Redesign for Armstrong class exploration ship

[PsiTraveller]

I am playing around with a module I am writing, and I need a long haul ship capable of traversing rifts. The Armstrong class ship showcased in the jayne's Guide is an excellent place to start, but I wanted to put my own spin on things and make hte ship even more fuel efficient.

I am trying to increase fuel efficiency for the ship, and it occurred to me that I've looked at that issue in my Jump Station product. Drop tanks are great because they provide fuel you do not need to pay hull space for. An empty fuel tank still needs power points equal to 20 percent of its tonnage, and hull space costs 50 000 per ton. This gets expensive. For a double jump ship you are paying 10% of the empty fuel tank * jump distance in fuel to move something that is empty. This is a waste of energy and fuel.

Solution. Dragonfly storage.
Instead of the 1000 ton hull the ship is 700 tons, and has 300 tons of Fuel Bladder inside a 300 ton jump net. At the starting system the ship uses the internal fuel to power the Jump.
Once the fuel tank is empty the bladder is drained into the now empty fuel tanks, and the Bladder is reduced down to 3 tons. The Jump Net is now 3 tons in the cargo hold as well. This makes the ship only 700 tons. This means that the second Jump only needs 210 tons of fuel (or in the case of the Armstrong class, 15 percent less than that.)

The Jump Net might not even be needed since the Jump Engines create a field for 1000 tons. A case could be made for either side.

The Core of the ship is still the same, but the energy needs of the ship are now based on a 700 ton ship, saving 60 points of Basic Power needs, that is 3 tons of TL 15 Power plant.

Using the Armstrong fuel needs the fuel bladder would only need to be 255 tons. If you made it 260 tons the ship could always be at full power plant fuel, and a Jump 3 tank full once a new system is entered. Any excess fuel could be jettisoned (if the extra 5 tons was too much for the Power Plants for example).

Some sort of foldaway tonnage space that creates protected tonnage space on External Cargo mounts for the initial Jump could be designed. This protective box would then fold down to reduce tonnage of the ship once the bladder was empty.

Fuel savings.
A 100 ton ship would save 90 tons of fuel on the second Jump (300 tons * 10% * Jump 3). This would add up to considerable savings in costs for a transport company. Several million a year if they were buying fuel, and a day's time saved if refining. This speeds things up and increases profits.

Any thoughts?

 

[AnotherDilbert]

Solution. Dragonfly storage.
Instead of the 1000 ton hull the ship is 700 tons, and has 300 tons of Fuel Bladder inside a 300 ton jump net. At the starting system the ship uses the internal fuel to power the Jump.
Once the fuel tank is empty the bladder is drained into the now empty fuel tanks, and the Bladder is reduced down to 3 tons. The Jump Net is now 3 tons in the cargo hold as well. This makes the ship only 700 tons. This means that the second Jump only needs 210 tons of fuel (or in the case of the Armstrong class, 15 percent less than that.)

Any thoughts?

Ingenious, but I would consider it fragile and dangerous.

Collapsible tanks are not hull, they are intended for cargo holds. We need sturdy hulls to withstand the rigours of both space and jump space.

Jump nets allows us to carry external cargo, but it is unprotected, so the cargo itself has to be hardened (containers?) or withstand space (ore?). Neither a cargo of unprotected oranges or fuel bladders can be assumed to arrive unharmed...

 

[PsiTraveller]

So an External cargo mount set of railings with foldable walls thatare nested together. These walls curve up and around to form a protective shell when needed. Once the walls have enclosed the volume of space the fuel bag expands into that now enclosed space. A Jump Net may not be needed since this is attached to the hull and the Jump engines have capacity. If needed the Jump Netting could either be dragged over the enclosed shell, or maybe even built into the enclosing walls.

https://www.youtube.com/watch?v=qmStVIOB7wA
https://www.youtube.com/watch?v=xSDsH6mwHqE
https://www.digitaltrends.com/home/ten-fold-engineering-foldable-buildings/

for some cool videos of housing unfolding. Great fro deployment to the lower tech worlds.

A whole new concept in ship design. Folding tonnage collapses unused volume when not needed, reducing the fuel needed for Jump. Even if the folding sections used 10, 20, 30 percent base volume you still save on fuel for the saved section.

The bladder concept is from the Aslan ship Bulk Hauler (Oukhaha class) from the Aslan book. Protecting it is just taking the folding roof sections of stadiums and enclosing the bladder under a protective skin.

No that I am thinking about it, an accordion style box on rails could allow all sorts of expandable tonnage to be protected. This could really push the ship design envelope for cheaper transport.

 

[phavoc]

It seems to (a) go against the spirit of ship design rules. It's very much exploiting holes because the rules are already rather loose to begin with. And (b) we already know space is a dangerous place with lots of danger from debris and such. Ships hulls are made of wonder material to withstand micro-metorioid impacts at the high interplanetary speeds they operate under. Jump nets are just that, they provide no protections for their cargo and are meant to haul either raw materials or other objects that have protection against the hazards of space.

The ship design rules cannot be ultra-detailed and still be fun. It's not to say that you couldn't have such a design, but since this isn't used normally there's probably very good reasons for this not happening. What risks are you designing in that would provide the balance to such a design?

 

[PsiTraveller]

Drop Tanks reduce the need for fuel tanks and can increase profits for merchant lines or attack values for attacking ships. The logistical issues of moving ships through Jumpspace have long been studied.

The issue for empty fuel tanks is that it still costs space, fuel, and energy to move an empty fuel tank through jumpspace. This is especially true of a ship like the Armstrong that is doing a double Jump due to its job/design. They saved 15% fuel by going Jump 3 with 3 tech advantages on the Jump Drive. Saving fuel is very important.

What would you say to a system like the cargo mount and folding walls of hull metal? A box of a specific volume is made and the fuel bladder is expanded into the box?

It could still be the same price to make, maybe even a little more adding in the actuators and such.

I just find it an interesting area to see how much you can push the technology (and rulesset) to address the issue of needed all that extra fuel to move volume you are not actually using.

 

[PsiTraveller]

Found 2 types of folding shipping container. If it was made out of space worth metal you could build an external volume of container and protect a fuel bladder.

https://www.youtube.com/watch?v=MNtJDzKC9bM
A Treck foldable container. Folds down to 25 percent of original volume.

http://staxxon.com/how-it-works/
The Staxxon version folds down to 20 percent of the original volume and can be stored racked together.

So the Origami ship is now a possibility. Stacking, folding panels that can extend outwards to allow a bladder to be filled inside them. This would allow variable hull tonnages to allow fuel savings when extra space is not being used. Maybe call it an accordion section that extends out and has a bladder fill in the now protected volume.

 

[phavoc]

Are you proposing the ship carry Lhyd in the bladders, or just plain water? Water would actually be far better since you could run it through your purifiers while in jump (assuming proper plumbing connections) and its far easier to store water than it would be to store Lhyd.

 

[PsiTraveller]

Either or, depending on how hard science you want to make the fuel processors. Does 20 tons of water transmute into 20 tons of LHyd? Where does the oxygen go?

My thinking on volume reducing ships is that if a fuel tank is empty, as it is when a 2 Jump capable ship is making a second jump, why pay the fuel cost to move empty volume?

Having a ship that can shrink allows for reductions in both fuel and energy needed for Jump. This is an advantage economically and militaristically. A ship saving on fuel can operate longer.

The Armstong spent an extra 60 million credits to save 45 tons of jump fuel per jump.
A folding ship with retractable volume that cuts the 300 tons normally needed to 80 tons.
Here I am envisioning 3 tons of bladder collapsing down into 2 tons of connecting piping for the bladder. Suppose the folding cubage collapses down into 25 percent volume, so that is 75 tons of space, plus the 5 tons of bladder tankage is 80 tons of collapsible tankage.
If car
This is 220 tons of fuel saved for the second jump. This saves 66 tons of fuel and does not cost extra money for tech advanced Jump engines. That is 780 tons of ship Jumping 3.

 

[phavoc]

Either or, depending on how hard science you want to make the fuel processors. Does 20 tons of water transmute into 20 tons of LHyd? Where does the oxygen go?

My thinking on volume reducing ships is that if a fuel tank is empty, as it is when a 2 Jump capable ship is making a second jump, why pay the fuel cost to move empty volume?

Having a ship that can shrink allows for reductions in both fuel and energy needed for Jump. This is an advantage economically and militaristically. A ship saving on fuel can operate longer.

The Armstong spent an extra 60 million credits to save 45 tons of jump fuel per jump.
A folding ship with retractable volume that cuts the 300 tons normally needed to 80 tons.
Here I am envisioning 3 tons of bladder collapsing down into 2 tons of connecting piping for the bladder. Suppose the folding cubage collapses down into 25 percent volume, so that is 75 tons of space, plus the 5 tons of bladder tankage is 80 tons of collapsible tankage.
If car
This is 220 tons of fuel saved for the second jump. This saves 66 tons of fuel and does not cost extra money for tech advanced Jump engines. That is 780 tons of ship Jumping 3.

You can vent anything you want into space, even jump space. H20 is not even the best way to store hydrogen (ammonia is actually). It has to do with the density of whatever it is you are cracking to get the hydrogen.

I see where you are going with your idea, and on the surface I don't dispute it. But to me it seems like it's cheating the rules (much like drop tanks). The basic premise behind Traveller is that everything is contained within the hull is what you take from system to system. Normal displacement would be based on actual square meters of hull. Traveller short-cuts that, but also prevents other types of cheating. A 1,000 ton distributed ship could be designed to enclose a larger space than a typical 1,000 ton ship, but still be within the rules. Do we count enclosed volume or just hull surface space? Different ship configurations would calculate that differently. And then hull shapes becomes the next big item to try to min-max.

So while your design would fly within the rules it just seems like it's a cheat because the rules aren't written tight enough to say 'nyet' to that sort of rules lawyering. I gave upon SFB v3.0 when I couldn't keep track of all the rules and we ended up arguing more about the rules than playing the game.

There isn't a 'perfect' answer to this sort of thing. With that being said your expandable fuel bladders do make sense.

 

[Condottiere]

Bladders aren't really an issue if you aren't in a hurry to get somewhere.

Design rules assume that they're hydrogen proof.

Noticeable shrinkage while transitting is an issue, since it throws the jump computations out of whack, and in our case will destabilize either the bubble or the pseudo universe, though not the drives themselves, since they are shut off.

 

[PsiTraveller]

Long post warning, I am waxing philisophical about ship design.

Taking the design philosophy of a ship needing everything within the hull to go into Jump is exactly what I am doing. I am just looking at what hull you need to take with you on the specific jump you are on, not one that you might have been on or go on later. A ship does not need an empty 255 ton section of hull to go into Jump. That hull is not useful to the ship at that time. That 255 tons of space is not being used by the Armstrong ship to Jump.

Most of the time a ship will need all the fuel it carries to go into Jump because the ship is designed to Jump just once and then needs to refuel, assuming it Jumps full distance. A Jump 2 ship jumping 1 will have enough to Jump again. The Armstrong has a performance benchmark the ability to do max Jump twice before needing to refuel. So this changes things.

But to my way of thinking the need to Travel 6 in 2 Jump 3 steps does not mean that the second Jump has to be identical to the first Jump, they are 2 different events with 2 different parameters. The first Jump is to get the ship, plus the fuel needed to get the ship to a Jump 6 location. Old system meant carrying an extra 255 tons of fuel. 1000 tons of ship with 510 tons of Jump fuel inside it.

So what options are there to reduce volume and save fuel?
Docking clamp with fuel in a pod, drain the pod into the interior tanks and drop the pod.
Modular section of hull that can be dropped off to save volume.
Jump net with fuel tank or bladder
Breakaway section of hull with extra fuel. This could be like the Manta ship from TNE that acted as the fuel tank.

The only issue with all of the above is the leaving of the item behind. This can get awkward in leaving a trail of empties behind. You can only do it once. The bladder could be drained and brought onboard, but someone pointed out it is vulnerable to getting hit during travel,

So we need to design something that can store fuel and come along for the ride after it is used. Fuel bladders fit the bill nicely. They take up only a fraction of space when empty. They just need to be protected.

This just leaves the hull section. Folding volume offers a chance to redesign rift ships in new ways to maximize travel endurance.

 

[Condottiere]

Bladder problems

For some reason, bladders can't take the sudden suction that creation of a jump bubble requires during the moment of transition (or twirl the turbines in other iterations), and then just flap along the side of the hull like a pair of basset hound ears.

 

[PsiTraveller]

The embarrassing part of Traveller is always premature oscillation.

 

[Epicenter]

Any thoughts?

Admittedly, like Phavoc, I feel that there's a certain amount "gaming" the ship design rules going on with the idea. While most "gaming" of rules is used for advantage against a human opponent, in this case what is happening is that the "canon" universe is your opponent.

What I mean is this: Humankind in the TU has had space travel for all 1,000 years of the Third Imperium, and thousands of years more than that during the Vilani Imperium. I feel that to preserve a sense of "realism" we have to assume there have been many, many smart, perceptive, creative ship designers and engineers during those years ... and not a single one of them has ever thought of this idea before? I think an idea like this, if it "worked" in the TU, would have been thought of many, many times before and it would either be a standard solution for any ship that requires the long legs within the constraints you're describing (eg; we should be seeing a lot of ships with this solution) or there has to be some extreme drawback to this method one(s) so nasty they make this solution so unattractive that no other ship in the universe has this solution (or perhaps a few other ships do, but not many), but unless the drawbacks are severe there's going to be no reason why every military ship would forego this advantage just to get more fuel tankage without depending on tankers or the time and bother of frontier refuelling).

One way would be to redesign a bunch of ships to have this system in your TU, since if it is cheap, easy, and safe, countless ship operators would be retrofitting their ships to do this in good, effective packages for most. Even the "not-so-well-informed" ship operators and various "risk takers" would jury-rigging this system up on their Free Traders to make them effectively Jump-2 ships. Needless to say, pretty quickly every shipyard making Free and Far Traders would be including this system in their new builds, something that would have pretty profound effects upon trade maps and so on.

The other way would be to consider some pretty nasty drawbacks - enough that nobody, not even "space rednecks" would consider doing this method because of the risks / costs involved and the Armstrong would be a ship that has, somehow has some expensive/finicky system that makes the system worth using whereas the vast majority of starship designers wouldn't use this method because of the drawbacks involved and the costs of overcoming the drawbacks are so high that other ship designs don't take advantage of the system. Again, the advantages of what you're suggesting are so great for pretty much any ship except for Fat Traders and similar ships on safe, predictable fixed routes, every other ship would likely already be doing it.

Just to nip a few 'drawbacks' in the bud:

* "Incoming fire is more devastating" wouldn't be enough, for instance - many ships in the TU are unlikely to ever come under fire, and most free merchant operators would know this and would be willing to undertake the risk for the greater profits, similarly the military would likely invest trillions of credits to find a way to have a "fast dump" fuel system or something make it less risky.

* "Jump Software has to be more complex/expensive to compensate for the mass differentials" - no it wouldn't. Again, this idea is likely to have been thought of in the Vilani Imperium. Maybe the Vilani banned it because of the social disruption it'd cause in their space, but once we get to the Second Imperium and the Third Imperium, they don't care so much about those things, so we're still talking a thousand years of software development. The costs for more robust software would have been paid out long ago, standard Jump software would already take this into account.

 

[Condottiere]

The CoDominium deliberately corrupted databases, and licensed all forms of research that could negatively impact society, especially weapon related.

We may be reinventing the wheel, but that's because, all mention of it previously was Ministry of Truthed.

 

[PsiTraveller]

Well I think the entire idea of a extendable section of ship volume is a cool idea and can create options for adventure and fun.

https://www.youtube.com/watch?v=REUwL3Jd97o

Rigid walls expandable shelter could easily be modified to unfold from within a cargo hold and out along external cargo mounts. This additional space could be filled with cargo or a fuel bladder.

As for the tech suppression police, The external mounts and dropping of external tonnage has always been available. People have been adjusting Jump tonnage per trip since the beginning of the game. I've just bolted the tech to the ship instead of dropping it off.

 

[Epicenter]

While I said that (and I still do think) you're sort of gaming the ship construction rules, I don't think your idea is inherently bad.

What I am saying is that the system you're introducing is going to have implications in a "living" Traveller universe that you should consider before introducing it.

A living universe in this case assumes that there are "real" people living in this fictional universe who'd behave like real people so changing things will have implications as those living in that universe will explore uses for new things (or maybe wonder why something so simple wasn't invented a long time ago).

 

[Condottiere]

The ship design concepts just lend themselves to gaming the system.

The moment you realize that performance is based on enclosed space rather than mass, you start trying to figure out how to get rid of it, or fill it up more effectively.

 

[PsiTraveller]

This is exactly the point, enclosed space is what matters for Jump travel, not mass. You could load the cargo bay with ingots of lead, or bags of feathers and the ship would handle the same thanks to M-Drive and gravitic control. All that matters is the volume of enclosed space at the moment of Jump.

This is what Traveller has been playing with since the beginning. You have external cargo mounts to reduce tonnage when there is no cargo to move. You have drop tanks at higher tech to not bring along a fuel tank at all. You also have fuel efficient engines that use less fuel to create the Jump bubble.

I don't see what the issue is in having a secion of ship fold in. Given all the other options to reduce volume this is one more in the arsenal.

I would put restrictions on it. I would not have a ship get hardpoints for the tonnage involved, so the 1000 ton ship with 300 tons of folding storage only gets 7 hardpoints, same as a 700 ton ship. Hull points are based on the 700 ton non folding tonnage and the folding section takes damage easier than regular hull. It is weaker than regular hull.

Cost wise I am still working on that. Hull is 50 000 a ton. External cargo mounts are 10 000 a ton. I may just split it and say 25 000 a ton.

As for Epicenter's concern that it would have an impact on a campaign. It may create some logistical improvements for Rift crossing, but the ability to save fuel on a second jump is a pretty specific niche to fill. The idea that this will change shipping is contradicted by the fact that reducing volume per jump is already possible using external cargo mounts. The Armstrong class ship could be redesigned t0 have a 260 ton cargo bay with collapsible bladder and 95 tons of cargo on external cargo mounts. The Ship would jump, then refill the tank from the bladder and then bring in the cargo from the mounts and save fuel for the second jump.

 

[phavoc]

This is exactly the point, enclosed space is what matters for Jump travel, not mass. You could load the cargo bay with ingots of lead, or bags of feathers and the ship would handle the same thanks to M-Drive and gravitic control. All that matters is the volume of enclosed space at the moment of Jump.

This is what Traveller has been playing with since the beginning. You have external cargo mounts to reduce tonnage when there is no cargo to move. You have drop tanks at higher tech to not bring along a fuel tank at all. You also have fuel efficient engines that use less fuel to create the Jump bubble.

I don't see what the issue is in having a secion of ship fold in. Given all the other options to reduce volume this is one more in the arsenal.

I would put restrictions on it. I would not have a ship get hardpoints for the tonnage involved, so the 1000 ton ship with 300 tons of folding storage only gets 7 hardpoints, same as a 700 ton ship. Hull points are based on the 700 ton non folding tonnage and the folding section takes damage easier than regular hull. It is weaker than regular hull.

Cost wise I am still working on that. Hull is 50 000 a ton. External cargo mounts are 10 000 a ton. I may just split it and say 25 000 a ton.

As for Epicenter's concern that it would have an impact on a campaign. It may create some logistical improvements for Rift crossing, but the ability to save fuel on a second jump is a pretty specific niche to fill. The idea that this will change shipping is contradicted by the fact that reducing volume per jump is already possible using external cargo mounts. The Armstrong class ship could be redesigned t0 have a 260 ton cargo bay with collapsible bladder and 95 tons of cargo on external cargo mounts. The Ship would jump, then refill the tank from the bladder and then bring in the cargo from the mounts and save fuel for the second jump.

Original Traveller didn't have this idea of external cargo or fuel tanks. Original Traveller had everything self-contained in the ship. The Gazelle was the first, and just about only, regular small ship that used a drop tank - it was was built incorrectly within the existing rule set. HG came up with drop tanks for capital ships to game the system for tournament play. But for the most part all ships have lived within the concept of you take your fuel and cargo with you, inside your hull.

Here's one of the general problems with bolting stuff on to your ship and hardpoints - the concept of weapon arcs in Traveller is very high level and the two issues don't mesh well together. Bolting stuff on externally works well on spreadsheets, but in reality it's not the best of ideas. Why don't warships today stuff their decks full of fuel bladders to increase their range? Soviet tanks in the 70s routinely trained with fuel barrels on the rear to increase their range, but everyone acknowledged it as generally a bad idea and one that would not do well once bullets and shrapnel and air-bursting artillery rounds came into play.

So Epicent has a point - it's not a bad idea, per se, it's a big gaming of the system because there's nothing there to explicitly stop it. Older Traveller at least restricted you to your hull with your lanthanum jump grid - anything more than 3ft away was destroyed upon jump. MGT changed it to a bubble, but of indeterminate size so we don't have a hard ruling on this - and should the bubble be calculated on your original jump drive, or on the increased ship displacement.

As far as mass goes, the rules are completely transparent to it. Though we do know the anti-gravity is NOT an anti-mass field, it just neutralizes the effects of gravity. Thus a ship that masses 100,000kg still masses 100,000kg when it activates its' anti-grav lifter system. Ships with more armor and mass should perform differently - at least in a gravity field. And ships with M-drives should have acceleration curves, thus adding mass through armor is another trade-off you have to consider - just like in real life.