Dorset County Hospital LINAC

Location: Dorchester
Sector: Health
Division: Regional Building

The project involved the design and construction of two reinforced concrete LINAC (linear accelerator) bunkers and support accommodation on a busy hospital site at County Hospital, Dorchester. The technical design was developed by Tilbury Douglas from completion of RIBA stage 3 by the client’s design team. Planning approval had been secured prior to our involvement during RIBA stage 3 by the client’s design team.

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The project involved the demolition of the existing medical records building and diversion of fire escape routes, drainage and building services prior to commencement of the project.

The support accommodation was provided in a two storey building which wrapped around the double storey LINAC bunkers. Magnetite concrete incorporating iron ore as an aggregate was used in designated locations within the bunkers to absorb the radiation from the linear accelerators. The linear accelerators were ordered directly by the NHS Trust with full technical liaison taking place between the NHS supplier Varian and our construction and design teams.

£4.6m

Project value

April 2018

Completion date

Poole Hospital NHS Foundation Trust

Client

The two storey accommodation was comprised of a steel frame which wrapped around the reinforced concrete bunkers. The bunkers were constructed on a reinforced concrete raft, with the steel frame supported by mass concrete pits with reinforced concrete ground beams and an in-situ reinforced concrete ground bearing slab. The intermediate floor to the support accommodation was constructed from precast planks with a structural topping. The building façade comprised face brickwork, punched windows and curtain walling.

The roof to the support accommodation was fibre cement slates, and to the bunker an insulated hot melt inverted system.

What facilities are provided

A ‘stand alone’ double LINAC bunker for radiotherapy cancer treatment with all supporting accommodation.

The construction of the bunker was to provide a ‘stand alone’ double LINAC bunker for radiotherapy cancer treatment with all supporting accommodation.

Innovations / sustainable solutions

The project was designed to BIM level 2 with a working 3D design model. The design minimised the use of magnetite concrete by only positioning this specialist and very expensive concrete in the locations designated.

Details of value engineering

The foundations were re-designed following the demolition of the existing medical records building. The existing ground under the medical records building comprised a significant depth of ‘made ground’ unsuitable for the intended solution. Due to the specialist nature of this project and the importance of ensuring complete compliance with radiation standards, we did not make any significant changes to the original brief.

The project was of national interest as a prominent local individual bequeathed a substantial proportion of the money for the development from his will. There was national coverage in the media and visits were accommodated from locally based VIPs to support fundraising for the final sum required for the development. We supported this fundraising appeal directly raising over £6,000 from a sponsored cycle trip to Paris by the construction team.

The project was registered under the Considerate Constructors Scheme and scored above 8 (Excellent) in every category for two inspections.

Architect: Stride Treglown
M&E Engineer: Arup
Structural Engineer: GAP
Cost Manager: McPhersons