Draft:Clame Door

A clam door or a clamshell door consists of two panels that spread open vertically, as those located on the underside of some cargo planes. These are also used on ship as an alternative to a bow visor.

Clam doors have been adapted over the bow visor after the Estonia sinking in 1994 for their water tight seal and not being under as much force as the bow visor being on the front of the ship.