Glasgow City Hall
It makes life so much easier both in terms of access and moving equipment around
Slingco supplied and installed ten Cablenet modular tensioned wire grids into the 1,066 capacity Grand Hall at the hub of the Glasgow City Halls complex.
Originally specified by the project’s theatre consultants Arup Acoustics, the Cablenet design had to be rigged amidst the original timber roof trusses and work integrally with the building's roof structure. The frames are supported by these trusses with their brackets straddling the bottom shard of the timber truss. In addition, no intermediate Cablenet members were to be visible from the underside.
The Cablenet grids are sized approximately 10.9m x 3.3m - with each one being very slightly different to account for fluctuations in the roof timbers. The grids are engineered to work in a back-to-back fashion: the frame side members form horizontal trusses over the bottom member of the timber trusses allowing a lighter section to be used for absorbing the loadings from the tensioning of the cable assemblies.
Constructed from 3mm wire, this Cablenet installation supports a total load of 3.6 tonnes distributed over the 10 grids, 360kg per frame. On the underside, the grids are separated by cosmetic plastered roof panels, so from the hall below it looks as if there are 30 smaller nets.
A four person team from Slingco completed the installation in two weeks.
The Grand Hall is frequently used by BBC Recording, who love it because they can easily position mics anywhere in the Hall.
Another reason for choosing CableNet involved practicalities relating to the overall task of improving the room acoustics. The stage has been lowered to increase the volume of the ceiling area above, aiming to create a bigger and fuller orchestral sound, so it was essential that the grid above would work in as shallow a roof space as possible.
Neatly concealed above the grid at the stage end of the Cablenet is a series of acoustic baffles.
Slingco's Peter Downham-Clarke says "From working out a suitable scheme with Ray at his Judds Farm base, developing the design to ensure an efficient manufacturing and installation method to carrying out the final inspection on the finished installation, the job’s proved to be one of the most interesting the team has worked on”.
The Grand Hall is now being utilised for a full programme of concerts, recitals, recordings and music events and is proving exceptionally popular..
- Architect: Glasgow City Council
- Main contractor: HBG Construction Scotland Ltd
- Theatre consultant: Arup Acoustics