A horn-and-sinew composite bow shoots better than a wooden bow of the same draw weight

The summary today

There is only one direct measurement of the horn-and-sinew composite. In 1988 six replicas of historical bows were shot by the same archer at a ballistics station: a 27-kilo composite sends the 50-gram arrow off at the same speed as a 36-kilo yew longbow and throws it more than 90 metres further. In the same test a 17.2-kilo Apache wooden bow backed with sinew launches a 28-gram arrow at 43 metres per second, against 30 for the 24.9-kilo Sioux hickory bow with a 30-gram arrow. The models explain where the advantage would lie: at equal draw weight, draw length and limb mass, six types of bow, from the ancient straight bow to the modern recurve, launch the arrow at almost the same speed, but sinew and horn store 2,500 and 1,500 newton metres per kilo against 1,100 for yew and 700 for maple, so by the calculation the composite reaches the same draw weight with shorter, lighter limbs, and the credit goes to the materials, not the shape. In 2020 a comparison at equal draw weight and draw length points the same way, with the elm bow about 14% slower, but the other bow is a modern one, with a wooden core between two strips of fibreglass, not a horn-and-sinew composite. The test on the historical composite compares a single bow of each type, and bows that differ in several things at once.

Also phrased as: "composite or wooden bow"; "horn and sinew bow"; "asiatic bow faster"; "longbow versus composite bow"; "efficiency of historical bows"

Evidence

• 1983
  Context Model Published later

  A doctoral thesis on the mechanics of the bow and arrow, with mathematical models and no participants. The summary concludes that the static recurve bow is not inherently better than, for example, a long straight bow, but that with an expert combination of materials such as wood, horn and sinew the Asiatic bow stores more energy per unit of mass than the wooden bow. The summary contains no figures.

  On the mechanics of the bow and arrow · Bote Willem Kooi

• 1988
  For Equipment tests Published later

  Replicas of historical bows shot several times by the same archer, speed measured with two screens 3 and 6 metres from the line: a 27-kilo (60 lb) composite sends the same 50-gram field arrow off at the speed of a 36-kilo (80 lb) yew longbow, and throws it more than 90 metres further.

  Experimental archery: projectile velocities and comparison of bow performances · C.A. Bergman, E. McEwen, R. Miller

• 1988
  Context Equipment tests Published later

  In the same test, backing a wooden bow with sinew raises the speed a great deal even at a lower draw weight: the sinew-backed Apache bow, 17.2 kilos, launches a 28-gram reed arrow at 43 metres per second; the Sioux hickory bow, 24.9 kilos, a 30-gram arrow at about 30. Here the comparison is between a sinew-backed wooden bow and a plain wooden one, not with a horn-and-sinew composite: it stays as context.

  Experimental archery: projectile velocities and comparison of bow performances · C.A. Bergman, E. McEwen, R. Miller

• 1988
  Context Equipment tests Published later

  In the same test, the overall picture: top speeds from 30 metres per second (Sioux bow) to 51-60 (Crimean Tartar composite), with the Egyptian composite between 32 and 52 and the yew longbow between 37 and 53 depending on the arrow; draw weights from 17.2 to 40.8 kilos, arrows from 13 to 90 grams, all strings in Dacron. The composite also allows a much longer draw for the same bow length: a ratio of bow length to draw length of 1.5 to 1 for the Egyptian composite against 2.4 to 1 for the yew longbow.

  Experimental archery: projectile velocities and comparison of bow performances · C.A. Bergman, E. McEwen, R. Miller

• 1991
  Context Model Published later

  A model of the modern working recurve, compared with historical bows through dimensionless coefficients: according to the author, what improved the bow was above all materials able to store more energy per unit of mass, and used in larger quantity, more than the shape parameters. It is a qualitative conclusion, with no direct comparison between a composite and a wooden bow.

  On the mechanics of the modern working-recurve bow · B. W. Kooi

• 1997
  Context Model Published later

  A mathematical model checked on replicas: at equal draw weight, draw length, limb mass, arrow and string, six types of bow launch the arrow at almost the same speed. Coefficients proportional to initial velocity: straight bow 2.01, Egyptian-Assyrian angular bow 1.92, Persian 1.94, Turkish 1.99, excessive recurve 2.08, modern recurve 2.09. Shape alone does not give the advantage.

  An approach to the study of ancient archery using mathematical modelling · B. W. Kooi, C. A. Bergman

• 1997
  For Model Published later

  In the same study, the energy materials can store per unit of mass: sinew 2,500 newton metres per kilo, horn 1,500, yew 1,100, maple 700, steel 130, fibreglass 4,300. This is why a composite reaches the same draw weight with shorter, lighter limbs.

  An approach to the study of ancient archery using mathematical modelling · B. W. Kooi, C. A. Bergman

• 1997
  Context Model Published later

  In the same study, several historical bows used only part of their materials' capacity: estimated energy density against the theoretical maximum of 230 against 1,100 newton metres per kilo for the Mary Rose longbow, 135 against 2,000 for a so-called Tartar bow, in fact Manchu-Chinese, which had not been drawn to its full length, 90 against 130 for a steel bow, 1,540 against 2,000 for the Turkish flight bow. Being composite is not enough: what matters is how the materials are used.

  An approach to the study of ancient archery using mathematical modelling · B. W. Kooi, C. A. Bergman

• 2007
  Context Model Published later

  A review chapter on bow design and materials, taking from the literature the elastic energy that can be stored per unit of mass: fibreglass 4,300 newton metres per kilo, sinew 2,500, horn 1,500, yew 1,100, maple 700, steel 130. These are the same values as in the 1997 paper, with no new measurements on bows actually shot.

  Design and materials in archery · B.W. Kooi

• 2020
  Context Equipment tests Published later

  Two bows of similar shape fixed on a mechanical device, same draw weight (34 lb) and same draw length (23.5 inches): an elm wooden bow with a linen string and a semi-longbow with a wooden core between two strips of fibreglass and a Dacron string; the wooden bow has longer limbs. With the 25.66-gram arrow the laminate launches it at 42.17 metres per second and the wooden bow at 36.31; with the 30.35-gram arrow 40.12 against 34.41. The wooden bow loses 13.90 to 14.25% of the speed and 25.87 to 26.46% of the energy, over 6 to 10 shots per combination, with no inferential statistics. The faster bow is a modern laminate, not a horn-and-sinew composite: for this claim it is context.

  The important role of bow choice and arrow fletching in projectile experimentation. A ballistic approach · Christian Lepers, Veerle Rots

Status history

1. 1983 Not studied The first indication is theoretical: a doctoral thesis on the mechanics of the bow concludes that the recurved shape is not in itself better than a long straight bow, but that by combining wood, horn and sinew well the Asiatic bow stores more energy per unit of mass than a wooden bow. The summary gives no figures and no bow was built and shot: it is a qualitative conclusion, which stays as context, and the question has not yet been put to the test.
2. 1988 Reported The first measurements arrive, at a ballistics station, on six replica bows shot by the same archer: a 27-kilo composite sends the 50-gram arrow off at the same speed as a 36-kilo yew longbow, with a range more than 90 metres longer, and a 17.2-kilo sinew-backed Apache bow beats a 24.9-kilo Sioux hickory bow (28 grams at 43 metres per second against 30 grams at 30). Direct evidence on the equipment, but from a single study and with bows that differ in several things at once: reported.
3. 1991 Reported The author of the 1983 thesis extends the model to the modern working recurve and compares it with historical bows: what improved the bow, he concludes, was above all materials that store more energy per unit of mass, more than the shape. It is again a calculation, which strengthens the reading of the mechanism without adding a measurement, so the direct evidence is still that of 1988.
4. 1997 Reported A model sets a precise limit on the claim: at equal draw weight, draw length, limb mass, arrow and string, six types of bow, from the ancient straight bow to the modern recurve, launch the arrow at almost the same speed, with coefficients between 1.92 and 2.09. The composite's advantage lies not in the shape but in the materials, which store from one and a half to more than twice the energy per kilo of wood and allow the same draw weight to be reached with a shorter, lighter bow. The model refines the 1988 measurement without overturning it: reported holds.
5. 2007 Reported A review chapter on bow materials reports the same table as in 1997, with fibreglass at 4,300 newton metres per kilo, almost twice sinew and four times yew. No new test on bows actually shot: the direct evidence is still a single study and the status does not move.
6. 2020 Reported The first comparison at equal draw weight and draw length arrives: two bows of similar shape at 34 lb on a mechanical device, one of elm and one with a wooden core between two strips of fibreglass. With the same arrow the wooden bow is about 14% slower than the laminate and gives it roughly a quarter less energy. It points the same way, but the faster bow is a modern laminate rather than a horn-and-sinew composite, and the two bows also differ in length and string: it stays as context, and the direct evidence on the historical composite is still that of 1988.

Related

Related articles

• What a bow is made of: what the materials of limbs, riser, string and arrows changeWood, horn, carbon, glass fibre: what bench tests on limbs, risers, strings and arrows have measured, and how much of it reaches the archer's hand.
• How much energy actually reaches the arrow, and where the rest goesHow much of the drawing work reaches the arrow: models say about three quarters, while the few measurements show where the rest goes and what the arrow changes.

Research lines

• 22 studiesHow much energy passes from bow to arrow: models and measurements since 1937
• 22 studiesTraditional and historical bows, from models to archers

Other claims in this domain

• CorroboratedAlong its flight the arrow loses an appreciable part of its launch speed12 studiesStatus since 2011
• CorroboratedAs it leaves the bow, the arrow flexes and snakes around the riser instead of leaving straight19 studies · 47 archers measuredStatus since 2012
• ReportedA camera-based scoring system misreads some arrows: the ones barely sticking out and the ones that shift the target face7 studies · 2 archers measuredStatus since 2017
• ReportedA chest band with fibre optic sensors measures breathing and mean heart rate with small errors, and an archer can wear it while shooting2 studiesStatus since 2019
• ReportedA compound bow stores between 70 and 100 joules and sheds about two thirds of the force at full draw4 studiesStatus since 2015

See all claims on equipment and tuning