Collision-bulkhead

The foremost transversal bulkhead below a ship’s upper-deck, usually extending from the floors to the upper-deck. It forms the principal bulkhead in a ve el and therefore as a rule strongly built, so as to withstand a pre ure of water, in case the fore part of the ship should get filled through damage to her bow by collision. See Plates 17. 9 & 18. 3.