Drop Tanks... Back From the Dead?

[ottarrus]

I've always thought that drop tanks were superfluous and only really suitable for a very narrow set of mission profiles.
In a TL 8 Earth example, I think of them rather like Jet Assisted Take Off [JATO] packs on a C-130: Useful on occasion, but not really used all that often.
Back to Traveller, if J4 is the Fleet Mobility standard, then why equip a patrol/escort corvette [which is what the Gazelle really is] with J-5 one way and J-3 another way? Wouldn't it be better /smarter /cheaper to just build a J4 corvette and save the hassle?
I guess what I'm saying is that drop tanks were interesting in 1980, but simply not that big a deal now.

 

[Condottiere]

Yeah, but do they function from -200 degrees to 200 degrees of temperature in the exterior environment all while pumping very cold stuff from one location to the other?

And then we have primitive hulls at technological level five onwards.

Which we should presume is actual steel, stainless or otherwise.

Plus, whatever they use for hull armour.

And, apparently, their hull insulation does have some shortcomings.

 

[Condottiere]

I've always thought that drop tanks were superfluous and only really suitable for a very narrow set of mission profiles.
In a TL 8 Earth example, I think of them rather like Jet Assisted Take Off [JATO] packs on a C-130: Useful on occasion, but not really used all that often.
Back to Traveller, if J4 is the Fleet Mobility standard, then why equip a patrol/escort corvette [which is what the Gazelle really is] with J-5 one way and J-3 another way? Wouldn't it be better /smarter /cheaper to just build a J4 corvette and save the hassle?
I guess what I'm saying is that drop tanks were interesting in 1980, but simply not that big a deal now.

You have to look at the overall ecosystem, as to what capability they bring to the table, and what infrastructure is/has to be maintained to support operations.

And then, whether the costs are worth whatever advantage you gain.

 

[ottarrus]

You have to look at the overall ecosystem, as to what capability they bring to the table, and what infrastructure is/has to be maintained to support operations.

And then, whether the costs are worth whatever advantage you gain.

I agree with your statement, Condo, but in my estimation it only reinforces my argument.
Something else to consider is that you can make a J6 corvette/escort out of a 400 dton fleet courier without having to fuss with drop tanks at all.
Perhaps this is like the difference between a sprinter and a marathon runner. Both can run, but one runs faster and the other runs longer.

 

[Condottiere]

I agree, but four hundred tonnes does, somewhat uncomfortably, allow this performance organically.

To a certain extent it depends on how time critical the information, in the case of that carried by the Fleet Courier, is.

You could place a double set of drop tanks on it, and it could jump two more times with minimal reorientation time, and reduce the number of relay runners needed to maintain.

In theory.

I wouldn't rely on this system, but it's an option.

 

[Fluffy Bunny Feet]

Something else to consider is that you can make a J6 corvette/escort out of a 400 dton fleet courier without having to fuss with drop tanks at all.

With drop tanks holding ALL the fuel the only difference from the incoming jump ship and a SDB of the same mass is that the jump ship "wastes" the mass of the jump drive and likely has a larger M-Drive giving better acceleration. A much closer match ton for ton.

 

[MasterGwydion]

If you look at it from a civilian perspective, it makes a lot more sense than from a military one.

 

[Vormaerin]

I agree with your statement, Condo, but in my estimation it only reinforces my argument.
Something else to consider is that you can make a J6 corvette/escort out of a 400 dton fleet courier without having to fuss with drop tanks at all.
Perhaps this is like the difference between a sprinter and a marathon runner. Both can run, but one runs faster and the other runs longer.

I agree that it's military application is pretty limited, bordering on non-existent. It's civilian application is where it is a game changer.

 

[Condottiere]

Assuming it's a megacorporation transportation company, than it's a question on how much they save on capital and operating costs of a smaller starship, versus maintaining the drop tank infrastructure in each system

 

[boggo2300]

I've always thought that drop tanks were superfluous and only really suitable for a very narrow set of mission profiles.
In a TL 8 Earth example, I think of them rather like Jet Assisted Take Off [JATO] packs on a C-130: Useful on occasion, but not really used all that often.
Back to Traveller, if J4 is the Fleet Mobility standard, then why equip a patrol/escort corvette [which is what the Gazelle really is] with J-5 one way and J-3 another way? Wouldn't it be better /smarter /cheaper to just build a J4 corvette and save the hassle?
I guess what I'm saying is that drop tanks were interesting in 1980, but simply not that big a deal now.

the original design for the Gazelle was J-4 4g, with an emergency J-5 dropping the tanks after the tanks are dropped it's 5g but limited to J-2 by fuel. the J-5 is obviously the run away to get help option, and only used in emergencies I'd say, or to allow for hugher g in system I guess.it just seems every version of the rules since then has made the gazelle quite different to what it was intended to be

 

[Condottiere]

Depends on what the Gazelle operator wants the Gazelle to do.

If it's fleet(ish) escort, than for the Imperium all you need is four parsec range.

 

[boggo2300]

Depends on what the Gazelle operator wants the Gazelle to do.

If it's fleet(ish) escort, than for the Imperium all you need is four parsec range.

As it's an Imperial Navy design, it's role is close escort of naval convoys generally speaking, especially when you consider the Fiery class Gunned Escort (which is exactly the same except the L-HYD tanks are fixed and it's streamlined, and permamently J-4 4g) my feeling is both of these classes are designed to escort IN re-supply squadrons, with the Gazelle's one off J-5 used for running for help

 

[boggo2300]

The problem for militaries is that of logistics. Drop tanks are primarily useful when jumping from somewhere the tanks can be recovered. So they are most useful for moving from one infrastructure rich locale to another. Also, military ships are enormous. Putting drop tanks on a cruiser is like 20,000 dtons of drop tanks? And they probably aren't interchangeable, so you need many different sets of drop tanks at whereever you want to launch your deep raid from. Stockpiling that kind of thing and not letting your enemies know that's where it's stockpiled seems quite a challenge.

Corporate freighters, on the other hand, tend to go from point A to point B and back. And they tend to be the same class of ship. So if you can add another 300 tons of cargo to your 1000 ton freighter and/or give it J6 capacity without crippling its cargo capacity. You could set up a direct Regina to Efate and back route that isn't spending 60% of the hullspace on fuel, no need to stop at all those D & E ports in between.

And freighters don't care about lost weapons capacity, especially if they can use drop tanks to go from high pop, safe world to hi pop, safe world directly and skip the backwaters.

When the Gazelle was first published the tanks were NOT recoverable, and needed to be replaced at a shipyard. the Gazelle is incidentally the only published ship I'm aware of that has L-HYD tanks

 

[Condottiere]

Probably more to raise the alarm.

If it's an ad hoc longish range courier (sub)role, it's one shot.

 

[boggo2300]

Probably more to raise the alarm.

If it's an ad hoc longish range courier (sub)role, it's one shot.

It's not, the Imperial Navy is quite good at naming it's ship types, and they HAVE fleet couriers (which tend to be J-6 incidentally) the Gazelle is called a Close Escort, and it's performance matches tenders and fleet freighters, so I'd be almost certain it's role is looking after the fleets supply train (which matches with it's size, it's the Imperiums Flower Class Corvette more or less (with the one off running for help jump) I would expect a supply squadron (or a wartime convoy) escort to be a combination of Fiery and Gazelle class, with the Escort commander being a Frigate, freeing up the bigger escorts (Corvette, Frigate, and Destroyer) for escorting combat ships.

 

[Condottiere]

It's going to be squashed like a bug during fleet actions.

And it's overperforming for convoy escort.

I would equip close escorts more with anti missile and anti smallcraft weapon systems, but that's just me.

It's a legacy design, and our understanding of how navies worked has increased since then, and the game mechanics have evolved.

Destroyer escorts would be the more likely choice for the fleet train, and plucky trawlers escorts for convoys.

 

[boggo2300]

Because Armed Merchants haven't been proven to be useless the only time they were actually used... A Destroyer as a convoy escort is way overkill, your escorting destroyers would be with your combat elements where they should be, the Flower class proved that large numbers of small escorts work really well against small commerce raiders (U-boats IRL but small raiding ships would be more likely to evade the combat fleets)

 

[Condottiere]

Technically, destroyers are three kilotonnes, and destroyer escorts one.

A lot depends on what a convoy expects to encounter.

Submarines are stealthed commerce raiders sneaking up on you, and you tend to mission kill it once it's been detected and located.

Starwarships escorting convoys are going to be a mixed bag of what's available, and it becomes a question as to what's more useful, protecting the convoy, or chasing down commerce raiders.

Important convoys are likely to have one or two old battleships lurking nearby.

At some point, escort carriers.

In theory, destroyer escorts would run down commerce raiders.

 

[Vormaerin]

When the Gazelle was first published the tanks were NOT recoverable, and needed to be replaced at a shipyard. the Gazelle is incidentally the only published ship I'm aware of that has L-HYD tanks

Yes, I know that. Drop tanks are pretty stupid per the original rules. As I mentioned earlier, they would have been made into something that works or they would have been trashcanned. The fiction from those original TAS suggests that they actually work and have changed how things work in the Core.

The only example we have is the Gazelle, which was basically the prototype test design and is positively ancient. Like a century old design, if you believe the ISW book. And it is defintiely not what was referred to in the TAS posts.

 

[boggo2300]

Yes, I know that. Drop tanks are pretty stupid per the original rules. As I mentioned earlier, they would have been made into something that works or they would have been trashcanned. The fiction from those original TAS suggests that they actually work and have changed how things work in the Core.

The only example we have is the Gazelle, which was basically the prototype test design and is positively ancient. Like a century old design, if you believe the ISW book. And it is defintiely not what was referred to in the TAS posts.

er a century old design in the TI is still new...