GURPS Steampunk 2: Steam and Shellfire

[Taneli]

Yay! My planning for GURPS Deadlands 4e -game progresses with me having to do anything! ^^

[Michael Thayne]

Something that initially made me go "oh cool" but on reflection raises a lot of questions: one use of Complexity 0 and Complexity 1 programs that's mentioned is providing support for the Artillery skill. The game mechanical effects of this are big: eliminating -3 or -5 in penalties. What's puzzling is this: this kind of support is said to be built-in to artillery at TL6 and TL7 respectively, and therefore "already factored into weapon details". However, this doesn't seem to be at all true of the artillery statistics we have. Increased Acc is the only thing I see that could be doing it, but (1) increasing Acc isn't quite the same thing as eliminating penalties and (2) Acc for artillery doesn't increase that dramatically with TL. Was this maybe something that's a holdover from 3e that wasn't properly adjusted for 4e?

[Rupert]

Originally Posted by Michael Thayne

Something that initially made me go "oh cool" but on reflection raises a lot of questions: one use of Complexity 0 and Complexity 1 programs that's mentioned is providing support for the Artillery skill. The game mechanical effects of this are big: eliminating -3 or -5 in penalties. What's puzzling is this: this kind of support is said to be built-in to artillery at TL6 and TL7 respectively, and therefore "already factored into weapon details". However, this doesn't seem to be at all true of the artillery statistics we have. Increased Acc is the only thing I see that could be doing it, but (1) increasing Acc isn't quite the same thing as eliminating penalties and (2) Acc for artillery doesn't increase that dramatically with TL. Was this maybe something that's a holdover from 3e that wasn't properly adjusted for 4e?

TL5 artillery doesn't do indirect fire. Not because the guns lacked the range, but because there wasn't the fire control technology to manage it. TL6+ artillery does - it's what makes it so darned lethal.

[a humble lich]

Originally Posted by Rupert

TL5 artillery doesn't do indirect fire. Not because the guns lacked the range, but because there wasn't the fire control technology to manage it. TL6+ artillery does - it's what makes it so darned lethal.

Are you sure? Most cannons were direct fire weapons at TL 5, but mortars have been in use as siege weapons since the 15th century because they could go over fortifications. It was my understanding that mortars used explosive shells long before cannons.
https://en.wikipedia.org/wiki/Mortar_(weapon)#History

[Michael Thayne]

Originally Posted by Rupert

TL5 artillery doesn't do indirect fire. Not because the guns lacked the range, but because there wasn't the fire control technology to manage it. TL6+ artillery does - it's what makes it so darned lethal.

If true, this does not appear to be reflected in the artillery rules in High-Tech. Also, even if the rules did support TL6 artillery being a huge improvement on TL5 artillery, AFAICT TL7 artillery doesn't average Acc 2 higher than TL6 artillery.

[Anthony]

Originally Posted by Rupert

TL5 artillery doesn't do indirect fire.

Sure it does; you can do indirect fire with TL 0 weapons. Without TL 6 ballistics and fuses you can't reliably do airbursts, which is a big difference in effectiveness, but indirect fire certainly isn't that recent.

[Phil Masters]

You can do mortar-type fire on ballistic trajectories at any TL, to be sure; plenty of siege engines did that in the Iron Age. But at low TLs, it tends to be done by eyeball and by walking the hits onto the target, and the target generally has to be in line of sight. What needs higher TL developments is calculated indirect fire against targets out of line of sight — hitting map coordinates sent by someone with Forward Observer skill and suchlike, thanks to detailed knowledge of ballistics. That was, specifically, a late 19th century development.

(Though, sure, you can find earlier ad hoc instances where people eyeballed it; one showed up at the Battle of Waterloo.)

This came up in the Steampunk 3 playtest, which means that, to be honest, I now know a bit more about the topic than I did when writing Steampunk 2. But we really need someone to sit down and work up a consistent treatment. What simple calculating systems (or perhaps their printed output) will tend to do, though, is turn indirect fire from an eyeball-and-instinct craft to a science, which makes them ahistorical wonder-weapons at TL5, part of the standard artillery officer’s toolkit at TL6+, and this “eliminates -X i penalties” note can be taken as a shorthand way of representing that.

Edit: Wikipedia has an article on this, naturally. In truth, it may be more the instrumentation than the calculating machinery that makes the difference at TL6 — but abstracting it out and letting a Babbage Gun Laying System be the TL(5+1) invention that brings the terrors of the mass artillery barrage to a steampunk world (somewhat as per The Difference Engine) isn’t too crazy.

[Rupert]

Originally Posted by Anthony

Sure it does; you can do indirect fire with TL 0 weapons. Without TL 6 ballistics and fuses you can't reliably do airbursts, which is a big difference in effectiveness, but indirect fire certainly isn't that recent.

Actually, Shrapnel at TL5 can do airbursts.

Sorry, I wasn't precise enough - you can't do long-range direct fire with observers, map reference fire, etc. until TL6, possibly TL5. The steampunk analytical engines, being effectively TL6+ will help enormously with this.

But try doing indirect fire with an observer passing fire corrections, etc. from far enough away that the weapon is out of sight of the target (because of range, not just because it's behind cover). You don't see long range indirect fire on land until TL6 or very late TL5. At sea it's very much a TL6 thing.

[Anthony]

Originally Posted by Rupert

Sorry, I wasn't precise enough - you can't do long-range direct fire with observers, map reference fire, etc. until TL6, possibly TL5. The steampunk analytical engines, being effectively TL6+ will help enormously with this.

You could have produced the books of ballistics tables by the 17th century, though I'm not sure the guns had sufficiently consistent ballistics to do much good. The big problem is that you don't have radio before TL 6, and forward observers aren't much use without near-instantaneous communication with the artillery.

[johndallman]

Originally Posted by Anthony

The big problem is that you don't have radio before TL 6, and forward observers aren't much use without near-instantaneous communication with the artillery.

That could be, and occasionally was, handled with visual signalling, via flags or heliograph.

I'm not sure the guns had sufficiently consistent ballistics to do much good.

That was much more the problem. Until you have rifled guns with shells manufactured on machine tools, you don't have sufficiently consistent performance. It gets a lot better when your guns have hydraulic recoil mechanisms, because that makes it far easier to fire consistently.