HMS Valiant Scaffold Shrink Wrap – Wood Group
Project: HMS Valiant
Purpose: Shrink wrapped Haki roof system around maintenance works
Main contractor: Babcock International Group
Client: Wood Group Industrial Services Limited
Products: Flame retardant 300µm Tufcoat shrink wrap
Wood Group is a global leader in the supply of energy services to a number of business sectors, operating in over 50 countries worldwide. Tufcoat have been involved in supporting numerous marine projects for Wood Group Industrial Services, who provide specialist coatings, access solutions and fabric maintenance to this market.
Tufcoat worked with Wood Group Industrial Services to install a shrink wrap Haki roof system over the de-commissioned Royal Navy nuclear powered submarine, HMS Valiant. This project took place at Devonport Dockyard in Plymouth, which is owned and operated by Babcock International Group.
Ex-HMS Valiant is a mothballed submarine, which has been decommissioned and is kept in long term storage at Devonport. In order to preserve its condition, the vessel undergoes continuous maintenance to its hull and casing whilst docked at Devonport’s No. 3 basin. In order to successfully carry out the planned preservation, Wood Group Industrial Services required an environmentally contained enclosure around the works taking place.
Ex-HMS Valiant Scaffold Shrink Wrap
Tufcoat installed shrink wrap on eleven spans between trusses from a previously installed Haki roof. Ten of the trusses measured 36m long x 6.2m wide, while one truss measured 36m long x 3.1m wide. In total, 2352m² of 300µm flame retarded shrink wrap was used by our installation team.
Shrink wrap was fitted between the trusses while they were constructed in sections still on the ground. After the sheeting was welded around the trusses and shrunk off with heat guns, each span was craned in to place over HMS Valiant.
A 3m wide bay was created in between each shrink wrapped span. Using crawler boards and self-rescue harnesses for safe access across the structure, Monarflex sheeting was then installed to cover the 3m gaps and complete the encapsulation of the Haki roof system.
Using alternating spans of shrink wrap and Monarflex to cover the Haki roof allowed for a more effective work process. Because the structure was lifted in sections and completed by simply clipping Monarflex between the shrink wrap spans, time was saved on the project when compared to using shrink wrap to encapsulate the whole roof.
The approach taken over the course of this project resulted in significantly improved control over health and safety practices. In particular, using crawler boards and self-rescue harnesses reduced the need for MEWP access, which reduced the level of risk around the working environment.
David Crook, Operations Manager at Wood Group Industrial Services commented:
“Having worked with Tufcoat on numerous projects at Devonport Royal Dockyard, HMS Valiant’s temporary roof presented new challenges for our respective teams.
Our approach, working closely with Tufcoat Installers, used a new methodology allowing us to reduce the requirement for MEWP access as well as meeting the programme schedule.
Tufcoat adhered to our requirements, providing an outstanding level of service throughout the course of the project. Results have exceeded our expectations and I would highly recommend their team”.
The temporary roof allowed works on the decommissioned submarine to take place unaffected by factors such as adverse weather, ensuring no harmful by products escaped to the surrounding environment and contributed to reducing project down time.