[AtE] Black Powder vs Smokeless

[Anaraxes]

Originally Posted by Daigoro

I think you do need workers at the top to boil up the molten lead.

Certainly I have no good practical sense of how this was done. But could you not just melt the lead at the bottom, then haul up your crucible, slide in your basin of water (or flood the bottom of your lift well) and then tip the molten lead through the copper screen to fall into the water below? It's not like the lead will solidify the instant it's removed from the furnace.

Did historical shot towers usually have their furnaces at the bottom of the tower, or the top?

[Daigoro]

Originally Posted by Anaraxes

Certainly I have no good practical sense of how this was done. But could you not just melt the lead at the bottom, then haul up your crucible, slide in your basin of water (or flood the bottom of your lift well) and then tip the molten lead through the copper screen to fall into the water below? It's not like the lead will solidify the instant it's removed from the furnace.

Did historical shot towers usually have their furnaces at the bottom of the tower, or the top?

It could go either way, I guess. The wikipedia and other articles I've quickly looked through didn't give that detail.

One thing is that the molten lead is poured over a plate with shot-sized holes in it, so I figure not all of the lead gets used with each pour. This would have to be collected at the foot of the plate and reheated, suggesting to me that it's done at the top of the tower. Also I'm a bit leary of the safety aspect of hauling a molten cauldron of lead up a 40m shaft.

[Celjabba]

Originally Posted by Daigoro

Also I'm a bit leary of the safety aspect of hauling a molten cauldron of lead up a 40m shaft.

If you are looking at industrializing ammunition production, this may actually be among the safest part ...

[Anaraxes]

Originally Posted by Daigoro

It could go either way, I guess.

More digging suggests the top:

The British Industrial Archaeological Society (BIAS) published this article on the Redcliff Shot Tower in Bristol. It has its furnace on the top floor, with some extra brick and timber support structure just under that furnace. (The office building lift wells will need a little adaptation... or maybe you can put the furnace just off to the side and have a couple of meters of channel down and over to your sieve.) It had several levels of cellar with tanks of different sizes for larger and larger shot.

This text description of a shot tower in Helena, Wisconsin says lead was "melted at the top of the tower". Similarly for this description of a tower in New Zealand.

If nothing else, furnaces at the top were popular. I'm willing to assume there's probably a good reason for that.

One thing is that the molten lead is poured over a plate with shot-sized holes in it, so I figure not all of the lead gets used with each pour. This would have to be collected at the foot of the plate and reheated, suggesting to me that it's done at the top of the tower.

Copper has a substantially higher melting point than lead. Make the sieves easily replaceable (all you really need is two grids or pans that are wider than the shaft rather than just one, that lie flat on the lip), and you can probably just put the sieve over the lead in the furnace and let any accumulated extra just melt off once it starts clogging the holes. You could also pre-heat that sieve with that arrangement, if that helps keep the lead from sticking.

Also I'm a bit leary of the safety aspect of hauling a molten cauldron of lead up a 40m shaft.

Given that our industrial tech has reverted to 18th century standards, our manufacturing safety standards might well do the same, especially if the alternative is getting overrun by the Lord Humungous.


Just for the record, this DTIC publication has the math on shot size, heat loss, and thus required tower heights for any given size -- which if nothing else proves there's someone even nerdier than I am about this kind of thing.

[Rupert]

Originally Posted by Anaraxes

If you have pulleys to lift the lead, you could lift workers -- just not all the workers.

But more simply, most or all of the workers stay at the bottom. They haul up the lead with those pulleys, then pull the release that drops the lead back down.

The lead needs to be molten, and dropped through a grating. The grating will need to be de-leaded between drops.

Unless you're dead-short of manpower, heating the lead at the top will be a lot easier - you won't have to lift crucibles of molten lead fast enough that it stays molten. So, while you'll have to lift more stuff, it's stuff that's easier and safer to handle. I suppose you could use one shaft as a lift shaft, and another as a drop shaft, as tall buildings have multiple lifts, and it's unlikely that only one will be useable if the building has any shafts useable at all.

That said, I think most of the workers will get to walk up the stairs each day - using the pulley system would be for those of high status, if it's useable by people at all (over the sort of heights we're talking it might simply be too unsafe, or have too low a capacity per lift).

According to that paper's formula, you'd need about a 100-floor building to be able to drop 00 buck, which is GURPS' default combat shot load. Unless someone has access to an old tower in what was once a city's CBD, large buckshot is going to have to be handmade with molds or swaging, and will thus be somewhat expensive. Birdshot for hunting fowl and small mammals needs a much lower tower, and will thus be (comparatively) plentiful and cheap.

[swordtart]

Better to melt the lead at the top (otherwise lead fumes would accumulate in the building and that wouldn't be good for your health).

Coastal communities could have them doubling up for lighthouses ;)

You could do without the towers and cast the old fashioned way. It is almost certainly less efficient in man hours spent in the actual casting, but once you take into account the man hours spend building (or converting) a tower plus all that heavy lifting. As you want to be using that tower frequently to offset the start-up costs and drive in efficiency you will need to be casting a lot of shot per day (tons). That requires tons of raw materials. Is lead really that plentiful that you have tons per day available.

The Bliemeister method is much more compact and might reduce your start up cost.

At TL4 economies what are soldiers doing in their off time anyway. You can spend a few hours casting shot over a camp fire in the evenings and make enough to last you all day.

Each shooter making their own powder is inefficient, but bullet moulds are included in most muzzle-loaders tool bags for a reason.

[evileeyore]

Originally Posted by Celjabba

Not to mention that if you have a 30+ floors tower and are planning to stay in the area for a while, keeping a couple of lookout on top at all time is a good idea.

Not just look-outs... your shot casters could simply live up there. If it's a skyscraper, your whole community could live in there.

Originally Posted by Anaraxes

Certainly I have no good practical sense of how this was done. But could you not just melt the lead at the bottom, then haul up your crucible...

The lead would cool too quickly. You've never done lead miniature casting have you? It cools pretty quickly.

For reference, it cools fast enough that hitting the water at the bottom of a 40 meter drop doesn't deform the shot.

[dcarson]

Baltimore has a 234 foot shot tower that is a historic building. When it was in use it produced 100,000 bags of shot a year at 25 pounds per bag. They could double that in wartime. So definitely a mass production investment unless you already have something you can convert easily.

[Luke Bunyip]

Originally Posted by Celjabba

Not to mention that if you have a 30+ floors tower and are planning to stay in the area for a while, keeping a couple of lookout on top at all time is a good idea. Preferably with some kind of scope, binoculars or refractor, and the most accurate guns you can spare...

Originally Posted by evileeyore

Not just look-outs... your shot casters could simply live up there. If it's a skyscraper, your whole community could live in there.

Apparently, office towers have their own set of tactical considerations. IIRC, the PLO and/or one of the Lebanese militia groups rediscovered that people don't fly (they got thrown off the roof by their foes).

Having said that, I once lived in a squat that was a converted pub in Sydney. The first floor (or ground floor, if you're Antipodean) was totally blocked off, not with boards but with supplementary brickwork. The entrance was the old fire escape, which was lowered and/or raised as needed. Apparently back in the day skinheads couldn't climb.

On the gripping hand, there's all the other buildings that surround it; basically somewhere opponents can set up and supply supporting fire for an assault force.

Lots of issues, but then, lots of opportunities. My NPCs will have to be inventive...

Originally Posted by swordtart

Is lead really that plentiful that you have tons per day available.

Setting wise, it's sort of locally available, along with some silver. There's this place called Broken Hill...

[Daigoro]

Originally Posted by Luke Bunyip

Setting wise, it's sort of locally available, along with some silver. There's this place called Broken Hill...

When I visited there, though, it seemed to be suffering a shortage of skyscrapers (but a surplus of artists).