Gregory ILBE Trial Packs

By Jesse Ables
Written 26 June 2015


In 2002, the United States Marine Corps began evaluating a number of commercial packs submitted to replace the then-standard issue MOLLE II system. These commercial entries were to provide "enhanced reliability, durability, wearability, and maintainability" while being "readily producible, simple and functional, [and] easily integrated with current body armor."

Specialty Defense System's submission included a main pack that featured an innovative quick release hipbelt mechanism.

All submissions were down-selected to packs designed by Arc'Teryx and Gregory Mountain Products. Each company submitted an assault pack and main pack, each of which were tested against the MOLLE II packs. A total of 800 pack systems from each company were issued to Marines during a six-month evaluation period in 2003. Though the Gregory system was rated significantly higher during user evaluations than the Arc'teryx offering, both systems were deemed superior to the MOLLE II.

A modified version of the Arc'teryx submission ultimately became the issued ILBE pack.

During biomechanical testing conducted by the U.S. Army Research Institute of Environmental Medicine with 11 Marines, 6 preferred the Gregory pack and 5 the MOLLE II, while none selected Arc'teryx as their favorite. The six-month field evaluation yielded a similarly favorable result for the Gregory system. Had it not been for a poorly redesigned pack submitted after the user evaluation period, it is likely the Gregory system would've been selected over Arc'teryx to become the ILBE pack.

Main Pack

The main pack measures approximately 34"x14.25"x10.5" (including storm collar) and weighs 7.94lbs. It features a zippered sleeping bag compartment with a removable divider to separate it from the main bag, while an excessive number of compression straps help keep a load tight a user's body. A removable radio pouch is attached at its four back corners through Looplocs on the inner sides of the frame. The frame itself is comprised of dual 7075 T6 aluminium stays, each measuring 0.75"x24", secured to a 3/16" HDPE panel (made up of one sheet each of 1/8" and 1/16" HDPE). Shoulder strap height adjustment slots are positioned 1 3/16" apart, allowing for nearly 6" of vertical adjustment to accommodate different torso lengths.

Construction quality of both the main pack and patrol pack is outstanding. All seams are taped and have a 1/2" seam allowance (larger than the industry standard 3/8"). The bottom of both packs are double-layered, and all high-stress areas are reinforced. The upper carry handle is riveted directly to the frame. The expertise that went into designing this pack system is impressive.

Assault Pack

The assault pack measures approximately 17.5"x12"x4.5", with the outside pocket measuring 11.5"x10"x3.5". It weighs in at 2.37lbs. The main compartment features a fixed hanging pocket made from the same lightweight ripstop material used on the main pack's storm collar. No sternum strap was included with the assault pack, to the disappointment of some evaluators. The back panel is lightly padded but doesn't include a framesheet. The 1.5" wide waistbelt strap can be stowed in the back panel sleeve and is secured using hook and loop closures.

Redesigned Pack

Halfway through the six-month user evaluation period, both Gregory and Arc'teryx were advised of their system's deficiencies and given an opportunity to correct them. The redesigned pack submitted by Gregory featured permanently attached mortar pockets on the side and overall was very different from the initial pack submitted. This redesigned pack, coupled with the higher cost of their system versus Arc'teryx, ultimately cost Gregory the ILBE contract.