July 20, 2011

Medieval Soldiers Were Weighed Down By Armor

Researchers studying the effects of wearing heavy battle armor found that France may have lost the Battle of Agincourt because their soldiers' armor was so heavy it left them breathless and slow-moving.

A new study, published in the Proceedings of the Royal Society B, shows that soldiers carrying armor in Medieval times would have been using more than double the amount of energy had they not been wearing it. This new study is the first experimental evidence of the drawbacks and limitations soldiers faced while wearing Medieval armor in combat.

The study suggests that the Medieval armor would have been so heavy, that soldiers would have been exhausted even before going into battle, and it may have affected the outcomes of many famous battles throughout history.

Scientists monitored volunteers outfitted with 15th Century replica armor as they walked and ran on treadmills. The body armor added an extra 66 to 110 pounds of weight to each volunteer. They found that the test subjects used high levels of energy and suffered from restricted breathing because of the excess weight.

Tests on the volunteers breathing and stride patterns showed that the energy required to walk in armor was 2.1 to 2.3 times higher than normal, while running was 1.9 times harder.

This rate was higher than the average 1.4-fold increase in the volunteers' body mass from the weight of the armor, showing that the strain of wearing the full battle attire was down to its positioning on the body, and not just its heaviness.

Based on the findings, researchers suggest that the heavily-armored French soldiers stood little chance in battle after advancing across boggy ground towards the more lightly outfitted British archers at Agincourt in 1415. The exhaustion caused by several days of marching while wearing the heavy armor may have also contributed to France's defeat by the English in the Battle of Crecy in 1346.

Dr Graham Askew, from the University of Leeds, and lead author of the study, said: "You look at these suits of armor, and they weigh between 30 and 50kg, so it is a huge fraction of the wearer's body weight."

"Because the French were wearing full, heavy armor and the field was so muddy, by the time they got to the enemy they would have been exhausted and easily killed," he explained.

The scientists also looked at how the volunteers performed while wearing armor compared with carrying the equivalent load on their backs, which is similar to the weight a modern soldier might carry in their backpack.

"Carrying this kind of load spread across the body requires a lot more energy than carrying the same weight in a backpack," he added. "In a suit of armor, the limbs are loaded with weight, which means it takes more effort to swing them with each stride."

The breast and back plates on a suit of armor would also have increased the load on the muscles used to breathe, making deep breaths harder to take, he added.

One of the main reasons the volunteers used so much energy is that wearing the suit of armor puts a huge load of weight on your legs, which are used to carry you, Askew explained to BBC News. "When you walk and you swing your legs, you are requiring a lot more muscular effort, and that costs you a lot more energy."

The team said the findings had given them insight into the battlefield trade-off between added protection alongside increased maneuverability and fitness to fight.

Askew said soldiers could have removed their leg armor, decreasing overall added weight and increasing ease of movement, "but it might have meant they would have been cut on the leg and killed that way."

But such problems may have been less of a problem in the 16th century, he added.

With the advent of guns, hand-to-hand combat decreased, and this also affected the design of body armor. "It is interesting to see though that as armor developed into the 16th Century, the part of the armor that was lost was the lower leg - the thing that we found increases the cost of movement," Askew told BBC News.

Thom Richardson, keeper of armors, from the Royal Armories in Leeds added: "It is interesting to use scientific method to answer these questions, and it confirms what we have always suspected - heavy armor would very much reduce your ability to run around. But no-one wears stuff on the battlefield if it isn't useful."

The research team included academics from the Universities of Leeds, Milan and Auckland along with experts from the Royal Armories in Leeds, UK. Researchers worked with highly skilled fight interpreters from the Royal Armories Museum, who wore exact replicas of four different types of European armor.


Image 2: Wearing armor has been shown to use more than double the energy required to walk and run. Credit: University of Leeds


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