Imperial Navy Ship and Shipyard Sizes

[Terry Mixon]

I was reading the new War Fleets of the Fifth Frontier War book, and I like what I saw. It did prompt some questions in my mind, though.

First, there is the massive 1,000,000 ton Duamu-Class Heavy Logistics Ship. That's big, but it made me wonder if there might be something bigger in the inventory or drawing boards.

What drove that question is that I'm roughing out an Imperial Navy shipyard and I suspect my estimates of how extensive it needed to be fell short of reality. Sure, the ships could be built in peices, but it made me wonder the max size that I should keep in my back pocket. There's also the sheer size of the Imperial Navy. There would have to be a lot of slips of varying sizes.

So, I'm looking to see what people think might be the upper end of ship sizes and guesses at how much overall tonnage could be under construction at one time. I know things are vague on purpose, but I'm curious what my fellow GMs would tell the visiting players to overawe them. Hit me with your best shots.

 

[Nelphine]

It's actually something I find interesting with traveller.

Most games make size a function of tech level, and sometimes even put arbitrary limits on size for logistical reasons.

Traveller does neither of these things. That means, ship size should be a matter of practicality.

This generally means, go with the smallest ship that puts out enough damage to kill the opposition*. (This leads to fighters with nukes if possible for one kind of opposition, or better yet, spinals, for a militarily advanced opponent)

Or, go with the smallest ship that can absorb all the damage the enemy can throw at it. (This leads to very very very large ships)

In terms of these, something like a tigress.. is neither. So it really shouldn't be an interesting ship. Which implies it's merely a stepping stone to a better design.

The ships that should get used, in the large categories, should be ones where a maximum size, maximum advantage spinal, cannot do enough damage to cause a critical based on damage. Meaning, they cannot do 10% of the hull of these large ships in a single shot.

On the small 'fighter' end, you take the maximum size/advantage spinal, and put it on the absolute smallest ship possible, and treat it like a fighter - no need for armour or crew amenities or a jump drive. They aren't expected to be able to fight the big ships and survive, so put the minimum in them. Fully automated if possible - they are meant to get one shot off and die.

On the actual fighter end, you build things that can't hurt military targets at all, but can destroy civilian targets.. and then you build a LOT of them. Say, vargr corsair, but where you build literally millions of them and simply ignore any capital ships. If enemy capital ships threaten you, you go and raze enemy sectors. Entire sectors, down to the last tiny homestead on backwards planets. Where your goal is scorched earth - you literally make the entire sector uninhabitable. You can't fight the spinal ships, but if the spinal threaten you, there won't be anywhere for them to go home to.

Almost all ships that exist in the lore fall outside these categories. Heaven help the third imperium, or anyone in charted space, if any major species decides to embrace these philosophies.

so for me, if I was third imperium, I'd want a shipyard capable of producing ships that have twenty times the hull of the strongest spinal possible. (That gives the maximum size shipyard)

And I'd want shipyards with literally tens of thousands of slips for small ships (another shipyard with the same size, but dedicated entirely to 500 dton ships)

 

[Nelphine]

Continuing on that thought, charted space feels like pre world War 1 to me. All the major species have this gentile idea of how war is 'supposed' to be, but it's not remotely efficient or important, and it won't stand up to someone who actually wants to seriously fight.

 

[Vormaerin]

People don't build ships based on what someone thinks is the optimized performance for a particular task. They build ships on the things they'll actually be doing and what it'll cost to build them.

A million ton battleship squadron is really powerful. But 5 200k battleship squadrons can be in a lot more places.

This also leads to the question of whether there really is a maximum size spinal you can outbuild. Spinal mounts are, largely, limited by length.

But it all comes down to the fact that this is a game based on things that don't exist. So we can imagine whatever we want. Will the zergling strategy work? I don't know. The imagineers behind the game made a conscious decision to make offense better than defense, because fast explodey fights are more fun to play.

The rules are the way they are so you don't have Trillion Credit Squadron fights that last hours as ships glacially whittle each other down. Would anyone actually build flimsy ships if they could afford to do otherwise? Obviously not.

 

[Nelphine]

Sure, but usually you also go on to build those kinds of limits into the mechanics of the game. They didn't do that with Traveller. I've just found that always odd. The Trillion Credit Squadron could be the 'key' size to the game, but they didn't do that either - the amount of money the third imperium (and it's neighbors) have to spend on military VASTLY outstrips that. That's nothing but a War Games amount, which then has set the standard for a military that it has no place in.

 

[MasterGwydion]

Max size Meson Spinals would be next to useless against a defensive ship with a crap-ton of Meson Screens so you'd be looking at other types of spinal mounts. I would go with multi-warhead torpedo ships. 1 or 200k tons with max possible Large Torpedo Bays - 2. Save the last two large bays for missiles. Anti-missile missiles and multi-warhead missiles for defensive purposes. I haven't done the math, but My guess is that it would be nasty. Supply would be the largest problem.

 

[Terry Mixon]

Max size Meson Spinals would be next to useless against a defensive ship with a crap-ton of Meson Screens so you'd be looking at other types of spinal mounts. I would go with multi-warhead torpedo ships. 1 or 200k tons with max possible Large Torpedo Bays - 2. Save the last two large bays for missiles. Anti-missile missiles and multi-warhead missiles for defensive purposes. I haven't done the math, but My guess is that it would be nasty. Supply would be the largest problem.

Lots of big logistics ships for something like that. Say, a million tons or so.

 

[Vormaerin]

Maybe they'll do that in some product in the 5FW line, but practically no one is trying to use MgT2e to actually play fleet battles. It barely has rules for them at the moment.

If they produce a new or updated 5FW boardgame, might get ships with reasonable survivability again. Or if they do a proper MgT2e fleet combat game like TRC was intended to be, they might bake in those limits.

The original TRC wanted to make naval campaigns with a single planet as your starting empire.

 

[MasterGwydion]

I was reading the new War Fleets of the Fifth Frontier War book, and I like what I saw. It did prompt some questions in my mind, though.

First, there is the massive 1,000,000 ton Duamu-Class Heavy Logistics Ship. That's big, but it made me wonder if there might be something bigger in the inventory or drawing boards.

What drove that question is that I'm roughing out an Imperial Navy shipyard and I suspect my estimates of how extensive it needed to be fell short of reality. Sure, the ships could be built in peices, but it made me wonder the max size that I should keep in my back pocket. There's also the sheer size of the Imperial Navy. There would have to be a lot of slips of varying sizes.

So, I'm looking to see what people think might be the upper end of ship sizes and guesses at how much overall tonnage could be under construction at one time. I know things are vague on purpose, but I'm curious what my fellow GMs would tell the visiting players to overawe them. Hit me with your best shots.

Imperial Shipyards are primarily at Depots. Depots take up a whole system, not just one world, so the shipyards should be equally as large since there are only on average 1 Depot per Sector and only 5 (I think) of those Depots are TL-15. So, their shipyards should be in the 10s of millions of tons. Also remember space shipyards are not constrained the same way planetary shipyards are. The framework of the shipyards can be reorganized to accommodate several huge ships or tons of smaller ships all being built at the same time.

Just My 2 cents.

 

[MasterGwydion]

Lots of big logistics ships for something like that. Say, a million tons or so.

Agreed.

 

[Nelphine]

To be clear, I'm advocating for a shipyard capable of building a ship that has 20 times the hull points of a 75000 ton Meson Spinal that rolls max damage (so 240,000 damage, so it needs to have, lets round to a nice 5,000,000 hull). So, that makes it ... 7.5 million dton ship. For simplicity, lets call it a 10 million dton ship.

And then a second shipyard, that is capable of making 20,000 500 dton ships at the same time.

(And to be super clear, IMTU, I've already created a single star system that has more than enough economy to support these kinds of numbers, let alone the entire third imperium. That star system has dozens of 10 million+ dton ships (mostly civilian).)

 

[Vormaerin]

Lots of big logistics ships for something like that. Say, a million tons or so.

Particularly since the Imperium having a fleet standard of J4 M6 means more than half your tonnage is just fuel and moving the ship. That million ton logistics ship only carries 200k tons of spare fuel? So you need to have 2 of them to refuel a typical Imperial Battleship squadron (330k of fuel or so after a jump 4).

 

[MasterGwydion]

Particularly since the Imperium having a fleet standard of J4 M6 means more than half your tonnage is just fuel and moving the ship. That million ton logistics ship only carries 200k tons of spare fuel? So you need to have 2 of them to refuel a typical Imperial Battleship squadron (330k of fuel or so after a jump 4).

J-4 yes, but no need for M-6 on a logistics ship. It would not designed to jump into systems that are not already secure.

Not that that saves you much space.

 

[Galadrion]

The real limit for ship sizes in the 3I is building time, not budget. Per canon, normal building time for a ship is approximately 1 day per MCr of ship price, although you can cut this using modular building techniques, crash priorities, and other methods... by as much as 90%, which means at an extreme, your ship takes 1 day per 10 MCr of price. At that last speed, a Tigress takes around a century to build.

This is a problem. Even ten years is too long a building cycle for warships, although it might be justifiable for a prototyping cycle - just barely. For productions warships which might be needed yesterday, you want something which can be turned out fast enough to make a difference - say, five years, tops, for a battleship or dreadnought. Otherwise, you may get your shiny new batron just in time to take it to your surrender ceremony.

 

[MasterGwydion]

The real limit for ship sizes in the 3I is building time, not budget. Per canon, normal building time for a ship is approximately 1 day per MCr of ship price, although you can cut this using modular building techniques, crash priorities, and other methods... by as much as 90%, which means at an extreme, your ship takes 1 day per 10 MCr of price. At that last speed, a Tigress takes around a century to build.

This is a problem. Even ten years is too long a building cycle for warships, although it might be justifiable for a prototyping cycle - just barely. For productions warships which might be needed yesterday, you want something which can be turned out fast enough to make a difference - say, five years, tops, for a battleship or dreadnought. Otherwise, you may get your shiny new batron just in time to take it to your surrender ceremony.

Right but you can dedicate more than the minimum shipyard tonnage to building a ship faster. Also, go double check to see if I am wrong, but I think the section of the book that you are quoting for "normal building time" actually says, "On average, assume that it takes one day per million Credits to build a spacecraft at an average commercial shipyard." Depots are not "average commercial shipyards".

 

[MasterGwydion]

I was reading the new War Fleets of the Fifth Frontier War book, and I like what I saw. It did prompt some questions in my mind, though.

First, there is the massive 1,000,000 ton Duamu-Class Heavy Logistics Ship. That's big, but it made me wonder if there might be something bigger in the inventory or drawing boards.

What drove that question is that I'm roughing out an Imperial Navy shipyard and I suspect my estimates of how extensive it needed to be fell short of reality. Sure, the ships could be built in peices, but it made me wonder the max size that I should keep in my back pocket. There's also the sheer size of the Imperial Navy. There would have to be a lot of slips of varying sizes.

So, I'm looking to see what people think might be the upper end of ship sizes and guesses at how much overall tonnage could be under construction at one time. I know things are vague on purpose, but I'm curious what my fellow GMs would tell the visiting players to overawe them. Hit me with your best shots.

I found this on the Wiki under Third Imperium

"

• Economy: The economic output (gross product) of this polity is estimated at 138,935,068 (BCr) (almost 139 quadrillion credits). The per capita earning of inhabitants in this polity is estimated at 7,723 (Cr). The resources available in this polity are estimated at 8,629,159 (RU). The shipyard capacity of this polity is estimated at 19,157 (Mtons). The Starport Authority population is estimated at 157,981,050 (employees).

19.157 Billion Tons of Shipyard Capacity spread across the Imperium

 

[Condottiere]

The clues are already in the narrative.

It's likely that the Sylean Empire is the only one that could afford to build and maintain megatonne battleships, since they have shipyards that can build megafreighters.

Being built in orbit, or deep space, it doesn't mean other interstellar political entities couldn't do the same, but you'd have to look at it from the Project Stardust perspective.

My take on the Confederation, with a bit of reverse engineering, is that they started with nothing, and built themselves up using available local facilities.

It's never been worth their while to go full Tigress, let alone build megadreadnoughts.

 

[MasterGwydion]

Any idea how many Class-A Starports exist in Imperial Space? I am kind of curious.

 

[Terry Mixon]

Any idea how many Class-A Starports exist in Imperial Space? I am kind of curious.

That’s a good question. Do they become more prevalent the deeper into the Imperium you go? Seems like that would be the case, but random die rolls don’t care.

The book says 11+ to get an A class Starport. There are DMs for population, but for simplicity’s sake, let’s say those cancel out.

The interwebz tell me there is a 5.56% chance to get an 11 and 2.78% for a 12. 8.34% for both combined.

We have 11,000 worlds, so by random rolls, that’s 917 Class A starports. Unless my math skills have utterly failed me, which is all too likely.

That wouldn’t count private starports or shipyards. Glisten, for example, has a number of shipyards and would skew the numbers up. You could have five thousand shipyards and that wouldn’t shock me.

 

[MasterGwydion]

That’s a good question. Do they become more prevalent the deeper into the Imperium you go? Seems like that would be the case, but random die rolls don’t care.

The book says 11+ to get an A class Starport. There are DMs for population, but for simplicity’s sake, let’s say those cancel out.

The interwebz tell me there is a 5.56% chance to get an 11 and 2.78% for a 12. 8.34% for both combined.

We have 11,000 worlds, so by random rolls, that’s 917 Class A starports. Unless my math skills have utterly failed me, which is all too likely.

That wouldn’t count private starports or shipyards. Glisten, for example, has a number of shipyards and would skew the numbers up. You could have five thousand shipyards and that wouldn’t shock me.

I am sure there is a way to use the Travellermap to figure this out, but that is beyond My abilities.