… what we want is not a light battalion but a light army…such mobility is only to be obtained when the army is formed of sturdy men, well-practiced in peace, well fed In the field, and carrying as regards all arms a really practical equipment. An army which marches light will also maneuver freely.
– Helmuth von Moltke
Following from my last post, I want to dig into weight. I’m not talking about how much you weigh, specifically, but how much your chosen equipment weighs and how effectively you can carry it for however long is required. I am not a hunter, but I have spent significant time backpacking through some pretty austere and difficult territory; and as an officer in the US military, my thinking tends toward the defensive in nature and that is how I will relate to the problem. Regardless of how I approach these ideas, take the principles and apply it to yourself and whatever your chosen mission will be.
The general rule from backpacking is that your equipment should weigh no more than 25-40% of your body weight. After you climb through that range, or exceed it (as the military often does), you will be unable to sustain effort and the risk injury is dramatically increased. Realize that these numbers represent an upper limit, not a lower one. There are plenty of light and ultralight hikers out there who can get by for seven days with a 27lb pack.
Army doctrine, going back for generations, has generally set a series of limits on soldier loading. The two most important categories I want to cover are the fighting load and the approach load. I base my definitions on Army Field Manual 21-18, Foot Marches.
The fighting load consists of all items that a fighter is wearing and using while “in contact.” This includes clothing, weapons, ammunition, radio, and minimum capability equipment. I consider minimum capability equipment to be survival/readiness items such as maps, compass, knife, water, medical kit, and other items that enable the fighter to continue surviving for some time, even if their other equipment is lost or destroyed. In modern tactical parlance, this would be your first and second line gear. Army doctrine states this should not exceed 48 lbs.
The approach load consists of the fighting load and any additional equipment needed for sustainment until resupply. It is typically carried in a backpack/rucksack and includes sustainment items like food rations, batteries, extra water, water filter/purification tabs, change of clothing, shelter, spare ammo, etc. This pack can be dropped upon contact without negative effect on the ability of the fighter to perform a mission successfully. It is otherwise known as your third line gear. The approach load, which includes the fighting load, should not exceed 72 lbs. From a practical standpoint, that means your pack should not exceed 24 lbs if your fighting load is already at the maximum of 48 lbs.
I find that these definitions fall roughly in line with each other. If I use 25% of my own lean body weight, I end up with 45 lbs as the recommended maximum. Similarly, If I use 40% as my fraction, I end up with 72 lbs. Why do I use lean body weight as opposed to actual body weight? In short, my body fat isn’t helping me carry the load.
Aside from gross weight, we must also consider the distribution of that weight. The old backpacking axiom says, “One pound on your foot is worth five pounds on your back.” The military actually did a study on this, and found that there actually is roughly 4.7 to 6.4 times more energy expended per pound added to the feet compared to the back. This also applies to weight carried on the arms and hands.
Similarly, weight supported on the hips is far more comfortable and energy efficient compared to supporting it on the shoulders- hence why heavy backpacks all have sturdy waist bands. Interestingly, a study in 2004 found that loads situated higher on the chest (as in chest rigs in plate carriers) are more energy efficient when traversing over flat ground; but loads situated lower (as in a belt) are more efficient on uneven terrain. Consider that when thinking about the problems we saw with the equipment used and terrain in Afghanistan.
For this reason, I’ve become a fan of the “battle belt” rather than the chest rig for my shooting needs. If I am to come up with an Everyday Marksman’s fighting/combat load, using the information above, I figure that the belt is a good place to start.