Jump Drive Efficiency Question

[mike wightman]

Economic base of Traveller?

You are joking now right?

People have been arguing about the economics of Traveller for longer than they have been discussing the changing ship paradigm.

We still don't know what the Imperial tax levy is, or how much the Imperial naval budget is.

As for the statement in the Kinunir, it is a reflection of the type of naval paradigm at work at the time. Even if it was one hundred Kinunirs (there are only fifteen left in Imperial service), they pale before the hundred kiloton monsters that were to come.

Funny how the civilian in that first adventure was unaware of all the AHL class cruisers and larger battleships that were really out there

The reason is they weren't there in the early Traveller universe.

It wasn't until High Guard and AHL that the "true" OTU was revealed to us.

Second edition CT was quite a major rewrite, and second edition High Guard is almost a new book. Try comparing editions side by side.

My guess is that the Gazelle, the Kinunir, and the AHL were produced from a work in progress copy of High Guard first edition.

Why it was replaced by High Guard second edition quite so quickly is a mystery, hopefully someone will one day enlighten us all as to what was considered so wrong with first edition.

Do I own Battle Rider?

Yes, I do.

Cheers.

Mike.

 

[Tobias]

Originally posted by Sigg Oddra:
People have been arguing about the economics of Traveller for longer than they have been discussing the changing ship paradigm.

Yes. And yes, there might even be people who totally refuse to see the basic scale we're talking about here. However, these people would be wrong.

We still don't know what the Imperial tax levy is, or how much the Imperial naval budget is.

No, but we can safely assume that it's more than 0.001% of GNP. Of course someone could dispute this, but then I would assume that he operates on a so totally different perception of reality that communication is effectively impossible (yes, I've been rereading Lem a lot lately...)

Funny how the civilian in that first adventure was unaware of all the AHL class cruisers and larger battleships that were really out there

I've seen worse from real life civilians. Considerably worse.

Second edition CT was quite a major rewrite, and second edition High Guard is almost a new book. Try comparing editions side by side.

HG, maybe, though even that didn't change the basic parameters for the design system, something that MT and TNE did.

Do I own Battle Rider?

Well, that should put any illusions of a TNE "small-ship universe" to rest.

The "small ship universe" is dead. Book 2 design rules are relics. 1st editions of Bk2 and HG have been superseded.
When arguing with Malenfant and others, I always strive to defend the grognards. But when people cling to even the most obscure, officially obsolete concepts, I have a hard time doing that.

Regards,

Tobias

 

[mike wightman]

The fact remains that Supplements 7 and 9 show that both the LBB2 first - not second - and the High Guard second edition ship designs exist in the same OTU, at the same time. Which is... odd.

The small ship OTU probably didn't exist really, especially since the Library Data supplements mentioned battlships etc.

The parameters that changed from HG1 to HG2 are:
maneuver drive percentages changed, power plants could now be larger than 6 and produced EP, EP were introduced to track power usage during design, hull configuration and armour changed totally, weapon factors changed, and computers changed (they now went up to 9, and you couldn't have bis models above 2).

Pretty major changes.

But when people cling to even the most obscure, officially obsolete concepts, I have a hard time doing that.

This thread began with Dominion Loyalty Officer letting us know about the changes he's made IHTU.
Most of my replies have been to list the foibles of the various design itterations over thet years.
Some of which may give him inspiration, or maybe not

I don't "cling to even the most obscure, officially obsolete concepts", I just find it interesting to discuss them.
Most of the ship designs I do at the moment are T20 based, with add ons from MT.
LBB2 remains my favourite design system for its simlicity - but there's no way the OTU can be based off the design parameters in the book.

Yes, I am a small ship universe heretic, you'll find quite a few of us out there, in that IMTU I have a maximum hull size derived from LBB2.
But I also really enjoy designing ships for High Guard, T20, GT, and TNE/T4.

 

[mike wightman]

One final thought.

A while ago there was a thread about proto Traveller - a version of the OTU rooted in the library data and adventure backgrounds of the first three adventures, and High Guard was never written.

There were a lot of different people interested.

 

[aramis]

WHomever posted the MT fuel Regime forgot that the baseline in MT AND TNE is not 10% of hull, but 5xJDriveVolume.

TNE also uses the High tech fuel reduction paradigm

 

[daryen]

Originally posted by Aramis:
WHomever posted the MT fuel Regime forgot that the baseline in MT AND TNE is not 10% of hull, but 5xJDriveVolume.

Which works out to be the exact same thing. So the statement was correct.

 

[mike wightman]

Originally posted by Aramis:
WHomever posted the MT fuel Regime forgot that the baseline in MT AND TNE is not 10% of hull, but 5xJDriveVolume.

TNE also uses the High tech fuel reduction paradigm

Which is why I gave it as a fuel % multiplier.

From MT:
</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;"> TL jump fuel required
9-16 5 x JDV
17 4 x JDV (80% of TL 9-16)
18 3 x JDV (60% of TL 9-16)
19 2 x JDV (40% of TL 9-16)
20 1 x JDV (20% of TL 9-16)
21 0.5 X JDV (10% of TL 9-16)</pre>[/QUOTE]JDV = jump drive volume.

 

[Sifu Blackirish]

Now that I've managed to stir up the mud, I want to explain why I made the changes I did IMTU.

* increased efficiency at higher TLs.
I wanted to see a real change across tech levels, with the same size jump drive being either smaller or more effective. This makes retrofitting worthwhile amd would theoretically make more 'obsolete' items availavle to poorer PCs

*increased jump distance past 6
Well, not really...by using a method called 'jump charging' ships IMTU can travel larger distances per jump, IF they have a high enough jump drive in a small enough hull AND they burn all the fuel required beforehand to fully charge the capacitors.
You still spend 125-150 hours per jump, and it's only in multiples (if you can do jump-2, you can do 4 or 6, not 3 or 5). Only military ships can do this, since it is stressful on the system and organics. It allows what I call 'courier-bots', automated 100 ton ships that are the equivalent of the x-boat network.

*jump capable small craft
Have to admit I haven't made my mind up on this one...although it was the original intention when I came up with this tweak. I am heavily biased toward a small ship universe

As far as fuel requirements, 60% is generous compated to some ATU I have seen. One used antimatter spiked hydrogen but took up to 90% of mass as fuel!

 

[Fritz_Brown]

Well, one thing that really influences this is how you think Jump works. If you view it as an analog drive, then fuel efficiencies make sense, as well as very small jump-capable ships.

If, though, you view it as a digital concept (on or off, discrete effects rather than continuous) you can see why it is the way it is. Also, if you accept the concept of using the fuel to tear a hole in space, then you can't really get much in the way of efficiency - you either have enough or you don't. Unless, of course, you make a tech leap - in which case, you will probably have a discrete fuel savings that doesn't translate to a smoothed curve (like that MT table).

 

[robject]

[off topic]

Proto-Traveller Lives!!

I suspect the limit of ship size was tied to the smallness of the Imperium. Everything scaled up, up, up.

Sigg, you need to resurrect the Proto-Traveller thread.

[/off topic]

 

[mike wightman]

Originally posted by robject:
[off topic]

Proto-Traveller Lives!!

I suspect the limit of ship size was tied to the smallness of the Imperium. Everything scaled up, up, up.

Sigg, you need to resurrect the Proto-Traveller thread.

[/off topic]

I'll find a reason...

 

[Renard Ruche]

Originally posted by Sigg Oddra:

and yet LBB2 second edition can't replicate the design of the X boat. [/QB]

I just came across the LBB2 Design for the X-boat in supplement 7 (pages 8 - 10). It makes mention that there is no power plant. According to the write-up on p10: 'Jump drives carry power plant cacpacities and functions.'

I just did two quick and dirty design on the x-boat using the 1977 LBB2 and The Traveller Book. This is the 'reverse-design' I came up with:
Bridge-20 tons, Mod/4 comp-4 tons, 2 cabins-8 tons, cargo-1 ton, J-drive B- 15 tons, J-fuel-40 tons. Total: 88 tons.

Both rules set (I believe my 1977 LBB is the first edition - nothing on the frontspiece mentions edition) give me the same totals. Did I miss anything?

 

[robject]

Interesting.

We don't want the XBoat to have enough room for a small power plant, maneuver drive, and laser, do we?

Sounds like the jump drive ought to be even larger. Ouch!

If we say the power plant is required, then the numbers work out. A power plant B would be another 7 tons, plus 4 more tons for fuel.

So, perhaps the text should be interpreted "these particular jump drives also have integral power plants, with a correspondingly larger volume and fuel requirements."

In other words, it sounds like XBoat jump drives are actually combo jump drive / power plants, much in the way that small craft have combo maneuver drive / power plants.

 

[Renard Ruche]

Robject: wouldn't P-plant fuel be 40 tons? The formula in both of my referances is 10Pn. Wouldn't fit in 100 tons, not even with the 20% allowance.

I like the idea of a larger j-drive. A J-drive C takes up 20 tons, would allow a J6 and you wouldn't go over the 100 ton limit. That would leave about 7 tons for the 'wonder' power-plant <g>. Of course, you could take out the spare stateroom, and jump that back up to 11 tons.

 

[mike wightman]

Originally posted by Renard Ruche:
I just came across the LBB2 Design for the X-boat in supplement 7 (pages 8 - 10). It makes mention that there is no power plant. According to the write-up on p10: 'Jump drives carry power plant cacpacities and functions.'

I just did two quick and dirty design on the x-boat using the 1977 LBB2 and The Traveller Book. This is the 'reverse-design' I came up with:
Bridge-20 tons, Mod/4 comp-4 tons, 2 cabins-8 tons, cargo-1 ton, J-drive B- 15 tons, J-fuel-40 tons. Total: 88 tons.

Both rules set (I believe my 1977 LBB is the first edition - nothing on the frontspiece mentions edition) give me the same totals. Did I miss anything?

Nope, the X boat is a functional 1977 first edition Traveller design.

The trouble is in 1981 a revised, or second edition, version of Traveller came out.

There are many little changes from first edition, but the significant ones for ship designers are:
power plants, and their fuel, are now required on all ships and must be equal to the maneuver drive or jump drive rating, whichever is higher;
and
the drive potential table changed.

 

[Renard Ruche]

Whew!....I got here before anyone caught my mistake (was tossing and turning all night...). J-drive C + fuel would be 80 tons. With a bridge, stateroom and computer, you'd have to use the 20% fudge, but it is still do-able. S7 mentions a couple of variations on the basic x-boat, so perhaps this could be one.

 

[mike wightman]

The 20% fudge is only for deck plans

You could make a jump 6 200t courier - until the new power plant rules came along.

I personally prefer the 1st edition rules, with a hybrid of the 1st and 2nd edition drive potential table.

 

[Renard Ruche]

I always assumed the 20% meant you could also fudge on a ship's final tonnage (i.e. if your deck plans are at 120 tons, wouldn't the ship be too?), ergo giving us the Kinunir. It doesn't actually say in the adventure what engine is placed in the ship, so I can't give hard evidence....but, 1200 tons is 1000+20%...

 

[aramis]

Originally posted by daryen:
</font><blockquote>quote:</font><hr />Originally posted by Aramis:
WHomever posted the MT fuel Regime forgot that the baseline in MT AND TNE is not 10% of hull, but 5xJDriveVolume.

Which works out to be the exact same thing. So the statement was correct. </font>[/QUOTE]No, it is NOT the same.
It only matches at J1
J formula is (1+Jn) %

J1 both: 2% Drive, 10% fuel = 12%
J2 CTBk5/T4/T20: 3% Drive, 20% Fuel = 23%
J2 MT/TNE: 3% Drive, 15% Fuel = 18%
J3 CT...: 4% drive, 30% fuel = 34%
J3 MT...: 4% Drive, 20% fuel =24%
J4 CT: 5 & 40 = 45%
J4 MT: 5 & 25 = 30% (15% less)
J5 CT: 6 and 50 = 56%
J5 MT: 6 and 30 = 36% (20 percent of hull less)
J6 CT: 7 and 60 = 67% (2/3rds of hull!)
J6 MT: 7 and 35 = 42% (25% less than CT)

This dichotomy in longer range fuel usage makes tremedous differences. MT can support a 3J4 ship design. 4% drive, 75% fuel. It will be M1 or so, basically unarmed, but doable.

Also note: MT does not have a bridge requirement, per se. No 2% or 20 tons. TNE likewise has a very small bridge requirement.

 

[mike wightman]

Aramis, I think you've missed the point of my original post
It wasn't to compare MT jump fuel requirements with CT, I am well aware of the difference.

The point was to adapt the jump fuel reduction progression for very high TLs to the CT jump fuel model.

MT is the only place in Traveller canon where such a reduction is explicitely stated:
</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">TL 17 4 x JDV (80% of TL 9-16)
TL 18 3 x JDV (60% of TL 9-16)
TL 19 2 x JDV (40% of TL 9-16)
TL 20 1 x JDV (20% of TL 9-16)
TL 21 0.5 X JDV (10% of TL 9-16)</pre>[/QUOTE]I just applied the percentage reduction, not the MT reduced jump fuel formula - which is a requirement of MT power plants being based on Striker fuel requirements.