Dutch develop safer bulkhead door for Royal Navy

The Royal Navy’s Type 45 destroyer will feature a new-style door far more able to withstand explosions than previous designs.

Developed by Dutch technology organisation TNO Prins Maurits laboratory in conjunction with doormaker Van Dam, the flexible membrane door, which has a simple concertina-like crush zone around the frame, is lighter and claimed to be stronger.

During the Falklands conflict, when ships took missile hits the blast pressure tended to blow out several internal doors in a row. The Dutch navy and TNO carried out test explosions on a decommissioned vessel and found that this type of conventional door, which is mainly designed to resist water pressure if an individual compartment floods, effectively popped out of its frame, allowing fire, smoke and shrapnel to spread around the vessel.

To make doors more explosion-resistant, the obvious solution was to increase their size and weight. this, however, meant they would be almost impossible to open normally.

The alternative is the TNO door. During an explosion the crush zone unfolds and absorbs energy, and the 4mm-thick steel door itself may also bend. The design is said to work regardless of the direction of the explosion and remains watertight in the aftermath.

TNO said the door has 10 times more blast resistance than a normal door while weighing only 120kg, meaning that a sailor can still open it with a single lever. BAE Systems Marine and Vosper Thornycroft should soon begin constructing the first of up to 12 Type 45 destroyers, the first of which is due to enter service in 2007.