Proposed additions to drop tanks description

[AnotherDilbert]

Drop tanks are not that strange or contrived. They can withstand atmosphere, they can withstand a bit of manoeuvring.

Starship drop tanks are a bit bigger, but we have had 3000 years to make them usable...

 

[AnotherDilbert]

I did a mockup of Chas' 2+2 concept, but with a breakaway hull section instead of the drop tanks.
It costs you GCr~ 7 and ~2.5 kT usable space, but the concept survives, no big deal. You end up with a 35 kT hull segment for fuel. As it is a regular hull it has to be crewed (maintenance&admin), but I quartered them in the main hull. It also requires power for life support, that I took from the main sections power plant, so you probably have a little less power for acceleration with the sections joined.

 

[Chas]

Yes. I worked through it a bit and figure it is a very nice work around to drive a ship up to a higher hull point advantage :lol:

And stops the one hit end of drop tanks - definitely worth the investment!

Alas it didn't solve my problem with my super bloated drop tank build I'm going to put up which will no doubt not be to the taste of some on this thread. Still haters gonna hate :wink:

 

[AnotherDilbert]

Yes. I worked through it a bit and figure it is a very nice work around to drive a ship up to a higher hull point advantage :lol:

I think each hull section must be legal on it's own. Drive performance is combined, hull points are not. So a 60kT section and a 40kT section do not get hull points as a 100 kT hull. By my interpretation of RAW...

While the sections are together, drives, power plants and weapons can all be combined when calculating performance.

 

[phavoc]

Yes. I worked through it a bit and figure it is a very nice work around to drive a ship up to a higher hull point advantage :lol:

And stops the one hit end of drop tanks - definitely worth the investment!

Alas it didn't solve my problem with my super bloated drop tank build I'm going to put up which will no doubt not be to the taste of some on this thread. Still haters gonna hate :wink:

That seems like rules lawyering/cheating to me. These are supposed to be temporary things designed to give a starship a bit more 'oomph', not permanent things designed to skirt the rules and min/max a player's warship design. So long as they seem reasonable under what we would think of 'realistic' circumstances in the future, I've no objection. But I do have objections to making a ships performance hinged upon them.

IF this is a patch we continue down, then I think, at a minimum, we split the hair down the middle. On the one hand we have cheap, generic drop tanks that have a lot of limitations, but won't blow your pocketbook when you jettison them and they crumple. On the other hand we have the more expensive military-grade ones that encompass things like re-usability, but increase the price, and still make them somewhat dainty in the damage department, giving them say an armor factor of 1 (and making them conformal so they don't block firing arcs - which begs the question should they get a giant single one, or should they have multiples, say no more than 10% of the overall external fuel tonnage being in any single tank - so more required collars to hold them).

RE: The image of the Typhoon flying upside down with a drop-tank attached - we have no idea if that is even full or not. If you look you'll see every rail is empty of ordnance, too. Empty drop tanks can be carried around, and typically are during training and normal flights, and the aircraft return with them still attached. But these are empty tanks, and they RTB with them because of accountants (they aren't exactly cheap, though far cheaper than say a AMRAAM or even the craft itself).

 

[phavoc]

So i was doing some digging. Price depends on the exact tank and all that, but here's something to consider:

Cost - $52,000 per drop tank. For that you get:

External Tanks are long and are divided into forward, center and aft sections to maintain CG.
Each section has pressurization and vent system.
Each section has a redundant feed system, typically pump-enabled and gravity/suction feed.
Each section has a refuel capability with high level shutoff valves.
Each section has fuel quantity quantity measurement devices.
Tanks have to survive many, many flights at +5 to -3 Gs, vertical shocks and horizontal whip loads.
Tanks have precise aero requirements to reduce drag and enable clean jettison.
Some tanks are coated with RAM to reduce RCS.

Source: http://forum.keypublishing.com/showthread.php?124710-Can-fighters-land-with-drop-tanks

 

[AnotherDilbert]

RE: The image of the Typhoon flying upside down with a drop-tank attached - we have no idea if that is even full or not. If you look you'll see every rail is empty of ordnance, too. Empty drop tanks can be carried around, and typically are during training and normal flights, and the aircraft return with them still attached. But these are empty tanks, and they RTB with them because of accountants (they aren't exactly cheap, though far cheaper than say a AMRAAM or even the craft itself).

That's not a Typhoon, as the URL hints.
It's just a random picture off the internet, I was just trying to illustrate that they can be used in atmosphere, and won't fall off under normal manoeuvres. Perhaps G-forces are limited while carrying drop tanks, I have no idea?

 

[AnotherDilbert]

Is this better?
https://www.dropbox.com/s/0te2cgiwmo4zsgy/Gripen.png?dl=0

 

[Nerhesi]

So... after 10% of hull damage, all external drop tanks destroyed? do we see any issue with this?

note: they are not providing you extra hull, they are simply being eliminated when the ship takes a "bit" (10%) of hull damage.

Focus folks

 

[AnotherDilbert]

Good enough for me.

I think that might lead to ships carrying the tanks into combat. The enemy will likely concentrate fire to kill ships quickly. The ships that survive will have their tanks intact.

 

[phavoc]

So... after 10% of hull damage, all external drop tanks destroyed? do we see any issue with this?

note: they are not providing you extra hull, they are simply being eliminated when the ship takes a "bit" (10%) of hull damage.

Focus folks

So how do you account for hull damage on the tanks themselves? How would it affect their carrying ability? Their fuel loads? Could you repair them?

They should not provide any sort of free armor whatsoever, nor should they provide any free damage soak.

Also, how do you handle multiple tanks? Say you have 10 tanks. Is one tank destroyed for every 1% of your hull damage taken? Does it all have to happen in a single round, or can you only lose one tank per round?

I think it's far simpler to say they get destroyed, or at least rendered inoperable and loss of fuel with any hit.

 

[phavoc]

Is this better?
https://www.dropbox.com/s/0te2cgiwmo4zsgy/Gripen.png?dl=0

Ah, the Gripen. The forward canards made me think it was a Eurofighter. I had forgotten about the Gripen (like most of the worlds aircraft buyers!). It's a nice aircraft for a fair price.

 

[Nerhesi]

So... after 10% of hull damage, all external drop tanks destroyed? do we see any issue with this?

note: they are not providing you extra hull, they are simply being eliminated when the ship takes a "bit" (10%) of hull damage.

Focus folks

So how do you account for hull damage on the tanks themselves? How would it affect their carrying ability? Their fuel loads? Could you repair them?

They should not provide any sort of free armor whatsoever, nor should they provide any free damage soak.

Also, how do you handle multiple tanks? Say you have 10 tanks. Is one tank destroyed for every 1% of your hull damage taken? Does it all have to happen in a single round, or can you only lose one tank per round?

I think it's far simpler to say they get destroyed, or at least rendered inoperable and loss of fuel with any hit.

They're not providing free armour or soak as I've stated. They're just going poof when the ship hull takes X damage. (x = 10%)
No need to boutique and create special damage rules for every single component. Just thinking about how they should be not-for-use-in-combat and not instantly-exploding the seconds a 50,000 hullpoint battleship takes 1 point of damage either.

 

[phavoc]

But the questions remain. If they CAN take damage, what does that do to any fuel inside of them? What about the ship takes 5% of it's hull points in damage. The external tanks are still usable? Are they able to contain 50% of the fuel (assuming they are full)?

A ship won't ever take a 'single point of damage' from another starship-class weapon. It's going to be hit by a missile, or a laser or something far worse. Drop tanks should be treated as delicate things, because in reality they are. They should also be priced accordingly, to reflect that reality.

 

[AnotherDilbert]

But the questions remain. If they CAN take damage, ...

They can't be targeted or damaged; they are either fine or they are completely destroyed. It's a game, it's a simplification.

They should also be priced accordingly, to reflect that reality.

The drop tanks we have talked about here costs hundreds of millions or even billions. They are not trivially disposable.

 

[phavoc]

We should really change the nomenclature on this discussion. DROP tanks are meant to be used by the starship and then dropped before jump. Remember that jump drives are based on displacement. An empty or full drop tank of 100Dtons is still 100Dtons. So carting them around by the ship means a significant change in the stats (we'd have to go back to using slashes on all it's stats to show encumbered and un-encumbered stats).

I still say drop tanks, by their name and implied nature, are cheap and fragile things. What you guys are proposing are demountable tanks, or some other nomenclature to denote a semi-permanance. Maybe conformal fuel tanks would be more apt, because they would have to be engineered to not block sensor ports, turret firing arcs, bay openings, airlocks, etc.

I don't care that they are part of the game, but they are being made out to be these magical things that can do all sorts of wonder, have no negative side effects, and are part of every-day Traveller life. And that's never, to me at least, been the point of them throughout the variations. Otherwise where are the canonical Free Traders and Scouts with their drop tank connections?

 

[phavoc]

We should really change the nomenclature on this discussion. DROP tanks are meant to be used by the starship and then dropped before jump. Remember that jump drives are based on displacement. An empty or full drop tank of 100Dtons is still 100Dtons. So carting them around by the ship means a significant change in the stats (we'd have to go back to using slashes on all it's stats to show encumbered and un-encumbered stats).

I still say drop tanks, by their name and implied nature, are cheap and fragile things. What you guys are proposing are demountable tanks, or some other nomenclature to denote a semi-permanance. Maybe conformal fuel tanks would be more apt, because they would have to be engineered to not block sensor ports, turret firing arcs, bay openings, airlocks, etc.

I don't care that they are part of the game, but they are being made out to be these magical things that can do all sorts of wonder, have no negative side effects, and are part of every-day Traveller life. And that's never, to me at least, been the point of them throughout the variations. Otherwise where are the canonical Free Traders and Scouts with their drop tank connections?

 

[phavoc]

I found this on the GURPS site, in the Traveller News Service.

Regina/Regina (0310 A788899-A) 097-1105
Officials of the General Shipyards on Regina announced that it has completed negotiations with Tukera Lines to locally manufacture L-Hyd drop tanks for use on high-capacity commercial vessels. General will assemble components at its more modern facilities on Pixie (0303 A1001030-D). The first production examples are expected to be available within six months, at which time Tukera Lines will begin high capacity service from the interior. Component assembly will be carried out at General's more modern facilities on Pixie (0303 A100103-D).

L-Hyd drop ships have only been in service for the last dozen years in the interior, being made possible by recent advances in the field of capacitor engineering, a joint press release explained. Commercial vessels equipped with the new generation of long-storage jump capacitors carry jump fuel in specially designed L-Hyd drop tanks in excess of their rated tonnage. Upon conversion of the fuel to the massive energy required for jump, the drop tanks are explosively jettisoned through the use of break-away connections and explosive bolts. Jump is executed when the remains of the tanks are a safe distance from the vessel.

A spokesman for General Shipyards explained that local yards are not yet capable of manufacturing the long-storage capacitors required for the process, but that production of the drop tanks is possible, thus allowing the high capacity starships of the Tukera Lines to begin service to the Regina subsector.

L-Hyd tanks are not reusable, and thus increase the absolute cost per jump. However, experience has shown that the increase in cargo tonnage resulting from the elimination of internal J-fuel storage more than makes up for this, the press release explained.

The joint press release concluded by stating that local manufacture of L-Hyd drop tanks marks the dawn of a new era of commerce and prosperity in the Regina subsector. Following the announcement, common stock in Oberlindes Lines plummeted 27 points on the Regina exchange before trading was suspended. Officials of Oberlindes Lines were not available for comment. [omega]


Regina/Regina (0310 A788899-A) 101-1105
Close on the heels of the joint announcement by General Shipyards and Tukera Lines that L-Hyd drop tanks would soon be manufactured in the Regina subsector, came word by express boat from the Imperial core that a decision has been made to deploy Jump-6 L-Hyd drop tank express boats on all major express routes. Initial feasibility studies indicate that such a system could average jump-5.5 per week by executing maximum jumps, and leaving current xboats to disseminate information between the new major relay points. The system is expected to cut communication time to the Imperial hub to under 25 weeks. The Initial System Deployment Schedule indicates that the Regina subsector can expect to be fully integrated into the network within a decade. [omega]

http://www.sjgames.com/gurps/traveller/CT-TNS/1105.html

 

[Condottiere]

If they're designed to channel explosions, they'd be similar to the torpedo bulges on battleships.

 

[PsiTraveller]

TL 14 Drop tanks allow for automatic survival of the drop tank. The TL-15 Jump Drive DM can be overcome by a skilled operator and should not be too much of a problem.

The use of Drop tanks makes a lot of sense for freighters, especially in 2nd edition and the 7000 Credit per ton shipping rate
Assume a 1000 ton ship J4 jump drive would need 105 tons. Fuel would be 400 tons of space for the J4 distance.
If you took the .4 % docking clamps that would be 1.6 Tons costing 0.8 MCr.

You would get 398 Tons of extra shipping space. Assume a 390 ton usage for freight and a single trip brings in 2.7 million Credits of income. Buying a new fuel tank is still profitable since it costs 1 Million credits.

I admit I am not seeing the advantage of having a permanently attached Drop tank. Could someone explain the advantages to me? Your Jump drive number is altered, as is your Thrust under M-Drive.

From a military prospect a ship with 100 tons of Jump drives and an extra 400 tons of space for bays offers more military power per ton. The intent seems to be to get SDB level performance and weapons per ton by removing the fuel percentage and replacing it with military tonnage. This is one step closer to a Battle rider where even the jump drive is removed and a transport ship carries the combat ships into the target system. A Battle rider with Drop Tanks would maximize carrying capacity.

Is there a way to use the Docking clamp to simply hold a pod of fuel? A 20 Ton clamp from page 45 could hold up to 2000 tons of ship at a cost of 4 MCr. The fuel pod could be easily released once emptied. The tank would be a Demountable tank and not cost that much. The max tonnage for the Type V clamp probably needs to be stated, otherwise some clever soul will have a 400 ship with a 200 ton Jump Drive and grab larger ships to Jump into distant systems.The distance possible would be the total tonnage into the size of the engine which would give the max Jump distance.

At some point somebody is going to be either be shipping a lot of empty tanks along to refill and reconnect to the troops, or each system will have to produce new tanks for the ships traveling through the system.