Testing lighter armor

From Moondragon
Jump to: navigation, search

By Tivar Moondragon

Introduction

This is a description of tests I made in April of AS XXXVI (2001) as part of a discussion with Don Giovanni, when he was Deputy Society Marshal for Rapier. The Kingdom of Ealdormere had asked for permission to experiment with using lighter armor in conjunction with their heavier blades.


History

The standard body armor for SCA rapier has been four ounce leather, four layers of Trigger cloth or the equivalent, ever since rapier was first officially allowed by the Board of Directors back in AS XIV (1979.) That standard has been pretty well shown to withstand broken foil blades and most broken epees. (Problems can arise when an epee breaks with a jagged, rather than a flat point; the only two serious broken blade injuries in over thirty years of SCA rapier fighting have been from jaggedly broken epees.)

When schlager blades were introduced to the SCA, Junior Scientists in the East Kingdom tested them and determined that four ounce leather or four layers of Trigger cloth would also stand up to an untipped or broken schlager blade, thus, the standard continued as it was.

Over the years, however, questions would occasionally arise about the necessity of this "penetration resistant" armor against blades that tended to break less frequently that either foils or epees. The Ealdormere experiment was the culmination of those questions.

My concern, when I heard about this experiment, was that doing preliminary testing of a new type of body armor by taking it on the field for full-speed combat was not a good idea. The only way to find out that the armor didn't work would be through a catastrophic failure--the armor, and quite probably its wearer being penetrated--sort of like the Calvin and Hobbes method of finding out the load rating on a bridge.

So I decided to dust off my Junior Scientist hat, and do some tests under more controlled circumstances.

The Tests

One of the things the East Kingdom's Junior Scientists had found was that an untipped schlager blade actually penetrated fabric more easily than a broken one. Presumably this is due to the fact that the tip has a smaller cross section than a broken blade. I decided that rather than break any of my blades, I'd just remove their tips and test them that way.


Testing an untipped heavy blade against SCA rapier armor, wet rawhide and various combinations of rawhide and cloth:

I tried samples of 4 layers of Trigger and 4-ounce leather on The Machine, hitting it with full-force blows, trying to penetrate. I used my schlager; AEthelyan's schlager (the one affectionately known as "Rebar," which is way too stiff for combat, and spends its time over the mantelpiece) my Mark I Del Tin and my daughter Rosalind's Mark II Del Tin. All of these blades have the tips cut flat and the corners rounded just enough so that there's not a point there. "Rebar" has a tip profile of 3.5 x 10 mm, which is pretty large (the other schlager is 3.5 x 6 mm, my Del Tin is 2 x 7 mm and Rosalind's is 3 x 7 mm.)

On multiple hits, the best I managed was a few small holes in the top layer of the Trigger, (it looked like one corner of the blade had started to penetrate, but it was nowhere near enough for a downcheck if I was testing armor) and one pinpoint-sized hole in the leather. These hits were registering at 8 lbs and up, many maxed out beyond the scale's 18-lb limit.

Against plain wet rawhide (simulating bare skin) I managed to penetrate about half the time; those penetrations were all at 2 lbs. The other shots just skidded across the rawhide. I figure a similar shot would leave a nasty scrape on bare skin and probably a friction burn on skin covered with cloth.

Against the rawhide with a single layer of Trigger, I penetrated about 1/3 of the time. Those penetrations were in the 7-9 lb range.

Against the rawhide with a single layer of linen, I got one penetration at 12 lbs before I decided that the rawhide was too full of holes to continue (I kept getting false penetrations, where the fabric got pushed through an existing hole.)


Drop tests

I then decided to test in the opposite direction. I took the lead weight from my old drop-tester and mounted it on the various blades (sans hilts) that I was using, and dropped them down the tube from my drop tester onto fabric samples clamped over a piece of 4" pipe. Because of the slightly greater weight of the blades compared to the rest of the drop-tester, this gives an impact slightly higher than the 4 joules of a standard armor test, but it still has the advantage of consistency and minimum variables.

I tested Trigger, Judy Linen and some medium-weight cotton fabric. Each test consisted of dropping the weighted blade from a height of 30 centimeters onto the fabric sample three times and observing the results.


Four Layers

Four layers of Trigger passed against all four blades. (Twelve drops, zero penetrations.)

Four layers of linen passed against all four blades, although my schlager and Rosalind's Mark II Del Tin penetrated the first layer. (Twelve drops, zero full penetrations, two with top layer damage--which still passes the SCA drop test.)

Four layers of the cotton passed most of the tests. AEthelyan's "rebar" schlager damaged the first two layers of the fabric and my Del Tin penetrated completely on two of the three tests. (Twelve drops, two full penetrations, two penetrations of the top two layers--which qualifies as failing the SCA drop test.)


Three Layers

Three layers of Trigger withstood my schlager, was penetrated once by "rebar" and twice by each of the Del Tins. (Twelve drops, five full penetrations.)

Three layers of linen were penetrated twice by my schlager, had the top layer penetrated by "rebar", were penetrated twice by my Del Tin and once by Rosalind's Del Tin. (Twelve drops, five full penetrations.)

Three layers of the cotton was penetrated on all three tests by my schlager, "rebar" and my Del Tin, and on two of the tests with Rosalind's Del Tin. (Twelve drops, eleven penetrations.)

I didn't see much need to test one or two layers.

Conclusions

  1. The "four layers of Trigger or equivalent" standard seems sufficient protection against a schlager or Del Tin that has lost its tip. This implies that it's sufficient protection against a broken blade as well, due to the larger cross-section involved, but I'd be interested to try this experiment with a broken Del Tin (considering that the only broken Del Tin I've seen had a sharp spur at one corner of the break.)
  2. Removing a single layer of fabric produces a significant increase in the likelihood of penetration (about 40%.) The threshold point for penetration seems to lie between three and for layers of Trigger. (This has been confirmed by independent tests done by Don Robin of Gilwell.)
  3. Combining the drop-test results with the Machine results, I think it's pretty clear that a single layer of Trigger, linen or other lightweight cloth will not reliably prevent penetration by an untipped blade. There was an injury in the Barony of the Stargate (Houston) in December of AS XXXIV (2000) which bears this out. A fighter was hit in the hand with a Del Tin that had lost its tip. The blade punched through his light leather glove, and penetrated about two inches into his hand.

I think it's doubtful that two layers of fabric would be sufficient either. Three layers might be sufficient, but if "lighter" armor means it’s only reduced by a single layer, what's the point?