The Main Pack of the USMC Pack system has an approximate internal volume of 3400 cubic inches in the main compartment and 1600 cubic inches in the lower compartment. The Main Pack and Assault Pack components are capable of carrying a maximum combined load of 120 pounds.
The Main Pack is composed of one Frame, one Shoulder Harness Assembly, one Hip Belt, and one Main Bag. The sustainment pouches, hydration pouches, and assault pouch are attachable to the Main Pack's Pouch Attachment Ladder System (PALS) webbing.
The Frame is capable of allowing the main pack to securely mount onto it without the use of tools. The frame is made of a lightweight, high strength polymer that is resistant to fracture. When used in conjunction with the hip belt and shoulder harness, the frame distributes the load contained in the pack onto the user's hips and shoulders. The frame is shaped in order to properly integrate with all fielded body armor systems.
The Shoulder Harness Assembly is able to be rigidly mounted onto the frame without the use of tools. The harness is able to be moved up or down on the frame in order to accommodate different torso lengths. The harness has adjustable, padded shoulder straps that are used to carry the main pack. Adjustable load lifter straps attach the shoulder straps to the top of the harness in order to pull the load carried in closer to the user's body. A sternum strap attaching the two shoulder straps together allows the shoulder straps to be properly positioned on the user's body. In the case of an emergency doffing situation, the shoulder straps are able to be quickly separated using quick release hardware, allowing the pack to fall off the user.
The Hip Belt is able to be rigidly mounted onto the frame without the use of tools. The hip belt is able to be securely tightened around the user's hips and fastened with a buckle. The hip belt tightens with a forward motion. The hip belt transfers the majority of the load contained in the pack onto the user's hips, reducing the weight burden on the user's upper body.
The Main Bag consists of two compartments separated by a shelf. The bag is able to be converted into one large compartment by opening a slide fastener located on the shelf. The bag is able to be closed at the top using cord and a locking hardware device. The bag has an extendable collar made of water resistant nylon material that extends approximately twelve inches and is capable of being independently closed. A lid containing a pocket covers the top of the main bag. The exterior of the bag has PALS webbing used to mount modular pouches. One large sleeve per each side is capable of retaining long items such as mortars or skis. Below each sleeve is a stretchable pocket in order to aid in the retention of the long item being carried. The bag has a handle on the top to aid in carrying when not worn on the back and two handles on the back to aid in donning. The bag has webbing straps attached to the exterior used to compress smaller loads carried. The bag is capable of internally carrying a radio. The radio pouch is able to accommodate the Single Channel Ground Airborne Radio System (SINCGARS) radio and the Advanced Lightweight SINCGARS Improved Program (ASIP) radio.
- Main Bag shall not exceed 80.0 ounces.
- Frame: 32.0
- Shoulder Harness Assembly: 35.0
- Hip Belt: 25.0
- Down East Inc. P/N 1606MC or equivalent
- Shoulder Harness Assembly: 8465-01-600-7938
- Hip Belt: 8465-01-600-7870
- Main Bag: 8465-01-600-7911