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Dr paradox
2018-05-23, 02:40 AM
If the names "Lugos Falk," "Worm," or "Jorgenson and Sons and Daughter" mean anything to you, I'd take it as good sportsmanship to read no further





So, I'm running a nautical D&D game, and the party is about to take part in a salvage mission. Does anyone have a ballpark range on how long late-medieval period steel could be submerged in seawater and still be useful as a weapon? I'm trying to figure what the resale price on a boatload of halberds is likely to be after a week and a half at the bottom of a shallow bay.

Mechalich
2018-05-23, 02:47 AM
So, I'm running a nautical D&D game, and the party is about to take part in a salvage mission. Does anyone have a ballpark range on how long late-medieval period steel could be submerged in seawater and still be useful as a weapon? I'm trying to figure what the resale price on a boatload of halberds is likely to be after a week and a half at the bottom of a shallow bay.

What's the exchange rate on bronze to steel? Because your boat got plundered by the local aquatic race within twenty-four hours of hitting bottom, and if you want those halberds back you'd better hope the merfolk are inclined to sell.

Brother Oni
2018-05-23, 03:07 AM
The steel halberd heads will be fine for the time period mentioned. There'd be minor tarnishing in fresh water and even less corrosion in salt water.

The wooden hafts should also be fine in salt water after a week and a half. If it's a fresh water bay then they're potentially ruined, so the merfolk are likely to be sitting on a bunch of steel heads attached to rotten/rotting bits of wood.

That said, the heads are the expensive parts, so the worst case resale value per unit would be the price of a halberd minus the price of a staff.

Cespenar
2018-05-23, 03:34 AM
The steel halberd heads will be fine for the time period mentioned. There'd be minor tarnishing in fresh water and even less corrosion in salt water.

Uh, actually salt water increases corrosion a lot. So much so that there are special stainless steel alloys devised specifically for maritime uses.

But one and a half week is pretty short, so I'd agree with a result of just minor corrosion that could be undone with some care.

Brother Oni
2018-05-23, 05:35 AM
Uh, actually salt water increases corrosion a lot. So much so that there are special stainless steel alloys devised specifically for maritime uses.

That's what I thought as well, but a number of papers seem to disagree, for example: Corrosion Properties of Plain Carbon Steels (http://theijes.com/papers/v2-i11/Part.1/D021101018024.pdf).

I found a paper on North Sea oil rigs and the corrosion rate of the support beams is ~0.5 mm/year, but also makes specific mention that the beams are exposed to both salt water and air, which isn't applicable in this case.

Some boat and yacht forums also mention that fresh water (ie rain water) is the primary cause of any corrosion woes they have on their vessels, which is unusual as sea water (or at least the spray) is likely going to be everywhere. Whether that's because the parts where fresh water accumulates isn't as corrosion resistant as the rest of the vessel or some special properties of fresh water isn't clear.

I do know that stainless steel alloys (at least 316L grade SS does) will corrode faster when exposed to ultrapure water and heat as the lack of electrolytes in the water degrades the protective microlayer added during passivation. Again, this isn't applicable here as the halberd heads are going to be a fairly hard steel (if they were cheaper mild steel ones, why both going to the hassle of recovering them?).

It's a very complicated subject (eg what electrolytes are in the salt water, oxidation from air), but for time period involved in the original post, the difference between fresh/salt water is not going to make any significant material difference, only a mild cosmetic one.

Cespenar
2018-05-23, 07:18 AM
That's what I thought as well, but a number of papers seem to disagree, for example: Corrosion Properties of Plain Carbon Steels (http://theijes.com/papers/v2-i11/Part.1/D021101018024.pdf).

I found a paper on North Sea oil rigs and the corrosion rate of the support beams is ~0.5 mm/year, but also makes specific mention that the beams are exposed to both salt water and air, which isn't applicable in this case.

Some boat and yacht forums also mention that fresh water (ie rain water) is the primary cause of any corrosion woes they have on their vessels, which is unusual as sea water (or at least the spray) is likely going to be everywhere. Whether that's because the parts where fresh water accumulates isn't as corrosion resistant as the rest of the vessel or some special properties of fresh water isn't clear.

I do know that stainless steel alloys (at least 316L grade SS does) will corrode faster when exposed to ultrapure water and heat as the lack of electrolytes in the water degrades the protective microlayer added during passivation. Again, this isn't applicable here as the halberd heads are going to be a fairly hard steel (if they were cheaper mild steel ones, why both going to the hassle of recovering them?).

It's a very complicated subject (eg what electrolytes are in the salt water, oxidation from air), but for time period involved in the original post, the difference between fresh/salt water is not going to make any significant material difference, only a mild cosmetic one.

I don't want to clutter here with material sciences references and derail the thread, but suffice it to say that there are numerous problems with that paper, and my professors, material science books, and every other engineer I met basically taught or are taught that seawater corrodes much, much faster than freshwater in otherwise similar situations. IIRC to a factor like 1-to-5, even. Electrochemical corrosion is a reality.

LibraryOgre
2018-05-23, 09:57 AM
After about 10 days in water, you don't have halberds, you have scrap metal. If they've been relatively undisturbed, there's a chance there's decent metal underneath the layer of corrosion, and someone with significant magic (I'd place this beyond a Mending spell, myself) could undo the damage, but they're not worth much unless your kingdom is metal-poor.

Cespenar
2018-05-23, 10:10 AM
After about 10 days in water, you don't have halberds, you have scrap metal. If they've been relatively undisturbed, there's a chance there's decent metal underneath the layer of corrosion, and someone with significant magic (I'd place this beyond a Mending spell, myself) could undo the damage, but they're not worth much unless your kingdom is metal-poor.

I remember corrosion rates of steel in seawater as being less than 1 mm per year, though. So, ten days should give something at the tens of micrometers level of rust, which doesn't sound that bad, honestly.

Corrosion is a more long term problem for steel, like fatigue and creep.

Dr paradox
2018-05-23, 01:31 PM
Additional details and caveats, I guess.

The bay is fed by a small freshwater river, but it's mostly saltwater. There's no aquatic weapon-users in the area, and the bay is sheltered by a reef, so it's pretty undisturbed. A halberd has a list price of 20 gold, but we're also talking water damage and a wholesale price. If there were, say, three thousand halberds in the hold when the ship wrecked badly, do people have any gut reactions to the resale price for the salvage? Also considering that the likely buyer is at war right now.

Rockphed
2018-05-23, 02:30 PM
Additional details and caveats, I guess.

The bay is fed by a small freshwater river, but it's mostly saltwater. There's no aquatic weapon-users in the area, and the bay is sheltered by a reef, so it's pretty undisturbed. A halberd has a list price of 20 gold, but we're also talking water damage and a wholesale price. If there were, say, three thousand halberds in the hold when the ship wrecked badly, do people have any gut reactions to the resale price for the salvage? Also considering that the likely buyer is at war right now.

Wholesale, in-bulk, buyer is going to war right now vs all the weapons have been submerged in sea water for about 2 weeks? Gut feeling is that if the buyer pays more than 30,000 gp he'll feel like a chump. On the other hand, prestidigitation should be enough to pull the rust off the halberds and what he doesn't know won't hurt him (after all, at the end of the day most of his soldiers will die before they get to find out how degraded their halberds are). If they lead with "we found these at the bottom of the bay", they will get an offer of 5kgp (which won't budge much without a thermal detonator), if they lead with "hey, we have the weapons your army needs" and manage to avoid mentioning the sea, they can probably walk away with 15kgp.

Brother Oni
2018-05-24, 08:58 AM
The bay is fed by a small freshwater river, but it's mostly saltwater. There's no aquatic weapon-users in the area, and the bay is sheltered by a reef, so it's pretty undisturbed. A halberd has a list price of 20 gold, but we're also talking water damage and a wholesale price. If there were, say, three thousand halberds in the hold when the ship wrecked badly, do people have any gut reactions to the resale price for the salvage? Also considering that the likely buyer is at war right now.

TL:DR: use Rockphed's values. :smallbiggrin:

Assuming that the players want to sell at a fair price and not suffer any potential stigma (whether legally or socially) associated with war profiteering:

Halberd (20gp list price) - quarter staff (5gp D&D 4ed list price) = 15gp list. Multiplying by 0.65 to get to wholesale price gives 9.75gp per unit.

Factoring in the poor quality of them (say a further 50% modifier) gives 4.875gp per unit, for a total of 14,625gp in total.
This is contingent on the players doing the bare basics of replacing the rotten/unusable hafts to have a basic functional weapon. If they just turned over the tarnished heads, they'd be lucky to get a sale, let alone a couple silver each.

On the other hand, if they put the effort in to clean up the weapons and get them both practically and aescetically functional, that wholesale price of 29250gp wouldn't be too much of a stretch.

Adeon Hawkwood
2018-05-24, 11:45 AM
Factoring in the poor quality of them (say a further 50% modifier) gives 4.875gp per unit, for a total of 14,625gp in total.
This is contingent on the players doing the bare basics of replacing the rotten/unusable hafts to have a basic functional weapon. If they just turned over the tarnished heads, they'd be lucky to get a sale, let alone a couple silver each.
Replacing 3000 halberd hafts would take a long time. They'd probably be better off cleaning up the heads and selling them as heads only, let the buyer worrying about getting new hafts. Shouldn't affect the profit to much either way though (PCs spend 5gp for hafts versus knock 5gp off their asking price).

Beleriphon
2018-05-24, 02:23 PM
Replacing 3000 halberd hafts would take a long time. They'd probably be better off cleaning up the heads and selling them as heads only, let the buyer worrying about getting new hafts. Shouldn't affect the profit to much either way though (PCs spend 5gp for hafts versus knock 5gp off their asking price).

Having never assembled halberd I can't directly comment on this, but shouldn't it be a matter of cleaning the socket, and the driving a pin through the shaft and socket. Its not fast, but with a small group of people over the course of a few days I imagine that getting them all done should be pretty quick.

Brother Oni
2018-05-24, 03:27 PM
Replacing 3000 halberd hafts would take a long time. They'd probably be better off cleaning up the heads and selling them as heads only, let the buyer worrying about getting new hafts. Shouldn't affect the profit to much either way though (PCs spend 5gp for hafts versus knock 5gp off their asking price).

Bear in mind that the client is at war and may not have the time or resources to prepare 3000 poles from trees and attach them to the heads.

If you wanted a quick snack while you were out and about, would you buy a loaf of bread and filling and make your own sandwich, or just buy a pre-made one? Convenience is usually worth a premium.

Wholesale price minus haft price is ((20*0.65) - 5) 8 gp per unit, which you then have to deduct a further 10-20% for not providing a finished product, so 6.4-7.2 gp per unit. I suppose they just come out ahead of the 4.875 gp/unit with replaced hafts but crappy heads, but you're depending more on how badly the buyer wants weapons.


Having never assembled halberd I can't directly comment on this, but shouldn't it be a matter of cleaning the socket, and the driving a pin through the shaft and socket. Its not fast, but with a small group of people over the course of a few days I imagine that getting them all done should be pretty quick.

You're missing an important step - getting 3000 six foot wooden shafts. While easier than forging halberd heads out of iron ore, finding enough suitable length and type of wood and turning them into poles with a pole lathe will also take a while.

If the players were sourcing and turning their own poles, then it wouldn't cost 5gp to replace the hafts, but now they're more weapons manufacturers rather than salvagers.

Kaptin Keen
2018-05-24, 03:41 PM
TL:DR: use Rockphed's values. :smallbiggrin:

But we also need to factor in the current market - with a war on, quality infantry arms are almost certainly at a premium, the market being essentially vacuumed. Then, multiply that by a modifier based on the PC's bluff - or similar - skill check. Final price might be in the 45-50k range.

Disclaimer: No actual math used. All numbers are either pure guess, or complete fiction.

Brother Oni
2018-05-24, 03:51 PM
But we also need to factor in the current market - with a war on, quality infantry arms are almost certainly at a premium, the market being essentially vacuumed.

Hence my disclaimer on the PCs not wanting to be war profiteers.

Beneath
2018-05-24, 05:54 PM
As an added complication, it's possible that the original owner of the shipment might want a cut. If the buyer already paid for the halberds, they might be unwilling to pay full price a second time; their leverage is going to be proportional to the difficulty the salvors might have in taking them to another buyer and any ability the local law might have to confiscate or impound them (recruiting a crew to smuggle something that you don't legally own out of town might be difficult if they don't have one 100% ready to sail).

While it is correct that corrosion is a long-term problem with steel, it's also very uneven. The edges will almost certainly be ruined, though some of them will be able to be re-sharpened (maybe most of them), while others would need to be re-shaped before sharpening to make up for pits.

The amount of oxygen at the bottom of the bay is also a likely factor, dependent on the local ecology and the churning of the water. It's also likely that the halberds were coated in oil for storage, which would be protective until it comes off. Without a reference saying otherwise, though, I doubt a medieval halberd blade would be anodized, so modern measurements with galvanized steel are probably going to be misleading.

How much the buyer would be willing to pay depends on how they're doing financially and in the war. They can't spend money they don't have and can't borrow, and how much they're willing to pay will depend on whether they're winning or not.

So between storage and legal regime, I can say that 30k is probably fine as an upper bound (higher if the buyer is rich and desperate in the war), with a lower bound of "thank you for salvaging my gear, we'll reprovision your ship, now go"

Rockphed
2018-05-24, 06:02 PM
TL:DR: use Rockphed's values. :smallbiggrin:

I was almost literally going with gut feelings on that. I'm just glad other people think my analysis got to the right spot (even if it made it there for the completely wrong reasons).

Brother Oni
2018-05-25, 01:56 AM
I was almost literally going with gut feelings on that. I'm just glad other people think my analysis got to the right spot (even if it made it there for the completely wrong reasons).

As a rule of thumb, wholesale prices are ~65% of list price. This will change significantly depending on the goods in question - I believe for some mass produced goods in highly competitive markets, the margins are tiny, with some selling at a loss to establish their market share and getting the money back through insurance and other accessories.

I remember seeing a D&D table with price adjustments for quality of goods, but I can't remember which edition or where I read it. Generally though, knock off 10% per drop in 'level' of item quality (pristine, very good, good, average, poor, etc).

However unless the campaign is trying to replicate Recettear or Spice and Wolf, this level of detail normally isn't required. :smallbiggrin:

Xuc Xac
2018-05-25, 04:08 AM
After about 10 days in water, you don't have halberds, you have scrap metal. If they've been relatively undisturbed, there's a chance there's decent metal underneath the layer of corrosion, and someone with significant magic (I'd place this beyond a Mending spell, myself) could undo the damage, but they're not worth much unless your kingdom is metal-poor.

It's 10 days, not 10 years. There will be some minor surface rust but the damage will be cosmetic. The soldier who receives it can clean it off while doing his regular maintenance.


Wholesale, in-bulk, buyer is going to war right now vs all the weapons have been submerged in sea water for about 2 weeks? Gut feeling is that if the buyer pays more than 30,000 gp he'll feel like a chump. On the other hand, prestidigitation should be enough to pull the rust off the halberds and what he doesn't know won't hurt him (after all, at the end of the day most of his soldiers will die before they get to find out how degraded their halberds are).

Do you know what the structural difference is between a piece of carbon steel that's been under water for 10 days then polished and one that's just been in regular storage and then polished? Nothing. They're both a tiny bit smaller for losing a few microns off their surfaces.



Assuming that the players want to sell at a fair price and not suffer any potential stigma (whether legally or socially) associated with war profiteering:


Unless you're selling antiques to collectors, being an arms dealer is always war profiteering. They could sell at full price and it would just be business as usual. The stigma would be a result of selling at higher than normal prices (over 20gp each of that is the list price) because there's a war right now. I don't get the "wholesale" thing. They aren't selling to middlemen who will resell them at retail prices. They're selling directly to the consumer.



If they just turned over the tarnished heads, they'd be lucky to get a sale, let alone a couple silver each.


This is like saying nobody would pay more than $20 dollars for a car if they had to paint it themselves. 5gp for a staff is ridiculously overpriced, but even in a ridiculous D&D adventurer based gold rush economy, a halberd minus the shaft is not significantly worth less. If you're planning to fight a battle in an hour, it might be a deal breaker, but otherwise you've got plenty of time to put new shafts on them.


Bear in mind that the client is at war and may not have the time or resources to prepare 3000 poles from trees and attach them to the heads.

It's difficult for one person or a small group to quickly acquire and attach 3000 poles, but it's pretty easy for 3000 soldiers to find and attach one pole each.


As an added complication, it's possible that the original owner of the shipment might want a cut.

This is where the ancient legal principle of "finders keepers, losers weepers" comes into play. It belongs to whoever brings it back to the surface. The law of salvage goes back to medieval times and it's pretty much universal. The original owner lost it. They can get it back by paying you the fair value of it or they can let you keep it. Some owners might want to break the law and steal it back from the salvors, but that would be piracy on their part.

Rockphed
2018-05-25, 01:41 PM
Do you know what the structural difference is between a piece of carbon steel that's been under water for 10 days then polished and one that's just been in regular storage and then polished? Nothing. They're both a tiny bit smaller for losing a few microns off their surfaces.

Hence "prestidigitation fixes the rust problem". Prestidigitation cannot fix structural issues, but it can clean things, and surface rust is pretty much just dirt.

Beneath
2018-05-25, 08:05 PM
This is where the ancient legal principle of "finders keepers, losers weepers" comes into play. It belongs to whoever brings it back to the surface. The law of salvage goes back to medieval times and it's pretty much universal. The original owner lost it. They can get it back by paying you the fair value of it or they can let you keep it. Some owners might want to break the law and steal it back from the salvors, but that would be piracy on their part.

That's very much not true in modern day (salvage awards are typically anywhere from a tenth to a quarter full price, depending on the complexity and danger of the salvage, according to wikipedia), and as I said in the rest of the post that you cut off, it's a matter of who has the power to impose their will. It's very likely that won't be the adventurers. Property law comes after power.

Ownership is a matter of law, record, and enforcement. A nonmagical hunk of metal does not know who owns it. It doesn't "know" it belongs to a buyer when it is bought to be shipped to a distant port, "forget" its ownership when the ship it's on sinks, and come to "know" that it now belongs to the salvor when it's pulled up. The law says "finders keepers" if the adventurers can force their host to treat them as lawful owner, and it says that an owner doesn't relinquish ownership just because the ship sank if the previous owner won.

More than that, if a bunch of strangers say they're going to find another buyer for 3000 weapons when the nearest other buyer who's likely to need that many weapons is their host's enemy, their host is fully justified in taking them as POWs and claiming the weapons as provisions bound for the enemy regardless of previous ownership, if they have the power to do so (which, with adventurers, is not a given).

That's why you avoid war profiteering. Not only is it unethical, it's also dangerous. You come into an armed camp of robbers (medieval soldiers are paid in loot) bringing something they need, and hope to not get robbed yourself.

Xuc Xac
2018-05-25, 11:36 PM
That's very much not true in modern day (salvage awards are typically anywhere from a tenth to a quarter full price, depending on the complexity and danger of the salvage, according to wikipedia), and as I said in the rest of the post that you cut off, it's a matter of who has the power to impose their will. It's very likely that won't be the adventurers. Property law comes after power.


In modern legal terms, "salvage" is saving the ship and cargo from being lost or destroyed. Getting an award of 10 to 25 percent is for things like towing a disabled ship back to port or pulling a grounded ship off a reef. The award can go up to 100% in cases where the stuff is written off as lost but you manage to recover it. In cases like that, the original owner doesn't care anymore. They were paid off by their insurance company and the insurer is the one that owes the salvage award. Instead of selling off the ship and recovered cargo to pay you its value, it's quicker and easier for them to just let you keep it (or force you to keep it by just not paying the award so you have to legally seize the property to settle the debt).

Sure, the prospective customer might just take all the weapons without paying you, but how are they going to supply themselves for the next war? Nobody is going to try selling to them again. At a minimum, merchants are going to expect payment in advance before delivering any goods.

Dr paradox
2018-05-26, 04:10 AM
Since the question of ownership and how to sell the salvage has come up, here's the context.

The party is actually working FOR the local authority on this salvage mission, the authorities being a gang of former pirates who decided it'd be more profitable to use their ships to monopolize trade to a backwater island with a few valuable natural resources. Their main trading partners are the ones at war who were initially in the market for the halberds.

They hired the party with a contract that entitled each of them to a little under 5% of the proceeds - half goes to the Seven Kings Trading Company, each of the nine crew on the job gets a share, the Captain of the salvage ship gets two shares. It's honestly a really generous deal for them to get considering it's 100% profit in mercantile quantities, but I figured getting any less than that would seem vindictive.