Royal Navy Submarine Escape Training Tank

Royal Navy Submarine Escape Training Tank
Name	Royal Navy Submarine Escape Training Tank
Location	Fort Blockhouse, Gosport, Hampshire
Established	1954
Closed	2020
Type	Training facility
Operator	Royal Navy
Country	United Kingdom

Royal Navy Submarine Escape Training Tank The Royal Navy Submarine Escape Training Tank was a specialist training facility at Fort Blockhouse, Gosport, delivering underwater escape and survival instruction to submarine crews from the Royal Navy, allied navies such as the United States Navy, Royal Australian Navy, Canadian Forces, New Zealand Defence Force, Indian Navy and NATO partners including French Navy, German Navy, Italian Navy and Royal Netherlands Navy. It supported operations tied to platforms including HMS Conqueror (S48), HMS Astute (S119), HMS Vanguard (S28), HMS Resolution (S22), HMS Triumph (S93), HMS Dreadnought (S101), and training integration with organizations such as Submarine Command Course, Fleet Diving Unit (UK), Permanent Joint Headquarters, Allied Maritime Command, and the NATO Submarine Rescue System program.

History

Established during the Cold War era amid tensions involving the Suez Crisis, Cuban Missile Crisis, and the naval strategies influenced by the Five Eyes intelligence alliance, the facility evolved from earlier escape rigs used by the Royal Navy Submarine Service and training influenced by incidents like the HMS Thetis (N25) disaster and procedures developed after Second World War submarine operations. The site at Fort Blockhouse, a historic fortification associated with HMS Dolphin and adjacent to Portsmouth Dockyard, was formalized in the 1950s with links to research at institutions such as Royal Navy Physiological Laboratory, collaborations with the Ministry of Defence, and exchanges with the United States Naval Submarine School and the Submarine Escape Trainer programs run by allied fleets. Over decades the tank trained personnel responding to peacetime incidents reminiscent of rescues such as operations involving USS Squalus (SS-192), studies from Royal Society journals, and recommendations from inquiries like those following HMS Truculent and other notable maritime safety reviews.

Design and Facilities

The installation featured a deep vertical tank with deck-level platforms, pressurization chambers, a recompression suite and simulated hull escape hatches, integrating hardware influenced by designs used in Royal Navy submarine classes and testing protocols aligned with standards from International Maritime Organization, Health and Safety Executive and NATO safety guidance. The complex included gas management systems, breathing apparatus storerooms, medical wards modeled on systems used aboard HMS Ark Royal (R07), recompression chambers akin to those at civilian hyperbaric centres connected with institutions like National Health Service hospitals, and control rooms staffed by personnel trained under curricula from Defence Equipment and Support. Structural elements referenced materials and engineering approaches from projects at Portsmouth Naval Base and collaborative work with manufacturers such as Rolls-Royce (civil nuclear) for life-support componentry. The suite accommodated trainees from classes taught at Britannia Royal Naval College, linked to simulation practices used in Submarine Command Course assessments and allied exercises with units like Standing NATO Maritime Group 1.

Training Curriculum and Procedures

The curriculum combined theoretical instruction on buoyancy, pressure physiology, hypobaric and hyperbaric effects, and practical drills replicating escape through torpedo and conning tower hatches, drawing on research from bodies including Institute of Naval Medicine, University of Southampton, and clinical studies published by the Royal College of Physicians. Trainees practiced ascent techniques using buoyant ascent systems, swimming procedures, and use of respirators similar to Draeger rebreathers, under supervision from instructors with backgrounds in Submarine Service operations, diving medicine specialists from Royal Navy Medical Service, and bailout protocol designers connected with Admiralty legacy manuals. Procedures emphasized staged decompression, emergency signalling compatible with assets like Submarine Rescue Vessels and the Submarine Rescue Ship (DSRV) concept, and integrated with multinational exercises such as Exercise Bold Monarch and interoperability trials with the NATO Submarine Rescue System and Royal Netherlands Navy rescue teams.

Safety Measures and Incidents

Safety systems included continuous medical monitoring, on-site hyperbaric treatment, redundancy in gas supplies, real-time observation suites, and incident review mechanisms coordinated with investigative bodies such as the Marine Accident Investigation Branch, Ministry of Defence Police and medical oversight by the Institute of Naval Medicine. Over its operational life the facility logged a small number of incidents and medical episodes that prompted reviews and procedural updates, influenced by heritage incidents like HMS Thetis (N25) and lessons from international accidents including the K-141 Kursk sinking and the USS Thresher (SSN-593) loss, which informed global submarine safety doctrine. Outcomes contributed to policy adjustments in training cadence, medical screening comparable to standards at Royal Naval Hospital Haslar, and equipment upgrades coordinated with defence procurement frameworks like MOD Capability Managers.

Role in Submarine Escape and Rescue Doctrine

The tank informed Royal Navy doctrine on crew survival, evacuation and rescue, complementing platforms such as LR5 Deep Search and Rescue vehicles, the NATO Submarine Rescue System, and allied rescue assets including the US Navy Submarine Rescue Chamber and civilian salvage firms like Smit Internationale. Its training supported operational readiness for submarines in deterrent patrols aboard Vanguard-class submarines, attack patrols with Astute-class submarines, and allied coalition operations tied to commands like Commander Submarine Flotilla. Doctrine contributions appeared in manuals, joint exercises with Allied Maritime Command, and research exchanges with academic partners such as King's College London defence studies and the Royal United Services Institute.

Decommissioning and Legacy

Closed in 2020 as part of rationalization of training assets and the consolidation of submarine escape and rescue training into multinational and shipboard programs, the site’s functions migrated to alternatives including mobile simulators, shipborne escape training suites, and international facilities such as those used by the United States Navy and the French Navy. The legacy persists in institutional memory at establishments like HMS Dolphin archives, instructional material retained by Submarine School curricula, and influence on contemporary rescue architectures involving the NATO Submarine Rescue System and civilian-military cooperation exemplified by Salvage and Marine Operations (SMO). The Fort Blockhouse location remains linked to broader naval heritage at Portsmouth Historic Dockyard and discussions about future redevelopment with local authorities including Gosport Borough Council.

Category:Royal Navy