By Anthony G Williams

A guest post by Anthony Williams who is a writer on military small arms, automatic cannon and related subjects. Tony has been the Editor of IHS Jane’s Weapons: Ammunition for 13 years and has an encyclopedic knowledge of this field. He has written and co-authored several books on military guns and ammunition, given presentations to many conferences in the UK and USA, and maintains a website at http://quarryhs.co.uk .  It is a pleasure that he has agreed to submit a blog post, on such a highly topical subject.

Contents

01 – Introduction
02 – A Breakdown of current loads
02 – Reducing the Collective Load
04 – Providing Individual Mechanical Assistance (Unpowered)
05 – Providing Individual Mechanical Assistance (Powered)
06 – Providing Group Mechanical Assistance (Powered)
07 – Providing Group Animal Assistance
08 – Conclusion

01 – Introduction

One of the most intractable long-term problems facing infantry is the excessive weight of the loads they need to carry. While vehicular transport of some sort will often be available, foot patrols are still a fundamental element of the infantryman’s role and are likely to remain so for the foreseeable future. That means wearing or carrying sufficient resources to provide protection (including high-grade body armour), weapons and ammunition, food and water, plus an increasing quantity of electronic sensor and communications equipment together with their associated power supplies.

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Overburdened British soldier in Afghanistan.

02 – A Breakdown of current loads

A detailed breakdown of the current infantryman’s load was put on display by the British Army at DSEi 2017, with weights for every element. The full list was collated by Nicholas Drummond and can be found here: http://quarryhs.co.uk/BritishArmyEquipmentWeights.pdf

IMG_1563
The British Army’s new VIRTUS Load Carrying System shown at DSEI 2017.

To summarise, the total load weighs 63.9 kg, divided as follows:

Assault Order, including VIRTUS system with 4.99 kg body armour, CBRN kit (4.71 kg), rifle and 4 magazines: 31.5 kg

Patrol Order, including more clothing, belted MG ammunition, etc: 16.26 kg

Marching Order, including more rations, sleeping bag, shelter etc: 16.17 kg.

Since the average weight of a soldier is around 70 kg, that means that he (or she) will be carrying very nearly their own weight when in Marching Order, and still nearly 48 kg in Patrol Order.

Furthermore, the total of 63.9 kg doesn’t include: spare batteries for radios; 40mm grenades; and additional ammunition (in Afghanistan, troops carried 7 or 8 magazines of 5.56mm, plus 200 rounds of 7.62mm link – considerably more than assumed in these calculations).

The consequences of such burdens are serious. From the immediate, tactical viewpoint the problem is the very limited mobility of such burdened troops, especially in rough terrain, and in high temperatures, and at high altitude. In such circumstances there is little chance of the troops managing to close with lightly-loaded irregular forces, and they will rapidly become exhausted if they try.

The longer-term issue is that of the effect on health. Any internet search for “soldier load injury or damage” will bring up a host of reports from around the world (this is a general problem, not peculiar to the British Army). Many of them are detailed medical studies, but in the past this has even reached the popular press: an extract from a Daily Express article of July 2010: https://www.express.co.uk/news/uk/188986/British-soldiers-suffer-injuries-from-too-heavy-weights

“The hostile climate and challenging supply chain in Afghanistan means that soldiers must prepare for every eventuality, carrying as much as 5 litres of water and even cans of oil. In addition, the Taliban use of Improvised Explosive Devices (IEDs) has seen British troops adopt the unique position of carrying heavy jamming devices, aimed at blocking all mobile signals and preventing the remote-controlled detonation of roadside bombs, in every patrol.

Although the Ministry of Defence does not collate figures regarding skeletal and ankle injuries, Unites States forces have seen a marked increase in “load bearing” injuries. According to the US Armed Forces Health Surveillance Monthly Report, published in April, 7,516 soldiers visited field hospitals for injuries associated with skeletal injuries in 2009 alone. Most of these were categorised as “intervertebral disc disorders”.

“You can’t hump a rucksack at 8,000 feet for 15 months and not have an effect,” said Gen Peter Chiarelli, the US Army’s vice chief of staff. Danish Army figures reveal that 15 per cent of its 750-strong contingent in Afghanistan returned home with long-term injuries. Half of those were caused by heavy equipment, made worse by the addiction to painkillers needed to cope with the load.

Patrick Mercer MP, a former colonel with the Sherwood Forresters who was forced recently to undergo back surgery, ten years after leaving the army, said: “The heavy weight of kit carried by British soldiers has always been a cause for lower limb injury, and I speak as a victim myself.” 

Overburdened soldiers
British soldiers struggle to stand prior to going out on patrol in Afghanistan. Many carried their bodyweight in equipment.

Can anything be done to reduce the infantryman’s load? There are several potential approaches, some of which are feasible now while others require further advances in technology, particularly in energy storage. 

03 – Reducing the Collective Load

One approach is to reduce the weight of the collective load being transported by the dismounted unit, in two ways: carry less kit, and/or reduce the weight of the individual items. The problem with the first of these is that the kit to be worn and borne has been gone over many times with a fine-toothed comb and the Army is reluctant to omit anything else. The only circumstances in which carrying less might be acceptable would be if rapid resupply were guaranteed, possibly by a drone like the IAI Air Hopper which can carry 100-180 kg and fly for two hours at up to 120 kph. However, armies are as subject to Murphy’s Law as anyone else, so relying on this to work all of the time is unlikely to do much for soldier morale.

Helicarry
IAI Air Hopper showing its capability for casualty evacuation

Reducing the weight of each item is an approach which has already brought reductions since the Daily Express article was written – e.g. the VIRTUS system and EMAG polymer rifle magazines – and some of the electronic equipment can be expected to become lighter and use less power; batteries themselves are becoming more efficient as well.

The US Army is exploring reductions in ammunition weight by making the cartridge cases of polymer or polymer/metal hybrid materials; this can save from about 20% of the ammunition weight for polymer/brass cases to 33% if all-polymer as in the Cased-Telescoped system also being tested (and up to 40% in MG ammunition by using polymer belt links as well).

This apart, scope for further reductions in weight seem marginal, and indeed more weight might need to be added back: western armies are realising that high-grade body armour is becoming cheap and available enough for anyone to acquire, so are beginning to consider how to defeat it. This might require more powerful (and therefore heavier) weapons and ammunition which may then generate a demand for even more effective body armour, which is also likely to be heavier.

04 – Providing the Individual with Mechanical Assistance (Unpowered)

There are two simple, low-tech approaches to the load-bearing problem which are worth a fresh look with an open mind: carts or trailers, and bicycles (don’t laugh yet – read on!).

The man-pulled cart has a long history and was a standard item of equipment in many armies in World War 2, as shown below (German Army):

Cart1

And in the following two photos from this site, showing US Army use: http://www.theliberator.be/handcart.htm

Cart2

Cart3

These carts are probably too heavy and cumbersome to meet modern requirements. However, something a lot lighter and handier which could prove useful is available off the shelf – the hiking trailer. Some of these have only one wheel as shown here:

Cart5

Others have two wheels, in some cases with separate shoulder straps so they can be carried as rucksacks when required:

Cart6

These trailers weigh around 6-9 kg and typically carry up to 40 kg.  At least some of them feature quick-release catches so they can be dropped instantly if required.

A 1974 study comparing the energy use of carts with backpacks* showed that on smooth roads pulling a 100 kg cart used up about the same energy as carrying a 20 kg pack. As the terrain becomes rougher so the energy use equalises, but even then trailers reduce the load carried by the soldier, as transmitted via a hip belt, by at least 50%, the rest being carried by the wheel(s). Such a device could therefore provide substantial benefits to mobility while reducing the risk of medical problems.

*(See Journal of applied physiology 36(5):545-8 ·June 1974 )

This is a link to a video showing one of these – a Monowalker – being used in rough terrain including significant vertical obstacles:  https://www.youtube.com/watch?v=Id5UTB2DHeQ

The humble bicycle also has a long military history. It has often been seen as a way of increasing the deployment speed of the infantry, since on a reasonably smooth path it can travel at several times the speed of a walking man without requiring any more energy. However, it can alternatively be used as a load-carrier, as demonstrated in the Vietnam War (see below). If it is not being ridden it can take a huge load, several times as much as a man can carry, and the wheels take 100% of the weight.

Bike1

The effort involved in cycling or pushing a bike along a smooth and fairly level track is relatively small, and only on the steepest and most rugged terrain is it likely to become a handicap compared with a backpack. Furthermore, even hard pedaling seems unlikely to cause the kind of impact injury seen from marching with heavy loads. Bikes are normally rather awkward to push as the user has to lean into them at an angle, but notice the extension poles on the bike shown above, which enable the man to walk alongside it.

A rugged mountain bike carrying the Patrol and Marching Order equipment as saddle bags, while the soldier carries the Assault Order load and rides the bike, could benefit mobility considerably – in terms of energy use, reduced physical stress and also in speed of movement. Furthermore, they can still be ridden on rough tracks, although maybe evolutions of the kind shown below would be beyond the capabilities of the average soldier! Such bikes typically weigh 12-15 kg and are built for rough treatment.

Bike2

05 – Providing the Individual with Mechanical Assistance (Powered)

Adding power to load-carrying systems will dramatically extend their capabilities but usually at a high price in terms of extra weight, and the need to refill their fuel tanks or recharge their batteries. For the present, nothing beats the energy density of liquid fuel, but internal combustion engines bring mechanical complexity and noise. Battery technology is currently developing with astonishing speed under the dual drivers of smartphone and electric car performance, but recharging points are few and far between. This could be ameliorated for infantry load-carriers by making sure that the army’s trucks, APCs etc are equipped to provide fast-charging.

The simplest form of powered load-carrier is the electric-assisted mountain bike. This isn’t much heavier than an unpowered one, typically 16-24 kg. With the most modern technology, the rider pedals all of the time, but the electric assistance engages automatically when climbing hills so this is no more difficult than pedalling along the flat. Regenerative braking helps to recharge the battery when going downhill. As a result, the effective range of these bikes varies between 30 and 75 miles, depending on battery capacity. Most importantly, when the battery does run flat the bike is still entirely usable – it will just be harder to pedal uphill.

Bike4
Electric-assisted mountain bike

Larger and more powerful motorbikes would be the next step, offering a huge jump in capability at a considerable cost. Dirt bikes like the two-wheel drive Rokon shown below are available off the shelf, and have reportedly seen military use. Logos Technologies in the USA has been awarded a DARPA contract to develop the hybrid petrol/electric SilentHawk 2WD trail bike for military purposes, while in 2017 Kalashnikov announced an all-electric-powered trail bike for military and police use, with a claimed range of 90 miles.

Individual transportation for each soldier avoids the all-eggs-in-one-basket problem of relying on a single vehicle which might break down or be blown up, but perhaps threatens to turn the infantry into the cavalry!

Monkeybike1
The 2-wheel-drive Rokon Trail Breaker Dirt Bike 

Looking into the future and assuming that batteries (or some other form of silent power, such as fuel cells) continue to develop rapidly, the most interesting possibility is the powered exoskeleton.

Exoskeleton1
Exoskeleton trials have shown promising results.

Exoskeletons might best be thought of as mechanical legs strapped to the natural legs in order to provide powered assistance.  Loads are attached to the exoskeleton rather than the body, so are taken by the mechanical legs. This has the obvious advantage that it does not require any separate load-carrier like a trailer or bike, which makes it the most attractive solution in theory. In practice, the endurance of the power supply is critical, because if this runs out, the exoskeleton not only becomes useless – it makes it very difficult for the user to move.

Even further into the future, the exoskeleton may be extended to include powered arms. Ultimately a powered suit of armour could be the end result, but for the foreseeable future that will remain in science fiction!

06 – Providing Groups with Mechanical Assistance (Powered)

One suggestion for dealing with the load is to take it off the soldiers and carry it on a vehicle to accompany the patrol. The vehicle may be autonomous, able to follow the patrol automatically for most of the time. The vehicle could also provide battery-charging facilities for the soldiers’ equipment, have hot drinks on tap, and even be equipped to act as a mine-clearance vehicle, bulldozer or trench digger to provide rapid protection. Since it would only have to travel at marching speed, it need not have a powerful engine: electric drive would be preferred because of its silence. This is technically feasible, but there is a major drawback – no current vehicle can match the ability of a human to traverse rough terrain.

The 8×8 vehicle shown below can carry a section’s load, but it is obvious that if it is faced with a vertical obstacle little more than half a metre high, something a human can step over, it will be defeated. So it cannot go everywhere the troops can.

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The HIPPO-X Light Tactical Mobility Platform.

This problem might be reduced to some extent by using a tracked vehicle, as shown below, although fording rivers may be a problem. Essentially, it will not be entirely solved by any conventional vehicle.

Trackedhippo2

Enter the robotic mule – a four-legged vehicle designed to have a climbing ability comparable with a human, as well as the ability to run. These are at the experimental stage and whether they will be adopted for military service remains to be seen.

RoboticMule1
Robotic mules at speed.

07 – Providing Group Animal Assistance

Finally, having discussed robot mules – what about the real variety, which have given good military service in the past (and still do in some circumstances)?  I pose this question only because it will inevitably be asked.

RealMule2
The Mk 1 Mule

Operating beasts of burden is neither cheap nor easy. They require stables, training facilities, feed storage, transportation etc. Soldiers need to be trained in how to look after animals, and specialists like veterinarians need to be available in theatre. Ensuring a steady supply of animals would require a breeding and training program. All of these would be very expensive to establish from scratch, and make operating beasts of burden at least as expensive as motor vehicles, with nothing like the same range of capabilities.

The useful load that beasts of burden can carry will vary greatly depending on the environment, because unless there is plentiful grazing and water available all along the route, large quantities of food and drink would need to be carried for them. They sometimes have minds of their own and refuse to cooperate (as indicated by the phrase “stubborn as a mule”), they make big targets and are bad at diving for cover when under fire. Finally, western societies are increasingly determined in regulating misuse of animals, and the troops understandably tend to get attached to them, so exposing them to the perils of close combat would be unlikely to be acceptable.

08 – Conclusion

There are no completely satisfactory solutions to the problem of the infantryman’s excessive burden. But the penalties of overloading the troops are very clear, both in terms of limiting tactical mobility and in long-term skeletal injury.

While they have some attractive advantages, the problem with all of the “group mechanical assistance” solutions is that they rely on the single vehicle being constantly available which, given the possibility of accident, breakdown or enemy action, will not always be the case. The vehicle also needs to remain in close proximity to its troops, which might not be feasible depending on the terrain. It is therefore desirable for the troops to be responsible for their own kit so it is immediately available to them.

The most promising future individual solutions such as exoskeletons are at a very early stage of development and require further breakthroughs in the density of power storage to provide the endurance needed. Motorists with electric cars already tend to suffer from “range anxiety”; the fear of being stranded if they have no guarantee of recharge facilities en route. This is likely to be a much more serious problem with a military exoskeleton when the user’s life is on the line.

In the meantime, the old but effective technologies of trailers and bicycles are available off-the-shelf. They may not entirely meet military requirements in their present form, but are close enough for evaluation to be worthwhile. It would be an inexpensive exercise to acquire various examples of hiking trailers and mountain bikes (including electric-assisted bikes) and give them to soldiers to use in a wide range of environments to see how their pros and cons compare with that of continuing to carry their present loads on their backs.

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