Exotic ancient weapons: (IX) Penobscot double bow

First, an engineering view of the double bow.

The Penobscot bow / Wabanaki bow / Mi'kmaq (double) bow is an advanced version of a cable-backed bow with very different mechanics. It's different in its performance from bows that simply use wider or thicker limbs or more limbs.

photo uploaded by "Judson"/"Judson127", taken from here

Mechanical engineers learn that everything can be considered to be a spring; even a solid block of steel is a spring. We can apply a force to it and it will either compress or elongate. We usually cannot see the tiny change in its dimensions, but it happens. Its spring constant simply requires a powerful force for very little change of its dimensions. Spring steels in coil spring shape make it much easier to experience how steel yields to mechanical forces.

A bow can be considered a spring as well - you pull harder, it yields more - and just like a spring, it stores energy in the process. This energy can be released for the purpose of accelerating the arrow (or with an arrow guide, the dart).

Bows (and many other spring arrangements) have no spring constant, though; the amount of force required to pull the arrow back by one more centimetre depends on how far you already pulled it back. The bow design doesn't simply compress or elongate, but changes its shape as it yields to the pulling force (the string notches approach each other).
The ideal bow design would accelerate the arrow with about the same force regardless of how far it's still drawn (but that's not feasible). The force must not be excessive (or the user couldn't draw and hold the drawn bow well or at all) and should not be low (for the sake of accelerating the arrow well).
This cannot be done with a single spring; you need a set of springs (or a more complicated design such as the recurve or composite bows) to approximate this ideal.

Springs of different spring characteristics can be arranged to  create a non-linear spring curve; this way compressing or elongating by a certain distance doesn't require the addition of the same force regardless of how much the spring system has already been manipulated.

The double bow is such a two-spring-ish system in spirit. The small front bow is not just an overly elaborate way of making the bow stiffer; it actually modifies the spring curve (requires more force to draw at first, thus also accelerates the arrow more) as a parallel spring, and by consensus of double bow users, it does so in an advantageous way compared to a self bow of equivalent technology. You get more performance out of such a bow for the same maximum (28" draw) draw 'weight' than with an otherwise equivalent technology self bow.

That, by the way, is the reason why people who create double bows with the front bow almost as long as the main bow either didn't get what the design is meant to accomplish or are merely trying to create a bow that can make do with poor material (poorly suitable woods). A proper performance double bow has a short front bow that gets fully drawn fairly soon in the drawing motion.

(BTW, the Penobscot double bow is supposedly not really "ancient", supposedly it's just over a hundred years old - I doubt this, but don't have sources that mention it earlier.)
edit: I decided to add this link, asthe author there actually shows a diagram with force-draw curves. The Penebscot double bow design essentially leads to a quicker rise in draw strength on the first centimetres (inches) of draw. During the shot, the arrow gets accelerated with more force when it's forward that much again. / I also cleaned up the text above a bit.

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Second, this video on African martial arts (unrelated to double bows):

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Third, some general remarks on non-firearm weapons:

It's amazing how after some study one becomes mostly able to tell the way a weapon was meant to be used by merely looking at it, including some requirements for the associated armour.

The hilt of a blade weapon in itself can be formed to almost force the user to use a certain motion for slashing. This particular hilt design alone tells the observer that the blade will be very curved sabre's blade.

Curved blades typically require a relatively high quality material because they almost never have two edges, and one edge could quickly become dull in an extended battle. Curved blades are especially meant for cutting, so holding a good blade is important (harder edge allows for a sharper edge) and difficult (harder edge ~ more brittle edge).
The one exception I'm aware of are the bronze age sickle swords, and their users were probably prepared to sharpen their weapon with a grindstone on their own as in agricultural use of sickles.

Curved blades are never made for thrusting into the body; they are made for cuts and slashing motions. The cutting motions may include a pushing and pulling motion, but only to cut along the side of the target. The pushing cut isn't really an option with forward-curved blades such as sickles, romphaia or falx.

Straight blades can be built for thrusting into organs, but don't necessarily have the point for it (Celtic swords were largely limited to slashing, as the point was often dull). Very fine points give away the intent to penetrate an armour type that's not very good against thrusting attacks (typically mail), and are thus uncommon in areas where such armours that are vulnerable to thrusting attacks are rare (example East and South Asia).

An extreme case are the smallswords and the like - straight sword-like blade weapons meant exclusively for thrusting with the point, without a shard edge. These continued to be in use after mail armour fell out of fashion in almost all of Europe (Balkans excluded). Frankly, my suspicion is that they were optimised for light weight, as respectable sidearms that aren't too much of a burden on their user.

Large handguards tend to be associated with no use of shields, or use of shields very unwieldy (pavise) or very small (buckler). Handguards can then help protect the hand when you cannot do it with a shield. An exception is the customary retention of large handguards along with late medieval plate armour, but one should keep in mind that swords were sidearms and thus also (if not primarily) used when the wearer wasn't fully geared up.
Blunt weapons such as maces and hammers (also hammer components in weapons such as the pollaxe) were either an extreme budget solution (clubs) or a response to very effective armour. Blunt force can even be effective against plate armour and equivalent helmets when blades and pointy weapons fail. The latter are usually built to be nimble in their use and thus quite lightweight. Axes and blunt weapons require a lot of mass where it matters the most; at the end of a pole or short shaft.

Single-handed weapons that are quite long among their kind (mace, sword, sabre) tend to be cavalry arms. Their increased length compensates for poor riding skills* or a loss of dexterity caused by the user's armour.

Lances and pikes were usually held low, while spears were held high (if used single-handedly) for a greater choice of movements.
Polearms with oval pole cross section and/or dedicated axe head, spike or blade elements (examples pollaxes, halberds, naginatas) were meant for slashing and/or swiping movements. This in turn indicates that they were meant for two-handed use, and thus lead to an emphasis on good armour protection for the user, since shields would be quite impractical.**

Javelins are particularly interesting; the very light ones were used in great quantity by dedicated skirmishers and cavalry, while the more elaborate ones such as the famous Roman pilum (no doubt the most advanced and most capable javelin design ever despite lacking an amentum or spear thrower) were carried in small quantity (one or two per legionary; that's still up for debate). The pilum's purpose was threefold; a demoralising/shocking salvo, disabling shields by sticking to them (making them unwieldy and enabling the enemy to push the shield sideways) and finally an emergency use as a spear, particularly against cavalry.***

Spears are capable weapons for one-on-one situations unless the enemy has good armour. Their use was typically rooted in at least one of three motives; poverty (spears as versatile budget option), horsemen threat (spears as anti-horseman weapon,**** obviously not helpful against missile horsemen) and third, disciplined forces employing closed order tactics (example Greek phalanx).

As with swords, the width of the spear tip usually indicates whether a spear was meant for use against armoured opponents or not. A wide, leaf-shaped spear tip would be for use against unarmoured opposition (example iklwa), or for the hunt. Boar spears and some other spears had some guards to limit penetration.

Particularly short stabbing blade weapons such as the Spartan short xiphos versions or Germanic seax were associated with very restricted close quarters combat, such as fighting in a phalanx or shield wall where the gaps between shields and the air above could be used for very short stabbing motions. Another use for such short sidearms was on board of warships (for boarding actions), usually with a blade that's well-suited to slashing (which makes it useful for cutting tows).

Likewise, the design of shields allows conclusions about their use.


*: Not all horsemen were good at horsemanship games and thus capable of picking stuff up from the ground while riding, so they needed longer weapons to strike targets lying on the ground. That in turn is important because to simply lie on the ground is a reasonable approach to protect oneself from a cavalry charge; horses will avoid to step on such irregularities to avoid injury.
**: This requirement finds in exception of the very late halberd-ish weapons such as partisans of the firearms era, about 17th and first half of 18th centuries. The same applies to bayonets. The requirement may not be met because of economical reasons, but two-handed polearms were rare when good body armour was unaffordable unless the use of powerful halberd-like weapons made it quite pointless anyway (example Japanese warrior monks with Naginatas).
***: The pilum slowly fell out of use when the longer spatha sword gradually replaced the gladius sword. The disciplined Roman infantry (even auxiliary infantry) was able to resist shock cavalry with disciplined closed order formations (horses don't run into spear tips, but the don't run into shield walls either) and a longer sword made the need for some spear-ish weapon against cavalry less pressing. There may thus have been such a relation between the rise of the spatha and the decline of the pilum (in favour of plumbata and cheaper simple javelins). Alternatively, the increased use of light javelins by horsemen may have led to a better opinion about them, eroding the pilum's role. Last but not least, the late imperial Western Roman infantry faced much more cavalry and actual spears became much more common in service again. Spears and pila don't go well along because spearmen tend to keep close formation, whereas pila require some more space for the user to throw. In the end, the pilum+gladius combination was unique to late Republican and early Imperial Rome, and a hugely successful approach that seemed to have been suboptimal in other times and places.
****: Long straight swords could be used to deter cavalry as well (Pallasch weapons were used by cuirassiers of the 18th century almost as if they were spears).


  1. Linking matt easton generally makes any further discussion on melee weapons moot, if just for the amount of time needed to watch all his videos.
    Regarding your opinion on straight swords, in one of his recent videos he claims that given sufficient training, a straight sword is the superior option even without armor being involved. Also, smallswords being weight-optimised is a historical fact - people at the time usually used heavier straight swords in war and smallswords in civilian life.

    1. His views are a bit tainted by his favourite practice - sabre duels where a hit counts even if armour would have made it ineffectual. He likes long blades in part because they make scoring hits easier.

    2. Historicaly a hit would nearly always had some effect (in regard for the further fight), even if no serious wounds would result from it because of armour. Moreover a good armour negates nearly all kind of sword cuts and a sword is therefore always a bad choice against an armoured enemy or more specifically against the armour.

      Also historicaly longer blades were favoured for the same simple reason: reach. The end was then the rapier which was more a short one handed spear from its nature than a sword.

      Concentrating further only on svords:

      >>This particular hilt design alone tells the >>observer that the blade will be very curved >>>sabre's blade.

      No it dont. Its the same hilt design that was used in india for a long period on straight blades. It shows not that the blades are curved, but that the svord is used mainly for cutting. And there were many straight swords which were used for cutting only in india.

      >>Curved blades typically require a relatively >>>high quality material because they almost never >>>have two edges, and one edge could quickly >>>become dull in an extended battle

      To the opposite the quality of the blade is more important for an thrusting svord. Especially sabres can have blades of inferior quality in comparison without loosing capacity. Moreover the blades does not become dull in battle, but most times from wearing them in the scabbard and a lack of maintaince. In a battle svord fights did not last long and there were not many of them.

      >>Celtic swords were largely limited to slashing, >>>as the point was often dull

      A "dull" point can be advantagous in thrusting because the resulting wounds are more serious and you avoid over-penetration which results in your svord stucking in the enemy. A point should not be to sharp but idealy a little bit dull.

      >>>Frankly, my suspicion is that they were >>>optimised for light weight, as respectable >>>sidearms that aren't too much of a burden on their user.

      There were also many very heavy ones: the rapiers were for example in the average heavier than ordinary period svords. you could also look at a Koncerz or a later french curassier svord and so on. Long and in comparions very heavy thrusting only blades.

      >>Large handguards tend to be associated with no >>>use of shields, or use of shields very unwieldy >>>(pavise) or very small (buckler).

      Highland Broadswords which had one of the largest handguards ever were for example used with the targe, a medium shield.

      The large handguards were here also used very offensive, to hit the opponent in the face or against the head.

      There are in most times so many reasons why something was like it was and not always this reasons are easy deducible. The context is in most times much more complex.

      Since i fence since many years and espially since around 8 years now mainly highland broadsword i discovered more and more within the years, that things are much more complicated than most people think.

    3. "To the opposite the quality of the blade is more important for an thrusting svord."

      That's not the opposite.

      "Moreover the blades does not become dull in battle"

      Many different kinds of battle damages happened to swords, especially bending (if the alloy doesn't flex back after a slashing strike) and becoming jagged/burred/notchy (better words than dull).
      Combat with shields and especially with edge-reinforced shields was a challenge for blade edges.

      >>Celtic swords were largely limited to slashing, >>>as the point was often dull

      "A "dull" point can be advantagous in thrusting because the resulting wounds are more serious and you avoid over-penetration which results in your svord stucking in the enemy."

      2nd century BC La Tène period swords tended to be round-ended; certainly not designed for stabbing. One could challenge my "largely", but I was not writing about what you thought.

  2. I learned how to use the Bo staff in karate practice while growing up and later did a bit of HEMA and Filipino martial arts (weapons based) while I studied in Vienna.

    And yes. A short spear is an amazing weapon in duels and even group fights against pretty much any weapon as long as you are not using shields. And still good weapons even then, but shields pretty much even the ground.

    No idea about good armor though. Never wore more than a heavy duty fencing mask and padding and killing your training partner wasn't a priority :D

  3. >>>The pilum's purpose was threefold; a demoralising/shocking salvo, disabling shields by sticking >>>to them (making them unwieldy and enabling the enemy to >>>>push the shield sideways)

    Mainly Pilums were desighned to thrust through shields. That was there main purpose. The long shaft of the tip penetrates suprisingly easy even through very heavy shields and the reaches the body of the enemy behind its shield. So Pilums are not about sticking in shields, but about penetrating them.

    >> The pilum slowly fell out of use when the longer spatha >>>sword gradually replaced the gladius sword

    There was a transition period between the mainly gladius and then mainly spatha period. And it was in this transition period, the pilum came out of use. In this time the infantry was still mainly armed with short (!) svords, not long ones. They are called ringknaufschwerter in german, i do not know the english name for it. The came from the sarmatians and spread with the use of much more cavalry (as you correctly wrote). In this time conventional spears as anti-cavalry weapons replaced the pilum and the gladius and were the main weapons. The short-svords were not longer the main weapon because of the cavalry centric combat of this time (which also leaded to the rise of the illyrians because of their importance in the cavalry). So not the spatha was the reason for the disfavour of the pilum, but the use of conventional spears (because of so many enemy cavalry). The gladius is superior in combat infantry against infantry. But against armoured sarmatian etc cavalry gladius and pilum were replaced by spears and ringknauf-svords. And only after that the short ringknauf-svords were then replaced by the spatha in the infantry (and for a further transition period also from longer ringknauf-svords and longer and cheaper forms of classical gladius pompeji).

    1. "So Pilums are not about sticking in shields, but about penetrating them."
      They stick after penetration. The barbs of the tip and the wide socket of the tip made removal difficult in a combat situation.

  4. Some of them stick after penetration. The main problem in removing pilums from shields is from my experience the length of the tip, and not so much that they stick. You must pull them out quite a distance and therefore this is difficult in combat situation. Of cause this difficulty was a useful side-effect, but as i said not the main intention. It was only a side effect and resultet from the length of the tip and that it was from metal so you cannot easily cut it away with your weapon.

    1. Rermember the wide socket of the tip; it's designed to keep the javelin from getting pulled out of the shield in one direction, the barbs (spears had rather leaf-shaped tips) were meant to block the other direction.
      The long iron part is but one of three elements that amde removal difficult.

  5. >>>Many different kinds of battle damages happened to swords

    I agree completly with that, but this is not so important in the question of the impact of svord cuts in battle even after such a damage occurs. Moreover high quality steel also not avoids such damage as some historical pictures even shows the best japanese blade with heavy battle damages and still in use.

    The sharpness of the blade was only reduced in some parts and maintained in others of the blade from battle damage. Most battle damage to a svord blade only "dulls" a small part of the blade. The most common are notches.

    >>>>2nd century BC La Tène period swords tended to be >>>round-ended; certainly not designed for stabbing

    Although you are right and some types of La Tene svords with such points were realy not meant for thrusting, funily a round ended point if it is realy sharp is advantagous in thrusting because it become not stick in bones like the short rips for example. So if the celts would made this rounded points sharp (which as far as i know it they did not) they would have been even advantagous.

    Some of this blades were so high quality that they could be bend tremendously even today and then spring back into their old form.

    PS: Most celtic svords had conventional points and the said longer la tene with rounded tips were as far as we knew it perhaps cavalry weapons. This would also explain the increase of length at this period 250 until 50 before christ.

    Also svords were not the main weapon of the celts in this period especially for their infantry which used spears, lances and much shorter svords which were in their hispanic form even copied from the romans. Also this is not an much known fact, that the gladius hispaniensis is not a genuin spanish svord form, but was a descendant of the La Tene svords of the celts and comes from the celto-iberians which were a mixture of celtic tribes and iberians. For that reason the early (middle republican) roman gladius hispaniensis was also much longer as most people think.

  6. >>>"To the opposite the quality of the blade is more important for an thrusting svord."

    >>>>That's not the opposite.

    I do not understand that point (for sure because my english is so bad). I only wanted to add, that in the middle the quality of straight svord blades was better than of curved ones and also this was even necessary because for thrusting you need a better (higher quality) svord blade than for cutting.

    Also two edges were not about to have a reserve edge if ones get dull / damaged. But for better penetration, better thrusting, to have broader and therefore more stable blades with fewer weight and for some special cuts with the back of the blade.

    Many straigth blades had also only one edge like the famous Backswords, Messers and others.

    Having only one edge is also advantagous for cutting because of the blade geometry and for that reason sabres had mostly only one edge, because this increases the cutting power.

    Logically most straight svords with only one edge were therefore designed mainly for cutting. Also such a design makes the blade heavier and more top heavy which also increases the cutting power.

    One word about very short svords to conclude this. Such svords were for sure meant for very close combat (the border to daggers is here fluent - look for example for an long dirk, a schweizer degen etc but this very close combat was not only a result of tactics in an battle. If you fight not in an battle but a duell like situation an opponent with an shield and an spear it is very clever to drop your own spear and charge into the opponent as fast as possible and attack him with your second weapon, aka the short svord. Also you can draw such a svord much faster if it is shorter. In many cases also for the other guy this is then the best defence, to drop the spear and to get the very short svord out as fast as possible.

    So not so much in battle, but in duell like encounters and small skirmishes such very short svords are useful and also for the everday carry / everyday violence. Especially because you can draw them so fast.