TL3+1 Mechanical Artillery

[Icelander]

Originally Posted by Tommi_Kovala

This might be a silly idea, but what if the stone throwers were mounted on a lower deck? All decks above them would have a hole that could be spanned by a removable gangway when the weapons are not in use. This could be covered altogether on the weather deck to keep seawater out.

How high does the weapon need to be?

Trebuchets, apparently, need to be far too high to be practical weapons on shipboard. Which sucks, since they're pretty much the only weapon with the range to counter powerful wizards in ship to ship engagements.

[Icelander]

Let's take a concrete example.

The TL2 monakon is a torsion device with one spring and a rigid arm. It uses either animal sinews or ropes wound of hair to store energy. Neither material gets much cheaper with higher TLs and they don't improve at all. Quite frankly, I'm not sure whether any low TL materials are better.

I guess the wood would be easier and cheaper to work with TL4 tools, but on the other hand, TL4 wages are higher. Is price a wash or should it be cheaper at TL3+1?

The design in Low-Tech has the familiar rigid 'spoon' at the end of the arm, which is less efficient than a sling pouch which is allowed to swing. So there is room for improvement there, I guess. How much improvement there is can probably be calculated, but how?

Also, there is a question whether performance could be meaningfully improved by assisting the torsion-action by a flexion steel lathe like this? Would this enable you to get the same performance as a TL2 monakon cheaper (as steel flexion at TL4 is far less expensive for the same draw weight than hair torsion)? Could it add to the performance of TL2 monakons? Would it make them lighter?

Would anyone care to essay a stab at TL3+1 onager stats? Assuming a sling pouch and any other improvements that are practical?

[jason taylor]

Originally Posted by Michele

Age of sail ships did catch fire easily. Not the hull, of course, but in combat in a sunny day they had immense lengths of tarred riggings and immense surfaces of cloth sails; the running riggings used fats as lubricants. Not to mention the fact that on a combat deck, there will be powder, to propel all those balls out of all those barrels.

At this time, fireships were an extremely effective weapon, especially against a fleet surprised at anchor.
Battle stations preparations on sailing ships included extinguishing down the galley's stoves and ovens, in fear that a shot hitting there could spread a fire.
As to heated rounds, I don't own Low Tech so I don't know what it says about them, but they were used by coastal batteries - firing positions that could include a stone or brick building that could be used as a furnace, or an all-metal furnace that would, nevertheless, not be in contact with wood, but rather, again, with stone or bricks or earth. I don't know of cases in which rounds were heated aboard a ship.

I suspect no admiral in his right mind would want a fire-siphon device aboard one of his ships. He'd think that it was more likely to destroy that ship than any enemy one.

That leaves coastal installations, of course; but there is the issue of range.

CS Forester says that the French once did experiments with hot shot aboard ship but that comes from losing every battle.

[Anthony]

Originally Posted by Icelander

Let's take a concrete example.

The TL2 monakon is a torsion device with one spring and a rigid arm. It uses either animal sinews or ropes wound of hair to store energy. Neither material gets much cheaper with higher TLs and they don't improve at all. Quite frankly, I'm not sure whether any low TL materials are better.

While not present in medieval Europe, treated rubber is possible at TL 3, though modern vulcanization is higher tech, but I'm not sure whether it actually helps with energy storage. However, a TL4 equivalent to a monakon can use a TL 4 axle, which has considerably lower friction. Note that any such device (a) stores some energy in the arm, which will flex, and (b) wastes some energy moving the arm. Optimization of the arm design (combination of reducing weight and maximizing energy storage) should make some difference.

[Icelander]

Originally Posted by Anthony

While not present in medieval Europe, treated rubber is possible at TL 3, though modern vulcanization is higher tech, but I'm not sure whether it actually helps with energy storage.

Does anyone know whether treated rubber is superior to animal hair for energy storage?

I lean toward 'no', because as far as I know, it takes modern (well, TL7) synthetics to match and exceed the performance of the best (though expensive) animal hair in this role.

I haven't heard of rubber used, though. Only in toys.

Originally Posted by Anthony

However, a TL4 equivalent to a monakon can use a TL 4 axle, which has considerably lower friction.

How much difference does that make? How much extra energy are we applying to the projectile here?

Originally Posted by Anthony

Note that any such device (a) stores some energy in the arm, which will flex, and (b) wastes some energy moving the arm. Optimization of the arm design (combination of reducing weight and maximizing energy storage) should make some difference.

Well, at TL4, there are better materials available for the arm than wood. It's just that such gains are proportionately small enough and such materials so fantastically expensive compared to easily available wood that it was never worth it.

Is there anything at TL4 which would make it worth it? A quick thought suggests steel, but that would probably increase cost considerably. By how much, though?

The monakon in Low-Tech is clearly made with some care, as it costs as much as three trading cogs.

If steel should be worth it, what are the gains we are seeing? Increase of efficiency in what range? +10%? +20%? More?

[Icelander]

Also, how much benefit does one really gain from denser projectiles? The rules that lead bullets double range, change damage type to pi++ and add +1 to damage suffer somewhat from scaling issues, I should think.

What would realistic rules for exchanging lead projectiles for stone ones look like? Some multiplier for range and damage, I should think, but which one?

[Anthony]

Originally Posted by Icelander

Also, how much benefit does one really gain from denser projectiles?

Lower air resistance, greater armor penetration. The rules for lead bullets look extremely generous.

[Icelander]

Originally Posted by Anthony

Lower air resistance, greater armor penetration. The rules for lead bullets look extremely generous.

Indeed.

So what would be more sensible rules?

Add +20% to range? Add +50% to range?

And as for damage, what do you reckon? The same modifier as for range? Less?

[fredtheobviouspseudonym]

Originally Posted by Icelander

. . . rain down Explosive Fireballs and other anti-material spells on the opposition. This means that tough hulls and gunwales are a worthwhile investment and that sails may be a dangerous weakness.

The wooden hulls were less of a fire-hazard than the cordage (hemp) and tar needed to waterproof the lines & hull.

So if fireballs are a constant for war at sea, and you have the Scientific Revolution of TL-4 or its equivalent, you might see people trying to find materials that meet the needs of ships for lines & damp-protection that are less flammable.

[Ze'Manel Cunha]

Originally Posted by Icelander

Also, how much benefit does one really gain from denser projectiles? The rules that lead bullets double range, change damage type to pi++ and add +1 to damage suffer somewhat from scaling issues, I should think.

What would realistic rules for exchanging lead projectiles for stone ones look like? Some multiplier for range and damage, I should think, but which one?

It's a substantial gain in range.
Lead has a density of 11.34 g/cm3, and granite has a density of 2.75 g/cm3:
Weight = Volume * Density

47.5 kg = 200 mm diameter lead ball

47.5 kg = 320 mm diameter granite ball

Which eyeballing it might mean the lead ball gets about a third less drag than the granite ball at the same velocity, which we could say gives it that extra third as a range boost, or get someone to do the math, but at high enough speeds that's a substantial gain in range.