LBB2 M-Drives in LBB5: When does it help?

[mike wightman]

Lol, very true.

But easily solved with a look up table for hull displacement modified by configuration to hardpoints determined by the square cube law application.

And since LBB2 doesn't worry about configuration it is easier still

 

[AnotherDilbert]

But easily solved with a look up table for hull displacement modified by configuration to hardpoints determined by the square cube law application.

Sigh, another table...

Well, the table is in MT if you care to house-rule it.

 

[mike wightman]

Look up tables are very common in engineering, and it is often faster to use than to calculate.

 

[kilemall]

My solution is that LBB2 ships are recalced for EP and wedge in tiny capacitors, the basic combat to hits are LBB5 but adjusted for a per 100k negative weapon rating, and a custom damage table that does damage by tonnage based on EP hitting. Missiles can go up in damage rating depending on relative impact vee and armor either deflects or penetrates.

 

[Grav_Moped]

You don't think it's a bit ironic to defend a system by saying it needs to be house-ruled to be reasonable?

LBB5 drives, as adopted by most(?) later editions, works perfectly from small craft to megaton behemoths, without need for constant tweaking by house-rules.

Not at all. Using a lookup table is simpler for the math-challenged.

I view the table as listing what's commonly commercially available, while its underlying formulae describe what's technologically possible. They didn't explain the math that built the table because they were maximizing simplicity.


(Subsequent post)

I was perhaps a bit sloppy; I meant percentage based drives, rather than lettered drives. I did not mean the percentages were identical to LBB5.

Again, the thing about LBB2 isn't really that the "lettered drives" are point cases of underlying formulae, it's that the formulae are different from those in LBB5. LBB2 includes a constant component in the formulae (+5Td for jump, +1Td for power, -1Td for maneuver) plus a percentage, where LBB5 uses a flat percentage. As you approach the upper end of the LBB5 hull sizes, those constants become effectively irrelevant and it may as well be a flat percentage.

Then you get to Drives W-Z and "LOL nothing matters".

Re: 10Td/Pn fuel requirement:

That is only a problem for very small ships, large ships thrive on it... Even at 400 Dt a PP-4 only needs as much fuel as a J-1, hardly a fundamental flaw.

I see it more as a part of the crippling of small ships that is at the core of LBB2, presumably intentionally.

It's not that it's a problem for very small ships, it's that it's broken, rooted an unrealistic (or perhaps more accurately, implausible) first edition fuel consumption rule that was entirely abandoned in both editions of High Guard and its basis never used for design rules after LBB2'81. The thing is, though, that fuel use couldn't just be fixed in isolation because it was the constraint on maneuver drive capability (though in LBB2'81, it was only really constraining Gs above Jn). If fuel use was set to HG rates, building 6G ships would be easy with LBB2 maneuver drives (though perhaps expensive). And it'd break or seriously distort larger LBB2 ships. The fix adopted for HG was simply to make maneuver drives larger -- but applying that to LBB2 would break all previously-published designs from that system.

 

[Condottiere]

Engineering and armour plating are linear.

So essentially, the interior spaces and weights of large spacecraft are in relative terms the same.

 

[Dragoner]

We have books filled with tables, easier to look up, and tell it is in spec, as well as many engineering equations do not work in reverse.

 

[Grav_Moped]

Engineering and armour plating are linear.

So essentially, the interior spaces and weights of large spacecraft are in relative terms the same.

The ratio of surface area to volume decreases linearly by increased volume, so armor mass should decrease in percentage of ship mass in larger ships. Rules don't reflect this. (It would be roughly correct, however, if all ships were subdivided into equal-sized compartments divided by bulkheads and decks of the same thickness and composition as the hull's exterior plating.)

 

[Grav_Moped]

We have books filled with tables, easier to look up, and tell it is in spec, as well as many engineering equations do not work in reverse.

Well, they do, once you chase down all the places in the equations where taking nth roots yields nonsense information (object measurements in negative centimeters, for example, or imaginary numbers). In practice this often isn't practical, and may not even be possible.

 

[Dragoner]

Well, they do, once you chase down all the places in the equations where taking nth roots yields nonsense information (object measurements in negative centimeters, for example, or imaginary numbers). In practice this often isn't practical, and may not even be possible.

One of my profs in school liked to use the example of projectile motion, never would it return on the same path (sometimes it actually does). However, with the tabular data, you can say you took it from x statistics book, and the inspector will just nod, vs saying you did the math, which can raise an eyebrow. It is faster too.

 

[mike wightman]

Imaginary numbers are really important when doing the calculations required for quantum stuff - so imaginary numbers in our maths do actually have meaning in the real world.

 

[Grav_Moped]

Imaginary numbers are really important when doing the calculations required for quantum stuff - so imaginary numbers in our maths do actually have meaning in the real world.

True, though slightly orthogonal to my point.

 

[mike wightman]

I will put it another way.
If you discover a maths formula that describes something and it works then great, use it. Newton's law of universal gravitation for example, or letter drive progression.

If your formula can not describe the extremes then your formula is wrong at those extremes and needs revision and any subsequent formula has to get the same results as the original when faced with the non-extreme parameters of the original. For example General Relativity.

 

[boomslang]

There is a rule in Mayday that really should be in LBB2 - the evade program DM costs you maneuver g rating on a one for one basis.

As I read that rule, it is a maximum 1G price for any amount of evasion. This would (for example) let a stock Free Trader get the full -2 DM from the Auto/Evade program at the cost of its 1G of acceleration -- meaning it pretty much has to coast and maybe cast sand whilst evading.

The other nice game effect is that a 6-G ship being pursued can choose to dodge the pursuer's lasers at up to -5 DM (for example and as per Maneuver/Evade-6) and at 5Gs or try to keep pace with pursuing 6-G missiles so they do not close range, but the ship cannot do both simultaneously.

That spices things up without completely upsetting game balance, in my experience.

 

[Murph]

What I did that made a big big difference and actually made space commerce viable was reduce fuel consumption to 5%/Jump number vs 10%/jump number. Try it and see how it works for you. It made the 200 ton Beowulf class actually viable.

 

[Condottiere]

If the spacecraft can't pay for itself, it doesn't make commercial sense to build and/or operate it.

And then you have government subsidies.

 

[infojunky]

What I did that made a big big difference and actually made space commerce viable was reduce fuel consumption to 5%/Jump number vs 10%/jump number. Try it and see how it works for you. It made the 200 ton Beowulf class actually viable.

Actually the power plant fuel fix is good enough fix the problem...

 

[Murph]

Actually the power plant fuel fix is good enough fix the problem...

What is that one please?

 

[infojunky]

What is that one please?

For book2 use M*Pn*0.01 instead of Pn*10.

As per Both editions of Book5.

 

[Grav_Moped]

For book2 use M*Pn*0.01 instead of Pn*10.

As per Both editions of Book5.

Traveller 5 modifies that with TL Stage Effects, but that's the rate at standard TL -- unless I'm misreading something and starship power plants are "centralized" in which case the standard rate is 2%/Pn (and how does a "decentralized" starship power plant even work?)

2% "feels" more correct for LBB2 drives IMHO, but I haven't really fiddled around with that to see how it affects what's possible.