Fuel/Cargo Containers from Deep Space Exploration book

[AnotherDilbert]

A drawback/risk is that if the ships needs to leave quickly it needs to unload the containers of the 35 000 tons of supplies and then refill the containers with fuel before it can Jump again, ...

It can do J-3 while keeping the drop tanks, so it can jump as usual with 35000 Dt cargo.



This is a small J-3 freighter.

200 Dt, J-3, M-2, 60 Dt jump fuel (in fuel/cargo), 60 Dt cargo (w Collapsible Tanks).

It can do two J-3 with no cargo, two J-2 with 40 Dt cargo, J-3 with 60 Dt cargo, J-2 with 80 Dt cargo, J-1 with 100 Dt cargo, or fly intrasystem with 120 Dt cargo. It's even quite profitable at J-3 and barely profitable at J-2. As cheap as a Far Trader.

The only cost is 3 Dt. The flexibility is obviously worth it...

 

[RogerMc]

Another example - your scout/courier now becomes both a viable mini-far trader and jump-3 capable.

This is because it already has to have a ten ton minimum jump drive which is 10% of 100t and at TL12 gives you jump-3.

So make all the fuel space and 10 tons of the cargo convertible between fuel and cargo and it can operate as a jump-3 ship with 5.5 tons cargo, jump-2 with 15.5t cargo, jump-1 with 35.5 cargo or operate as a non-jump seeker with 65.5.

Similarly your far trader can upgrade to jump-3 with only minimal impact on its financial viability.

So yes quite revolutionary...

 

[AnotherDilbert]

This is because it already has to have a ten ton minimum jump drive which is 10% of 100t and at TL12 gives you jump-3.

Sadly, no.

A jump drive is base 5 Dt + a percentage, so the Scout drive is 5 Dt + 2×2.5% of 100 Dt = 5 Dt + 5 Dt = 10 Dt for a J-2 drive.

 

[Condottiere]

Ten tonne is the default minimum, seven tonnes is tweaked at technological level three plus.

One shot doesn't alter ten tonnes, what you'd get is a 125% boost in performance, I think.

You'd have to examine RAW to figure out if it applies to a shrunk version.

Jump factor three is possible on a hundred tonne hull, but you'd need a twelve and a half tonne default jump drive, in which case you probably would find that convertible cargo space a great option, for when you have more baggage at shorter hops.

 

[RogerMc]

This is because it already has to have a ten ton minimum jump drive which is 10% of 100t and at TL12 gives you jump-3.

Sadly, no.

A jump drive is base 5 Dt + a percentage, so the Scout drive is 5 Dt + 2×2.5% of 100 Dt = 5 Dt + 5 Dt = 10 Dt for a J-2 drive.

Which I believe is a new rule only found in High Guard 2 and which I suspect was put in precisely to address the so why aren't all TL12 scout/couriers J-3? question.

And so with this rule you need to add 2.5t to your jump drive and 1t to your power plant and lose another 2.5t of cargo - which still seems a very acceptable tradeoff as it leaves you with 13.5t cargo for speculative trade - which is just fine given that Classic Traveller scout/couriers only had 3 tons of cargo space.

Certainly if a noble character of mine rolled up a yacht - which at J-1 is pretty useless for gadding about between the stars - I'd let them design a customised J3 scout/courier instead (which would still be a lot cheaper than a Type-Y).

IMTU I'd also make the Serpent Class J-3 to differentiate it and allow a Scout with 2+ scoutship benefits to have one.

 

[PsiTraveller]

Yes! I am a big fan of adding an extra couple of tons of Jump Drive to ships. That and a cargo net can add 100 tons of freight capacity.

The new fuel/cargo option is well worth the 5 percent loss if it opens up flexibility for trade.

Of course the added fun is the critical hit that hits cargo now takes out a lot of fuel. Or a fuel hit that destroys cargo capacity.

And the roleplaying options when the valve fails and your cargo is flooded with Liquid Hydrogen from the neighbouring tank.

 

[phavoc]

Something else this rule change needs to account for is that a hit on a container should be far more likely to have the potential to cause an internal explosion (hydrogen & oxygen loose in a hull...).

Most fuel tanks should be designed to minimize leakage of hydrogen into the crewed-areas. This version specifically puts it into crew areas. We should get new hazard charts for this.

 

[AnotherDilbert]

Which I believe is a new rule only found in High Guard 2 and which I suspect was put in precisely to address the so why aren't all TL12 scout/couriers J-3? question.

The ships in Core are built with the HG system, which is why it has a 10 Dt jump drive in the first place.

And so with this rule you need to add 2.5t to your jump drive and 1t to your power plant and lose another 2.5t of cargo - ...

And MCr 5, absolutely.

Certainly if a noble character of mine rolled up a yacht - which at J-1 is pretty useless for gadding about between the stars - I'd let them design a customised J3 scout/courier instead (which would still be a lot cheaper than a Type-Y).

I agree, anything of roughly equal value should be acceptable (as long as it is luxury oriented, not combat oriented).

 

[Condottiere]

You can also make your engines more fuel efficient.

At hundred tonnes, that's shaving off half a tonne at a time.

 

[RogerMc]

Which I believe is a new rule only found in High Guard 2 and which I suspect was put in precisely to address the so why aren't all TL12 scout/couriers J-3? question.

The ships in Core are built with the HG system, which is why it has a 10 Dt jump drive in the first place.

I don't have the books to hand but doesn't the 10 ton minimum jump drive rule go back to Classic Traveller - where the smallest available J-drive A was 10 tons? (although IIRC CT HG didn't have any such minimum and so did allow for those infamous jump torpedoes from Leviathan).

And while I was initially annoyed by the lack of a ship design system in the corebook yes having just the one system and removing all those inconsistencies was a big step forward for second edition.

And re costs of upgrading a scouts drives money - at least at the low megacredits scale - is hardly an issue for the Scout Service so of course they would have multiple variants of their type S workhorse with J3 for missions where that is a operational requirement.

 

[RogerMc]

Re bigger issue of this breaking a basic assumption we all had about Traveller ship design an obvious solution is that The Imperial Ministry of Commerce long ago decreed that dual use fuel/cargo space is never certified for commercial use and so no starship with this feature can carry paying any passengers or freight or mail.

So while exploration and military vessels might take advantage of this design feature your player-level far trader or even scout/courier (which do carry mail, small cargoes and even paying passengers if they are willing to accept the discomfort) can't.

Also while a purpose built vessel can design its dual use compartments to accept standard Imperial cargo containers all those standard designs have fuel tanks that don't allow for that - so conversion is not really an option.

Which removes the problem while still allowing special exploration vessels to use this feature.

 

[Rikki Tikki Traveller]

While that is certainly an option, I personally don't like saying "That is the Imperium's rule".

I would rather come up with an in-game "rule" that makes sense without resorting to bureaucracy.

Modularity is quite nice and could be applied to these units as well. They can be one or the other, but it takes TIME (not in space) to switch it from one to the other.

 

[Condottiere]

Optionally, you can have default fuel tanks, and dump in fuel tank compartments.

 

[phavoc]

Since this fundamentally changes the concept of fuel tanks, now HGv2 is wrong.

Does anyone know if they are planning on updating the pdf version with these changes? And whatever else they put into the boxed sets??

 

[PsiTraveller]

How game breaking the containers are is up to the Gm's. Are these containers movable, stackable? How fast can they be plumbed into the Jump engine? It takes 4 weeks to plumb in Demountable tanks. I am guessing there would have to be a statement on the ship design that there is now a cargo area connection for fuel plumbing. The containers could then connect to that.
This offers a weak spot for boarding attacks to threaten the fuel supply, and power plant of a ship. You also double the chances of having a fuel loss, and possible cargo loss during combat. (Fuel tank hit, cargo area hit. These containers qualify for both now.

The 5000/ton cost shows at is a more serious investment than Demountable tanks (by a factor of 5).

As for fundamentally changing the concept of fuel tanks, I disagree. The concept change is in the removal of space that is not needed from the design of a ship. This has been touched on with Drop tanks, fuel bladders, the Aslan ship with the bladder whose name I forget right now, etc.

A ship going through Jump space is all about volume moved. A good design will reduce that volume as much as possible to reduce the cost per volume of travel.

And since the same book has a Collector ship now gadding about a cargo/fuel container is the least of a ship designers worries.

 

[Reynard]

One thing I find useful for Fuel/Cargo containers is development of a civilization's spread under the mechanics of Traveller. The F/C would be a must have when your tech level limits your ability to cross open regions starting with your first steps at Jump 1. You would be stuck in Mains until the next Jump break through or, as I have designed on low tech ships, you carry double loads of jump fuel at the expense of cargo. Most Importantly is the spread of trade and having the flexibility to cross gaps then use the same space to use your ship to conduct business locally. F/C isn't for everyone since you lose something to gain a specific function.

 

[phavoc]

Carrying spare fuel as cargo isn't a game changer. What changes things is the consideration of the fuel container as a vessels fuel tank. The idea is easily, and reasonably, transferable to making say 100 ton cargo holds and calling them fuel tanks/cargo holds.

The idea of every vessel is that you need to dedicate a specific volume to a function. The fuel tanks of a MGT jump ship are required to near instantaneously convert the fuel into 'exotic particles' and then the ship disappears from the known universe into a pocket universe. But the fuel tanks are specifically designed to do this, and they also fulfill a single function.

This new concept can fundamentally change ship design. Why have dedicated fuel tanks in a small freighter when you can simply slap in a fuel container for the desired trip, and if you aren't using it for a specific jump you can put cargo inside of it. That would mean ship designs should radically change to accomodate this - at least freighters should. I don't see any warship changing because they aren't built to carry cargo.

So if this is the new norm I'd like to see HG updated to reflect this. Since the big push to PDF these sorts of things should be added and updates released.

 

[PsiTraveller]

You might be able to make a combination fuel tank/ cargo hold of 100 tons. I would have the insulation and plumbing take up the 5% extra volume just like the containers do, no free lunch. ( So you 100 tons of fuel would take up 105 tons of space.)

The catch then is that if you have any fuel in the tank you cannot carry any cargo. In the cargo/fuel container you might have the units in 20 ton containers, 21 tons volume each. Then you could have 40 tons of cargo and 60 tons of fuel stored in the cargo hold if all you needed was 60 tons of extra fuel.

As for redesigns, ships probably should get a redesign. Reft sector is ripe for small ships with big cargo holds and F/C containers of varying sizes. Captains fill as needed with whatever combination of fuel and cargo they need.

As for warships... I am looking at designs that have a Jump 1 tankage and then the rest in F/C. This allows spare parts and other equipment to be moved along a main when the ship is not going at full Jump rating. The increase in logistical capacity could really move gear along a supply line.

This is similar to the Drop Tank discussion that has popped up on this board. Drop Tanks have been in traveller for years, but few designs use them. They make great sense, and combined with F/V containers really move materiel along a supply line. But very few people use them in their designs, because the early game did not use them much.

Now imagine a J4 warship with all cargo holds and a Drop tank moving along a Drop Tank equipped route. Lots of cargo moved.

 

[baithammer]

Now imagine a J4 warship with all cargo holds and a Drop tank moving along a Drop Tank equipped route. Lots of cargo moved.

Which would be less efficient than having a specific design for the mission, drop tanks also are too vulnerable for a combat mission as they are removed once the hull takes 10% or more damage.

This is more for small time operators to cheaply extend a given hulls operating range without having to invest in a more expensive hull, given the same budget it would be better to get the more capable ship than rely on adhoc modification.

 

[PsiTraveller]

The ship has all the same mission specific design elements as any other ship. The only difference is that any space that used to be fuel only is now capable of carrying 95% of the volume as cargo if no fuel is needed.

The ship AnotherDilbert listed has J3 with drop tank in tow. This would allow 35 000 tons of additional cargo to be brought along. The merits and risks of any weapons being transported in a cargo bay as opposed to an explosion proof magazines is another topic, but the ability to carry something useful when fuel is not needed is something to look at.

For supply ships this is an obvious win, as with cargo ships of all sizes. Anytime you do not need a full load of fuel, take something along that pays the bills.

Let's look at a ship to see what it might miss.

Atlantic class Heavy Cruiser from highguard. pg 196
75000 tons Jump 4
30 000 tons of fuel needed for the Jump 4, 860 tons of fuel needed for 8 weeks operation.
The ship has 1174 tons of cargo space

Lets leave the 860 tons alone, and a J2 normal tank because Jump 2 is a conservative safety net.
If we converted the fuel tank area into cargo space and installed fuel/cargo containers we would need 750 tons of space from the 1174 tons of cargo space to accomodate this design. Yes, this would mean shuffling things around on the deckplan, or a redesign of the ship. The cruiser would lose a lot of cargo capacity during Jump 4 operations. 1174-750= 424 tons remaing, a big loss I admit. (Jump 3 tankage would only leave 50 tons of cargo)

This is a point against the tankage. At maximum output you lose the extra 5% of space, and that can be a problem.

Where the advantage can appear is when the ship is not jumping 4 hexes. If the ship only needs to Jump 3, it can carry an additional 7500 tons of cargo, 15000 tons if it only has to go Jump 2. In a pinch this heavy cruiser could carry 180 000 missiles into a system to help supply a fleet. That's not bad.

If you wanted to save the cargo space you could make the Jump 4 engines TL 13 and make them 5% more fuel eficient and then you leave the cargo space alone and the 15000 tons of fuel tankage holds all the fuel and piping needed. That would raise the cost of the ship by a billion credits for the Jump Drives, and the 15 000 tons of tankage costs 75 million.

This may be too expensive for the times a warship needs to carry cargo, but it does offer some interesting options.