T5 Only: Liberty Ship Development Discussion

[whartung]

Engineers are clever. Give them a floating box, and they can readily cram all sorts of things in to it, and they can do it reasonably quickly and cheaply.

For a short term ship, anything like modularity is more complexity and fiddling than not. Longer term, perhaps, but short term, war time? Certainly not.

Looking at a modern container ship, it's hardly modular. It's a big hole in the water to stack legos in to.

My father used to do work on systems for submarines. And one thing that he learned quickly was to not finagle things. Specifically, if something on the sub needed to change to accommodate the equipment -- they would change it. They would cut it with a torch and weld the new stuff in to it and that would be that. Cutting and welding are cheap operations, and they pretty much work and stay welded.

If an engineer wanted to convert a container ship in to a troop carrier, they likely wouldn't be creating "troop containers". They just don't lay out that way. I mean, they could, you know, make sleeping containers, stairway containers, weld a bunch of boxes together and just start cutting ala Minecraft, removing all the parts that don't look ilke a troop ship.

But they probably wouldn't. They'd just weld in bulk heads and decks and fixtures as needed. After the war, they could cut that all out and salvage the hull, if it was actually cost effective to do so.

The point being, expedience tends to not beget subtlety or clever designs. They'll just make it work in the most expeditious way possible.

 

[Enoki]

I'd say merchant ships could be very modular in design. Also, the extent to which they're intended for warfare could be included in their design too. For example, from the late 20's to the beginning of WW 2, the US Navy included in the design of fast passenger liners the ability to take these ships into a yard and turn them into auxiliary aircraft carriers in a matter of just a few months, some in under 90 days. The Japanese did two of these, even if on a more ad hoc basis.

There's no reason you couldn't do that in Traveller. I'd think tankers would make excellent carriers as they'd have the room for fuel and converting a few of the fuel cells into magazines or hangers gives you lots of room for small fighters and such.

That's how CVE worked. Even in the Falklands war a container ship was quickly converted into a makeshift carrier.

A container ship in Traveller would be no less convertible. A large cargo bay serves as the hanger, and cargo containers with shops and equipment to support the craft would be brought aboard to complete the conversion. There'd already be fuel and power built into the design to handle the conversion.

Maybe a ship design where the cargo bay(s) could become weapons bays with the necessary power hook ups and such already included in the basic design of the ship could be done.

The hull is just a box for all intents. It's how you do the design details that would allow it to easily be converted. All those British ocean liners mentioned had foundations built into them to allow mounting 6" guns on their decks in wartime.

It's all in the details. If the ship is designed from the start to be converted it makes it much easier to do when you need to.

 

[flykiller]

If the ship is designed from the start to be converted it makes it much easier to do when you need to.

more appropriately, designed to carry pre-designed modules. slap on a fuel module, or a marine battalion module, or a cargo module, or a mobile shipyard module.

 

[Condottiere]

Basically, a carrier is a large steel box.

With elevators.

Occasionally, catapults.

Unless you park the craft on the deck.

 

[aramis]

LBB2 gives that impression, but LBB3, p15 says otherwise.

No, it doesn't. It does state that the bigger ones need higher TL to build.

The implication is that lower TL places can't manage some singlecast component past a certain TL dependent size.

A trope mirrored (pun intended) in Bujold's Falling Free

 

[AnotherDilbert]

LBB2 gives that impression, but LBB3, p15 says otherwise.

No, it doesn't. It does state that the bigger ones need higher TL to build.

The implication is that lower TL places can't manage some singlecast component past a certain TL dependent size.

A trope mirrored (pun intended) in Bujold's Falling Free

Sorry, I do not understand you?

LBB2 does not discuss TL of spacecraft much?

And what does Quaddies being obsoleted by artificial gravity have to do with it?

 

[aramis]

Sorry, I do not understand you?

LBB2 does not discuss TL of spacecraft much?

And what does Quaddies being obsoleted by artificial gravity have to do with it?

The Mirror they cast - it has to be cast in one piece...

And, as is well documented from astronomical telescopes, the technological level has a huge amount to do with how accurately one can grind the glass...

LBB2 doesn't at all discuss the TL of spacecraft, but Bk2 was never designed to stand alone. It's part of a 3 book set. Likewise, Bk 1 doesn't much discuss the TL of most personal equipment - Bk3 does, tho'.

 

[kilemall]

Sorry, I do not understand you?

LBB2 does not discuss TL of spacecraft much?

And what does Quaddies being obsoleted by artificial gravity have to do with it?

They are all referring to the tech table in LBB3 which lists starship component sizes per TL right alongside when fusion power or anti-gravity tech is possible.

Which does not limit the TL of jump whatever per se, but certainly does limit the overall size or maximum performance of a given hull size.

 

[aramis]

They are all referring to the tech table in LBB3 which lists starship component sizes per TL right alongside when fusion power or anti-gravity tech is possible.

Which does not limit the TL of jump whatever per se, but certainly does limit the overall size or maximum performance of a given hull size.

Actually, it does limit jump, just not in the same way, and not as directly, as later versions.

Since you cannot get J6 performance in a 100Td hull under Bk2...

Spoiler:

Bk2-77 design

J6 100Td
020 Bridge
020 JD C
060 JFuel J6
004 Stateroom
001 Model 1

105 tons of required equipment, and 1d6 days of LS... pack some vacc suits.
Adding the PP A adds 14 tons (4 of drive, 10 of fuel).

And at 200 Td, J6 is TL 10 - due to a drive F.

Spoiler:

Bk2-77 design

200 Td
020 Bridge
035 JD F = 6
004 PP A = 1
120 JFuel 1j6
010 PP Fuel A  4 weeks
008 Staterooms (P, E)
001 MD A = 1
001 Model 1
=== ============
199 total tonnage

That's per the 1977 edition, at least.
For the 1981, it is MUCH different...
TL9 Max Jump is 4... in a 200Td Hull... but requires a TL 10 computer ...

Spoiler:

Bk2-81 design
200 hull
020 bridge
025 JD D=4
013 PP D=4
080 JFuel 1J4
040 PP Fuel
012 SR x3 (PNE)
004 Model 4 (TL 10)
=== ============
194 Td

Adding a 1G maneuver drive is 1 Td; adding a 4G is a whopping 7Td, and so cannot be done, but 3G can for 5Td.
As can be seen, adding the needed 25 Td for J5 is impossible...

The 100Td hull under Bk2-81 is limited to J2 due to the power fuel formulae...

 

[Silverhawk]

no it is not. j3 could be considered militarily justifiable if it reduced the amount of time the ship spent in transit and therefore reduced the chances of enemy forces finding it or trapping it at refueling choke points, but in a civilian setting it's hard to make j3 work. the design almost certainly was heavily subsidized during wartime, but now the war is over and so are the subsidies - most of them, at least. free government money is quite addictive.

Another point to keep in mind though is that sometimes wartime designs live on after the war is over. During WW1 the Federal Government took over the railroads in an effort to eliminate problems of coordination. This included the design of standard locomotive designs for new construction. Typically each railroad had its own philosophy and preferences about locomotives.

Unfortunately, control by the government was a terrible failure for the most part. However, the locomotive designs turned out to be something that the railroads did like and many which had received them during the war continued to buy them through the 1920's likely getting them cheaper since the design work and tooling was already done and in place.

I could see this being played out in the case of this ship. Design is done, technology isn't cutting edge but works, and the price is right.

 

[AnotherDilbert]

LBB2 doesn't at all discuss the TL of spacecraft, but Bk2 was never designed to stand alone. It's part of a 3 book set. Likewise, Bk 1 doesn't much discuss the TL of most personal equipment - Bk3 does, tho'.

I do not think it is suggested that in LBB1-3 that a yard on a TL10 world cannot produce a starship with Z-drives, even if the drives and computers might have to be imported.

The Mirror they cast - it has to be cast in one piece...

Thank you, I had forgotten that. I thought that was a question of manufacturing a precision component without the precision machinery normally used, rather than TL.

 

[Silverhawk]

My earlier post got me rummaging around in my model railroad magazines for an article on the WW 1 ships built for government under the auspices of the Emergency Fleet Corporation. These were in the same vein as the WW2 Liberty ships.

The majority were built on by shipyards on the Great Lakes and model railroaders who are interested in creating dockside scenes refer to them as 'Lakers' their size determined by the size of the (ca. 1918) St Lawrence Seaway locks. Although a large number were scrapped in the 1920's, some lasted and served through WW2 into the 1950's in both American and foreign service.

The article mentions that many were actually more economical to operate in the 1930's during the depression than larger vessels.

 

[Major B]

Which points us right back at the canonical Marches Auxiliary Naval Service.

Those "Blue Ribbon liners" Cunard, HAPAG, White Star, and many others built and operated between ~1880 and ~1950 all relied on government construction and operation subsidies with government input on design.

This reminds me of the Civil Reserve Air Fleet. I don't know the details of how it works but I understand that US Air Carriers can have their aircraft "called up" in the event of an emergency. I only remember it because it was a central part of the REFORGER plan to rapidly build up forces in Germany should the Soviets attack. Several division sets of equipment were prepositioned and the troops would be flown in from CONUS when needed.

Major B's modular/subhull idea provides a great deal of flexibility. A ship can "flex" from freighter to tanker to transport to SDB tender simply by swapping out modules/subhulls.

You weren't supposed to mention SDB tender! That is actually the idea that caused me to dig the original Liberty Ship design up again. I want to write a vignette of these being refitted and used to give some strategic mobility to the SDB force in the 5FW. But I didn't plan to mention that until I was done.

this would allow any tech level yard to participate, as the subhulls could be assembled and fitted with tech 12 components.

Exactly what I was thinking. I am still doing some comparisons and am thinking now about 200-ton subhulls making this easier. It is more feasible to build these smaller subhulls at a downport and lift them into orbit for assembly (I think) using existing cargo lighters for lift. I'm assuming surface construction would be quicker than in an orbital yard ad would also free the orbital yard to do more simultaneous assembly work.

For a short term ship, anything like modularity is more complexity and fiddling than not. Longer term, perhaps, but short term, war time? Certainly not.
[edit, snip for continuity]
If an engineer wanted to convert a container ship in to a troop carrier, they likely wouldn't be creating "troop containers". They just don't lay out that way. I mean, they could, you know, make sleeping containers, stairway containers, weld a bunch of boxes together and just start cutting ala Minecraft, removing all the parts that don't look ilke a troop ship.

But they probably wouldn't. They'd just weld in bulk heads and decks and fixtures as needed. After the war, they could cut that all out and salvage the hull, if it was actually cost effective to do so.

The point being, expedience tends to not beget subtlety or clever designs. They'll just make it work in the most expeditious way possible.

Yeah, I have been thinking about this Whartung so thanks for stating the idea this way. While it may seem like a good idea to an engineer to build the ship so that modules can be swapped as needed, I think in practice there would be more of a tendency to modify than swap. This is part of the reason why I thought of reducing the container size.

This is especially true when you think across the life of the design. When first designed during the war it might be relatively easy to find and assemble the right modules to customize for a mission but with each year after there would be fewer modules around and more of a tendency to customize the modules on hand as needed.

Clay's notes did mention extensive modification.

My father used to do work on systems for submarines. And one thing that he learned quickly was to not finagle things. Specifically, if something on the sub needed to change to accommodate the equipment -- they would change it. They would cut it with a torch and weld the new stuff in to it and that would be that. Cutting and welding are cheap operations, and they pretty much work and stay welded.

I think I can illustrate the same point. The M2 Bradley was engineered to provide exactly enough space for a lot of stuff but that engineering didn't account for the conditions they served in. Later versions fixed some of this but I still liked the M113 APC for being able to put everything you needed where you could easily get it when you needed it. That said, I'd rather be in a Brad if anyone was going to shoot at me - APC stands for Aluminum Personnel Coffin. Or was it Crematorium?

I'd think tankers would make excellent carriers as they'd have the room for fuel and converting a few of the fuel cells into magazines or hangers gives you lots of room for small fighters and such.

That's how CVE worked. Even in the Falklands war a container ship was quickly converted into a makeshift carrier.

A container ship in Traveller would be no less convertible. A large cargo bay serves as the hanger, and cargo containers with shops and equipment to support the craft would be brought aboard to complete the conversion. There'd already be fuel and power built into the design to handle the conversion.

So I guess my idea about an SDB carrier wasn't so original after all.

 

[Enoki]

Of course, this sort of thinking is extended to small warships too in wartime. Most nations embark on programs to build cheap small warships to fill roles where using something more expensive to build, or elaborate, is really unnecessary of would result in too few vessels being available. Some historical examples, then a short discussion on what might be seen in the Traveller universe.

From the USN

WW 2 Frigates. These went almost entirely to allied nations for ASW work.
Submarine chasers A small, cheap boat meant for a presence in areas needing "something" there.
Conversion of landing craft into gunboats.

British
Monitors for bombardment work. Getting big guns on the cheap for use as naval artillery.
Corvettes like the Flower class. These were basically a fishing trawler design modified for ASW work.

Everybody: The converted trawler. The US, Japanese, British, Germans, etc., all converted trawlers into ad hoc naval vessels for minesweeping, patrol work, and ASW.

In Traveller I could see something like this occurring in wartime. The Far trader would make a good equivalent to the converted trawler. A couple of turrets for weapons, the cargo bay loaded with a boat or two, or maybe partially converted for use by a small marine contingent.
Other types might range up to say, 1000 tons.
The whole "close escort" type ship for accompanying convoys would fit in this class. Here, something that is J2, M2 to 4 would be acceptable. It only has to stay up with the merchants it escorts.

 

[flykiller]

The Far trader would make a good equivalent to the converted trawler ... It only has to stay up with the merchants it escorts.

what would the armed far trader gunboat do that armed merchants could not?

 

[flykiller]

I still liked the M113 APC for being able to put everything you needed where you could easily get it when you needed it. That said, I'd rather be in a Brad if anyone was going to shoot at me - APC stands for Aluminum Personnel Coffin.

the apc originally was intended to move troops forward under artillery suppression - it was only meant to minimize splinter/fragment casualties getting troops to a point of attack. was never meant to be any kind of tank.

So I guess my idea about an SDB carrier wasn't so original after all.

nope. but a modular and modularly-constructed ship bears discussion.

 

[mike wightman]

what would the armed far trader gunboat do that armed merchants could not?

Carry half a dozen fighters...

 

[Enoki]

Carry half a dozen fighters...

Exactly, or a couple of armed boats for use with marines.

Best, it's relatively cheap as the military can simply impress available ships into service.

Of the canon plans, the larger subsidized merchant with four turrets and a cargo bay full of fighters would make a decent escort for its size. Throw in a ship's boat or such and marines in the passenger staterooms and you have a pretty good small assault force too.

 

[Major B]

the apc originally was intended to move troops forward under artillery suppression - it was only meant to minimize splinter/fragment casualties getting troops to a point of attack. was never meant to be any kind of tank.

I know what it was meant for and the A3 version actually did that quite well. The IDF called them Zeldas and they were a great improvement over the refurbished halftracks their mech troops were riding around in because they had overhead cover.

But this makes a point that bears reinforcing. In my experience the M113 was often used in a role for which it was neither designed nor intended. I think it would be plausible to say that the Liberty Ship was designed for one purpose but was used for a number of other purposes for which is was not intended but for which it performed relatively well.

 

[Whipsnade]

This reminds me of the Civil Reserve Air Fleet.

Bingo. Thanks to the example of Reforger - I was in the USN during Able Archer - and the specific references to it in A:4, MANS has been part of my settings' "furniture" for decades.

IMTU Clan Addakkumak has cannily used the MANS program for centuries build and operate more and larger ships than they normally could afford. Their DiGroat Packet Line provides a jump4, 400-hour service along a Glisten-Grote-Strouden route with vessels subsidized through MANS and liable for imperialization as situations warrant.

(IIRC Jeff kindly hosts material about DPL, it's history, and some designs at Freelance Traveller.)

Also IMTU...

Spoiler:

... Clan Addakkumak's continued ability to use the MANS program is tied directly to their long time role as a plausibly deniable asset for the Ducal House of Glisten.

You weren't supposed to mention SDB tender!

Ooops...

IMTU SDB wings are routinely "forward deployed" much like how MTBs, PTBs, and other "brown water" naval assets are and have been. For example during the 5FW and to a lesser extent the 4FW, the Imperium began deploying SDB wings from the empire's "interior" along the Lunion/Glisten border with the Swords and in District 268 to first act as tripwires and then strategically "hem in" Confederation forces.

IMTU, however, there are tenders and then there are tenders.

IMTU most tenders resemble the USN's old AD and AS types. That is they provide logistic, berthing, maintenance, and other support but not strategic lift capability. They provide SDBs with beans and bullets, but they don't carry SDBs between systems.

So I guess my idea about an SDB carrier wasn't so original after all.

Original or not, it's still a very good one. It's also one which has occasionally been written about but never actually "deck planned".