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I know giant bows aren't a novel concept on this site, but since I am trying to figure out a good ranged option for high-level Rangers, and I have a very specific concept, I will venture.

The bow itself is made of steel, along with the bowstring. As for size, it's made to fire javelin-sized flechettes (steel arrows) and is sized accordingly. Basically a giant steel longbow. Why steel? Because most monsters with acid attacks (or acidic/caustic physiology) do nothing or next to nothing against steel. Either way, that sums up a Greatbow.

My question is, How Useful Will A Greatbow Be?

Assumptions:

  1. Thanks to the Engineering class' discovery of advanced metalworking, steel of modern-grade quality can be created for this bow, which is meant to fire javelin-size flechettes as far and as hard as possible given the materials.

  2. High-level Rangers (300 and up) can use (AKA nock, draw, and fire) this giant bow and its arrows with the same ease as a trained longbowman and have speed and range to match. EDIT: A Greatbow can fire its projectiles just as easily as it would fire an arrow of the right size for it, so expect supernaturally high range and force.

  3. The bow's arrows (hereafter referred to as 'bolts') may have the Sharpen or Pyris Enchantment for added punch, with the former hopefully allowing a Ranger to kill a Glutton or Savage with one shot.

  4. The bow is meant primarily for large, powerful monsters, with or without armor, such as a Giganto or the aforementioned Savage.

Specifications For Best Answer:

  1. The best answer will first take into account how strong a Ranger would have to be to use a Greatbow.

  2. Second, the best answer will determine and take into account the range and power of a Greatbow made of modern-grade steel.

  3. Third, the best answer will determine how deadly (or destructive) a Greatbow's bolts would be.

Alendyias
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  • I'm a little worried that the projectile is so heavy. Even the most powerful bows/crossbows of the most modern materials are made with super-light projectiles. Even ballista bolts were made of wood with a metal tip. The arrows may end up with poor accuracy and mediocre range because the projectile's mass relative to it's velocity will cause it to tumble. – DWKraus May 18 '21 at 19:51
  • @DWKraus: no problem, I edited in to clarify that the Greatbow can fire these projectiles as well as it would a regular arrow sized for it. – Alendyias May 18 '21 at 19:59
  • And according to what I found here, a steel-tipped wooden arrow may be more effective because it achieves the same force with greater velocity. https://www.quora.com/Why-aren-t-arrows-made-of-steel – DWKraus May 18 '21 at 20:03
  • You may want to look at actual war-arrows, they are quite a bit larger and heavier than hunting arrows. Probably exactly what you want. https://www.youtube.com/watch?v=BV8kt-bDxnk – John May 18 '21 at 22:08
  • It sounds like you want quantitative answers, like the range, speed and impact force of these arrows. We need to use physics to figure that out. It's unclear how to do that while -- as you say -- ignoring the physical problems with metal arrows being too heavy. So we have to use some parts of physics but ignore or modify other parts? It's a headscratcher. . . . – Daron May 20 '21 at 15:08

3 Answers3

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If you use steel for the bow, it does not have to be huge. Steel crossbows could be to stiff to draw with human strength (like windlass drawn arbalest) yet not that big (around 90cm long).

That said, huge bows with arrows as large as to be usable as javelins were used by many cultures throughout the world. Some actually drawing them with legs laying o their backs!

How powerful it can be? English longbows topped at about 60kg draw weight. Internet say the strongest used was 90kg in 2004. You want more, somewhere in crossbow range. In general, it depend mostly how strong your rangers are.

If you want to check penetrative power, look for the penetrative power of a high powered crossbow, but the damage will not be massive vs very large monsters, unless you actually penetrate vital organ. Arrow is a rather narrow projectile.
Edit: I mean as long as you can penetrate the skin (and possibly bones, like ribs) and hit vitals the excess draw power will not deal proportionally more damage. It may deal a bit more but not much.

The name "bolt" refer specifically to the crossbow projectile so you will confuse readers if your characters will shot bolts from a bow.

Archelaos
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  • For reference, bows in the 16-20 kg draw weight range can take down caribou in the hands of expert bowmen. – The Square-Cube Law May 18 '21 at 18:55
  • Yes: the formidable footbow. – Willk May 18 '21 at 23:29
  • Mary rose long bows maxed out around 80kg, the single most common draw-weight was around 70kg so English longbows definitely got more powerful than 60kg. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1095-9270.2011.00333.x – John May 19 '21 at 00:49
  • Additional draw weight means you can use broadhead arrows rather than bodkin points while still being able to penetrate armor (natural or otherwise). – Mark May 19 '21 at 03:28
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A steel longbow is NOT a good idea

Wooden longbows were long because they had to be to be able to distribute the forces of the draw through enough material to bend instead of breaking, but longer bows are actually less efficient because the ends of your bow suffer from a leverage disadvantage. A little bit more weight to your bow slows it down more the farther from your handgrip you get. Steel is heavy; so, this problem is much worse in steel bows than wooden bows which is a big part of why you do not see steel longbows being used in any historical contexts. Instead, what really well tempered modern steel allows you to do is make a short steel bow that can flex enough to give you a long and powerful draw without breaking.

Instead of replicating the longbow, your steel bow should more closely resemble the shorter recurve bows used by the Eastern Mediterranean and Steppe civilizations. This design is ideal for maximizing draw length out of a shorter more flexible material for a more efficient shot.

That said, even making it as efficient as possible still does not make it shoot faster than a normal bow per-say. Any material you make a bow out of is limited by its snap: a theoretical maximum speed it can go from flexed back to its resting state. For a steel bow, this limits projectile speeds to about 50-55m/s with a max volley range of about 250-300m. Shy of introducing a better than steel material like fibreglass or a compound pulley mechanism, this is about the fastest and farthest your bow will shoot no matter how well you design it... which is no better than a good wooden bow.

But what a steel bow CAN do that a wooden bow can not it support a much higher draw weight. The means it can fire heavier arrows. A standard Roman cheiroballistra was excellent at piercing armor and shields with arrows that weighed ~ 100 to 200 grams. In archery, you generally want your arrows to weigh about 1 thousandth of the draw weight. So firing an arrow that weight would require a bow with a draw weight of 100-200kg. this is about 3 times the draw weight of most historical warbows.

To get an idea about penetration, some accounts say cheiroballistra could go through multiple armored targets (though Roman historians are not exactly known for their cold hard facts so this may be a slight exaggeration). Also, a chiroballista had a higher missile velocity than a steel bow could have because it used a torsion coil mechanism instead of a tension bow; so, even if these accounts are accurate, your steel bow would not be quite so powerful as to pierce multiple armored opponents, but it could probably punch through atleast one opponent's shield and armor.

All this said, if your archers are strong enough to draw such a bow, they would be much better off carrying an aforementioned cheiroballistra or manuballista. While these weapons weighed in at about 100lb or more making them too heavy for a normal person to carry, if you have the super strength to wield them, they could fire faster and farther than any steel bow.

Nosajimiki
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Rock on!

Steel bows were used in India in the 1700s.

Steel bows, while lacking in cast and range, were popular in late Mughal India in the 1700s. They were both military weapons and status symbols. Often handmade and hand-forged, with extensive decoration, they often came in two pieces for easy transport. This example has a detachable upper limb.

While steel bows are not as efficient as composite bows, they did not need to be unstrung, allowing them to be kept in the house as a defensive tool. Steel bows were also once common in Western target archery, especially around the early part of the 20th century. (Source)

We also know of non-utilitarian (possibly decorative) metal bows dating from the Bronze Age:

The second group comprises metal weapons, which were mostly non-utilitarian (given their slightly reduced size, material and/or unfinished state). They consist of five battle-axes, five daggers with crescent-shaped pommels (characteristic of the Iron Age II), around fifty arrowheads, and five complete bows. The bows are made up of a flat, curved bowstave bent at both ends, which are connected by a string made of bronze. The size of the bows (70 cm on average), and above all the material used, shows that they were imitations of bows made of perishable materials (wood and tendons). Objects of this type have never been found before: bows made of metal were totally unknown in the Arabian Peninsula and the Middle East until now. (Source)

And a discussion about WWII-era metal bows that has some useful information in it:

I have seen a few of these and i beleive they were popular in the post war years in the UK. (sadly i can't seem to find much on them) Our club coach said that they fell from grace as they suffered from fatigue and gave no warning of their impending (often painful) demise. He even said because of this that people wore caps to protect themselves. (Source)

From all this we can reasonably conclude the following:

  • CON: Your bow will lack the range and force of a laminate bow of the same size.

  • PRO: They do not need to be unstrung (they lose their spring over a much longer period of time), allowing them to be immediately available all of the time.

  • CON: When they do fail, they fail immediately and dramatically. This can be thought of as a semi-PRO. They will be operationally valuable for a longer period of time. But when they finally become inoperative... they'll likely hurt the user significantly.

Best Answer Requirements

  1. Metal can be formed to many spring strengths just as laminate wood can. A 30# pull is a 30# pull regardless of the material used to build the bow. Therefore, the ranger need be no stronger to pull the bow string. However, the metal bow will be heavier than the laminate wood or solid wood bow. So, given a right-handed ranger, the right arm need be no stronger, but the left arm will need to be stronger to permit prolonged use. However, I don't believe the strength increase is particularly abnormal.

  2. "Modern grade steel" is a nearly meaningless statement. There are hundreds of grades of modern steel.[1], [2] The problem is that you need to balance the weight of the bow against its utility. You could make a "bow" out of suspension spring leaves, but you'd need a hydraulic jack to pull the bow (and it would throw the bolt with the proverbial force of a cannon). A spring bow light enough for practical use will, based on the data provided, likely always be less efficient than a laminate or composite bow of the same size. Remember, the advantage is that it need never be unstrung and, now that I think about it, so long as it's oiled, would be less affected by weather.

  3. No more deadly than any other arrow has been. (Please note that determining bolt/arrow damage against that entire list of people/creatures/things violates the one-question rule and is only partially a function of the bow. Given what my sources say about steel bows, you could get the force numbers from any equivalent composite bow, reduce them by, say, 10%, and calculate all those killing force references yourself.)

JBH
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