A trench knife is a knife which has been specially designed for close-quarters combat such as that which characterized the trench warfare of the First World War. In fact, the trench knife design originated during this conflict, and it proved so useful that militaries continued to issue trench knives long after the days of trench warfare were over. Suppliers of knives and military equipment often carry trench knives, including replicas of famous models from the First and Second World Wars.
The key feature of a trench knife is that it is short, allowing a solider to use it in close quarters, and also extremely sharp. The blade is classically straight, and it may be grooved with a single channel. The earliest trench knives were simply personal weapons or modified bayonet blades and swords, but military strategists quickly realized that issuing a special-purpose trench knife would be highly advisable.
In addition to having a rather wicked blade, many trench knives also have a heavy, solid pommel which can be used very effectively for punching, especially for blows to the skull. Some trench knives also have a hand guard which can theoretically double as yet another surface which can be used for punching. These “knucklebuster” trench knives sometimes have handles shaped like brass knuckles, providing a solid grip while offering hand protection to the user.
Soldiers utilized trench knives when they went over the wall into the trenches of the opposing side. The blades could be safely used in crowded and cramped trenches, and they also carried the advantage of being silent weapons. Scouts and other individuals who went over the wall first often used trench knives to remove sentries and guards so that the enemy would not be aware of the approaching attack. Silent weapons were often preferred for trench raiding missions, because they attracted no attention, reducing the risk of alerting the enemy.
In some regions, civilians are not allowed to carry trench knives. The length of the blade can become a factor, with people not being permitted to carry blades over a certain length in public. The presence of knucklebusters can also be an issue, as knuckled weapons have been specifically banned in some areas due to concerns about their use in criminal activity. In these situations, people may be allowed to display a trench knife in the home, especially if it is an artifact of military service, but they may not carry the blade in public.