Jump 6 cruiser?

[rancke]

Is there an Imperial jump-6 cruiser class mentioned anywhere in canon?


Hans

 

[Swiftbrook]

Don't shoot the messenger ....

From MT Fighting Ships of the Shattered Imperium, p. 52 & 53: CJ-15 Cruiser Imperial

 

[rancke]

Don't shoot the messenger ....

From MT Fighting Ships of the Shattered Imperium, p. 52 & 53: CJ-15 Cruiser Imperial

Don't worry, I'm prepared to glean my nuggets from the most dross-like of dross. But I was looking for a class name, so that I could make up a name for a particular ship. (Though stats would also be appreciated, e.g. tonnage, hull configuration, armament).


Hans

 

[mike wightman]

There is the jump 6 cruiser counter in FFW; you can get an idea of configuration and armament from the counter stats, which then allows an estimation of tonnage in HG2 terms.
4-2-8, fully streamlined.
Meson spinal (N?), limited missile bays and/or fighters, maximum screens and defensive batteries - I'd estimate something in the 50-70kt range.

 

[Carlobrand]

I've never encountered a class name for a J6 cruiser in CT/MT canon. Maybe there's something in GURPSville or Mongooseland.

 

[pendragonman]

Mongoosia. It's Mongoosia.

 

[Carlobrand]

As to design:

Mandated (TL15):
Bridge 2%
Jump drive 7%
Power Plant 6%
Jump Fuel 66%

81% of the ship is spoken for in the effort to achieve J6. 19% remains for maneuver, weapons, armor, screens, power plant to power that, fuel for that plant, and crew. Maneuver 6 is out of the question: 17% of the ship in drives, you're basically left with crew and maybe a few turrets. You can make a workable scout destroyer on that model but not anything that could stand as a cruiser.

Near as I can figure, you're looking at a variant on the Azhanti High Lightning fleet intruder - high jump, little armor, weak maneuver drive, intended to go deep behind enemy lines but not really up to a toe-to-toe fight against a well-armed cruiser. I'd go with a Meson-J, smallest TL15 meson spinal, and it'll have to be pretty big to support that spinal and still do J6.

Either that, or - and maybe your best bet - you're looking at a Jump-6 battle tender that can carry a decent light rider into the fray. At TL15 you can wrap an 8000 dT battlerider around a J-meson and give it agility 6 and max armor. (I refer to them as J-class, after the weapon, and they all get names starting with J, after the Brit convention for naming certain destroyers.) Secondary weapon load is light, but its size advantage helps offset the weak point defense weapon array, the tender's turrets can supplement for ground attack for worlds without significant planetary defenses, and the squadron's probably not up to tackling worlds with significant planetary defenses anyway since those will also have significant SDB defenses.

I can put one J-class rider on a 75,000 dT battle tender - there's not room for much more after making it jump-6 capable. Of course, you can make a bigger tender, but I prefer not to put all my eggs in one basket, lest an unlucky event leave my eggs without a basket.

One possible design, then:

Class: 8000t J-class Light Battle Rider
Tech Level: 15

USP BR-H106NJ8-F99905-957J7-0 MCr 10,499.000 8 KTons
Bat Bear..............1.....1.27111 Crew: 101
Bat.....................1.....1.27111 TL: 15

Cargo: 2; Crew Sections: 8 of 13; Fuel: 1,760; EP: 1,760; Agility: 6;
Shipboard Security Detail: 8
Fuel Treatment: Fuel Scoops
Backups: 1 x Model/9fib Computer; 1 x Bridge; 1 x Factor 9 Nuclear Damper; 1 x Factor 9 Meson Screen

Architects Fee: MCr 104.990 Cost in Quantity: MCr 8,399.200

Detailed Description
(High Guard II Design)

HULL
8,000.000 tons standard, 112,000.000 cubic meters, Needle/Wedge Configuration

CREW
18 Officers, 83 Ratings
Book 5 Crew Breakdown
Command section: 7 officers and 4 ratings; Engineering section: 4 officers and 28 ratings; Gunnery section: 4 officers and 29 ratings; Service section: 2 officers and 14 ratings, 8 security; Medical Section: 1 officers and 0 ratings

ENGINEERING
Jump-0, 6G Manuever, Power plant-22, 1,760.000 EP, Agility 6

AVIONICS
Bridge, Model/9fib Computer
1 Backup Bridge, 1 Model/9fib Backup Computer

HARDPOINTS
Spinal Mount, 1 50-ton bay, 57 Hardpoints

ARMAMENT
Meson Gun Spinal Mount (Factor-J), 10 Triple Missile Turrets organised into 1 Battery (Factor-7), 20 Triple Beam Laser Turrets organised into 2 Batteries (Factor-9), 7 Single Fusion Gun Turrets organised into 7 Batteries (Factor-5), 10 Particle Accelerator Turrets organised into 1 Battery (Factor-7)

DEFENCES
1 50-ton Repulsor Bay (Factor-5), 10 Triple Sandcaster Turrets organised into 1 Battery (Factor-9), Nuclear Damper (Factor-9), Meson Screen (Factor-9), Armoured Hull (Factor-15)
1 Nuclear Damper Backup (Factor-9), 1 Meson Screen Backup (Factor-9)

CRAFT
None

FUEL
1,760 Tons Fuel (0 parsecs jump and 28 days endurance)
On Board Fuel Scoops, No Fuel Purification Plant

MISCELLANEOUS
53 Staterooms, 2 Tons Cargo

USER DEFINED COMPONENTS
None

COST
MCr 10,603.990 Singly (incl. Architects fees of MCr 104.990), MCr 8,399.200 in Quantity

CONSTRUCTION TIME
156 Weeks Singly, 125 Weeks in Quantity

carried by a

Class: 75000t J6 Battle Tender, Intruder
Tech Level: 15

USP BTI-Q7626JZ-009900-95707-1 MCr 50,974.200 75 KTons
Bat Bear.........................771.7 Crew: 454
Bat................................AA1.A TL: 15

Cargo: 87; Crew Sections: 75 of 7; Fuel: 49,500; EP: 4,500; Agility: 2;
Marines: 44
Craft: 1 J-class battlerider, 2 x 50T Cutters, 2 x 400T Fuel Shuttles, 4 x 20T Marine APCs, 10 x 10T Scout Fighters
Fuel Treatment: On Board Fuel Purification
Substitutions: Z = 75

Architects Fee: MCr 506.522 Cost in Quantity: MCr 40,843.760

Detailed Description
(High Guard II Design)

HULL
75,000.000 tons standard, 1,050,000.000 cubic meters, Dispersed Structure Configuration

CREW
42 Officers, 358 Ratings, 10 Pilots, 44 Marines
Book 5 Crew Breakdown
Command section: 7 officers and 31 ratings; Engineering section: 14 officers and 121 ratings; Gunnery section: 4 officers and 36 ratings; Flight section: 1 officers, 10 pilots and 34 ratings; Service section: 15 officers and 135 ratings; Medical Section: 1 officers and 1 ratings; Marines: 44

ENGINEERING
Jump-6, 2G Manuever, Power plant-6, 4,500.000 EP, Agility 2

AVIONICS
Bridge, Model/9fib Computer

HARDPOINTS
220 Hardpoints

ARMAMENT
100 Triple Missile Turrets organised into 10 Batteries (Factor-7), 100 Triple Beam Laser Turrets organised into 10 Batteries (Factor-9), 10 Single Fusion Gun Turrets organised into 10 Batteries (Factor-5), 10 Particle Accelerator Turrets organised into 1 Battery (Factor-7)

DEFENCES
Nuclear Damper (Factor-9), Meson Screen (Factor-9)

CRAFT
1 8000.000 ton J-class battlerider (see above), 2 50.000 ton Cutters (Crew of 2, Cost of MCr 17.680), 2 400.000 ton Fuel Shuttles (Crew of 2, Cost of MCr 88.320), 4 20.000 ton Marine APCs (Crew of 0, Cost of MCr 5.600), 10 10.000 ton Scout Fighters (Crew of 2, Cost of MCr 8.760)

FUEL
49,500 Tons Fuel (6 parsecs jump and 28 days endurance)
No Fuel Scoops, On Board Fuel Purification Plant

MISCELLANEOUS
230.5 Staterooms, 87 Tons Cargo

COST
MCr 51,158.722 Singly (incl. Architects fees of MCr 506.522), MCr 40,521.760 in Quantity, plus MCr 322.000 of Carried Craft

CONSTRUCTION TIME
195 Weeks Singly, 156 Weeks in Quantity

 

[Swiftbrook]

As to design:

Mandated (TL15):
Bridge 2%
Jump drive 7%
Power Plant 6%
Jump Fuel 66%

Wow 66% for JD fuel! You could go with a MT design instead. 35% Jump Fuel in MegaTraveller. Shoot, CT is only 60% for Jump Fuel. Haven't looked at the new rule system but I'm really surprised they increased the amount of fuel needed for jump.

 

[rancke]

Wow 66% for JD fuel! You could go with a MT design instead. 35% Jump Fuel in MegaTraveller. Shoot, CT is only 60% for Jump Fuel. Haven't looked at the new rule system but I'm really surprised they increased the amount of fuel needed for jump.

It's 60% jump fuel and 6% [<shudder>] power plant fuel.


Hans

 

[McPerth]

Wow 66% for JD fuel! You could go with a MT design instead. 35% Jump Fuel in MegaTraveller. Shoot, CT is only 60% for Jump Fuel. Haven't looked at the new rule system but I'm really surprised they increased the amount of fuel needed for jump.

In all Traveller versions I know but MT, Jump fuel is 10% tonnage per jump number (in MT it was 5% x (JN+1). This made posible in MT some ships absolutely imposible in other paradigms (as a J5 ship with fuel for 2 consecutive jumps).

See that this broke the canon in some ways (as allowing the Great rift to be crossed, or making the Islands not so isolated).

 

[Carlobrand]

Wow 66% for JD fuel! ...

Okay, okay, one wrong word ...sigh. Yes, it's total fuel, not jump fuel. Fixed now.

In all Traveller versions I know but MT, Jump fuel is 10% tonnage per jump number (in MT it was 5% x (JN+1). ...

I suspect that was done to alter the jump economics for the longer-range ships. Never got around to calculating the impact. I suspect Aramis has something on it someplace. What would be wild would be to retrofit that to CT.

Of course, there were always ways to push limits for reaching across the Rift. J6 plus drop tanks clears 12 parsecs. I also once mentioned filling a J1 tanker with water, all but what was needed for the J1 and power plant fuel, then cracking the water as you went. Water delivers 50% more H2 per liter than LHyd does. So your million-ton rift tanker has a 110,000 dTon LHyd fuel tank and 800,000 dTons of water supplying 1.2 million dTons LHyd. It crawls partway and then serves as a deep space gas station for smaller crossers.

There's also this.

http://www.travellerrpg.com/CotI/Discuss/showthread.php?t=33690&highlight=hydrogen

 

[mike wightman]

It was done because the folks at DGP set themselves the task of basing their ship design rules off Striker numbers.

When they found fuel for power plants was way over CT/HG2 requirements their solution was to reduce jump fuel and thus alter a major setting element.

The fuel rules remained broken hence the rules were fudged to allow building different power plants to power different systems, and fuel was only required for operational endurance.

Later MT capital ship designs may only have enough fuel for a day of combat.

 

[WistfulD]

It was done because the folks at DGP set themselves the task of basing their ship design rules off Striker numbers.

When they found fuel for power plants was way over CT/HG2 requirements their solution was to reduce jump fuel and thus alter a major setting element.

The fuel rules remained broken hence the rules were fudged to allow building different power plants to power different systems, and fuel was only required for operational endurance.

Later MT capital ship designs may only have enough fuel for a day of combat.

Can you elaborate a little more on this?

 

[Carlobrand]

Can you elaborate a little more on this?

His conclusions are based on an examination of MegaTraveller's ship design system in MT's Referee's Manual. You'd need to review that book for details but, as he said, the power plant design rules are more or less a lift from Striker's power plant design rules (with some tweaks to fossil-fuel-burning engines, if I recall), and the jump fuel rules demand less fuel than is the case in CT Book-2 or High Guard. MT also did not specifically require a spaceship to carry 30 days of fuel. Also did not specifically prohibit multiple power plants. The "fudge" he was talking about arose from a suggestion in a Traveller's Digest article (#13?) pointing out that, since weapons were only used in battle, one could use less fuel by designing a ship with one power plant serving drives and other systems needing power 24/7 and a separate power plant that was kept "warm" but only brought on line when battle was imminent to serve the immense power needs of the weapons.

 

[WistfulD]

I see. That does seem to be the dominant difference in ships between MT and the others--MT wants you to have two jumps worth of fuel, the others want you to have one.

 

[McPerth]

I see. That does seem to be the dominant difference in ships between MT and the others--MT wants you to have two jumps worth of fuel, the others want you to have one.

Is not that. Is that in MT fuel needs for PP are quite high, while the jump fuel is lower than in other version (for what I've read here, they lowered it to compensate the larger needs for PP). The fact that this allows to carry fuel for more than a single jump even at J6 is a side effect (more so as the JD did not use power from the PP, so you could enlarge your JD without enlarging the PP).

 

[WistfulD]

Which makes sense. Whatever the J drive is doing with that hydrogen, it is clearly using that to do all the high-energy stuff that the J drive needs to do to cause interstellar transit. The drive undoubtedly uses shipboard power to run some systems (and as such, can't work if the PP is disabled), but those aren't the kind of things that would vary based on the jump distance.

 

[McPerth]

Which makes sense. Whatever the J drive is doing with that hydrogen, it is clearly using that to do all the high-energy stuff that the J drive needs to do to cause interstellar transit. The drive undoubtedly uses shipboard power to run some systems (and as such, can't work if the PP is disabled), but those aren't the kind of things that would vary based on the jump distance.

In CT, it's clear the JD needs the PP, as a ship cannot have a jump capability greater tan the PP's, but in MT (and, IIRC, other versions too) they are fully independent (or nearly so), and while you need a PP for the life support, MD, sensors, computer, etc..., you don't need it for your JD.

As I understand it, in MT you could jump without an operative PP, as long as you can power you computer (the only PP fed item needed for jumping) from batteries, to give you an example. Of course, the lack of operative MD would mean your jump vector cannot be choosen, so I guess missjump is (at least) very likely...