CT Only: Book 2 Design and Construction plus Book 3 TL table

[snrdg082102]

Hello everyone,

I've sent a possible Supplement 7 revised design to Donald McKinney and I'm checking after the fact that the revision under Book 2 1981 is not broken.

Background:
Book 2 1977 pp. 11,13 Engineering Section Each starship is fitted with a:

1. Power plant to provide
a. internal power
b. power to the maneuver drive
c. The installed power plant must be of a letter type equal to the drive letter of the maneuver drive (the power plant letter may be higher than the maneuver drive letter (p.13).

2. maneuver drive (for interplanetary travel).

3. jump drive (for interstellar jumps).

In Book 3 1977 pp. 10 and 11 the technology levels for computers TL 5 through 13, non-starships TL 7, starships TL 9, and Jump drive letters* were available from TL 9 through 15 . (*I guessed back when that the drives referenced where those that allowed interstellar jumps and drives A - G where available at TL 9.)

Book 2 1981 was published which provides the following information in the Engineering Section p. 13

1. A non-starship must have a maneuver drive and a power plant.

2. A starship must have a jump drive and a power plant; a maneuver drive may also be installed, but is not required.

3. In all cases, the power plant letter must be equal or exceed either the maneuver drive or the jump drive letter.

In Book 3 pp. 14 and 15 the technology levels for computers TL 5 through 13, non-starships TL 7, starships TL 9, and jump drives by drive letters* were available from TL 9 through 15 . (*My guess is that the referenced drive letters are for the jump drives.)

In Supplement 7 the express boat appears to have been using Book 2 1977 with wiggle room which under Book 2 1981 can not be done.

Following Book 2 1981 rules an express boat must have a jump drive and a power plant with type letters that are equal to each other or the power plant could have a higher type letter.

Per Supplement 7 an 100-ton express boat is capable of a four parsec jump. On Book 2 1981 Drive potential table p.22 to achieve four parsecs the choices are between jump drive letters B and C. Checking in Book 3 1981 under the Space Technological Levels column p. 15 Jump Drive Letter types A - D are available.

The choice made in Supplement 7 appears to be Jump Drive type B with a range rating of 4. Per the rules the power plant letter must be equal to or higher that the jump drive letter which means the express boats power plant drive letter is at least B and could be C.

Here is where I may be bending if not breaking the Book 2 1981 rules between the jump drive and power plant.

The power plant type B has a rating of 1.

Have I bent and/or broken the Book 2 1981 rules?

Note that if a maneuver drive was installed both the power plants letter type and rating would match the maneuver drive's letter type and rating.

 

[Carlobrand]

...

The power plant type B has a rating of 1.

...

In what rating system?

 

[aramis]

The X-Boat cannot be built legally under 2E unless you reduce the fuel.

Don, Robject, and I went through all this 4 years ago. Accept that it's an artifact, or accept the errata, and move on, man.

See: http://www.travellerrpg.com/CotI/Discuss/showthread.php?t=22130

And, at one point, Don mentioned not wanting to invent the model/3bis... but Marc beat him to doing so... models 1bis to 7bis are in HG 1E, page 29, as a formulaic addition.

 

[snrdg082102]

Evening Carlobrand,

In what rating system?

The jump drive type B's rating is 4 parsecs which is used to determine the required fuel.

The power plant type B rating is 1 unidentified something or other in Book 2 1981, in Book 2 1977 this would be the internal power rating and is used to determine the power plant's required fuel to operate for four weeks.

If the express boat had a maneuver drive type B with a rating of 2G the power plant rating would be 2 to power the maneuver drive and the ship's internal power output.

 

[Carlobrand]

...
The jump drive type B's rating is 4 parsecs which is used to determine the required fuel.

The power plant type B rating is 1 unidentified something or other in Book 2 1981, in Book 2 1977 this would be the internal power rating and is used to determine the power plant's required fuel to operate for four weeks.
...

Oh, I remember now. Okay, look at the Drive Potential Table. It tells you that in a 100 dT ship, the Power Plant B is a 4 unidentified something or other, not a 1.

This is part of what triggers all the handwringing about the x-boat, and why we say it can't be built under the Book-2 rules: a Power Plant B, with it's rating of 4, requires 40 dTons of power plant fuel (10 Pn). On top of the 40 dTons of jump fuel and the 20 dTon bridge, you no longer have room for the drives or anything else.

So far, the best effort in that direction is the one in the errata: a 105 dT X-boat with a 54 dTon fuel supply, enough for a jump and 10 days operation. With the 20 dTon bridge, 22 dTons in drives, and 4 dTon Model/4 computer, that comes to 100 dTons. So, either your hapless pilot sleeps on the bridge in his seat and you replace the second bridge seat with a chem-toilet or some similar low-volume waste disposal system, and put a few jugs of water and some rations in with him (which makes x-boat piloting a pretty rough and unpopular job), or you go over target so he can have someplace to sleep, eat, shower and so forth. (I'm not sure why they're getting 105 out of that; I'm getting 104.)

Or you could cut the power plant fuel to 12 dTons and put a half-stateroom in, but that's only fuel for 8.4 days. Cuts things pretty tight.

Me, if I were bending rules that far, I'd forgo the stateroom and make the pilot rough it on the bridge. If a recruit can't handle a year of that duty, then he's not Scouts material. :devil:

 

[snrdg082102]

Evening aramis,

The X-Boat cannot be built legally under 2E unless you reduce the fuel.

Don, Robject, and I went through all this 4 years ago. Accept that it's an artifact, or accept the errata, and move on, man.

See: http://www.travellerrpg.com/CotI/Discuss/showthread.php?t=22130

Per the errata the express boat has 54 tons of fuel onboard which allows one jump, I am guessing the one jump is the maximum of 4 parsecs, and 10 days of operation.

I think that the total time the power plant has to operate is between 6.3 and 7.7 days in jump plus 10 days of operation in normal space waiting on the tender. The power plant at a minimum has to provided power for 16.3 to 17.7 days. The fuel load for a power plant allows operation for 28 days.

The Jump 4 Drive Type B requires 0.1 x 100 x 4 = 10 x 4 = 40 tons of fuel

54 - 40 = 14 tons of fuel for the power plant.

The formula for power plant fuel is 10 x Pn which allows the power plant to operate for 28 days.

14 ton = 10 x Pn = 14 tons / 10 = Pn = 1.4

The Power Plant Type B has a rating of 1.4 that requires 14 tons of fuel allowing four weeks or 28 days of operations.

Reducing the Power Plant Type B's rating from 1.4 to 1 requires a fuel load of 10 x 1 = 10 tons.

The ship's computer has to be able to run a Jump 4 program and the navigate program at the same time which requires a computer with a capacity of 5. A Model 3, no bis models past 2 or any fib models are in Book 2, would be a maximum capacity. If the generate program is also used a Model 3 is not going to handle the jump calculations. I'm going with a Model 4.

From CT Book 2 1981 2nd ed.

Hull: 100 tons
Jump 4 Drive Type B: 15 tons
Jump Fuel: .1 x 100 x 4 = 10 x 4 = 40 tons to make one 4 parsec jump.
Power Plant 1 Type B: 7 tons
Power Plant Fuel: 10 x 1 = 10 tons for 28 days of operation
Bridge: 20 tons
Computer Model/4: 4 tons
1x Stateroom: 4 tons

100 - 15 - 40 - 7 - 10 - 20 - 4 - 4 =
85 - 40 - 7 - 10 - 20 - 4 - 4 =
45 - 7 - 10 - 20 - 4 - 4 =
38 - 10 - 20 - 4 - 4 =
28 - 20 - 4 - 4 =
8 - 4 - 4 =
4 - 4 = 0

Hopefully, I followed the Book 2 1981 Second editions

And, at one point, Don mentioned not wanting to invent the model/3bis... but Marc beat him to doing so... models 1bis to 7bis are in HG 1E, page 29, as a formulaic addition.

In either Book 2 1977 First edition or 1981 Second edition there are only two bis model computers available.

 

[snrdg082102]

Evening Carlobrand,

Oh, I remember now. Okay, look at the Drive Potential Table. It tells you that in a 100 dT ship, the Power Plant B is a 4 unidentified something or other, not a 1.

This is part of what triggers all the handwringing about the x-boat, and why we say it can't be built under the Book-2 rules: a Power Plant B, with it's rating of 4, requires 40 dTons of power plant fuel (10 Pn). On top of the 40 dTons of jump fuel and the 20 dTon bridge, you no longer have room for the drives or anything else.

So far, the best effort in that direction is the one in the errata: a 105 dT X-boat with a 54 dTon fuel supply, enough for a jump and 10 days operation. With the 20 dTon bridge, 22 dTons in drives, and 4 dTon Model/4 computer, that comes to 100 dTons. So, either your hapless pilot sleeps on the bridge in his seat and you replace the second bridge seat with a chem-toilet or some similar low-volume waste disposal system, and put a few jugs of water and some rations in with him (which makes x-boat piloting a pretty rough and unpopular job), or you go over target so he can have someplace to sleep, eat, shower and so forth. (I'm not sure why they're getting 105 out of that; I'm getting 104.)

Or you could cut the power plant fuel to 12 dTons and put a half-stateroom in, but that's only fuel for 8.4 days. Cuts things pretty tight.

Me, if I were bending rules that far, I'd forgo the stateroom and make the pilot rough it on the bridge. If a recruit can't handle a year of that duty, then he's not Scouts material. :devil:

My understanding is that the 4 unidentified something or other is the maximum potential that the drive letter can attain.

The express boat's Jump 4 Drive B, the maximum potential on the table, requires 0.1 x 100 x 4 = 10 x 4 = 40 ton good for one four parsec jump.

Instead of the express boat making a nice neat four parsec jump the ship does a Jump 3. The only Drive type capable of making a three parsec jump is the Type B and the fuel requirement for the drive type B would be .1 x 100 x 3 =10 x 3 = 30 tons of fuel and the jump drive takes up 15 tons of space.

Using the errata the express boat has 54 tons of fuel 40 tons is required by the jump drive leaving 14 tons for the power plant.

14 tons of power plant = 10 x the power plant number =

14 tons / 10 = the power plant number

1.4 = the power plant number which is not the Type B potential of 4.

My understanding is that the power plant fuel load is good for 28 days which is the smallest legal duration allowed by Book 2 1981 Second edition and HG 1980 Second edition.

Forty tons of the fifty-four tons is dedicated to the jump drive leaving 14 tons for the power plant.

14 tons = 10 x Pn =

14 tons / 10 = Pn =1.4

According to the fuel formula the Power Plant Type B has a plant number of 1.4.

If the Type B potential of 4 is used to calculate the power plant fuel load the express boat needs 10 x 4 = 40 tons.

Jump Drive 15 tons + 40 tons of fuel = 54 tons
Power Plant 7 tons + 40 tons of fuel = 47 tons
Bridge 20 tons
1x Stateroom 4 tons

54 + 47 + 20 + 4 =
101 + 20 + 4 =
121 + 4 =
125

No light bulbs, okay candles, have illuminated letting me know I may have caught on to the rules as you and the others have yet.

Anyone got a forty pound sledge hammer and time to show up at my door/

 

[aramis]

Supplement 7 postdates the draft of HG 1E. Some HG draft materials made it in.

 

[Carlobrand]

...
Using the errata the express boat has 54 tons of fuel 40 tons is required by the jump drive leaving 14 tons for the power plant.

14 tons of power plant = 10 x the power plant number =

14 tons / 10 = the power plant number

1.4 = the power plant number which is not the Type B potential of 4.
...

???

Why are you calculating the power plant rating based on the amount of fuel aboard? That's like calculating your car's engine output based on the size of your gas tank.

Power plant rating must match the higher of jump drive rating or maneuver drive rating per Book 2. Ergo, if your jump drive rating is 4, you must have a power plant rating of at least 4.

The 40 dTons power plant fuel provides fuel for 4 weeks - 28 days. If you make the fuel tank smaller, you run out of fuel sooner. It does not affect power plant rating; power plant consumes fuel at the same rate whether it's being fed by a 1 dTon or a 40 - it just runs out quicker if the fuel tank is smaller. Only the jump or maneuver drive - which the power plant is presumably powering - have any influence on power plant rating.

 

[snrdg082102]

Morning aramis,

Supplement 7 postdates the draft of HG 1E. Some HG draft materials made it in.

Yes, the system defense boat has magazines which was part of High Guard 1979 First Edition on page 32.

"Magazines: Any ship with missile racks installed in bays may allocate a magazine equal in tons to the points used in determining missile factor for a bay or turret. The total of such points (un-averaged) is then available as a planetary bombing factor. Planetary bombing is not available to ships without missile magazines."

I could have sworn that High Guard 1980 Second edition retained the part that planetary bombardment requires magazines, but I cannot seem to dug the material out.

Can anyone point me to the right source pleas,

Supplement 7 does say that the designs where created using both Book 2 (First edition) and as noted by the missile magazines, High Guard (First edition). Further the designs are rated to produce the Universal Ship Profile and supporting data from High Guard (First Edition)

 

[snrdg082102]

Morning Carlobrad,

???

Why are you calculating the power plant rating based on the amount of fuel aboard? That's like calculating your car's engine output based on the size of your gas tank.

Simple math states that to solve for an unknown value you use the information given. I know for sure that the express boat is capable of jump 4 and that the total fuel load is 54 tons.

The onboard fuel requirement is determined by the formula of (0.1 x Hull x Jump Number) + (10 x Plant Number)

Per the background in the errata the total fuel load is
54 tons = (0.1 x 100 x Jump Number = 4) + (10 x Plant Number)
54 tons = (10 x 4) + (10 x Plant Number)
54 tons = 40 tons of jump fuel + (10 x Plant Number)
54 tons - 40 tons = (10 x Plant Number)
14 tons = (10 x Plant Number)
14 tons/ 10 = Plant Number
1.4 = Plant Number

Power plant rating must match the higher of jump drive rating or maneuver drive rating per Book 2. Ergo, if your jump drive rating is 4, you must have a power plant rating of at least 4.

The 40 dTons power plant fuel provides fuel for 4 weeks - 28 days. If you make the fuel tank smaller, you run out of fuel sooner. It does not affect power plant rating; power plant consumes fuel at the same rate whether it's being fed by a 1 dTon or a 40 - it just runs out quicker if the fuel tank is smaller. Only the jump or maneuver drive - which the power plant is presumably powering - have any influence on power plant rating.

Book 2 1977 First Edition p. 11 Engineering Section:

"Each starship is fitted with a power plant (to provide internal power and power the maneuver drive, a maneuver drive (for interplanetary travel), and a jump drive (for interstellar jumps),

Book 2 1977 First Edition p. 13 Engineering Section:

"The installed power plant must be of a letter type at least equal to the drive letter of the installed maneuver drive (the power plant letter may be higher than the maneuver drive letter."

Book 2 1980 Second Edition p. 13 Engineering Section:

"A non-starships must have a maneuver drive and a power plant. A starship must have a jump drive and a power plant; a maneuver drive may also be installed, but not required. In all cases, the power plant letter must equal or exceed either the maneuver drive letter or the jump drive letter, which ever is higher."

High Guard 1979 First Edition and 1980 Second edition changed the rule to read.

First edition page 23: "On any given ship, the power plant number must at least equal the higher of the jump drive number or the maneuver drive number.

Second edition page 22: "On any given ship, the power plant number must at least equal the jump number or the maneuver number whichever is higher.

In Book 2 1977 First edition a starship, in my understanding, required a power plant, maneuver drive, and jump drive. The power plant has to match the maneuver drive potential since the plant provides the energy needed to produce the maneuver drives Gs of acceleration. My understanding of the first edition rules does not indicate that the jump drive requires the power plant to operate. The power plant is needed to provide a ship with internal power.

Book 2 1981 Second edition, High Guard 1979 First edition, and High Guard 1980 Second edition allows starships the option of having a maneuver drive.

I have not found anything in the any edition of Book 2 or Book 5 that makes me to believe that the power plant provides any power to the jump drive. The jump drive has a fuel load requirement which is separate from the power plant ± the maneuver drive. Both editions of Book 2 and Book 5 agree that the maneuver drive's power requirement does not have a measurable affect on the power plant's fuel consumption.

Please let me know where in Book 2, Book 5, or some other source that allows the fuel tanks allowing them to be smaller than what the required fuel load formulas determine as being the minimum fuel tankage allowed?

I've checked TCS and looked through my slightly out of date physical copies of BITS The Traveller 1999 and Traveller Periodical 2000 Bibliographies with my usual rate of success, which means I've not found a darn scrap of information.

 

[mike wightman]

They broke the x-boat by changing the ship design system.

You can fudge it, you can build it anew using HG1 or 2, but you can not build it using LBB2 81 edition using the rules as written.

Unintended consequence...

CT suffers from having 4 ship design systems which share superficial similarities but can be very different in final outcome (not to mention some glaring differences )

You can cherry pick the rules you want from each system for YTU, but for the OTU you are tied to the design system rules for the particular iteration you are building for.

 

[aramis]

They broke the x-boat by changing the ship design system.

You can fudge it, you can build it anew using HG1 or 2, but you can not build it using LBB2 81 edition using the rules as written.

Unintended consequence...

CT suffers from having 4 ship design systems which share superficial similarities but can be very different in final outcome (not to mention some glaring differences )

You can cherry pick the rules you want from each system for YTU, but for the OTU you are tied to the design system rules for the particular iteration you are building for.

Worse still: there are 5 eras of ship design for the CTOTU:

Bk2-77 only
Bk2-77 + Bk5-79
Bk2-77 + Bk5-80
Bk2-81 + Bk5-80
Bk2-81 + Bk5-80 + T20 (Bk5-00)

At no point but the first was Bk2 alone.

The T20 dual-stat books were, per the contract, canon for the OTU; they used the close variant of Bk5-80 in the T20 core book. And they suffer from all the same issues as Bk5, except that you can upgrade streamlining, and airframe configurations were added, and you can have matching spinals, bays, and turrets (which aren't legal in Bk5-80).

 

[rancke]

...and you can have matching spinals, bays, and turrets (which aren't legal in Bk5-80).

That particular bit (not being able to have the same weapon type in two or even three sizes) has always struck me as a prime example of a practical game rule (USPs don't work if you're allowed that) rather than an emulation of "reality" (Is the Great Bird of the Galaxy going to swat any ship with both a meson spinal and meson bays?)


Hans

 

[snrdg082102]

Hello Hans, aramis, and Mike Wightman,

That particular bit (not being able to have the same weapon type in two or even three sizes) has always struck me as a prime example of a practical game rule (USPs don't work if you're allowed that) rather than an emulation of "reality" (Is the Great Bird of the Galaxy going to swat any ship with both a meson spinal and meson bays?)


Hans

HG Frist edition I think one was able to mix bay and turret weapons of the same type into one weapon factor. Determining the weapons factor was what I was not able and still have not figured out how to use, which is why I went with HG Second edition.

I may have missed the information but as far as I know the Book 2 design and construction rules are separate from Book 5 rules. However, Book 5 does allow the use of Book 2 drives and fuel requirements and recommends that hulls 1,000 tons and under follow Book 2 crew rules.

In my posts I have quoted the sources showing that in Book 2 Second Edition there is no mention that the power plant digit rating has to match the jump drive's digit rating. The matching of digits was introduced in HG. I agree that the digits and type letters must at least match between the power plant and the maneuver drive.

Book 5 HG computer model numbers correspond with Book 2, but I do not see anything that says Book 5 computers replace Book 2's computer requirements.

Further I still have not found anything in the Book 2 rules that allows the fuel tankage to be smaller than what the calculated fuel load formulas require.

By the same token there isn't anything that clearly says one cannot have a smaller tank either.

Going by the rules as written the minimum fuel load is equal to (0.1 x Hull x Jump Number) + (10 x Power Plant Number) for Book 2 hulls.

I would really like to have a physical reference source that support being able to have a smaller power plant fuel load than the fuel load formula calculates.

 

[Carlobrand]

...Simple math states that to solve for an unknown value you use the information given. I know for sure that the express boat is capable of jump 4 and that the total fuel load is 54 tons. ...

Yes, but you're solving for the wrong value. The power plant rating is not an unknown value. It's value is dictated by the rules: 4, per the table.

The rationale here is clear: for the maneuver drive or jump drive to operate at full performance, there must be a power plant of the same letter likewise operating at full performance. We see the rationale later in the combat damage rules: "Each hit achieved on a drive or power plant reduces its letter classification by one. Thus C becomes B, X becomes W, etc. The potential of the drive or power plant is then computed based on its temporary new letter. Note that the letter rating of a power plant must equal or exceed that of a maneuver or jump drive in order for the drive to function."

By chopping the power plant rating to 1.4 in order to make the fuel last four weeks, you are in effect making the power plant operate as a less-than-A power plant, which means the jump drive can no longer function. There's no rationalization by which a power plant draws less fuel and still delivers the same amount of power to the jump drive.

...I have not found anything in the any edition of Book 2 or Book 5 that makes me to believe that the power plant provides any power to the jump drive. The jump drive has a fuel load requirement which is separate from the power plant ± the maneuver drive. Both editions of Book 2 and Book 5 agree that the maneuver drive's power requirement does not have a measurable affect on the power plant's fuel consumption. ...

I don't see how you're arriving at that conclusion.

Book 2: "In all cases, the power plant must equal or exceed the higher of the maneuver drive and the jump drive letter. ... Each hit achieved on a drive or power plant reduces its letter classification by one. Thus C becomes B, X becomes W, etc. The potential of the drive or power plant is then computed based on its temporary new letter. Note that the letter rating of a power plant must equal or exceed that of a maneuver or jump drive in order for the drive to function."

How do you rationalize that the jump drive needs a power plant of the same rating to operate but does not receive power from the power plant?

Book 5: "On any given ship, the power plant number must at least equal the jump number or the maneuver number, whichever is higher ..." And later in the combat section, "A ship which breaks off by jumping must have a destination and enough fuel to get there. It must expend energy points equal to two turns output from a power plant whose number is equal to the jump being attempted. ... A ship which cannot summon the required energy in two turns may not jump at all. ... "

Yes, the jump drive draws fuel for the jump. It ALSO needs energy points from the power plant. It can also draw power from the capacitors served by the Black Globe. However, it very much does not meet its own power needs: the jump drive does not deliver energy points, only the power plant or the Black Globe capacitors can deliver that.

... Please let me know where in Book 2, Book 5, or some other source that allows the fuel tanks allowing them to be smaller than what the required fuel load formulas determine as being the minimum fuel tankage allowed?...

... and why we say it can't be built under the Book-2 rules ...

I'm sorry, I was unclear again. The X-boat cannot be built under Book 2 rules. The errata resolves the conflict by ignoring one Book-2 rule: the minimum fuel rule. Since there were craft in the game with as little as 1 dTon of fuel (the launch), there was no rationalization for requiring 4 weeks of fuel other than, "It's the rule." It was therefore simplest to break that rule rather than continue to have a ship that broke other rules.

And, it is easier to rationalize breaking that rule (because other than the rule itself there's no real reason the fuel tank can't be smaller and deliver fuel for a shorter time) than it is to rationalize breaking the rule that says a Power Plant B in a 100 dTon hull has a rating of 4: if you say it has a lower rating, then by definition it is no longer meeting the performance criteria of a Power Plant B and is no longer adequate to serve the jump drive, per the combat rules.

Book 5 makes no mention of allowing fuel tanks to be smaller than the minimum required. However, errata now allows small craft to use smaller fuel tanks, with a minimum of 1 dTon. This resolved the puzzling requirement for craft to carry 4 weeks of fuel when they could only operate for 24-48 hours in space (when they did not have a small craft cabin).

MegaTraveller, which draws heavily on Book 5, recommends a minimum but does not require it.

 

[snrdg082102]

Hello Carlobrand,

Yes, but you're solving for the wrong value. The power plant rating is not an unknown value. It's value is dictated by the rules: 4, per the table.

Book 2 1977 First edition p. 11 offers a much better explanation of the (Maximum) Drive Potential Table than Book 2 Second edition.

The digit 4 under the drive/power plant Type B on the Drive Potential Table is the highest or maximum number available for use as the drive and power plant numbers.

The Jump Drive's maximum jump on the table is 4, however the ship can make a jump of 1, 2, or 3 parsecs.

In Book 2 the fuel rules are explicit that a ship requires fuel tankage equal to (10 x the Plant number) + (0.1 x Hull size x Jump number). Book 5's fuel rules are also explicit using the formula of (0.01 x Hull x Plant number) + (0.1 x Hull size x Jump number).

Per the errata the total fuel tankage is 54 tons.

The express boat has a jump number of 4, which is the maximum potential of a Jump Drive Type B. The Jump 4 Type B drive requires 40 tons of fuel using the Book 2 formula.

If the power plant has to be both the same type letter and potential number by Book 2 fuel rules the required fuel load is 40 tons.

The total required fuel tankage is 40 + 40 = 80 tons.

Based on the explicit fuel tankage rules the Book 2 express boat requires 80 tons of fuel tankage.

Fifty-four tons is twenty-six tons shy of eighty which is not, in my opinion, as bad as omitting the power plant, however without a documented rule allowing the power plant fuel tankage to be less than the required amount by the formula the design cannot be built at all.

The rationale here is clear: for the maneuver drive or jump drive to operate at full performance, there must be a power plant of the same letter likewise operating at full performance. We see the rationale later in the combat damage rules: "Each hit achieved on a drive or power plant reduces its letter classification by one. Thus C becomes B, X becomes W, etc. The potential of the drive or power plant is then computed based on its temporary new letter. Note that the letter rating of a power plant must equal or exceed that of a maneuver or jump drive in order for the drive to function."

Please, what page is the above on?

As usual I seem not to be find the information in my books and if I was researching something I would have stumbled on the information.

Never mind I found the reference on Book 2 1981 Second edition p. 32

I stand corrected and admit that I am in error.

By chopping the power plant rating to 1.4 in order to make the fuel last four weeks, you are in effect making the power plant operate as a less-than-A power plant, which means the jump drive can no longer function. There's no rationalization by which a power plant draws less fuel and still delivers the same amount of power to the jump drive.

My understanding of the above reply means that I cannot build a 1-J and/or 1-G 100-ton ship using Book 2 because the two drive potential numbers are smaller that Type A drive potential of 2.

How much power does the jump drive require, or computer, or laser, or life support, or maneuver drive in Book 2?

We don't know, Book 5 gives us a better gauge on how much power a computer and weapons, expect sandcasters and missile racks, needs. Book 5 kind of mentions that the power needed for the maneuver drive is not enough to require extra fuel to operate the power plant.

We are still in the dark on how much power the jump drive requires to operate under normal conditions, as you have shown later in the reply there is some relationship under Book 5 rules.

I don't see how you're arriving at that conclusion.

Book 2: "In all cases, the power plant must equal or exceed the higher of the maneuver drive and the jump drive letter. ... Each hit achieved on a drive or power plant reduces its letter classification by one. Thus C becomes B, X becomes W, etc. The potential of the drive or power plant is then computed based on its temporary new letter. Note that the letter rating of a power plant must equal or exceed that of a maneuver or jump drive in order for the drive to function."

The letter is the type rating not the digit rating that is between a minimum of 1 to a maximum of 6.

What drive type letter would a Book 2 2,000 ton need to use the digit 5?

The only drive letter I see that allows a digit rating of 5 would be Z. However, what I am understanding from the replies is that I would have to use 6 since that is the digit rating of the letter rating Z.

Unfortunately, Book 2 Second edition's detail on the functions of the power plant are less clear that in the first edition.

In Book 5 Second Edition on p. 17 is this bit of information that is similar to what was in Book 2 1977 First edition:

"Power for the maneuver drive is provided by the starship's power plant, which must be equal to or exceeding the drive number of the maneuver drive."

This clearly shows that the power plant and maneuver drive rely on each other and is the second sentence of the first paragraph under Starships: Movement.

The second and third paragraphs cover the jump drive which does not mention any relationship between the jump drive and power plant.

How do you rationalize that the jump drive needs a power plant of the same rating to operate but does not receive power from the power plant?

Book 5: "On any given ship, the power plant number must at least equal the jump number or the maneuver number, whichever is higher ..." And later in the combat section, "A ship which breaks off by jumping must have a destination and enough fuel to get there. It must expend energy points equal to two turns output from a power plant whose number is equal to the jump being attempted. ... A ship which cannot summon the required energy in two turns may not jump at all. ... "

In Book 5 there is a formula that determines the power output of the power plant which just also happens to be used to allocate fuel tankage.

Book 2 does not calculate power consumption or production.

Yes, the jump drive draws fuel for the jump. It ALSO needs energy points from the power plant. It can also draw power from the capacitors served by the Black Globe. However, it very much does not meet its own power needs: the jump drive does not deliver energy points, only the power plant or the Black Globe capacitors can deliver that.

Please provide the page number in Book 2 that supports that the jump drive has capacitors.

I'm sorry, I was unclear again. The X-boat cannot be built under Book 2 rules. The errata resolves the conflict by ignoring one Book-2 rule: the minimum fuel rule. Since there were craft in the game with as little as 1 dTon of fuel (the launch), there was no rationalization for requiring 4 weeks of fuel other than, "It's the rule." It was therefore simplest to break that rule rather than continue to have a ship that broke other rules.

And, it is easier to rationalize breaking that rule (because other than the rule itself there's no real reason the fuel tank can't be smaller and deliver fuel for a shorter time) than it is to rationalize breaking the rule that says a Power Plant B in a 100 dTon hull has a rating of 4: if you say it has a lower rating, then by definition it is no longer meeting the performance criteria of a Power Plant B and is no longer adequate to serve the jump drive, per the combat rules.

Book 5 makes no mention of allowing fuel tanks to be smaller than the minimum required. However, errata now allows small craft to use smaller fuel tanks, with a minimum of 1 dTon. This resolved the puzzling requirement for craft to carry 4 weeks of fuel when they could only operate for 24-48 hours in space (when they did not have a small craft cabin).

MegaTraveller, which draws heavily on Book 5, recommends a minimum but does not require it.

The original, in my opinion, express boat designed using Book 2 First edition rules also ignored the need for a power plant.

Now in order to allow a design another rule is ignored to permit the design.

Under the power plant fuel rule that allows for 28 days of operations a 10 ton small craft at 6G needs a power plant of at least 6 which allocates tankage for 0.01 x 10 x 6 = 0.1 x 6 = 0.6 tons of fuel. To operate for one day the tankage requires is 0.6/28 = .0214 tons of fuel.

One ton of fuel allows the 10 ton to operate for about 39 days at 6G, I think.

Thank all of you for putting up with me and I do appreciate finally understanding the error of my thinking.

However, the express boat under Book 2 rules is not fixed by ignoring the fuel requirements, the design cannot be built in Book 2, as you all have finally got me to understand.

At this point the best recommendation is to junk any reference to Book 2 and work to create one in HG 2 that may or may not use the jump drive and/or power plant from Book 2.

As a quick calculation I think a Book 5 J-5 Drive is 20 tons while the Book 2 J4 drive is 15 tons. The power plant I think would be Book 5 is the fuel tankage requirement is better.

Again thank you all for the help.

 

[aramis]

As a quick calculation I think a Book 5 J-5 Drive is 20 tons while the Book 2 J4 drive is 15 tons. The power plant I think would be Book 5 is the fuel tankage requirement is better.

Again thank you all for the help.

Nope. Book 5 J4 drive for a 100Td ship takes 5Td and costs MCr20. And requires TL 13 (D), 40Td of fuel, and a PP of rating 4 (TL13 PP: 8Td MCr24, uses 4Td fuel per 4 weeks; At TL15, 4Td, MCr12, uses 4Td fuel.) Under Bk5, there is no reason to not include the M1 capability.

 

[Carlobrand]

...Please provide the page number in Book 2 that supports that the jump drive has capacitors. ...

Capacitors are introduced in Book 5 as part of the Black Globe rules.

...The original, in my opinion, express boat designed using Book 2 First edition rules also ignored the need for a power plant.

Now in order to allow a design another rule is ignored to permit the design. ...

Yes, that pretty well sums it up. I'm told the 1977 version did not require the jump drive to have a power plant. There was something about drawing life support power from the jump drive, or maybe it was batteries, I don't know. I guess sometime between '77 and '81, it occurred to someone that the idea could be abused.

...
At this point the best recommendation is to junk any reference to Book 2 and work to create one in HG 2 that may or may not use the jump drive and/or power plant from Book 2. ...

Yeah, that's what most of us using HG do. The x-boat ends up being a bit different because HG leaves us with room for a maneuver drive, but it's not a major problem.

 

[snrdg082102]

Evening aramis,

Nope. Book 5 J4 drive for a 100Td ship takes 5Td and costs MCr20. And requires TL 13 (D), 40Td of fuel, and a PP of rating 4 (TL13 PP: 8Td MCr24, uses 4Td fuel per 4 weeks; At TL15, 4Td, MCr12, uses 4Td fuel.) Under Bk5, there is no reason to not include the M1 capability.

I did say it was a quick look which I did using paper and pencil, my calculator died.

The trade off is having the maximum amount of data storage and communicator power to transfer the data or maneuver in normal space. Apparently the scout service opted for the ability to handle data and one ton of cargo in the original express boat design.

Would having a maneuver drive be a good idea I'd agree to having one, however the option of not having one is the one selected by the original author/designer. In my opinion the best fix is to doe the least amount of changes, which in this case would be leaving out the maneuver drive or introducing the upgrade.

Yes, I know in Book 5 Jump 4 is not available until TL 13, however per the Technology Level Table in Book 3 Jump Drive Types A through D are available at TL 9. A Book 2 Jump Drive Type B allows a maximum jump of four parsecs at TL 9.

Thanks for the help.