Marine gadgets that give veriety to the map..
It doesn't look like most people have ever used it, but the torch works with two functions. torchable and weld .
Right Cick in Dedit, and select ADD OBJECT, and choose a Torchable Lock under the Props object.

The actual proeperties of Torchable and hackable are similar, in that both generate a model on screen that needs to be placed in a specific location, rotated as necessary, and set with a time, that will destroy it.

In the Torchable situation, the location remains, and a weld can be placed in the same place, and thus unlike hackable, the tirchable can be reused in MP. There is also a TorchEventCounter that keeps track of the bolts that get torched, if say you need to blow 4 bolts before the door unlocks.

The result is weldable doors in MP?
Marines can LOCK and UNLOCK doors in an MP game using the torch's dual function, weld and torchable. And as you can see it is easy to implement.
Create a door, example door27, set it to being locked.
Place a torchable lock at the door. In the ON CUT Command, add the message; msg door27 UNLOCK