Friday, October 21, 2005

Body Armor Part II:

Romans, Weight Distribution and Armpits

In Part I we reviewed the historical evolution of body armor with images of body armor over the centuries. In this section I wanted to review why body armor changed and what those historical changes might mean to developing body armor for the modern warrior.

With each successful attempt at reducing harm to the individual warrior, the opposing force has always spent an equal amount of time figuring out how to defeat that protection.

Equally, armorers spent as much time trying to counter each evolution of new or improved weapons. Of equal import was the type of injuries that could be sustained in battle:

Third, the type of wounds that can be suffered do not change. They can be broadly classified into three types: blunt force trauma, penetrating wounds and amputation of limbs.

Along with each of these advancements in armor and weapons, additional advancement in general tactics and even in medicine or treatment of wounds and their perceived survivability had an effect on what was deemed most important for effective protection of a warrior. At some points in history, armor nearly disappears and then reappears again only to be "re-invented" with new materials, making the same long and sometimes agonizing journey to it's last, latest and greatest form. This was alternately (and sometimes simultaneously) due to collapses of civilization which forced technology back centuries; the advancement of weapons and tactics that warriors felt precluded effective armor; the cost factor.

Take for instance the period between the French Cuirassier and the World War I soldier with a simple steel plate in a bag around his neck to protect his chest.

That is one hundred years without any real advancement or use of personal body armor for soldiers. Why? Weapons and tactics. By the time of the Napoleonic Wars, hundreds of thousands of men could be amassed in lines with muskets with a ball or amunition size and velocity that could now easily and relatively cheaply penetrate armor. Add to that volley fire en masse and even an armored cavalry charge could be devestated. Why go to the expense of armor if it was not effective? Instead, the cavalry changed it's tactics to include flanking manouvers and charges timed with artillery and infantry. The same went for the infantry: no need for armor when muskets at close range made it moot.

By the time breachloading and repeating rifles and pistols came on to the field, any consideration for armor had been all but relegated to a past time for military equipment research and development. Most of the time was spent on how to make weapons even more effective. In short, the arms race seemed to have left armor far behind. Why did it make a reappearance in World War I?

There were multiple reasons. During the Napoleonic Wars, the first real ambulance and field hospitals had been created. By the American Civil War (post Crimean Conflict), the idea of a dedicated medical corp was being advanced. With a dedicated medical corp came information in the form of reports back to headquarters about the number and types of injuries. Quite possibly, the Civil War period may have seen the first real attempt to collect data and develop better medical care and procedures on a mass scale.

By the time of the "Great War" (WWI), the concept of a dedicated medical corp had been refined to the point where they were separate units within the military and wore recognizable insignia generally respected by all sides as non-combatants. Even more reports and data were generated regarding numbers and types of casualties. Further, surgery had advanced to the point where a bullet in the leg or arm didn't necessarily mean amputation, soft tissue wounds could be easily sutured and even wounds to the torso that did not effect major organs might be survived. However, repairs to vital organs and arteries would mean death and so would traumatic head wounds.

Weapons had advanced to the point where men could be killed from a munition fired a mile away. A single three man team on a machine gun could be responsible for the deaths of hundreds of opposing forces. At the beginning of the war, men would just as likely die from a bullet as from any other munition. By mid war, the most likely wounds were from shrapnel from the far flung bombardment of trenches or other hand held shrapnel devices. Since the men were in trenches, the most likely places they would suffer wounds were the head and upper torso as these were the exposed areas of the body.

Finally, World War I saw casualties the likes of which had never been seen before. War no longer meant the death or wounding of thousands or tens of thousands or even hundreds of thousands, but millions of able bodied men. These casualties were both strategically and politically damaging. Training, equipping and transporting soldiers was expensive. People, both military and civilian, began to realize that everything, including soldiers, had a finite limit. No matter how advanced the weapons were, you still needed men to operate them and men to hold the land. Otherwise, war was futile. The man who created the modern machine gun was credited as saying that he had created the machine, not to help win wars and make it more efficient, but because he hoped that it would be so devestating people would think twice about going to war (the same reasoning for nuclear weapons?). He greatly underestimated human nature and ingenuity.

Another period in time when armor seemed to go backwards, though not disappear, was the beginning of the dark ages. Like much technology developed through the Greco-Roman period, once the empire collapsed, so did certain advancements including running water, sewer drainage, math, writing and even armor. This loss can be contributed to the steady decrease in the flow of information from the civilized centers of the empire. Roman roads were no longer protected by vast armies patroling or securing them thus traveling, which precipated the spread of information, tradesmen and technology, could no longer be safely undertaken, slowing the speed of dessimination. This also meant that advanced materials, such as iron ore, were no longer able to move freely, limiting the amount and inflating the cost.

Secondly, without the fiscal power of the state, it was no longer economically feasible to equip and maintain large armies. It became the responsibility of individuals to provide their own weapons and protection. Third, the value of a foot soldier's life, and life in general, was greatly depreciated. Thus, the cost to benefit ratio equaled little armor for the common fighting man called up out of his field to form the untrained foot soldiers of a fuedal lord. Peasants, which formed the foot soldier ranks, were easily replaced.

Obviously, modern defense spending has a lot in common with it's predecessor; armor must be effective AND inexpensive to be procured for individual soldiers.

So, what can we learn from body armor of the past that can be useful to a modern body armor manufacturer and the soldiers they serve?

Romans, Weight Distribution and Armpits

This is a set of modern body armor called the Interceptor. Like it's Roman predecessor, it has a front closure that makes it easy for the individual soldier to remove by himself or by another soldier/medic who may have to treat him. It is a full vest that protects the front, the back and the sides. However, the most protection is found in the front and rear ceramic plates, unlike the Roman armor which provides the same protection all around. The Roman armor uses metal strips or "lames" (pronounced "la-mays") to provide protection and maintain flexibility. The Interceptor uses layers of Kevlar or Spectra armored clothe to provide similar protection and maintain flexibility. However, the areas not covered by the ceramic plate can still be penetrated by fast flying shrapnel from an IED, the 7.92 AK 47 bullet or larger rounds preferred by snipers, particularly at close range. The extremities are largely unprotected, but the fatal areas are the face, neck and around the arm areas where the armor ends. Recent reported deaths include soldiers that have been shot in the armpit area, having the bullet travel through the chest damaging heart, lungs or severing major arteries. Snipers in Iraq and Afghanistan are learning the strengths and vulnerability of our body armor just as opposing forces in the Greco-Roman and Medieval period took the time to learn how to defeat their armored opponent.

The Romans had a similar problem and corrected this by adding several articulated "lames" (pronounced la-mays)over the shoulders, long enough to hang down slightly past the arm pit and provide additional protection at the shoulder joint where limbs could be severed. The articulated shoulder maintained mobility, provided layered protection to the joint and allowed the shoulder "lames" to cover the armpit even when the arm was fully extended overhead. Medieval armorers addressed this problem by adding padding, chain mail and rondels (round metal armor) to the arm pit area. This had it's own problems since the leather straps holding it in place could become damaged and the placement of the rondels could hinder the mobility of the arm.

Modern armorers may want to investigate the use of "lames" or "rondels" (using modern kevlar, spectra and ceramic materials) to add this protection. Several issues may arise from this addition. First, the segmented "lames" would add bulk to the shoulder area that is used to stabilize a weapon for accurate shooting; a problem the Romans did not experience. Second, they may cause some arm mobility issues though it is widley known that Romans had perfected the art of javelin throwing in battle, so this may be minimum. Last, the added weight may be one more impediment to the speed of the infantry. Although, it may surprise you to know that the Roman armor is approximately the same weight as the modern interceptor including upper arm and groin protection devices.

The added weight issue could be minimized by improving weight distribution and the materials used to make the "lames". The lames could be made of layered kevlar and/or spectra that lays over the shoulder like the Roman model, but would be more flexible and possibly less heavy. The layering of the "lames" (aside from the layered kevlar) could act as a sufficient deterence without actually making these items from a metal alloy or the ceramic materials used in the SAPI plates. Or, for added protection, small ceramic plates could be added at the ends of the "lames" to cut down on the general bulk, distribute the weight and provide additional coverage over the open areas of the arm pit/joint.

The Romans understood the impact of weight on their infantry forces. They needed to be able to march hundreds (sometimes thousands) of miles and still be fresh for battle. The battle itself could last from 15 minutes to three hours not inlcuding multiple small skirmishes along the way. Looking at the modern interceptor armor above, the same weight distribution problems can be seen throughout the development of armor.
The interceptor, like other armor of it's kind, rests on two muscles close to the neck: levator scapulac and the trapezius. Continuous weight on these muscles can lead to neck and back pain from strained muscles or compressed spinal discs.

Romans combatted this problem by adding the subarmalis. Just as it sounds, the subarmalis was worn under the armor. While the leather vest provided protection from rubbing, an equally important part of the vest were the shoulder pads. These shoulder pads "squared up" the shoulders and provided equal distribution of the weight across the entire shoulder area. Simple velcro shoulder pads could be attached to the modern soldier's uniform (inside or out) or under the shoulder piece of the interceptor armor itself to produce the same effect without adding another layer of clothing. Adding the shoulder pads to the soldiers uniform would be the easiest and least expensive method to achieve this. It would be a simple issue of "sewing glue", velcro strips and the pads with a directive to add it to the specified area. It may even be the best method, sans tailor, to insure that the shoulder pad is "custom fit" (placed) since every soldier has a different shoulder width.

One problem with this concept may be the narrowness of the shoulder interface of the current interceptor. This does not appear to reach the point of the shoulder joint where the shoulder pad would be located for weight distribution (based on the above image). This could be overcome by one of two methods:

1) Adding the segmented "lames" to the shoulder would act as the levering device, resting on the shoulder pads and helping to distribute the weight.

The shoulder interface could be lengthened just at the top to meet the point of the shoulder blade. The shoulder interface or strap would look like a bell curve with the top of the curve meeting the shoulder joint or ending just before.

This would mean that the upper arm protection would need to be slightly modified to allow the shoulder a full 360 degree range of motion. This modification would mean simply shortening the top of the bell curve on this upper arm protection by as little as half an inch.

In summary, the Romans could teach us a thing or two about weight distribution of armor and protecting vulnerable areas. They may even have used fancy words like anthropometric compatability to explain how they reduced cost by standardizing shape and size.

Update: Researching modern sports "armor" I came across a few items that reminded me that even I may be re-inventing a wheel that has already been created and simply needs to be adapted to modern body armor for the warrior.

Modern Day Subarmalis (football undershirt with pads):
Under armor shirt with shoulder pads to support vest and upper arm protector. The shoulder pads on this model might be a bit too much, possibly needing to eliminate the last "lame" (la-may). Also, missing the rib belt and would need to be modified to provide the blunt force trauma protection in the rib and chest area. The other important aspect of this under armor is the moisture wicking material of the shirt, killing two birds with one stone since the military is moving towards moisture wicking t-shirts.

Another football "subarmalis" with light shoulder padding and a rib belt that could provide blunt force trauma protection. Although, the rib belt may be too thick to fit under modern body armor and would also need to be modified. Additional shoulder padding would be needed to help raise the armor a little more and distribute the weight across the entire shoulder.

Motocross subarmalis. This also provides an articulate spine protection. This model may present a problem with additional weight.

And idea for shoulder protection that is articulated, allows for full rotation and, looking at the arm pit area we can see how a simple addition of a small pad of kevlar, sown to maintain articulation, could provide extra coverage in the area without adding bulk that could interfere with bringing up a weapon or accurate aiming or even throwing a grenade. This could also be added to the modern interceptor with velcro or a strap as is being used to connect the upper arm protection currently used. That upper arm protection could part of that assembly.

In Part III, Body Armor: Re-inventing the Wheel, we will review the problems experienced with the modern SAPI boron carbide plates and explore how Greco-Roman and Medieval armorers used contoured armor to overcome similar problems with weight, strength and blunt force trauma.


riceburner147 said...

Kat: Hate to be a pain (not really) but...did you finish the motorcycle diaries ? and if not...wil you PLEASSSSSEEEE. :)
(I can beg good, cant I)

Kat said...

Rice, I've been a little lax on the personal story area for a bit, but I will see if I can scare up the brain power to complete the last four days of the return trip.

It was funny, but only the last day was as funny as the first seven.

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