Trench Tank
Trench tank, abbreviated as TT, is a role in all dual tank DoASC tactics. It is mostly done by an assassin, although any profession can do the job effectively as /A; ranger trench tanks are fairly common, especially in speed tactics.
Role
The TT often splits off from the team, doing pulls in all 4 areas without bonds. Because of this independence, and the complicated nature of some of the pulls, TT is generally considered to be the most advanced role in DoASC, often left to the most experienced player in the team.
Trivia
The name "trench tank" comes from before the Necrotic Traversal nerf, when the TT would teleport down into the trench and pull all of the lords into spiking range of the hills, so the rest of the team didn't have to go down any trenches. After pulling the lords, the TT would teleport into gloom and ball all of cave before the team even arrived!