Experiments with hemp warbow strings
A lot of time and effort has been spent sourcing authentic period materials for the medieval and Tudor martial longbow. By using contemporary sources, design savvy and the matchless data gleaned from the Mary Rose longbows, accurate replicas have been made and tested. This has given us a good understanding of the potential of the yew weapon and to a lesser extent its white wood cousin. However, the vast majority of this experimental archaeology has been carried out with modern synthetic strings. As the string is a quarter of the arrow/string/bow/archer ‘delivery system’, such testing cannot give us the full picture. It also does nothing to enhance our understanding of how hemp, nettle, flax and silk strings were made or, indeed, what was their design and performance may have been.
To this end a small number of warbow enthusiasts, including Master Bowyer Joe Gibbs, have recently been making natural string that truly astonish and contradict previous preconceptions.
My own initially experiments were based around using side nock bows (a vital ingredient) fitted with strings made from strong 3-ply hemp commercial tread from the 1970s, the like of which I have not seen equalled in more recent times. These strings were of single looped Flemish twist construction. This seemed, perhaps, the most economical design for a liveried string offering the capability of fitting bows or varying lengths, at least to a point. The knot area was reinforced with extra strands and the loop similarly reinforced (and later served as the strings did not cope well with abrasion of bracing). A red silk tracer was laid in to enable an even twist of the plys. Twisting keeps the string round but does increase the stress on the outer surface so needs to be done judiciously. The strings were finished with a beeswax and rosin mix and measured from 1/8” to just over this dimension for bows up to 150lbs. The strings typically lasted for an unimpressive 30-40 shot. Being so thick the speed was also slow due to the hefty mass. Some early experiments ‘self-retired’ and always broke at the end of the loose, as the limbs slammed home, never at full draw. This usually spared the bow from breaking as most of the energy still went into the arrow. Interestingly, these ‘swan song’ shots seemed to go the furthest and imparted a little extra energy to the war arrow. In ‘Toxophilous’ Ascham warns of old strings breaking and breaking bows “or to suffer to tarry over-long on (the bow)”. Clearly, a 30 shot old string is still quite new and the results were unacceptable. Being a bowyer and testing the strings with semi-sacrificial heavy white wood bows a fairly Cavalier attitude was taken as to the possible ramifications of a broken string!
Surprisingly, some commercial thread, like ‘Barbour’s Best Irish Flax’ had a moderately impressive strand tensile strength, which proved stronger than thread spun from some hemp fibres. This was very disappointing to find given the disproportionate effort involved. It seems the unspun hemp fibres used had been retted inappropriately and lost a good deal of tensile strength. Anything that looks like it may have been bleached is also of very like use for strings and fit only for darning socks.
Further experiments were made using thinner strings made by gluing the strands together with hide glue (isinglass may be better) and using a double loop design which negates the need for tight bends to be placed in the string that are necessary with a timber hitch. Gluing the strands removed any weak links in the string as it homogenises it. It also does not need to be twisted as a Flemish string does. Close inspection of the archers depicted shooting at the butts on the early 14th Century Luttrell Psalter clearly depicts a double looped string of some design. As its date is post ‘Statute of Winchester’ the butts are likely to be a furlong apart. This image is before the use of perspective so little can be assumed about distance by a literal reading of the image. Graphically, the image is very strong yet a naturalistic representation of even 50 yard buts would look too elongated and unbalanced. Having double butts is also more far worthwhile for distance shooting. Therefore, the bows shown are likely to be of heavy draw-weight but may be personal bows with bespoke strings.
Image C/O the British Library
Clearly, such strings would be less suitable for liveried bows but, nevertheless, provides useful insight.
Currently, I have been making full length hemp fibre strings made using a double looped design after information from Japanese archery enthusiast, Steve Fletcher. He informed me that the hemp yumi strings were very strong and thin and I really needed to look at one. The hemp on the strings below is from the same source as Japanese ‘yumi’ strings. Complete yumi strings can be modified but if a manufacturer can be approached directly it is easier as the glued on ribbon loop serving is difficult to remove. The results have been breath taking and it has been possible to produce very strong and durable strings around 1/16” in diameter. These strings have coped with bows well over 120lbs for many, many shots. Again, the most highly stressed areas of the string, being the nocking point and loops, were double reinforced. It seems no coincidence that these areas have the tightest bend in them and great care must be taken not to bend the hemp strings at an angle either in use or storage. The shooting performance is certainly the equal of modern strings. It is interesting to note in the production of the double looped strings that they are so un-elastic no account needs to be taken for string stretch in use. For shooting tests with precious 150lb self yew bows a less casual attitude was adopted and 2mm strings were used. Joe Gibbs has shot bows strung with hemp of some 170lbs with success. Inspection of extant Medieval and Tudor arrow nocks indicate that a string plus serving diameter of 1/8”was common , so a considerable tolerance must have been added for warfare to produce a very resilient string indeed.
Left, a slender glued hemp string matched to a 120lb ash warbow. Right, a re-infored looped, serve with hemp in hide glue on an elm side nocked bow.
Whether the double looped string was ever used with liveried bows is unknown. However, conversations with a fellow hemp warbow string experimenter pointed me to information I had initially missed in the Mary Rose publication on its military artefacts, “Weapons of Warre". Intriguingly, analysis of the MR bows suggests that the slot angle cut into the bow nocks differs slightly from top to bottom which may suggest a different fixing system at either end. I'm not sure why a dissimilar angle would be needed to be filed into a top or bottom bow nock, with either a knot or loop, but I have much to learn. Certainly with side nocks and a double looped hemp string, keeping both loops quite small helps the string track better down a bow. The upper loop needs to be made just a little larger to facilitate bracing.
Interesting, modern yumi bows, albeit of light weights, successfully use hemp strings with a modified timber hitch at one end and a loop at the other that apparently avoids fibre-rupturing bends by wrapping the string ends in silk. It is quite possible that medieval archers would lay in a second flemish twist that could be fitted to their own bows length.
Undoubtedly, we need a great deal more testing and investigation to gain a better understanding of this oft neglected area - the medieval/Tudor bowstring. Tensile strength test are due to be made on the strings in the laboratory and will provide finite data.
It is undeniable that hemp is a natural ‘super’ material with qualities that simply astound.