Eberron players want to build the Yamato, and can probably afford it

[Miasmic_fate]

So, let's start with the pitch for this campaign. I wanted a challenging campaign, so I pitched to my friends, a bunch of power gamers that I set them hard challenges, but usually with some hint on a smarter way to approach them. Rewards would be commensurate. Beat an umber hulk at level 3. Break into Lyra lyrandars secret lab and steal the macguffin to repair the core of the genesis forge. Normal daily xp allotment in one fight things. Fast forward to them now hitting level 10 and they have about 700k gold between the 4 of them.

So, this idea is cool, and it fits the position they are in now, having saved a few world leaders and began organizing against the goblin races that are poised to take over the continent.

What I am trying to figure out, is how big a ship is reasonable, how many favors they will have to call in (probably all of them), convincing lyrandar to do it, cause who else could even begin to try, and finally, that magic cost part. A lot can be handwoven by multiple elementals powering it, maybe the Phoenix egg they captured a few levels ago.

And also to be clear no, I don't regret giving them loads of gear and gold. It's allowed us to use a lot of cool monsters you normally don't get to in a regular campaign. And they're still excited to play.

So how do we science this 🤔 😁

[JackPhoenix]

Lyrandar doesn't build the airships, Cannith does. Zilargo does the elemental binding, and soarwood comes from Aerenal, with only limited amount exported every year.

Canonically, biggest airship was the Golden Dragon (from 3.5 adventure Voyage of the Golden Dragon) at 200' length and 60' windth, which required 2 elemental rings.

[Martin Greywolf]

Well, if it comes to science, let's first state that Wunderwaffe approach to warfare Does Not Work and if you have a ton of cash and need to stop an army, there are More Efficient Ways to spend it. But if your characters really want to build a massive airship...

For dimensions, here are some of the largest wooden warships ever built, given in length x width in meters (multiply by 3 to get feet):

Syracusia - 55x14

Ming Treasure Fleet ships - 70x?

Venetian galeasses - 50x13

Nuestra Señora de la Santísima Trinidad - 61x16

Which gives you a pretty clear limit on its size unless you use some sort of metal as main component to hull construction. If you do, some of the ironclad era ships look like this:

Warrior - 128x18

Merrimack - 84x12

Gloire - 78x17

So, a bit bigger, but not that much bigger. WW2 era battleships, on the other hand, are hell of a lot bigger:

Missouri - 270x33

Yamato - 263x39

Bismarck - 251x36

For crew, modern battleships take about 2000, Warrior had 700 and Santissima Trinidad about a thousand. This is... a lot more than your players probably expect, but ship of that size does need a lot of men, even without oars - there are three shifts in a day, so you need to fill postions, triple the number and have a bit in reserve. Even something like a comparatively small Mary Rose (~40 ish meters) had almost 500 men aboard.

As for how expensive this is... You're effectively building a skunkworks-style cutting edge machine, it will be at least two or three times more expensive than the largest standard thing around.

[Miasmic_fate]

Yeah, my initial thought was millions of gold, and my theory is this would be around the equivalent to early revolutionary period, for size and cost. Also iirc airships are still relatively new RAW so while the technology to build large sailing ships would be known, larger airships would be a newer notion, and even floatwood would be potentially problematic to scale up, and likely they'd run into the same problems as they did in the revolution bringing wooden ships up against heavier cannon and rifling.

And as far as the big ship is an inefficient use of money, absolutely. The player that pitched this has admitted as much already lol. But its a fantasy game and they are not the army but the crazy guys running off to do crazy stuff. No sense in logic 😁

[Martin Greywolf]

Yeah, my initial thought was millions of gold,

Mary Rose cost ~1600 pounds at a time when full plate armor cost ~10 pounds (well, from 4 for Milanese harness to 14 for gun proof set), so by multiplying PHB's 1500 gp, we get 240 000 gp for Mary Rose, which was top of the line in its time - and half the size of what was possible at the extreme end. In theory, that makes the 700k gold the party has barely enough for what they want, but... Mary Rose wasn't magic. And DnD's price list is blursed beyond belief, so take it as a very rough estimate, if we scale it off of axes, we get 640 000 gp per Mary Rose.

Also consider that this is pretty much just the ship, maybe with furniture, and crew and their equipment and food and a host of other things need to be purchased separately - and with five hundred crewmen, that's not a cheap proposition.

[False God]

Just for clarification:

The Yamato?
https://i.pinimg.com/originals/aa/ca/ca/aacaca11dd6691a3ee0ffaa084db86a9.jpg

Or the Yamato?
https://i.pinimg.com/236x/da/d4/20/dad420eb822879efe0c6940abd43cb23--star-blazers-battleship.jpg

Notably, one of these can fly, can travel into space, and has a death-laser.

[Miasmic_fate]

😂 the second is the goal, but he's being somewhat realistic in implementation

[Temperjoke]

Honestly, I don't know that it's possible, at least given the world of Rising from the Last War. The Aerenal limitations on soarwood would make it very difficult to build something on that scale.

That being said, there is a floating fortress, Argonth, in Breland that could be a better founding idea than an airship. Another approach would be a re-design of the standard airships. They use soarwood because it's buoyant on it's own, so they can shut off the elemental engines and it will keep floating without worrying about crashing on its own. Nothing says that they couldn't come up with a unique design that is riskier but more feasible to construct within the world.

[Unoriginal]

My main concern wouldn't be the price, but the time and the consequences.

Even in Eberron, building anything of this size takes time, and that's not counting all the straight up new calculations, innovations and inventions the builders would have to manage in order to go past the usual limitations for airships.

And once you've started creating a superweapon, well... Others will try to stop you, copy the weapon, or create counters against it. Not to mention all the political games around the implications supporting or antagonizing the fabrication of the potential new superweapon creates.

Now, from a purely engineering POV, I would say it'd be much easier for Eberron magic craftpeople to create a Yamato-sized floating structure if it was vertical (like the Devils' flying fortresses in DiA) rather than horizontal like the typical "flying ship".

[Temperjoke]

Just for clarification:

The Yamato?
https://i.pinimg.com/originals/aa/ca/ca/aacaca11dd6691a3ee0ffaa084db86a9.jpg

Or the Yamato?
https://i.pinimg.com/236x/da/d4/20/dad420eb822879efe0c6940abd43cb23--star-blazers-battleship.jpg

Notably, one of these can fly, can travel into space, and has a death-laser.


😂 the second is the goal, but he's being somewhat realistic in implementation

You know, the death-laser thing isn't farfetched in Eberron. According to Rising From the Last War, the Warforged Colossi could do that, powered by bound elementals. Like, the whole of what the players want is absolutely within the range of possibility, it's just I don't think it's something that throwing money at it will solve. Which isn't a bad thing, as now there is fodder for more adventures. They'll have to find someone who can design a new type of airship, probably have to visit Metrol in the Mournland for plans and designs for components that were lost in the disaster. They'll need people with the appropriate dragonmarks to control things. Not to mention they're gonna need a lot of dragonshards, and some big ones!

[Damon_Tor]

Any first level wizard can maintain 6 Tenser's Floating Disks indefinitely, for a total lifting power of 3000 pounds per caster. In a wide-magic world like Eberron hiring a small crew of first level wizards should be entirely possible. You should still use floatwood as much as possible to keep the weight down, but Floating Disk "pilots" to offset the weight of heavier components is entirely doable.

The maximum elevation of the disks is easily solved by making the disks internal components, with floors underneath them. Theses floors could be raised and lowered with levers to act as elevation controls for the ship.

[JackPhoenix]

Any first level wizard can maintain 6 Tenser's Floating Disks indefinitely, for a total lifting power of 3000 pounds per caster. In a wide-magic world like Eberron hiring a small crew of first level wizards should be entirely possible. You should still use floatwood as much as possible to keep the weight down, but Floating Disk "pilots" to offset the weight of heavier components is entirely doable.

The maximum elevation of the disks is easily solved by making the disks internal components, with floors underneath them. Theses floors could be raised and lowered with levers to act as elevation controls for the ship.

Yeah, I doubt any sane GM will allow object carried by the disk act as a ground for the same disk.

[Damon_Tor]

Yeah, I doubt any sane GM will allow object carried by the disk act as a ground for the same disk.

I just came up with a way to calculate crew requirements for a vessel with a given weight, 1 first level caster per 3000 pounds of lift required.

[JackPhoenix]

I just came up with a way to calculate crew requirements for a vessel with a given weight, 1 first level caster per 3000 pounds of lift required.

I'm not sure that works either. Even if you spread out the pressure the object creates... assuming that's a thing in D&D... that doesn't change the object's weight.

[Toadkiller]

This excited me enough that I jumped up and sketched it on my office whiteboard, though I will spare you my crappy drawing skills.

I think you have to decide how powerful you want it to be and go from there. Something “big” might have 3 fireball turrets- if I were the player I’d put two on the bottom and one on top. They could fire to either side of the craft and either above or below. Maybe? The thing is to give them fields of fire that make maneuvering the ship a thing someone has to do- ship handling checks for advantage and to get optimal field of fire against the target.

The fireball turrets (or whatever spell is the right level for what you want) need to have the “right amount” of range and firepower. Maybe after they fire they skip a round to reload. Maybe they have a recharge role they have to make? I would give them a serious punch (defined such by the DM) and some sort of to-hit against mobile targets (other ships). If they are blasting ground targets just use the dex save?

More later - got to go to a meeting.

[Toadkiller]

Continued

If you want to go with the dreadnought feel you could, in addition to the fireball main armament, have secondary “guns” firing something like eldrich blast. Think AA guns or the turrets on the Falcon in Star Wars. Again, scale the power to fit what you want it to do.

Vessel speed- 30 knots? Much faster than mundane travel. Still takes awhile to get someplace. Maybe smaller vessels go faster? You could also consider a power level pool where the more they fire the guns the less power becomes available for propulsion. I wouldn’t make that super punitive but being able to shoot till you are drifting would be an interesting limitation. Then they have limited abilities until things recharge. Lots of ways to run that to keep the vessel powerful but not limitless.

The vessel will need hit points or something like that. I recall seeing something like that for water ships that could be a starting point. Personally, I would rule of cool all that and keep it abstract, but different tables are different.

I would not be really worried about the power of the guns. You can always create situations where they have to leave on an away team to resolve the problems. Kirk could not always solve things with a photon torpedo.

Oh, speaking of which. Bombs. They will want bombs. I would scale that off of alchemist fire - again setting the damage dice and number of bombs where you want them.

Also keep in mind that the main and secondary guns are going to require hands to fire them. They might have a limited crew and only be able to fight one side (port, starboard, top, bottom) of the ship at a time. They might be able to fight more. If they have limited crew then flying attackers with more speed become a real boarding risk. Which could be fun. A couple rounds of ship to ship, then a boarding party comes flying in from the other side that had been hiding in a cloud to attempt to board while they were distracted - now you have to fight the ship and engage in melee.

Lots of cool options.

[Damon_Tor]

I'm not sure that works either. Even if you spread out the pressure the object creates... assuming that's a thing in D&D... that doesn't change the object's weight.

"If more weight is placed on it, the spell ends" has to mean net weight or the spell would never work inside atmosphere.

[Temperjoke]

Amusingly enough, Keith Baker posted on his blog a few days ago about airships, and some of the concepts surrounding them that he uses in his personal games (as opposed to strictly to what is in the books).

http://keith-baker.com/dm-airships/

[SharkForce]

well, if you want it to go into space, you could always look at a spelljamming helm.

2nd edition had minor helms at 100,000 gp and a maximum of 50 spatial tons (a measurement of volume, not weight, and with somewhat inconsistent values across different books and very poorly adhered to by ship deckplans and listed dimensions, but originally measured as 100 cubic yards).

major helms at 250,000 gp could power 100 spatial tons (and had a better rate of travel).

these ships would be able to fly through space easily, and once in space and sufficiently distant from other objects could travel 100,000,000 miles per day. you do need a spellcaster of some variety to be sitting on the helm 100% of the time though, since by default the hulls are not actually capable of flight.

100 tons is the largest you're likely to get out of a typical spelljamming ship; larger is possible, but in general people don't know how to do it (and the arcane aren't making it available). hypothetically if you could get your grubby mitts on a ki helm, that can do up to 200 tons, and there was evidence that it was definitely possible to link major helms (and death helms, for that matter) together in such a way as to power some very large ships.

alternately, you can get yourself an artifurnace, which is basically where the ship is powered by a hijacked artifact and frankly, all bets are pretty much off since generally speaking people who can muck around with artifacts are frequently not terribly subject to the same limitations as your average mortal.

using these, the hull can look pretty much like whatever you want, though fair warning poorly designed spelljammers suffer from poor maneuverability. so pretty much if it can support its own weight, you can strap a spelljamming helm to it and make it fly (until the helmsman gets off the helm, in which case it will plummet. oh, and you can only power a helm for a limited amount of time before you have to take a break, and getting a new helmsman in place while operating in a typical planet's gravity well takes several minutes, so you might want to have a plan for how you're going to not crash it while switching the helmsman :) )

now, YMMV for how you want to integrate spelljammer into eberron, and I can *definitely* tell you that the limited glimpses of 5th edition spelljammer we've had so far are *very* different from the old 2nd edition rules in a lot of ways. so, take it with a grain of salt.

[Miasmic_fate]

There is some excellent theories here, sorry I got pulled away for a few days 😅

Eberron being the setting, and the major power source at the time being caged elementals, im likely to stay with that head Canon for now. Right now the plan is not to take this off world, though the Weatherlight was also mentioned in the inspiration conversation.

Ultimately the goal is their flagship for large scale battles, and if nothing else this thread has made it very clear its a cool idea to be encouraged 😁

[noob]

While they can afford a giant ship please note that the threat is right now the threat of war with goblins.
For preventing such a war a superweapon can be an useful propaganda tool but a single one is not enough to convince the opponents to not go to war.
So the idea of making a giant airship might be good but a better idea is either making multiple superweapons(it is easier to prevent war through fear when you have a giant airship, a magical tool that creates a city wide acid storm and a pocket carriable fortress that can be deployed and take full size with heaps of weapons) or making sure the one they have is so dangerous and unbeatable it is a sufficient threat for armies that even if the opponent wins the war you can then turn in to piracy and progressively kill and loot all the goblins for great profit.