Trench Knife

The Trench Knife is a melee weapon that appears in the Operation: Anchorage add-on for Fallout 3.

Although used during the Anchorage Reclamation simulation, you can obtain it for use in the Capital Wasteland by retrieving it from the sealed armory in the Outcast Outpost after completing Operation: Anchorage. It can be repaired using standard Combat Knives.

Though the in-game information claims that the Trench Knife is weaker, the only real difference between it and the Combat Knife is that it has a spiked handle guard and a slightly longer blade.

Trivia

 * In the first World War, this was a weapon used by both sides when jumping into trenches for close quarters ambush operations. The blade was designed particularly for use on an enemy's helmet, with maximum damage for a blade of its size in mind. This model may have been classified as a "knuckle-duster" knife.
 * There were plans to make schematics for it. You would need Wonderglue, a Combat Knife and Spiked Knuckles to make one. The schematics never made it into the game.