TL3+1 Mechanical Artillery

[Icelander]

Originally Posted by Ze'Manel Cunha

Military acquisitions and supply take time, even when the need is immediate.

True.

The PCs are managing to get theirs built in ca two months, by contract with maritime engineers and subcontracting to master smiths in around five different cities. They'll want to move up that production schedule, now that they have captured ships to arm.

So the two sides will be competing for intricate spring steel artillery from the neutral cities nearby. The PCs' side, though, is being covertly supported by the leading political forces in that part of the world. Not that this will prevent private engineers and smiths from taking lucrative contracts from the Egyptian-esques, if offered.

I wonder how many of such artillery pieces can be built at one time by a collection of port cities (and any inland cities they could subcontract to) that amount in total to around five million people? Assuming that until then, their industry was not on any kind of wartime footing, but that they had experience in building that kind of artillery to arm their own ships, rich merchant ships and the occasional military ship for the regional superpower (still neutral, but covertly supporting PCs' side). And that some of them had pretty good crossbow-making facilities.

Will ca 200 pieces ordered by PCs and several times that potentially ordered by the Egyptoids swamp the facilities or will they reorganise, hire new staff in a hurry and turn them out quickly while counting their mounting wealth?

Originally Posted by Ze'Manel Cunha

I would expect that they would be sending out people to buy this type of equipment from abroad, asap, but that's still going to take weeks or months before it gets into the field.

The importance of this is enough so that after the political decision to commit to foreign-made steel weapons is made, the emissaries to buy it will be dispatched by magical means. Thus, no travel time to reach the markets.

On the other hand, the weapons would have to be shipped in the normal way, as teleportation of tons is prohibitively expensive except in very special circumstances (involving portals and such). That would add from five days to a month, depending on where they were made, prevailing winds and how eager the polity whose flag the trade ship carrying the weapons was to deliver. Since it will have to be one of the 'neutrals' that really aren't all that happy about the expansion of the Egyptian-esque empire, they'll refuse to ship it to any but the safest of ports. On the other hand, private citizens do own ships and for sufficient cash will overlook such minor issues as their rulers and their political concerns*.

*Especially since you can't enforce a secret policy of compromised neutrality by legal punishment. At most, you can strictly enforce neutrality toward one side only, but that doesn't allow you to punish those of your citizens who carry out perfectly normal business with the less favoured neutral side, forgetting in the meantime to impose unfair and arbitrary conditions designed to slow down the pace of military operations.

Originally Posted by Ze'Manel Cunha

The most likely scenario would involve replacing a few weapons on their newer/faster ships, especially on ones coming out of the ship yards.

Just so.

Originally Posted by Ze'Manel Cunha

Then you'd have the situation of cheaper lightly armed chaser ships with longer ranged weapons being fielded well in advance of upgrading the range of their much more expensive and extensively armed line of the wall ships.

Could be. Could be. Of course, since their shipbuilding industry is local and they aren't in financial difficulties, they could lavish expense on their new vessels. Foreign steel is rare, but they have plenty of good wood and good craftsmen.

They could trick out their lighter galleys as 'gunboats', with a heavy steel spring piece in the bow. That would mean fewer rowers and therefore less speed, but a long-ranged main piece that could be be easily aimed by moving the agile galley around.

I don't know how much weight galleys can carry in the bow without taking an awful performance hit, though. 10% of their total cargo capacity? Less? More?

Of course, it doesn't have to be right in the bow. In fact, you could probably have it fairly close to the center, for good balance. That would require you to shoot explosive rounds over the heads of your rowers, which requires either exemplary safety protocols and smart, conscienteous free rowers, or draconian discipline over slave rowers.

The Mulhorandi (Egyptian-esque) have slave rowers, but these are regarded as property of the gods (in fact, the churches own them and collect the profits of their work) and mistreating them is sacrilegous. I'd expect conditions on the rowing benches to resemble the free rowers of the Ancient world more than the slaves of the medieval world.

There is the fact that the few capital dromonds that they are turning out in the next few weeks will likely bear the brunt of any fighting. The lighter galleys just don't have the endurance* to stay on station anywhere, which means that the sailing ships of the PCs' side can bypass them with insolent ease. The Mulhorandi do have sailing ships, but these are trading ships with simple rigging plans that lack any capacity to maneuver in battle.

They are hiring foreign sailors that allow them to use more complex rigging, but that's a slow process. Expect that their dromonds will be their best choice for time on station for a while yet.

*They can't carry enough food and water to stay out for more than a day.

[Ze'Manel Cunha]

Originally Posted by Icelander

The PCs are managing to get theirs built in ca two months, by contract with maritime engineers and subcontracting to master smiths in around five different cities. They'll want to move up that production schedule, now that they have captured ships to arm.

One thing to keep in mind, those 5 different cities should be producing 5 different incompatible and non-interchangeable devices, even the ammunition is unlikely to be fully compatible.

You'd probably need to be at TL3+3 in artillery to have them be fully interchangeable compatible devices, and at least TL3+2 for fully compatible ammunition.

In other words, the city of X is making 10" Dragons, the city of Y is making 10" Shriekers, but the Y's and X's 10"s don't measure the same, precision measurements like that are TL5-6.

[Icelander]

Hmmm, at TL2, Roman artillery shot 'standardised' ammunition, in that it conformed to certain legion standards, no matter where it was made.

No doubt artillery pieces had minor differences of appearance and such, but I doubt that it mattered excessively when it came to whether or not they could shoot a stone of certain weight or not. Artillerymen would have had to learn quirks of each weapon, no doubt, but that was true for any weapon up to TL5 and throughout much of TL5 too.

For that matter, the legionary procurement system had armour and swords made to certain requirements in all Europe. I don't think that it's accurate to say that no standarisation of any kind is possible before TL5-6. Just because Europe happened to be incredibly balkanised during a millenia or so doesn't mean that this was a technological constraint.

Three of the cities involved are making copies of a 10-lb ballista that can shoot small lead spheres as well as larger glassware shells and copies of a 20-lb one that is essentially a scaled-up version of the same. The cities are mutually independent, with one of them belonging to a large polity but the others amounting to city-states, but they are all along the same coast and share culture, language and history. For that matter, the independent city-states have in the past been ruled by the larger polity and currently are independent on sufferance, taking care to show the right politics and so forth.

Craftsmen from all the the cities were shown the same piece and asked to produce close copies, being required to shoot the same ammunition. So far, all the ammunition has been produced in the same place, by the PCs' own men, where it is weighed with magical precision.* Any piece of artillery that can't fit it would be rejected by the quartermasters as unusable.

Craftsmen with TL3+2 exist in the world, with the widespread acceptance of the technology limited mostly by the fact that no power sources and few supporting technologies exist other than magic. For sufficiently rich customers, though, mages, alchemists and artificers can easily match a lot of TL5 things in our world, including clockwork, gears, navigation, measurement and naval engineering.

The other two cities are far away, but also share some culture and history. The craftsmen in question are copying different designs, lighter and more expensive, and the main design is a 15-pounder. They are all working from the same plans, though, and have a working model to test and match their work against.

*In practice, the weighing is fast enough and the demands of service constant enough so that anything not wildly varying in weight is passed. Taking more time and rejecting more examples might produce Fine (Balanced) ammunition, but so far, the use of it has been too profligate to make that practical. Even so, I would say that the variation is no more than a couple of ounces either way. Of course, combined with the variability in draw weight produced by different steels, this means that ranging shots are de rigeur and a broadside will rarely hit the same spot or anything close. No more than the cost of doing business with Acc 2 weapons.

[PhoenixPaw]

*curses his tired brain at about half past nine pm local time*

I just had some really fancy idea about how perhaps get more "umph" out of an catapult, but ... can't frame it well in words.

In any case, why not allow the arms to work from 45 to 135 degree angle instead of from 0 to 90-ish.

Do I make sense?

[DanHoward]

The ancients spent a thousand years experimenting with different designs. By the time of the Romans the design would already be optimised for the most efficient configuration.

[Anthony]

Originally Posted by PhoenixPaw

In any case, why not allow the arms to work from 45 to 135 degree angle instead of from 0 to 90-ish.

Because that means the angle of release is around 45 degrees downwards and your shot plows into the ground right in front of the launcher.

Originally Posted by DanHoward

The ancients spent a thousand years experimenting with different designs. By the time of the Romans the design would already be optimised for the most efficient configuration.

I guess this comment is specific to torsion catapults, since it certainly isn't true for trebuchets. I doubt it's true for torsion catapults either, but the most efficient configurations probably require higher tech pulley mechanisms (much like compound bows).

[DanHoward]

The most efficient for the technology available. There is little point adjusting the angle or length of the throwing arm, for instance, since that would already have been optimised.

[sir_pudding]

In our history ballistics is really TL5 and Fire Control is TL 6, but I don't see any reason they aren't doable with TL3+1 Mathematics. So you could use the High-Tech rules for Fire Control for pre-planned targets at least. Forward Observation is a problem because of communication, but an FO could be collocated with the firing element, and allow even better FC.

[Icelander]

Originally Posted by DanHoward

The ancients spent a thousand years experimenting with different designs. By the time of the Romans the design would already be optimised for the most efficient configuration.

I don't see why that assumption is given.

The typical target for a heavy stone-throwing catapult is something immobile during a siege. It's not a priority to design your weapon to be especially light, since you aren't going to move it and green wood is rarely that hard to obtain in quantity, and it may be that you don't especially care about a few extra percent of range and power, not if it would add noticably to the price.

In a siege situation, which the heavy stone throwers were designed for, you could always throw a heavier stone or build more catapults. If a given design compromise made them faster to build, enabled less-skilled smiths to carry out certain parts of the work or required less material that could not be obtained on site, it is not unlikely that these considerations were given more importance than the performance of each piece.

Historical artillery was not designed for the role I'm envisioned for ahistorical artillery in a world with more expensive gunpowder and thus it is not necessarily going to be optimised for it. Historical heavy artillery, in fact, was most probably designed to be quick to build and to require as little material that your army had to carry along as possible.

Only a few types of battlefield artillery had been designed explicitly for anything like this role and these were rarely in use for long enough for it to be inevitable that they be optimised.

We can point out how engineers today have built copies of the best-guesses for historical designs of one-armed stone-throwers and then improved upon these using the same materials, for example by adding a sling at the end. This tells us that 'onagers' were far from optimal in design, if we judge by performance alone. No doubt the sling added some complication, reduced durability or introduced another problem in field service, however. Or perhaps it just made it harder to aim the weapon without sufficient mathematical knowledge.

[Icelander]

Originally Posted by sir_pudding

In our history ballistics is really TL5 and Fire Control is TL 6, but I don't see any reason they aren't doable with TL3+1 Mathematics. So you could use the High-Tech rules for Fire Control for pre-planned targets at least. Forward Observation is a problem because of communication, but an FO could be collocated with the firing element, and allow even better FC.

The players have gleefully adopted spells from GURPS Magic to communicate such details as precise range, azimuth, wind direction and strength and so forth to the PC who directs the artillery. He is a skilled mathematician and calculates aiming point data for the weapons he directs, usually one or two that are side-by-side, when shooting at long range.

He also likes to use Find Weakness on his arrows and he's working on a way to enchant ammunition to seek out his arrows, after he sinks them in the desired spot on the target.

So far, communication is handled by the fire control officer remaining next to the artillery crew and gathering his information by magic at long range. He also has incredible vision, thanks to inborn gifts as well as having a hawk familiar and two magical tattoos giving him Keen Vision and Hawk Vision upon activation (as well as knowing the spells himself, if he needs them cast at higher level). He generally functions with Observation at 22 and three levels of magnification, equivalent to x8 or x10, but he can add ca +2 to his Keen Vision and two more levels of Hawk Vision if he has to do really long shots.

He can also see through the eyes of his familiar, as long as he's within a mile. Hasn't used it for fire control yet, but he's used it to pick out targets for his bow.

That character has Mathematics (Surveying), Mathematics (Applied), Cartography and Forward Observer skills. Another PC who also has magical vision and boots that allow him to fly also has Forward Observer, since he often uses spells that are visible from far off to indicate and select targets for artillery, as well as give signals like 'over', 'under', 'right' or 'left' to correct their fire.