The Compleat LBB2 Ship Design

[robject]

LBB2 ship design is officially larger than its official section in Book 2 or Starter Traveller or The Traveller Book.

This bout of insanity came on when we were talking about the Gazelle. I brought up the Xboat, the Scout, the ANNIC NOVA, and the Gazelle, to which it was argued that they are permitted under one set of rules or another -- '77 and onwards.

So now I want to bring in some of those published elements that expand LBB2 ship design, and get them into a LBB re-do if possible.

Note on Navy and Scout ships.

• Navy ships get a -1 DM on misjumps, Scout ships get a -2 DM on misjumps. '81 p11 or TTB 55.
• Both have 4x the detection range of other ships. '81 p32 or TTB 76.
• "Naval" and "Scout" ships are only defined as neither "ordinary" nor "commercial", thus the decision is not based on ship design.

POTENTIAL OFFICIAL EXPANSIONS

Name	Reference	Tons	Credits	Notes
5 ton Particle Accelerator barbette	JTAS 4 p19	5	4,000,000	Gazelle
Radiation Damage Table	SS3 p15	-	-	Non-revised SS3
Fuel Scoops for ocean refueling (rule)	HG80	-	-	= Ten times slower.
Four Alternate Types of Fuel Tankage	TCS pp13-14	var	var	-
Fuel Refineries	TCS p15	-	-	-
Orbital Refueling (note)	TCS p10	-	-	-
Dual Occupancy Staterooms	TCS p15	-	-	-
Nuclear Damper	JTAS 4 p19			Gazelle
Black Globe	AD01			Kinunir
Drop Caps + Launcher	AD01			Kinunir
Capture Tanks	AD10			Safari Ship

5 Ton Barbette. Grafted into Book 2 from HG. As "heavy" beam lasers with a DM+2 to hit. Most likely effect is 1 roll on the normal damage table, and 1 roll on the radiation damage table.

Radiation Damage Table. In the original SS3, a Book 2-style radiation damage table was given.

L-Hyd Drop Tanks. From HG'80, these cost Cr10,000 plus Cr1,000 per ton.

 

[mike wightman]

Off the top of my head and without actually looking stuff up this is a list of things found in 'LBB:2' ship designs - i.e. appeared in early adventures or supplements or proposals.
1. 10 ton bays that manifest as two 5t barbettes
2. allocate a cost for declaring a drive military grade
3. allocate a cost for declaring sensors as military grade
4. nuclear damper
5. armour
6. solar collector and accumulators in lieu of jump fuel tonnage.
7. hydroponics
8. workshops
9. black globe
10. drop capsule launcher and drop capsule ready area
11. ordnance magazine
12. holding pen
13. drop tanks
14. jump governor

 

[AnotherDilbert]

Scout-Grade J-Drives. Capable of burning unrefined fuel without penalty.

Don't forget power plants, also scout-grade needed to burn unrefined fuel without risk.

 

[AnotherDilbert]

1. 10 ton bays that manifest as two 5t barbettes (for the cost of 1 hardpoint, a bargain)

No hardpoint cost at all. The original Gazelle was, as far as I can tell, ~250 Dt with two hardpoints (w. turrets) and a bay.

 

[AnotherDilbert]

Military-Grade J-Drives. With high-capacity accumulators in the jump drive. Required to use L-Hyd Drop Tanks (JTAS 4 p19).

There is no "military-grade", it was just an addition to any jump drive:

LBB5'79, p32:
L-Hyd Tanks: Disposable fuel tanks which are fitted outside the ship, and drop away before jump. The result is more interior space available for cargo and passengers. Cost: Cr 10 000 plus Cr1000 per ton of fuel. Usable only with jump drives if a special high capacity accumulator is installed (tech level 12; Cr500 000).

That was dropped in LBB5'80, and never heard of again...

 

[AnotherDilbert]

Drop Caps + Launcher	AD01			Kinunir
Magazine	AD01			Kinunir

Drop capsules are defined in Striker, B2, p43. Slightly different from Kinunir, I believe.

Magazines are an optional feature in LBB5'79. Only used for planetary bombardment.

 

[mike wightman]

Note that the effects of the particle accelerator bay/twin barbette was prior to the release of the missiles special supplement that gives us a LBB:2 compliant radiation damage table and finally the effect of a crew hit. So you could probably say two damage results (like the pulse laser) one on the normal damage table and one on the radiation.

 

[AnotherDilbert]

If we look at LBB5'80, it should be less likely to hit than a laser, but be unaffected by countermeasures (sand), and as you suggest, do two hits.

Ignoring sand could make it viable?

 

[Spinward Flow]

Military-Grade J-Drives. With high-capacity accumulators in the jump drive. Required to use L-Hyd Drop Tanks.

Whut?

That was dropped in LBB5'80, and never heard of again...

@AnotherDilbert has it correct with respect to the accumulators, which disappeared along with Jump Governors (which appeared in LBB5.79 and got overwritten by LBB2.81).

In LBB2, naval grade drives get a -1 DM on misjumps ... and scout grade drives get a -2 DM on misjumps.
Use of unrefined fuel is a +1 DM on misjumps.
Throw 13+ to misjump.

So that is how naval drives can basically use unrefined fuel, because provided you're beyond 100 diameters 2D=12-1+1=12 ... which still isn't enough to misjump (requires 13+).

11. ordnance magazine

I've always considered it to be a sort of "unfair advantage" for missiles that they require no EP and no additional tonnage beyond the turret itself ... while lasers do require EP (and thus both power plant and fuel tonnage) without shortchanging Agility.

If you take the approach of 1 displacement ton is either 14m³ or 1000kg (whichever comes first) ... then 20 missiles or sand canisters at 50kg each adds up to 1000kg and defines the capacity per ton of a magazine.

 

[Grav_Moped]

That was dropped in LBB5'80, and never heard of again...

As was the Jump Governor as an add-on component for LBB2 drives. As Spin noted...

And I definitely agree that the lack of a magazine requirement for missiles is a serious oversight in the LBB5 rules.

 

[AnotherDilbert]

And I definitely agree that the lack of a magazine requirement for missiles is a serious oversight in the LBB5 rules.

I would call it a minor detail. LBB5 is way to abstract to count rounds. Turrets don't use all that many missiles, and bays presumably contain their own magazines?

Fixed armour percentages and the same armour on fighters and battleships is a major design "feature"... But it makes design and combat easy, so I can live with it.

 

[Grav_Moped]

I would call it a minor detail. LBB5 is way to abstract to count rounds. Turrets don't use all that many missiles, and bays presumably contain their own magazines?

Fixed armour percentages and the same armour on fighters and battleships is a major design "feature"... But it makes design and combat easy, so I can live with it.

LBB2 turret missile launchers have only three turns of ordnance (one in the launcher, two at the ready), after which they require reloading. HG turret missile launchers are functionally identical. In LBB2 (though the missile supplement might clarify this) there isn't a description of how much space a magazine requires, but it's clearly a non-zero amount.

 

[AnotherDilbert]

Agreed, but stacking half the size of a Sidewinder (~90 kg) in a 14 m³ magazine, we can fit quite a few.

Estimate: A missile is 50 kg, let's say 2 m long and 10 cm diameter. That is a volume of 2 × π × 0.05² ≈ 0.016 m³ per missile, let's call that 0.02 m³ as stored. So we can fit about 14 m³ / 0.02 m³ = 700 missiles in a Dt, or about 230 turns worth of ammunition for a triple turret.

OK, military LBB5 battles can be quite long, but an ACS battle is over long before that.


Now compare that 1 Dt to the 10-15 Dt armour and 20-30 Dt drives a warship needs for each 100 Dt = 1 hardpoint: Magazines are a minor detail.


Edit: Basic math...

 

[Grav_Moped]

That's a bit excessive.

A turret is 1Td, half of which is the control couch for the gunner, more or less (assume that this also includes the traverse/elevation mechanism). So, 9 missiles in half a ton of space in the turret. 18 missiles (6 salvos from a triple turret) per ton of magazine?

Crated missiles would store at a higher density, but would require unpacking and assembling to all-up-round configuration before loading.

 

[AnotherDilbert]

Formally a turret is just an inconsequential blister outside the ship. The fire control equipment takes 1 Dt.

Presumably that is just for practical reasons (ease of upgrading), but still...

18 missiles (6 salvos from a triple turret) per ton of magazine?

Missiles are tiny, displacement tons are huge. 18 missiles even in an autoloader are way to few...

 

[mike wightman]

I am of the understanding that what Rob is trying to do here is find everything included in a LBB:2 based ship design in canon that isn't actually in LBB:2.

So stuff mentioned in HG 79 or 80 is only fair game if it is included in a LBB:2 based design write up. We can use those rules to get an idea of cost, tonnage and rules.

The jump governor has to be included because it is mentioned in some ship descriptions eg the far trader in S7

 

[mike wightman]

The Leviathan has a 7fib computer so bis and fib models of 1 through 7 as mentioned in HG79. Sadly it also has a fuel refinery.
It also has external demountable fuel tanks, while internal demountable tanks are in the Traveller Adventure.

Meanwhile in Beltstrike we have:

A 25-ton mass driver system and a 400 ton processing bay are also installed.

 

[AnotherDilbert]

I am of the understanding that what Rob is trying to do here is find everything included in a LBB:2 based ship design in canon that isn't actually in LBB:2.

So not stuff from the Gazelle and Kinunir, as they are LBB5 designs?

 

[AnotherDilbert]

The Leviathan has a 7fib computer so bis and fib models of 1 through 7 as mentioned in HG79.

The Leviathan is presumably a LBB5 design, as it is armoured?

 

[mike wightman]

So not stuff from the Gazelle and Kinunir, as they are LBB5 designs?

Did you bother reading the rest of my post?

So stuff mentioned in HG 79 or 80 is only fair game if it is included in a LBB:2 based design write up. We can use those rules to get an idea of cost, tonnage and rules.