A Torpedo Boat (or T.B.) was a small, fast warship type designed to deliver torpedo attacks against larger surface fleets.
Originally, they were tiny vessels and not capable of true sea-going operations. The threat they posed to larger vessels eventually inspired the creation of the Torpedo Boat Destroyer type, whose larger size and greater gun power was intended to keep the torpedo boats from being able to get close enough to fire effectively.
In time, the torpedo boat type was largely supplanted by the torpedo boat destroyer which could better operate at sea. Many navies reclassified their earliest destroyers as torpedo boats when the growing displacements of recent destroyer types made the old boats seem to have become logical torpedo boats. The German navy persisted in calling most of its torpedo boat destroyers "torpedo boats" in light of their comparatively small size relative to those of their enemy.
- Lyon, David (1996). The First Destroyers. London: Chatham Publishing. (on Amazon.com and Amazon.co.uk).