Holmegaard bow

To begin our tour of Europe, let’s travel all the way up to the far north where lies, deep in the cold desolated lands of Denmark, the origins of the bow…

Well preserved in the peat bog of the Holmegaard Mose settlement, the oldest bow artifact known to date was found. Dated around 7000 years BC, it is broken in several pieces and strongly decayed but still displays its unique characteristics…

Other artifacts were found in more recent sites nearby Holmegaard and showed a variety of shapes, width and poundage. However a recurring design seemed to take place.

Artifact of the Holmegaard bow – Danish National Museum

This bow is made from a small elm tree. The tree was split in two and reduced so that the flexible sapwood layers on the back of the bow and the hard heartwood for the belly. Elm is a good bow wood because it has a good balance between tension and compression strength.

At a first glance, the bow seems to have a simple pyramidal shape but on closer inspection, we can see “shoulders” or sudden width reduction a little past mid-limbs, creating pointy tips. These were first thought to be due to decay but they are in fact a proof of the ingenuity of the mesolithic bowyer.

To be efficient, a bow must have fast moving limbs. And, to make the limbs to move faster for a given stored energy, the only way is to reduce their mass. From a leverage effect, the effect of mass reduction on arrow speed is more and more important as we get closer to the bow tips or ends.

The purpose of the narrow tips of the Holmegaard bow was, thus, to optimize its efficiency. While the wide and thin inner-limbs store a lot of energy and are able to sustain the tension, the narrow thicker limbs give most of this energy back to the arrow at release, thanks to their low weight. Arrow marks from the Mesolithic period were found on large animals such as deers. The fact that Mesolithic hunters could hunt such large game, demonstrates how excelling their bow craftsmanship was.

Schematic view of the Holmegaard design.

Knowing the story and characteristics of the oldest bow ever found, the temptation to make my own was irresistible. Testing this 9000 years old design is also a way to show that old doesn’t mean inefficient or unsophisticated. On the contrary, crafting such a bow with nothing but stone tools is a very demanding challenge. Unfortunately, because I did not have a lot of time and wanted my buildalong to be easily reproduced, I made my holmegaard bow with steel hand tools. However, showing the making of a stone age bow with stone tools is definitely on my list!

Now, time to move to the workshop!

The first issue to solve when starting a bow is to find the proper material. In this case we have a full wood bow or self-bow, so we just need to focus on deciding which piece of wood, also called stave, we will use. However, the wood choice will be even more critical in a self-bow since there’s nothing to back it up as in a sinew-backed (tendons applied on the back of the bow) or a composite bow.

The main characteristics to look at to see if a type of wood is suitable are the tension and compression strength. Since a bow is bent in an arch to be shot, it has to be elongated on the outer side (back) and compressed on the inner side (belly). Our bow must sustain both these constraints. Tension and compression strength should be high but also balanced. If the wood is only strong in compression, its back won’t resist upon bending and cracks are likely to appear if the bow’s back is not reinforced by an elastic material such as plant or animal fibers.

As I mentioned above, the Holmegaard bow was originally made out of elm, which has a balanced tension and compression strength. I didn’t use elm for my replica for the simple reason that this tree species has become extremely rare in Belgium because it has been ravaged by a fungus and is now a protected species.

Instead of elm, I decided to use bird cherry (Prunus padus) for my bow, which has similar or even slightly better properties than elm according to “The Wood Database” (https://www.wood-database.com/), a useful website for wood identification and mechanical properties. Comparing the properties of Prunus padus and wych elm, I found that Prunus padus has a slightly better elasticity and a higher modulus of rupture than Wych elm. Of course, these properties are extremely variable from tree to tree and within a single tree so they should not be trusted blindly. However, this means that I should be able to follow the dimensions as the original 9000 years old artificat without risking that my bow becomes overconstrained.

Comparison between the mechanical properties between elm and cherry (www.wood-database.com).

Here is the stave I chose, which was cut from a 25cm diameter hackberry tree in my garden. An important feature to look at when selecting a stave is the wood grain (the direction of the fibers along the tree axis. In my case, since the stave was a little bit crooked, partly from drying, we can see that the grain does not follow a straight line. Luckily, the stave I had was much longer (2,20m) than the finished bow (1,60m) so I could end up with a straight-grained segment.

Selected stave to be turned into a bow with other staves drying in the background. Note the space between the staves to allow the air to circulate.

Once we have our stave ready, the first step is to draw the center line of the bow, which will allow us to cut it into shape. This can be easily done by streching a string on the stave and place it under a source of light. The shadow casted by the string indicates the center line to be drawn.

String trick to draw the center line of the bow.

The stave is now ready to be reduced in width and thickness to fit the final bow shape. Before that, the design and dimensions should have already been decided. As I wanted to replicate the design of the Holmegaard artifact, I used the same dimensions, which can be found in the Traditional Bowyer’s Bible volume III (an amazing series of reference books to begin bowmaking).

Simplified dimensions in cm of a casting Holmegaard artifact as found in the Traditional Bowyer’s Bible vol III. The measurements occur each 10 cm along the limb. The drawing is not scaled.

The first reducing of the stave width and thickness is done using an adze or a little axe.

The shape of the bow is then drawn on the stave and cut out using a drawknife, handplane and a chisel.

Back of the bow showing the drawn shape.
Japanese handplane (kanna) used to remove small amounts of wood on the sides and belly of the bow.

The next step is to obtain the right thickness profile. The most useful tool to achieve this is the caliper. A good method is to control the thickness of the stave each 10 cm. The first objective is to reach the desired finished thickness profile with an excess margin of about 4-5 mm, so that the bow starts bending about 5-10 cm. At this point, both limbs should bend equally, if this is not the case, wood should be removed on the whole the length of the stiffer limb with the drawknife.

Checking the thickness of the stave with a caliper.
The use of the drawknife to reduce the belly of the bow.

Once both limbs bend equally and sufficiently, it is time to prepare the nocks of the bow before moving on to the tillering phase, where we will give to the bow its final shape.

In the case of the Holmegaard, the narrow tips of the limb do not have a lot of material available to cut nocks. Instead of cutting grooves for the string, the Holmegaard bowyers decided to attach a bundle of fibers at the tips to hold the string. They could have come from an animal source, like tendons or rawhide, or taken from fibrous plants or tree bark. For my part, I used some leftovers of flax fibers that I prepared to make bow strings.

Built-up nock made of linen fibers.

When the nocks are in place, the bow is ready to be strung for the first time. To do this, I use a thick string, about the size of the bow. To be able to observe how the limbs are bending and measure the strength, or draw weight, of the bow as we are pulling it to longer draw, it is very useful to use a tillering stick. A tillering stick can simply be a ruler holding the bow at one end and with an attach point for the string every inch or two. It can then be combined with a spring scale or a normal scale to measure the pulling strength. It can also be useful to have a tillering stick attach on a gridded board, which will help to examine the curve of the bow.

Pulling the bow on a tillering stick. Notice the spring scale to measure the draw weight and the grid to observe the curve of the bow.

I start by pulling the bow at around 4 inches of draw and compare the cuvre of both limbs. At this point, it is important not to overstrain the bow to avoid deformation to occur in the weaker areas of the limbs. This is why I do not pull the bow much further than half its final draw weight. As we remove wood to balance both limbs, we can start pulling the bow further.

When the limbs bend equally, we can take a look at each limb and see how it bends along its length. According to the chosen design, it is important to make sure that the bend is not excessive anywhere, otherwise we need to remove around the areas that bend too much. In the case of the Holmegaard bow, the end part of the limbs, right after they narrow, as well as the handle should bend only slightly. A long bow should have a constant bend all along its length, while a flatbow will generally not bend at the handle.

After examinating my bow on the tillering device, I usually mark the places where wood should be removed with crosses and places to be left alone with circles. As we advance in the wood removing process we should progressively become more and more careful with how much material is being removed and gradually switch to lighter tools. I personally start with the drawknife until I reach a draw of about 10 inches, I then switch to a wooden rasp until I am one or two inches close to full draw and I finish with the small adjustments curve using a metal file.

Do not lose your patience if you feel like your bow is not bending fast enough, it is probably time to take a break. If you go too fast or use the wrong tools, especially as you get closer to the final draw length, you risk creating a weak spot in the bow by removing too much wood at one place and end up with either a broken bow or a bow that is twice as weak as what you desired.

If you managed to reach the full draw while keeping the right curvature and a sufficient draw weight then congratulations ! You have made a shootable bow.

You should now give it a try with a few arrows to see how the bow reacts, it might take a bit more set. Try also to feel how the bow shoots : if you feel a lot of hand shock, it can mean that the tips of your bow are too heavy or that your bow bends too much close to the handle.

Bow at full draw : 48# for 24 inches of drawlength.

If you are happy with how your bow shoots, there is only one step for you to cross : the finishing.

The first task is to sand the belly of your bow to remove all the tool marks. You might want to use the metal file first if the marks are big, then start sanding using gradually finer paper.

As for the back of the bow, it is up to you to decide if you want to leave some of the inner bark of the tree or remove it all by thorough sanding. As I don’t think that the Holmegaard bowyers went through the trouble of sanding their bow completely (remember that they were using stone tools), I decided to leave most of the bark on the back of my bow. I think it also gives it a more natural look.

You can give a final touch to your bow by oiling it. Oil will make the growth rings of the wood come out and slightly taint it. More importantly, oil will ensure that the moisture of the wood doesn’t change if it is move from dry to wet environment and vice versa. I used flax seed oil, because I like the renders it gives to the wood. However, other vegetable oils or animal grease can be used alternatively.

Finished bow back, ready to be oiled.

Here it is, our finished bow ! Congratulations if you kept going until here !

The bow of Holmegaard, brought back to life after thousands of years sleeping in the northern peatlands…

I found that it shoots surprisingly fast for a non-recurved bow. It is only when shooting and feeling the speed of your arrows that you realise how well thought this design is. This bow is a living proof that the bowyers of the mesolithic period were skilled crafters and engineers.

I hope you enjoyed reading about the Holmegaard bow, please share any thoughts or experience you have had building this bow or simply reading this article.

Alright, all aboard ! Time to sail off from Denmark to the coast of England ! As in a few millenias, another iconic bow is awaiting for us…

References :

Csaba Bálint, 2014. The bow from Holmegaard settlement and some remarks on the Mesolithic bows.

– Jim Hamm et. al. “The Traditional Bowyer’s Bible Volume III”

– http://www.theinf initecurve.com/archery/the-oldest-bow-in-the-world/