These cutlasses are outside the officers quarters on HMS Warrior. There are also more cutlasses, also in sets of 4, above each cannon on the gun deck.
Although also used on land, the cutlass is best known as the sailor's weapon of choice. A naval side-arm, its popularity was likely because it was not only robust enough to hack through heavy ropes, canvas, and wood, but short enough to use in relatively close quarters, such as during boarding actions, in the rigging, or below decks. Another advantage to the cutlass was its simplicity of use. Employing it effectively required less training than that required to master a rapier or small sword, and it was more effective as a close-combat weapon than a full-sized sword would be on a cramped ship.