The vehicle itself has the same design as the Barracks OL, but the rear is adapted to attach trailers, as the name suggests. Like the transport variant and other military ground vehicles, it patrols Fort Zancudo and is seen parked in several areas.
Due to its shorter wheelbase, it has better performance in speed and turning, thought the brakes are less responsive than its cousin, the Barracks OL. It is also said that the Barracks Semi is capable of pulling trailers twice as fast as civilian tractors.
- Found at Fort Zancudo, patrolling and parked in many places, especially some of them next to the southeast checkpoint.
- Can be found on the highway outside Fort Zancudo if the player approaches and leaves the base.
- The Barracks Semi is the only military vehicle (besides the Titan and P-996 LAZER) that cannot be purchased on Warstock Cache & Carry, therefore the only way to obtain one is by invading Fort Zancudo and quickly stealing one before the player gets killed by the Military.
- The Barracks Semi can pull trailers. It has its own trailer which is a unique brown camouflage tanker trailer. The fuel could also be aviation fuel for aircrafts because of the way it explodes or normal fuel or both.
- In a Heist Setups mission Minisub, a brown camouflage flatbed trailer appears pulled by a Packer. Cosidering the fact that in this mission the player can change trucks, the Barracks Semi would look properly with this trailer.
- The Barracks Semi does burnouts easilly, but will not do donuts on pavement (possibly due to a the double rear axle and comically oversized front wheels), it will however do extremely slow donuts on dirt.
- Unlike its cousin, the truck is named HVY Barracks Semi, showing the manufacturer. However, it reveals that the transport variant is evidently an HVY Barracks.