the Williams Room with a reinforced concrete slab using Cintec anchors to tie the Cathedral building fabric into the new floor and relaying of the existing clay paviours on a lime mortar.

This project was the first of its kind. Advanced surveying and 3D Point Cloud modelling techniques were used to ensure sub millimetre accuracy of setting out and construction. This included the 17th Century oak wrap around staircase and the original Cathedral fabric. The detailed surveys of the staircase provided the critical dimensions for the size of the new lift as it had to be installed between the existing newel posts.

We used micro piling rigs that could access the site via an 800mm narrow passage in the South Transept. This required stripping down the piling rig to the minimum width possible and re-build it once inside the Cathedral.

From the initial 3D Point Cloud survey, the engineers, Ramboll were able to model the existing vault and accurately forecast how it would act when the required section was removed. Their calculations predicted that if any movement occurred, it would be a lift of up to 1mm. Before breaking through the vaulted ceiling, Ramboll installed tilt sensors on the existing cathedral fabric to monitor any movement throughout the works.

Following completion of the works to create the aperture in the vault, the actual movement detected was less than 1mm in any given direction.

On completion of the aperture within the vaulted ceiling, specialist sub-contractors were employed to install the steel frame to the lift. Extensive scaffolding, gantry beam and lifting hoist were designed and erected at Triforium level above the aperture.

Internal and external ramps were installed and protection of the Cathedral floor was put in place along the south nave aisle to enable the steel frame to be brought into the Cathedral safely in sections on trolleys.

The steel sections were lifted up to Triforium level and then carefully lowered down through the aperture to construct the 12m high steel frame. The steel frame was clad in 21.5mm toughened and laminated glass panels containing a bronze mesh interlayer. With the largest of the panels being 4.5m x 2.5m and weighing 600kg. This was again carried out by lifting the glass panels up to Triforium level and carefully lowering them through a 150mm gap between the steel frame and the concrete aperture in the vault. Following completion of the works, the distance between the glass panels and the 17th century oak wrap around staircase was less than 50mm.