Water-tight VS Weather-tight Doors

Watertight Door	Weather tight Door

A watertight door prevents the passage of water when exposed to head of water. A typical head of water for a ship could range from 3-10 meters(tested up to 20 meters resistance)	A weather tight door is designed to be located on the deck of the ship above the waterline, where they can be subject to the adverse weather conditions experienced offshore.
Watertight doors are tested using a pressure tank where a hydrostatic pressure can be applied to the door.	Weather tight doors are also designed to withstand brief submersion experience from green seas. This means a weather tight door can withstand a small head of water(generally no higher than the height of the door)
The door is generally pressurized form the inside as this is worst case scenario.	A weather tight door is generally tested with a high pressure hose, which is directed at the seal.

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Marine Engineering

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