A unique series of valves and controllers developed by UK company Hale Hamilton under contract by the Connecticut shipyard of the Electric Boat Corporation and used to facilitate an emergency escape system for submariners has been adopted by the US Navy.
It is the intention of US Naval Sea Systems Command to retrofit the Hood Inflation System (HIS) to an initial six submarines during 1999. All 55 nuclear and non-nuclear US Navy submarines in service or under construction will be equipped with the system which replaces the previous Steinke Hood escape system. The contract is set to be worth some £2m to Hale Hamilton, which will supply the controllers and valves for up to six trunks on each submarine.
The system, already in use with the UK Royal Navy and several Commonwealth and European navies, includes a small valve fitted to the submariners' lightweight escape suit which he puts on when entering the trunk. Within 30 seconds the escape trunk is flooded and pressurised to the outside water pressure. The crewman's suit is maintained at a positive pressure in the trunk by use of a Hale Hamilton Stole Valve and HIS Pressure Controller before the upper escape trunk hatch is opened and the crewman escapes. The escape trunks allow submariners to escape from depths up to 180 metres (600 feet)
Hale Hamilton's factory near London includes the special test facility, sponsored by the UK Ministry of Defence and used to recalibrate the nickel aluminium bronze controllers and stole valves following planned maintenance, calibration and refurbishment. More information: Defence Systems Daily