Sunday, November 21, 2010

Warbow Strings vs. Draw Weight

There is a school of thought within the English Warbow community that the warbows rarely, if ever, went over #100lbs in draw weight.  The argument is made using evidence from the artifacts recovered from the sunken Tudor ship the Mary Rose.  Since no bowstrings have in fact survived the centuries under water, scholars and enthusiast have looked to other aspects of the medieval archer's aresenal for support of this theory.  The evidence they use comes from arrow shafts recovered from the shipwreck.  Scholars and enthusiasts have looked at the nock (the portion of the arrow that is mounted upon the string) to determine that many so called "warbows" were probably less than #100lbs.  The nocks on the recovered arrows were only 1/8 of an inch wide, therefore, only able to accomodate a string 1/8" thick or less.  They theorize that it is unlikely a string of 1/8" thickness can support more #100lbs of draw weight.

Looking at the string of my warbow, I measured the thickness of my string at the nock point.  The thickness was exactly 1/8".  At the nock point there is and extra layer of cordage know as the serving, so I measured a portion of the string without the serving and it was less than 1/8".  The string material I use is called FastFlight and is a modern manmade material.  Warbow archers of medieval and Tudor times would have used natural linen or hemp fiber bowstrings.  I have a linen string for one of my #55lb bows.  Upon measuring that string, it too is less than 1/8" thick.  No doubt that a #55lb bow is going to require a less intense string than that of a #100lb+ warbow.  However, Myself and other warbow archers believe that warbow of draw weights greater than #100lbs could indeed have strings no more than 1/8" thick.  Here is a link to a forum thread on this very topic...
http://paleoplanet69529.yuku.com/topic/39555

As the topic is still in debate, I believe that warbows of the medieval and Tudor times were often over #100lbs in draw weight.  Please add your thoughs and comments...

3 comments:

  1. So, here’s some more string-things to think about.

    There is much lore surrounding archers keeping their strings dry. I’ve heard it said by some that this is because the string would become weak and stretchy if wet. Not so. Linen actual becomes stronger when wet. Perhaps the string might be heavier when wet…but I expect much of water would fling free in a shot or two. So then why?

    I will have to go in search of the source, but I recall reading a complaint (possibly a Victorian era source) that good strings could no longer be had as the best string maker had died taking his recipes (for some kind of glue or sizing used on the strings) to the grave with him.

    I believe, and I’m not alone, that medieval strings may have been treated with a glue/sizing as well. Sir John Smythe in 1591 writes of “water-glewe” used on strings.

    Now, I’ve done some glue research for other reasons and have not come across another contemporary reference to water-glewe . I think he might be talking about hide glue of some kind.

    This would make sense since hide glues will re-wet – creating a need to keep the string dry. It may be that such a glue applied to the string would bind any wee little fibers hairs together making the string stronger.

    There seems to be lots of people making linen strings but I’ve yet to see anyone experiment with glues (would love to hear from someone who is!).

    Likewise, flax/linen has a very long staple fiber (contrary to what some have written in relation to bowstrings) but the staple length of fiber is reduced by modern harvesting methods (breakage). It would be worth trying to produce flax fiber from scratch. Flax harvested and carefully retted and spun by hand (especially if wet spun which produces very strong smooth threads) might well be quite a bit stronger.

    Thanks for posting this – been ages since I thought about strings!

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  2. Totally true about wet linen! My linen string performs just fine in the all-to-often rain that we have where I live. And the water does fling off after a few shots anyways.

    That is most intriguing about the string maker! I have heard man folks on forums mention a hide glue type of string keeping system. And of course the purpose of string wax today is to "bind any wee little fiber hairs together making the string stronger." So that would make sense that that was at least one purpose of the hide glue.

    I agree completely that modern harvesting methods take away from the effectiveness of flax. Many folks on the forums have harvested their own with significantly better results than machined thread.

    Strings have fascinated me since I picked up my first warbow in January 2010. Anyone can make a bow, but to make a worthy string takes special care and skill.

    p.s. I read your blog and noticed you are in the SCA, so am I! Kodhran Avgronndal from the Shire of Riversbend An Tir at your service!

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  3. Hello Kodhran!
    After I posted last I went and bought a new spool of Irish linen shoemaker's thread based on some suggestions by other string-makers (on-line forums). Much to my annoyance it tested worse than any of the linen I'd bought before.

    Since I was already in the mood for mucking about with strings I decided to pull out some silk I bought from India for tablet weaving.

    I had two: a 40d reeled filament silk and a 20/2 spun silk used primarily in carpet manufacture.

    To my surprise both tested much better than any of the linen I've used so far. Once more, the number of strands calculated to produce the strength of string I needed yielded a string which was actually TOO thin for my knocks; I had to use a thicker serving to compensate.

    With linen I sometimes have the opposite problem. I've often wondered how you'd make a string for a really heavy bow and still have it thin enough to fit period arrow-knock sizes. Likewise (unlike you) I shoot at a pretty light draw weight so I'm sensitive to anything that will tend to slow my arrows; I don't like a bulky heavy string.

    I did one string waxed and I hide-glued the other. In both cases, since I understand silk is far more prone to creep. I left them hanging under tension (weights) overnight to stretch. Both seem to be performing well though I haven't shot them all that much yet.

    Not sure at this point what benefit there is to gluing the string (stronger? less creep?). The end product is interesting, it's stiff like wire. It can still be coiled up but not too tightly. The glue adds a bit of weight as well.

    One interesting note - In both cases the silk strings are quite noisy and sometime continue to hum long after the arrow is gone.
    Cheers,
    Lucrece

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