This case study highlights Shanco’s achievements in the expansion of the HMP Category D facility, a project that involved complex engineering and logistical challenges. The expansion comprised of a two-storey 60-bed modular housing block, a new storage container and refurbishments to the healthcare block for a dentistry area. The goal was to provide a high level of technical support whilst delivering high-quality work in line with the MOJ specifications. The priority was doing all of this safely, on programme and without causing any disruption to the prison.

The Project

Located on a floodplain, this project posed unique engineering and logistical challenges, which Shanco successfully addressed by implementing innovative solutions and careful planning. A deep pile foundation system was employed to ensure the structure’s stability on the flood-prone soil. A series of pile caps and RC concrete columns were then cast, which supported a 707m2 suspended reinforced concrete slab to keep the new accommodation block elevated above potential flood water. This was cast over two pours and supported by a complex temporary deck formwork, also erected by Shanco.

As the team already had a great relationship with a specialist formwork designer, we assisted the client by taking on the temporary works design for the suspended deck. We then cast 93 concrete plinths on top of the suspended deck to locate the base plates of the modular accommodation units.

Following the completion of the deck work, we began work on the underground services installation. As specified by the MOJ, we installed all the below-slab drainage using a ductile iron pipework system which fed the individual accommodation units.

To service both the new accommodation block and upgrades to some existing buildings around the prisons we were contracted to install 1km of new ductwork, spanning the full length of the prison. Again, to comply with MOJ specifications, we cast in-situ reinforced concrete duct chambers every 20m along the service routes which then allowed an easy cable pull for installers.

The Challenges

Working within a live prison environment presents a number of logistical hurdles that require collaboration and adaptability. These include restricted delivery and plant movement times, pre-booking of deliveries, escorted movement around the prison and the necessity of attaining enhanced security clearance requirements for all staff, to name a few. In order to meet a demanding programme Shanco developed and maintained a great working relationship and robust communication system with the prison staff and escorts that were involved with the expansion.

Our priority was to ensure all parties were informed of any construction activities, deliveries and any potential security risks that could arise due to the proposed works. This ensured that the appropriate safety measures were in place and security was maintained throughout the project. Detailed schedules proved critical in making sure all deliveries were expected, that way escort resources could be allocated to them and no delays were encountered.

The Results

“I would like to take this opportunity to personally thank you for giving this HMP Cat D Facility expansion project such a great team of workers. It has been my pleasure to work alongside a clearly dedicated and knowledgeable team.”

Stuart Miles – HMP Custodial Manager

As a result of strong communication and forward-thinking, we have successfully delivered a technically challenging project both on time and to a very high standard, all whilst causing no disruption to the live prison site and encountering no safety issues.