Javelin - 1H Spear or Thrown?

[Atgxtg]

On 12/13/2018 at 6:36 AM, Joerg said:

 

 

On 12/13/2018 at 6:36 AM, Joerg said:

Any archer who wants to return with as many of his arrows as possible best had a "detect substance" spell and use that highly specific substance somewhere in the making of his arrows. Possibly a sliver of silver, with the detect magic doubling as a "find coins" spell that also works as an indirect "detect civilized rich people".

Except they wouldn't want too. When an arrow is fired it bends around the bow stave, which actually weakens the arrow. Especially with more high powered bows.  That's one reason why wooden arrows aren't all that popular today for practice shooting. Then there is the effect of impact, especially on the arrow head. So most archers probably wouldn't want to scavenge for arrows, unless they were were in a fix. 

[Joerg]

1 hour ago, Atgxtg said:

Except they wouldn't want too. When an arrow is fired it bends around the bow stave, which actually weakens the arrow. Especially with more high powered bows.  That's one reason why wooden arrows aren't all that popular today for practice shooting. Then there is the effect of impact, especially on the arrow head. So most archers probably wouldn't want to scavenge for arrows, unless they were were in a fix. 

Given that you have no alternative material to use in Glorantha (no aluminum arrows, pretty please - not even Mostali are certain to have the technology to produce them, and of course even less inclination to do so as their crossbow bolts don't have this exact problem), and given the time and care you put into creating an arrow that is perfectly attuned to your draw weight and draw length for those last 25% of accuracy, scavenging for your own arrows is exactly what an archer will do if he has the opportunity.

There is the issue of impact breaks, which is why already neolithic archers would dovetail the front end bearing the arrow tip into the major part of the perfect shaft, the ends bearing much less stress and providing an easily replaced part.

The reason why wooden arrows aren't popular in modern target shooting is their mass to stability rate. Aluminium-carbon composites with tapering thickness of aluminium take the same stress at much lower throw weights, reducing vertical deviations significantly, and they are way more easy to mass produce than arrows that you have to tune (in the end: carve and sand) individually.

Most of the arrow shafts you can buy commercially are cut from blocks of wood, providing bad fault lines in terms of the grain of wood. Longbow archers would havest straight young branches from coppiced trees that would provide radially symmetric grain way more suited to the stresses the arrow undergoes. Getting access to these basically requires years of preparatory gardening.

[styopa]

11 hours ago, Atgxtg said:

Except they wouldn't want too. When an arrow is fired it bends around the bow stave, which actually weakens the arrow. Especially with more high powered bows.  That's one reason why wooden arrows aren't all that popular today for practice shooting. Then there is the effect of impact, especially on the arrow head. So most archers probably wouldn't want to scavenge for arrows, unless they were were in a fix. 

While I agree with you for modern bows, I'd disagree with you for this-era:

- every arrow has to be crafted.  This is not a trivial amount of labor.  Nobody wants to essentially 'throw away' an hour's work (at least) not to mention the materials.  "Disposable" for most of human history only meant "it can't possibly be repaired or used for something else any more"
- I think the effect of this flexing is FAR more prevalent with today's compound cam-action throw.  An archer needs regular practice and musculature to hold a 40#+ recurve for any length of time, while a 60#+ compound is actually fairly common (ie holding maybe 12# at draw).  Not to mention thowing faster, I'm not sure if it's proved but personally I feel like a compound bow is 'snappier' than a recurve...where the recurve has a longer, gentler acceleration on the arrow, a compound is more like a crossbow's forceful short throw.  https://sites.google.com/site/technicalarchery/technical-discussions-1/arrow

[Atgxtg]

32 minutes ago, styopa said:

While I agree with you for modern bows, I'd disagree with you for this-era:

I'm skeptical, especially when dealing with high draw weight bows, such as long bows. Yeah a 20 pound bow probably isn't that hard on the arrows but an 80 or 100 pound one? Add to that the impact from wherever the arrow does hit (Target, tree branch rock). I'd rather waste the hour than have the arrow snap in my face. 

 

38 minutes ago, styopa said:

  Not to mention thowing faster, I'm not sure if it's proved but personally I feel like a compound bow is 'snappier' than a recurve...where the recurve has a longer, gentler acceleration on the arrow, a compound is more like a crossbow's forceful short throw.  https://sites.google.com/site/technicalarchery/technical-discussions-1/arrow

It is provable.. F=ma, so if the mass is a constant, and the force is increased, then the acceleration must be increased at the same ratio. So a 60 pound compound bow would have 50% greater acceleration than a 40 pound recurve,

 

 

[M Helsdon]

1 hour ago, styopa said:

- every arrow has to be crafted.  This is not a trivial amount of labor.  Nobody wants to essentially 'throw away' an hour's work (at least) not to mention the materials.  "Disposable" for most of human history only meant "it can't possibly be repaired or used for something else any more"

Throughout history, there have been a few attempts to prevent spent arrows being shot back. One was to have heads that would become detached on striking the target (also making extraction more difficult) with one method being the arrow head socket simply pushed onto the shaft, and the other was to use short arrows and an arrow guide. The latter were known to some steppe cultures, but are best known by the Korean name Pyeonjeon or Pyunjun. Unless the enemy also had suitable arrow guides, they couldn't return the short arrows, which also gave a few other advantages: being lighter they flew at a higher velocity.

There are numerous examples of arrows being collected and shot back (if they are embedded in something or someone, recovery is unlikely, but missed arrows could be reused). Some armies had boys tasked with collecting them; at Poitiers in 1356 the archers ran forward to recover spent arrows. At Towton in 1461 the Lancastrian archers ran out of arrows, and suffered the indignity of having the Yorkists shoot their own arrows back at them... [Both sides were using long bows.]

http://www.battlefieldsofbritain.co.uk/battle_towton_1461.html

Edited December 23, 2018 by M Helsdon

[Joerg]

2 hours ago, Atgxtg said:

I'm skeptical, especially when dealing with high draw weight bows, such as long bows. Yeah a 20 pound bow probably isn't that hard on the arrows but an 80 or 100 pound one? Add to that the impact from wherever the arrow does hit (Target, tree branch rock). I'd rather waste the hour than have the arrow snap in my face. 

In my years of archery, the only arrows ever coming to endanger my face were carbon arrows that had a split I had not noticed when recovering them. In competitions, I used to shoot a 40 lbs recurve bow, or a 70 lbs flat bow, with arrows adapted to my draw length and draw weight.

I don't see how raising the draw weight from 70 to 80 lbs would cause such drastic changes.

 

2 hours ago, styopa said:

An archer needs regular practice and musculature to hold a 40#+ recurve for any length of time, while a 60#+ compound is actually fairly common (ie holding maybe 12# at draw).

While true, that concerns modern style archery.

Shooting a monster bow of 70+ lbs means that you make drawing, aiming and releasing as short and smooth as possible

 

Quote

It is provable.. F=ma, so if the mass is a constant, and the force is increased, then the acceleration must be increased at the same ratio. So a 60 pound compound bow would have 50% greater acceleration than a 40 pound recurve,

Not quite. The force of the string changes with the draw length. A conventional bow (longbow, recurve) has the greatest force at maximum extension and gets weaker towards the point where the arrow leaves, whereas the translation of the compound has less force at maximum draw and most force at the moment the arrow leaves the string, making it about half again as effective as a conventional bow at the same draw weight.

About using arrow guides: Shorter arrows means lighter and less thick arrows, which means faster arrows (momentum should remain the same) and less air resistance, reducing the deviation coming from high ballistic curves.

[Atgxtg]

56 minutes ago, Joerg said:

In my years of archery, the only arrows ever coming to endanger my face were carbon arrows that had a split I had not noticed when recovering them. In competitions, I used to shoot a 40 lbs recurve bow, or a 70 lbs flat bow, with arrows adapted to my draw length and draw weight.

I don't see how raising the draw weight from 70 to 80 lbs would cause such drastic changes.

It doesn't, but going from shooting straw to hitting bone, rock and tree, probably would. 

 

56 minutes ago, Joerg said:

 

While true, that concerns modern style archery.

Shooting a monster bow of 70+ lbs means that you make drawing, aiming and releasing as short and smooth as possible

For a Longbow 70 pounds wasn't a monster bow. 

 

 

56 minutes ago, Joerg said:

 

Not quite. The force of the string changes with the draw length. A conventional bow (longbow, recurve) has the greatest force at maximum extension and gets weaker towards the point where the arrow leaves, whereas the translation of the compound has less force at maximum draw and most force at the moment the arrow leaves the string, making it about half again as effective as a conventional bow at the same draw weight.

What's happening is that you actually do put the extra energy into the bow, but the nature of the pulley system stores it in a way that itis easier to hold back. 

56 minutes ago, Joerg said:

About using arrow guides: Shorter arrows means lighter and less thick arrows, which means faster arrows (momentum should remain the same) and less air resistance, reducing the deviation coming from high ballistic curves.

I'm not certain about momentum. Lighter and less thick means less mass, and less inertia, and so greater susceptibility to crosswinds, although the lower surface area would help. Now just how much of a change would be needed to have a significant effect is the question.

[Joerg]

3 minutes ago, Atgxtg said:

1 hour ago, Joerg said:

I don't see how raising the draw weight from 70 to 80 lbs would cause such drastic changes.

It doesn't, but going from shooting straw to hitting bone, rock and tree, probably would. 

As someone who practiced field archery, I have to pass on bone, but I had plenty of misses hitting rock, metal or tree/solid wood.

 

5 minutes ago, Atgxtg said:

For a Longbow 70 pounds wasn't a monster bow. 

For someone wanting to hold the bow for half a melee round to improve the aim, 70 lbs are monstrous. For someone pulling it through in a smooth move, monster begins past the 100 or 120 lbs zone.

 

8 minutes ago, Atgxtg said:

What's happening is that you actually do put the extra energy into the bow, but the nature of the pulley system stores it in a way that itis easier to hold back. 

Yes - you have to put the same work into drawing the bow to full extent, but the force curve is completely inversed - maximum effort when the string is straight, and minimum and maximum extension. That means you get an accelleration gradient that is positive throughout the acceleration of the arrow, unlike the negative acceleration gradient in conventional bows.

Since I talked about putting the same work into the bow, I expect to get the same amount of work out of the bow. WIth velocity coming in squared in the kinetic energy term, perhaps momentum isn't exactly the same, but close enough for back of a napkin calculations.

Exposed area and time of exposure play a major role in wind drift. Shorter flight times of speedier missiles reduce this quite a bit. They also make hitting moving targets easier.

[Atgxtg]

14 hours ago, Joerg said:

As someone who practiced field archery, I have to pass on bone, but I had plenty of misses hitting rock, metal or tree/solid wood.

Does that have an effect or arrow or arrowheads? I would think it would,e specially with higher draw weights. I would expect hunting arrow heads  to fare worse than combat arrows though,.as the former has long, sharp edges and the latter are designed to penetrate armor.

14 hours ago, Joerg said:

For someone wanting to hold the bow for half a melee round to improve the aim, 70 lbs are monstrous. For someone pulling it through in a smooth move, monster begins past the 100 or 120 lbs zone.

Yes, which is why the high draw weight Welsh warbow probably wasn't used much for hunting. Then again, all that required practice time, would have helped with that.

14 hours ago, Joerg said:

Yes - you have to put the same work into drawing the bow to full extent, but the force curve is completely inversed - maximum effort when the string is straight, and minimum and maximum extension. That means you get an accelleration gradient that is positive throughout the acceleration of the arrow, unlike the negative acceleration gradient in conventional bows.

Actually it's more work, but it's easier and in smaller increments. It's like the inclined p[lane or a block & Pulley.

14 hours ago, Joerg said:

Since I talked about putting the same work into the bow, I expect to get the same amount of work out of the bow. WIth velocity coming in squared in the kinetic energy term, perhaps momentum isn't exactly the same, but close enough for back of a napkin calculations.

I wouldn't. I'd expect less, per the laws or thermodynamics, which is what happens. 

14 hours ago, Joerg said:

Exposed area and time of exposure play a major role in wind drift. Shorter flight times of speedier missiles reduce this quite a bit. They also make hitting moving targets easier.

Yes, and velocity is more important than mass as far as energy goes. and probably penetration as well It's a question if the extra speed offsets the loss of mass. That would depend on the numbers.