The OR in US MARINE CORPS

“The soldier cannot be a fighter and pack animal at one and the same time, any more than a field piece can be a gun and a supply vehicle combined. The idea is wrong at the start. Yet is always being repeated.“

What was true in 1948 for Major General JFC Fuller is unfortunately still true for many armed forces. In Operation Herrick (Afghanistan) British soldiers patrolled with an average of 56kg[1] of kit, but the British Army’s more recent ‘fight light’ policy does suggest some lessons have been learned.

Across the pond, a US Marine Corps Captain has begun making waves with some compelling operational research around the combat effectiveness of marines carrying different loads in different simulations.

Captain Courtney Thompson, an engineer with the United States Marine Corps, applied operational research principles to the question of kit weight and its impact on the performances of both individual marines and their 13-rifle squads.

She also planned carefully how her audience would receive the results: “I thought if I could quantify weight in terms of casualties and probability of mission success, that’s what the Marine Corps understands,” she said.

The combat engineer drew on Australian soldier data and infantry demographics because of the Australian Defence Department’s own rigorous studies on its tiered body armour system. She looked at physical fitness and marksmanship scores to closely represent the average squad member within the US Marine Corps.

The Marine Corps’ has four loads configurations – fighting load, assault load, approach march load and sustainment load – with the type being dependent upon the mission. Captain Thompson’s research looked at fighting and assault loads, running nearly one million simulations in which squads of marines engaged a competent enemy whilst carrying between 20kg and nearly 30kg of body armour and equipment.

Perhaps unsurprisingly, when more weight was added the “casualties just went up.” However, when faced with more and more competent enemies, “the more the difference in weight mattered."

Regarding the marines’ performance, “the slower they are, the higher the chance they have of getting hit," she said. Fighting peer-level enemy would see the casualty rate increasing even more. But it wasn’t just patrol speed that was impacted: response times and accuracy of fire was also noticeably impaired by higher kit weights.

The results threw a new perspective onto the 2017 government watchdog report which revealed US marines and soldiers were carrying an average of around 53kg of kit.

Thompson would not be drawn into making specific recommendations regarding changes to kit and equipment, perhaps not wanting to remove options for commanders’ decision-making about marines’ capability. However, she did encourage all senior commanders to pack the entire list into a bag, put it on their backs and “see if it is a reasonable amount of weight.”

Captain Thompson’s research won the Military Operations Research Society Stephen A. Tisdale Thesis Award at the Naval Postgraduate School in Monterey, California.

[1] www.thinkdefence.co.uk/overburdened-infantry-soldier/