All Warships Should Have Drop Tanks

[Starviking]

How many aircraft in WWII were equiped with drop tanks to increase range?
How many tanks were carried and dropped, being lost and needing repacement?
Why do we still use drop tanks on modern aircraft if dropping them is cost ineffective?

P51 Mustangs were equipped with drop tanks in order to perform the bomber escort mission. Arado Ar-234 had drop tanks to increase range in the reconnaissance mission. The P47 Thunderbolt, P38 Lightning, BF109, F4U Corsair and Hawker Hurricane were also equipped with drop tanks.

So you have at least all the major US fighters, a major British fighter, a major German fighter and a minor bomber using drop tanks. I wouldn't like to put a figure on it - but a lot.

As far as I know most drop tanks were dropped, as their drag would lead to unnecessary performance degradation - something not wanted in combat.

Modern use of drop tanks - I guess they're only dropped in occasional training and combat, so the expense is only occasional.

 

[rancke]

How so? Wouldn't the reduction of the maneuver drive result in a decrease in tonnage which is within the rule of "may not be increased in tonnage"?

I would interpret it to mean that drives and power plant have to be in the engineering section and you can't change the size of the engineering section. So if (as Theophilius' upgrade has it) one drive/plant is decreased in size at least as much as another is increased, but the sum total remains less than or equal to the original engineering space, that works.

(I still think his proposed upgrade is prohibitively expensive, though).


Hans

 

[Theophilus]

I would interpret it to mean that drives and power plant have to be in the engineering section and you can't change the size of the engineering section. So if (as Theophilius' upgrade has it) one drive/plant is decreased in size at least as much as another is increased, but the sum total remains less than or equal to the original engineering space, that works.

(I still think his proposed upgrade is prohibitively expensive, though).


Hans

Prohibitively expensive? And yet all modern navies since 1905 have done just that.

How many British Battleship of WWI vintage were upgraded before WWII. Hood was upgraded from battlecruiser to battleship, with an increase in tonnage to 45000 tons (and subsequent loss of freeboard).

Japanese Ise class, increased disp from 29K to 40K, length by 25'.
Kongo class, 27.5K to 31K, length 26'.

All the American battleships, except the Wyoming class were upgraded. And the Iowa upgrades continued into the 1980's.

How many Carriers were upgraded? Angled flight decks added? The last US non nuclear carrier was just retired and the current fleet is one homogenous design. Yet older carriers continued to be upgraded.

FRAM I, FRAM II? (Fleet Revitalization and Modernization programs I and II anybody?)

Why not just build all new warships rather than modernize? Which is cheaper, building 180 new dreadnaugths or modernizing 180 older ships? Especially when one considers the service life of some Imperial ships. The Chrysantemum, Fer De Lance, Azhanti, Atlantic, and Possibly Kokirraks have served 100 years. Compared to these the American Iowa's are just babies.

 

[HG_B]

I would interpret it to mean that drives and power plant have to be in the engineering section and you can't change the size

The definitive word "increased" was used. Unless the writer made an actual error, it can mean only one thing.

 

[rancke]

Prohibitively expensive? And yet all modern navies since 1905 have done just that.

They've performed upgrades that cost 50% of the cost of a new ship?


Hans

 

[Selandia]

upgrade

In wet navies, the life of a well built hull tend to outlast by decades the technological life of the weapons systems or the geopolitical considerations that presided to its purpose and design. Henceforth the conversions craze.

Examples:

Geo politic

Ships build to fight against nuclear soviet subs in the atlantic sealanes are now used in fight against terrorists that have nothing more than suicide craft or MG /RPG armed very light attack craft

London naval treaty, that lead to the breaker yard perfectly workable ships and had some battleship or battle cruiser hull converted to carriers


Technological,
U-Boat
Pre WWI Destroyers and escorts, without Dept Charge before 1916, massively converted.

V and W class RN WWI destroyers designed for fleet operation were converted to extended range and re-armed for AS escort in WWII

The retro-fitting of Asdic/Sonard

Missile developpements:

WWII Cruisers converted as missiles cruisers.

Massive retrofiting of Surface-Surface missiles and point defense systems after the Falklands (started after the 1967 sinking of the Eilath)

Air power
The above examples of capital ship conversions (although not the only explanation for same) before WWII

The conversions against Airborne Air-Surface Missile mentionned above.


Mixture of both geo political and tech

All RN protected cruisers scrapped after WWI although perfectly seaworthy

Armored cruisers, some built as late as 1906, obsolete by 1916 at the latest.

Would the same applies to spaceship? Look like it

Have they the price right? Duno

Selandia

 

[aramis]

They've performed upgrades that cost 50% of the cost of a new ship?


Hans

In some case 100% or more. Cumulatively, often over 300% over the hull lifespan.

Due to treaty compliance issues, often.

 

[HG_B]

They've performed upgrades that cost 50% of the cost of a new ship?


Hans

USS Missouri [BB-63] ("Mighty Mo")

 

[PFVA63]

Hi

...
How many aircraft in WWII were equiped with drop tanks to increase range?
How many tanks were carried and dropped, being lost and needing repacement?
Why do we still use drop tanks on modern aircraft if dropping them is cost ineffective?

Hi, I guess something to keep in mind about aircraft drop tanks are that they are/were kind of small in comparison to the size of the aircraft crrying them, as opposed to say an AHL, whose drop tanks may need to be 50% the size of the bare ship (without drop tanks).

Specifically, according to Wikipedia, the standard size of Gerandrop tanks during the 2nd World War was 300 liters (a little over 0.02dtons if I did the math right). In addition it indicates that a P51 belly tank was about 168 gallons (0.64 cubic m or a litle over 0.045 dtons) while a P38 could carry 305 gal (1.15 cubic m or 0.082 dtons). It also shows a 330 gal (1.25 cubic meter or 0.09 dton) unit that looks typical somewhat typical of some for modern aircraft.

In comparion to the overall size of the aircraft carrying them, these tanks do not appear to be in the same league as the relative size of tanks that would be required for a large Travleer type space ship. As such, this may affect how likely a Navy might be to resort to treating them as expendable in Traveller.

Regards

PF

 

[Theophilus]

Well, I had some down time today so I decided to tinker with a tanker design. A basic Tanker at TL15, 1,000,000 tons:

I need 480,000 tons of fuel for a squadron of 8 Kokirraks BB's. so 1 million tons is minimum size since basic hull and fitting use up most of the space.
Hull 100,000 Mcr
Jump-3 160,000 Mcr
Maneuver-1 30,000 Mcr
PowerPlant-3 90,000 Mcr
Bridge 5000 Mcr
Total: 385,000 Mcr
Hull used 44%, 440,000 tons, add 480000 tons fuel and I've got 80,000 tons for crew, computer, etc.

Now a Squadron of 8 Kokirraks cost 1,080,816 Mcr (that's one trillion, 80 billion, 816 million credits), whereas 8 60kton drop tanks only cost 240 million credits (240 Mcr) or around 2% of the squadron cost.

For the basic cost of one tanker, I can buy 1604 drop tanks.

Also see the Drop Tank Rules from TCS page 14 for more "fuel options".

Also, the cost to upgrade the Kokirraks PN from TL14-8 To TL15-10 is 90,000 Mcr
Refitting Meson-Q to Meson N 1100 million credits,
Upgrading M-4 to M-6 25,500 Mcr
Total cost: Mcr 116,600 Mcr

 

[PFVA63]

Hi

That's an interesting example but just buying the tanks doesn't really seem to do address everything that you might need. Specifically, unless you have some way to transport the tanks or have enough of them in every hex that you may travel too how would your fleet normally get around? Additionally in the event of war and you have to fall back or move out of some system, are you just leaving these tanks for your enemies use?

Just curious.

Regards

PF

 

[Starviking]

Prohibitively expensive? And yet all modern navies since 1905 have done just that.

How many British Battleship of WWI vintage were upgraded before WWII. Hood was upgraded from battlecruiser to battleship, with an increase in tonnage to 45000 tons (and subsequent loss of freeboard).

The difference is that tonnage increase on wet navy ships can be completely due to the added weight of upgrades displacing more water, as ship's tonnage is defined by the water they displace. Spaceships and starships tonnage is more fixed.

That said, expanding engineering spaces should be possible - but from history making major modifications to ships can result in a ship which is much more expensive than just building a new one: The postwar rebuilding of HMS Victorious being a case in point, the cruisers HMS Tiger and Blake being another.

 

[Theophilus]

Well, I was cleaning my desk and I came across my original TL14 Kokirraks design, I'll post it here for Hans.

Hull 200kton                           Cost 12,000
Armor-12 13%  -26000 tons            39,000
Jump-3 34%     -68000                  32,000
Man-6 17%      -34000                   17,000
Power-8 16%    -32000                   96000
Pn Fuel            -16000
Bridge 2%         -4000                     1000
Total 90%      -180000                197,000 MCr

Weapons:
Meson-Q              -7000                      1000
20 100 ton Rep-8  -2000                      220
100 50 ton           -5000                        50
    50 FG-8                                           400
    50 Msl-9                                          600
730 Hp                 
    250 Trp SC-7      -250                        187.5
    400 Trp BL-9      -400                       1200
     80  Sng PA-7     -240                        240

ND-6                      -24                         50
Msn-6                     -12                       1200

Comp 8fib              -22                         140
Total:                  -14984                     4125.5

793 Stateroom        -3172                      396.5
Purif Plant              -1480                        10.36
Scoops                                                   200

Total: 199636 tons (364 remain)   Total Cost: 201732.36

Weapons and Screens consume -6369 EP
Remaining EP allow Agility 4.89631 Ag-4

BB S4368H4-C76608-987Q9-0 TL14 200000tons

25 Battery Sandcaster-7
20 Battery Repulsor-8
40 Battery Beam Laser-9
50 Battery Fusion Gun-8
50 Battery Missile-9
8 Battery Particle Accelr-7
Crew 1580
16000 EP

Or: you can reduce the PN to 7, and get 6000 more tons for cargo/small craft. This reduces the crew by 40, and total staterooms to 773. Agility reduces to 3.8 (agility-3)

BB S4367H4-C76608-987Q9-0 TL14 200000 tons
Cost 189722.36 MCr
EP 14,000

Please note reducing PA turrets to 80 removes 500 tons from weapons vs TL 15 Kokkiraks

 

[McPerth]

Trillion Credit Squadron Page 34 Refitting Ships fifth paragraph:
"The degree to which a ship may be changed is limited. Power Plant, M drive, J drive, and spinal mount weaponry may not be increased in tonnage."

I quess that nix's the reduction of a Kokirraks Maneuver drive to M4.

Supplement 5 Lightning Class Cruisers Pg 3, paragraph 1:
"Carrying the most advanced ship-board main armamenet and defensive systems then available, the AHL and the sister ships of this new class became the most cost effective addition to the Imperial arsenal in dedades."

Another thing to consider is the effectiveness of secondary weaponry against the lightly armored cruisers found in Supp9.
The Ghalalk- armor 5, Azhanti- armor 5, SEH- armor 0, Arakoine- armor 0. Only the Atlantic class has decent armor.

Looking at the ship damage tables in HG:
Apply armor as a DM, and add +6 for factor 9 or less weapons allows-
SEH and Arakoine: Weapon-3, Maneuver-1, Fuel-2, Weapon-2, Maneuver-1 hit on rolls of 2-6. or secondary lasers and fusion/plasma guns and missiles render ships combat ineffective very quickly.

Ghalalk and Azhanti: Minimum roll (A5+6+2=13) no maneuver hit's ship runs away.

Atlantic and Plankwell armor 10, +6, +2=18 Role 2-5 minor damage, role 6+ no effect. mostly immune to secondary weaponry.

Compare to Kokirraks (armor 12) Tigress (armor 15): 12+6+2=20 on a roll of 2 or 3 minor weapons hit, Tigress is immune to all secondary weaponry.
Even a spinal Particle Accelerator has a hard time killing a Tigress since the +15 armor gives a minimum roll of 17, and only a roll of 4 hits fuel, the weapon-1 hits really don't reduce combat effectiveness till you've gotten 532 of them!

Anyway, back to Drop tanks.

How many aircraft in WWII were equiped with drop tanks to increase range?
How many tanks were carried and dropped, being lost and needing repacement?
Why do we still use drop tanks on modern aircraft if dropping them is cost ineffective?

About your combat analysis, just let me say a cupple of things:
- You assume pulse lasers are not used. THe fact that they make poorer batteries than beam lasers makes one to think so, but never forget about this wonderful -2 to combat damage, that gives you a slighty higher chance to do seccondary damage (in the case of pankwells you told about, the chance goes to 2-7, so over 50% chance of doing some minor damage). I also assume that when big ships go to battle, they mostly use nuclear missiles, so the +6 for smaller than 9 factor is offset and they can do secondary damage .
- I think the most important defenses of a warship is agility and computer: as we saw earlier, once a spinal meson hits, you're dead, so the best way to avoid that is by avoiding being hit. To avoid that, the best options are hight agility and big computer. That makes maneover hits quite important, as they reduce your agility and let the spinals make ther work. This is the true advantage I see from BB over smaller ships, they can fire lots of secondary batteries, having a better chance to reduce your agility, before using ther big spinals and cripple your ship. Spinals, while usually have better to hit numbers, shoot only once, so are less effective against hight agility ships. I don't talk about computer hits because most of them are on the radiation table, and I assume most of capital ships have fib computers.

And, about drop tanks (the true subject of this thread, I think to remember):

Yes, many aircraft use drop (or at least external) fuel tanks since WWII, but don't forget you only have to have them on their bases, knowing where to take them to be used, so easing quite a lot logistical matters.
In traveller, just having them on your bases won't help you much, unless moving reserves (see my previous entry), and not at all if you are on the offensive (so, little use for jumping to an hostile system to have fuel to jump out if needed).

 

[PFVA63]

...
Yes, many aircraft use drop (or at least external) fuel tanks since WWII, but don't forget you only have to have them on their bases, knowing where to take them to be used, so easing quite a lot logistical matters.
In traveller, just having them on your bases won't help you much, unless moving reserves (see my previous entry), and not at all if you are on the offensive (so, little use for jumping to an hostile system to have fuel to jump out if needed).

Hi,

Other issues to me about using drop tanks in Traveller also include just normal peacetime ops as well. For instance, if you wanted to transfer a squadron of regular Azhanti high Lightnings from Rhylanor to Jewell there are a couple of different paths that should get you there in about 5 jumps (ranging from Jump 4 to Jump5 each). If however, these AHLs were outfitted with drop tanks then transferring them could be more complex if they have to take the tanks with them.

Specifically, if I am understanding correctly the size of the fully loaded ship would go from 60,000 to 93,000 dtons (which in High Guard terms actually makes it a Type R or ~100,000 dtons ship) , and as such with drop tanks attached I think that the max Jump drops to 2(?) instead of 5, making for a much longer trip.

(I suppose that you could leave the drop tanks somewhere along the way and assume that new tanks can be assembled for you at Jewell once you get there - but that seems kind of backwards to me).

Regards

PF

 

[McPerth]

Hi,

Other issues to me about using drop tanks in Traveller also include just normal peacetime ops as well. For instance, if you wanted to transfer a squadron of regular Azhanti high Lightnings from Rhylanor to Jewell there are a couple of different paths that should get you there in about 5 jumps (ranging from Jump 4 to Jump5 each). If however, these AHLs were outfitted with drop tanks then transferring them could be more complex if they have to take the tanks with them.

Specifically, if I am understanding correctly the size of the fully loaded ship would go from 60,000 to 93,000 dtons (which in High Guard terms actually makes it a Type R or ~100,000 dtons ship) , and as such with drop tanks attached I think that the max Jump drops to 2(?) instead of 5, making for a much longer trip.

(I suppose that you could leave the drop tanks somewhere along the way and assume that new tanks can be assembled for you at Jewell once you get there - but that seems kind of backwards to me).

Regards

PF

But they needn't to carry them attached if you have preplanned drop tanks chaches for moving reserve forces (see my second entry on Dec 8th, page 14 this thread).
In the same example you say, your azhanties jump from Rhylanor using drop tanks to Echiste (2313), from there, using internal fuel, to Regina (1910), where the naval base (warned of their arrival by courriers sent before the azhanties leave Rylanor) has ready drop tanks to attach to your azhanties. Using those drop tanks, they jump to 1407 (void hex), from where they jump using again internal fuel to Jewell.
So, the use of presituated drop tanks on your naval bases (only) your 5 jumps have been reduced to 4: a 20% time response reduction.
By the way, for a fast courrier (jump 6) to go from Jewell to Rylanor to ask for those reserves, the route without drop tanks is 4 jump long (e.g. Jewell to Alell (1706), from there to Yurst (2309) or Yori (2110), to Fulacin (1613)and finally to Rylanor. This same message with drop tanks takes 3 jumps: from Jewell (usng drop tanks) to 1709, from there (internal fuel) to Kkirka(2212), GG refueling and to Rhylanor. 33% time saving.
See that your ships only used drop tanks at naval bases, where they are prepositioned, so, should they be reusable (as TL14+ are in MGT), your expense for using them is nil. If not, your expense I think is affordable if you need those azhanties 'quickly' on Jewell (2 weeks saved from asking to arrival, and even so they take 7 weeks plus time to ready them and refuellings (say one or two days per jump, so another week or two if using drop tanks and some days more if not using them).

By the way, in your example, the drop tanks need to be just the jump fuel (30000 dton), pushing your ship to 90000 dton, so with 3600 dton jump drive, it could do jump 3.

 

[Dragoner]

I still see strategic tanker fleets being more cost effective in the long run, particularly if subsidized as commercial tankers during peacetime. Drop tanks would seem to be a hazard to navigation after thousands of jumps, plus if they are jettisoned by explosive bolts, they would have to be remanufactured and reinstalled by capable technicians. Depending on the extra fuel they would supply might be a disadvantage if the fleet becomes involved in a series of running battles where reinstallation may become an issue.

 

[Selandia]

Drop tanks would seem to be a hazard to navigation after thousands of jumps, plus if they are jettisoned by explosive bolts, they would have to be remanufactured and reinstalled by capable technicians.

True, that is the problem of the CT OTU, unless the referee impose non canonical constraints (see some of the early posts), cost of drop tank is 10KCr/tank+1,000 Cr a ton (plus filling) and that is supposed to take everything into account, including orbital garbage handling and cost of fitting. Of course yard time for fitting is taken as 0 hrs with yards always available. HG treat them as nothing more complicated than Book 2 missile reload. Unless the Referee step in, the L-Hyd dropable in CT are seriously broken.

Depending on the extra fuel they would supply might be a disadvantage if the fleet becomes involved in a series of running battles where reinstallation may become an issue.

Sure, if the Referee impose constraints that are not spelled in A5 or HG. If he does so, the situation become akind to the one of the merchants. The commercial liner services, that are moving between points were facilities have been setted up to handle the situation, use tank or jump tankers like the Fleet's logistical operation or the positionning of its ships. Offensive operations, moving out of your comfort zone become like free trading, somewhat uncertain about what is next. This may explain why warship should never totally droptank dependants.

Selandia

 

[Dragoner]

Interesting thoughts.

I think a navy would not like uncertainty in it's logistical operations. I could also see a high jump traffic world banning the use of drop tanks, or otherwise the taxation becomes prohibitive.

I know the Navy moved from a Defense in Depth strategy to a Mobile Defense strategy. Even with the more centralized fleets, there still would be the need for tanker fleets, thus drop tanks do seem an extra expense. The logistics follow the strategy, though as the old saying goes: "you can lose a battle and still win a war, if you lose supply, you lose the war."

 

[PFVA63]

Hi

But they needn't to carry them attached if you have preplanned drop tanks chaches for moving reserve forces (see my second entry on Dec 8th, page 14 this thread).
In the same example you say, your azhanties jump from Rhylanor using drop tanks to Echiste (2313), from there, using internal fuel, to Regina (1910), where the naval base (warned of their arrival by courriers sent before the azhanties leave Rylanor) has ready drop tanks to attach to your azhanties. Using those drop tanks, they jump to 1407 (void hex), from where they jump using again internal fuel to Jewell.
So, the use of presituated drop tanks on your naval bases (only) your 5 jumps have been reduced to 4: a 20% time response reduction.
By the way, for a fast courrier (jump 6) to go from Jewell to Rylanor to ask for those reserves, the route without drop tanks is 4 jump long (e.g. Jewell to Alell (1706), from there to Yurst (2309) or Yori (2110), to Fulacin (1613)and finally to Rylanor. This same message with drop tanks takes 3 jumps: from Jewell (usng drop tanks) to 1709, from there (internal fuel) to Kkirka(2212), GG refueling and to Rhylanor. 33% time saving.
See that your ships only used drop tanks at naval bases, where they are prepositioned, so, should they be reusable (as TL14+ are in MGT), your expense dor using them is nil. If not, your expense I think is affordable if you need those azhanties 'quickly' on Jewell (2 weeks saved from asking to arrival, and even so they take 7 weeks plus time to ready them and refuellings (say one or two days per jump, so another week or two if using drop tanks and some days more if not using them).

By the way, in your example, the drop tanks need to be just the jump fuel (30000 dton), pushing your ship to 90000 dton, so with 3600 dton jump drive, it could do jump 3.

Hi,

I hope I haven't come across as too negative in my posts because I think its important that everyone play the game they way they want, and if that includes drop tanks for warships, they should be allowed to do so.

However, for me, with regards to drop tanks, for all the possible benefits for using them on warships there seem to me to be more potential drawbacks, as have been posted previously.

For the example I posted before, what if part way to Jewell orders come through diverting part of the squadron to Efate or Pixie. Do we assume that drop tanks will be availble there as well. Or for that matter, what if instead the squadron were deployed to Asurus, 728-907, Nakege, or some other system with a "D" type starport where it may not be possible to locally build tanks. In those cases it would seem that either the squadron would have to pick the tanks up somewhere or somehow tanks would have to separately be transferred in system.

Then there is the added issue of what type of drop tanks each ship uses. Can tanks from one ship be interchanged with those from another class? Specifically,are the tanks for an AHL the same as or completely different from those for a Plankwell? What then about the Fer De Lance class?

Do we instead assume that there are a certain set limited sizes of standard tanks that can be used? If so, would they fit different types of ships (ie streamlined vs nonstreamlined, close structure vs open structure, spherical vs cylindrical, etc)?

I guess kind of one of the issues in my mind is that for merchant ships on a set schedule, maybe drop tanks would work potentially pretty well *, but for naval vessels, whose schedule and deployments may be much more irregular, its hard for me to see how drop tanks would be off use most the time, as per my previous example. I guess I could see how they might be advantageous for an occasional special operation, but for normal ops they would seem to be disadvantageous as they leave you with a ship that kind of maneuvers like a cow.

Regards

PF

* Maybe they might even be useful for X-boats, etc