Case study 16: HMP/YOI ISIS, Thamesmead, South East London, Interserve Construction Ltd

Client: Ministry of Justice

The projectUnder the MoJ Strategic Alliance, Interserve recently constructed a 480 place Category C (built to Category B standards) secure training prison for young male adults (18 to 24 years) on the unused sports pitches and farms and gardens area of HMP Belmarsh, South East London.

BenefitsCost: more rapid construction on site leading to cost savings in preliminaries and more efficient working on siteTime: substantial reduction in construction time on siteQuality: right first time quality adding to zero defects at completionSustainability: reduction in waste

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The £115m project comprised:

�� a 480 bed house-block with integral sanitation and showers

�� combined gatehouse, entry block and vistors’ centre�� prisoner reception and discharge unit�� kitchen for 500 meals per sitting, three times per day�� education department�� workshops�� care and control block (segregation)�� sports facilities and external works.

Outside the secure perimeter a single storey energy centre housed a combined heat and power plant, biomass and gas boilers and meters.

During both the design and construction phase there were a number of challenges including very poor ground conditions, confined working areas and working next to Britain’s most secure prison.

The project achieved BREEAM “Excellent” for all of its constituent parts.

The constructionAn integrated supply chain and design team both with a track record on similar projects included HLM architects, Arup, Tier structural engineers, and building services design and build contractor SPIE Matthew Hall. Their long term relationship with Interserve facilitated continuous improvement in support of process and product innovation.

For this project the vast majority of building components were manufactured off site and delivered “just in time” for installation on site.

The houseblocks are constructed using precast concrete modular units that provide a number of benefits including reduced time and number of operatives on site. A precast core is typically erected in three weeks using six operatives as opposed to 11 weeks with 40 operatives for a cast in situ core on site. The level of co-ordination included casting in of window bars, cell door frames, building services containment and builders’ work holes. This achieved significant reductions in manual handling, working at height and materials stored on site.

Manufacturing under factory conditions gave reduced material waste and a finished product that was ready to receive decoration.

Prefabricated service riser frames consisting of structural steel elements provide the structural stability to the modular units. This is in addition to the association space balconies that are fully loaded with “plug and play”

distribution boards, lighting control, hot and cold water manifolds, ductwork and plumbing, further reduces safety risks and increases programme gains.

The external façade to the Entry, Central and Sports buildings is constructed using TIMS (Thermally Insulated Modular System) panels, which were developed by Interserve to reduce typically high risk activities on-site such as brick and blockwork. The panels were cast off-site and delivered “just in time” to be erected.

TIMS panels provide programme gains on milestone activities such as a watertight building, enabling following trades to start sooner and reducing the overall construction programme.

ContactDavid LargeInterserve Construction Ltd, 395 George Road, Erdington, Birmingham B23 7RZTel: 0121 344 4888Fax: 0121 344 4801Website: www.interserve.com

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