CT Only: Supplement 7 Express Boat

[snrdg082102]

Hello all,

I just started to check Supplement 7 designs using the spreadsheet I created using the CT Book 2 design and construction process only to discover that the Express Boat on pages 8 through 10 can not be built. Nor can the design be built using CT Book 5.

The Express Boat in Supplement 7 states that the power plant and jump drive is built as one unit.

This is not possible since both Book 2 and Book 5 clearly state that all starships and non-starships require a power plant and all starships require a jump drive.

Per Supplement 7 the Express Boat is built on a 100-ton hull and is capable of Jump-4. A Jump-4 Drive requires 40 tons of fuel to make a single four parsec jump.

How is power being generated to run life support for the approximately one week in jump space and then having to wait to be picked up by the tender?

Does anyone know how the Express Boat was designed, because I sure can't figure this one out even after reading the Consolidated CT Errata?

 

[atpollard]

I don't have the details (or care enough to look for them) but my understanding is that the key to the design of the X-boat and Tender lies in the earlier 1977 (?) LBB2 rules.

After that it is an issue of preserving an iconic legacy design.

 

[snrdg082102]

Howdy atpollard,

Thank you for the information.

I don't have the details (or care enough to look for them) but my understanding is that the key to the design of the X-boat and Tender lies in the earlier 1977 (?) LBB2 rules.

After that it is an issue of preserving an iconic legacy design.

I have a copy of LBB2 1979 7th printing and page 13 has the following rule:

"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 may be higher than the maneuver drive letter)."

Unfortunately, I'm still not able to recreate the design as published in Supplement 7. In order to get 1 ton of cargo capacity I need to have 51 tons of fuel and I get MCr55.8.

Basically the Express Boat and the Express Boat Tender is in need of a total rewrite to conform to CT Book 2 1981 rules and very probably for Book 5 too.

 

[aramis]

None of the standard designs were done using CT-81. They were all CT-77. The X-Boat can't be done under CT-81.

 

[mike wightman]

As has been said:
in '77 edition a jump drive doesn't need a power plant as well
in '81 edition a jump drive does require a power plant of equal rating, plus power plant fuel.

By fixing something that wasn't broken the designers of revised edition invalidated an iconic design of the 3I setting.
They tried the old "write some fluff" to explain it, but the bottom line is the X-boat is a broken design thanks to ship construction rule changes.

 

[mike wightman]

I have a copy of LBB2 1979 7th printing and page 13 has the following rule:

"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 may be higher than the maneuver drive letter)."

The x-boat has no m-drive so it doesn't need a power plant under '77 edition rules.

Unfortunately, I'm still not able to recreate the design as published in Supplement 7. In order to get 1 ton of cargo capacity I need to have 51 tons of fuel and I get MCr55.8.

It doesn't have a power plant, you don't need to install one or provide fuel for it, the fluff text is an attempt to paper over a broken design.

Basically the Express Boat and the Express Boat Tender is in need of a total rewrite to conform to CT Book 2 1981 rules and very probably for Book 5 too.

A jump 4 x-boat can not be built using '81 revised without major rule fudges

 

[rancke]

The best solution (IMO) would have been to reduce the ridiculous power plant consumption rates and give X-boats a small maneuver drive. A fractional maneuver drive would do.

Even if jump drives didn't need a power plant, the maneuver-challenged X-boat is (again IMO) a silly idea.


Hans

 

[mike wightman]

It's almost as if either the authors didn't know their own rules or didn't consider the consequences of changing the rules...

 

[snrdg082102]

Morning PDT Aramis, Mike Wightman, and Rancke,

Aramis:
I have completed running CT Book 2 1981 standard ship designs through my spreadsheet and with some work I was able to match all their costs per Consolidated CT Errata. I know that the mercenary cruiser's cargo capacity is less that the 80 tons shown in the write-up with 48 tons allocated to fuelling the two 50-ton modular cutters. Without checking I think that the only other issue was crew.

From what I'm getting only the standard designs in Book 2 1981 got recalculated using the revised deign and construction rules.

No wonder there a issues in recreating the designs using the processes in Book 2 and Book 5.

Mike Wightman:
Supplement 7 states that the jump drive carries out the power plant capacities and functions, which technically means that the express boat does have a power plant just not the standard type.

Per Supplement 7 the express boat has a range of approximately seven days in jump space and three days in normal space waiting to be picked up by an express boat tender or other assigned ship. If my guess is right part of the forty tons of fuel is needed to keep life support going for the three days. When making jumps between one and three parsecs there should be enough fuel to run the jump drive's power plant capacities and functions for at least three days. All the fuel is used to make a four parsec jump which in my opinion means there isn't anything left to generate power for three days waiting for pick-up.

To me this looks like a broken design at least when the express boat makes a four parsec jump.

Comparing the ship write-ups and their deck plans I've discovered more often than not including the tonnage of airlocks and ship's lockers reduces the ship's cargo capacity. When I brought the question up on I believe ct-starships the census was that airlocks and ship's lockers are part of the cargo capacity, which doesn't make a whole lot of sense to me.

Personally, I think Book 2 1977 did some fudging to get the express boat design to work.

I'm guessing that the people using and editing the 1977 and 1981 Book 2 design and construction rules didn't have the final draft of the rules or had the time to use them verifying the work.

Rancke:
Your comment about the maneuver drive made me realize that an express boat has to be towed to the outbound jump point which means they have an almost non-existent acceleration.

Thank you everyone for the replies.

 

[GypsyComet]

Traders & Gunboats predates the Book 2 revision, IIRC. 30+ years later we tend to forget how much of that seminal work was done under the 77 rules.

X-Boats aren't towed unless they end up in the wrong part of a system for their next jump. They are already outside any jump horizons, and will likely go back the way they came in once refueled.

Airlocks and the Ship's Locker have certain unstated default tonnage that is part of Bridge allocation, IMO. Anything beyond that is coming from Cargo, Subcraft, "Standard" Engineering, or Stateroom allocations. The Marava's huge cargo airlocks are cargo space, for example, or in some cases are the Air/Raft bay doing double duty. Unless a Ship's Locker shows up on the deckplans, it it just a collection of Engineering Lockers, closets on the Bridge or in a crew stateroom, and odd bits of bulkhead stow spaces. If a deckplan maker goes so far as to designate a "Secure Cargo" space, it can certainly double as the Ship's Locker (or part of it) and would be part of Cargo, but that is not the only way to approach it.

 

[mike wightman]

Let's try to explain this again.

The x-boat is a LBB2 '77 edition design and has no power plant, power plant fuel or manoeuvre drive. It even says so in the text.
The stat block is just misleading hand wavy fluff to try and conform to HG compatibility - but it doesn't work except as a 77 design.

Here is the direct quote from S7:

the express boat is fitted with drives producing jump-4, and nothing else. There is no power plant or maneuver drive installation. Fuel tankage is forty tons, enough for one jump.

Note also it has a 1bis computer but under 81 and HG rules it needs a model 4.

You can build a TL13 x-boat using HG2, but not using 81 LBB2

 

[aramis]

the 40 Td of fuel is absolutely needed for stock Bk2 (either edition) J4. The X-boat has no life support fuel. NOT A DROP.

There is an emergency power rule buried somewhere.

And, no, the designs generally didn't get redesigned for the 1981 edition. The only one in '77 that needed it was the Type S - due to the change in computer rules.

CT 77 Core has only: A, C, M, R, S, Y
CT 81 Core has only: A, C, M, R, S, T, Y
CT 82 (TTB) has: A, C, K, L, M, R, S, T, Y

Note that the X-Boat isn't in the 1977 core, but is a valid 1977 design.. it's introduced in the 1980 Supplement 7. Its 1st appearance in a core rulebook is the 1987 MegaTraveller rules

 

[mike wightman]

Hmm, just noticed the entry for the type M in TTB is missing a line of text from the LBB2 version.

 

[snrdg082102]

Howdy GypsyComet,

Thank you for dropping by and sharing your wisdom.

Traders & Gunboats predates the Book 2 revision, IIRC. 30+ years later we tend to forget how much of that seminal work was done under the 77 rules.

Unfortunately I was one of those people who never did get Book 2 to recreate the published designs and went with Book 5. As indicated I have finally got a handle on Book 2 1981 enough to get MCr right. Of course I may have discovered possible errata on one or two of the Book 2 1981 standard designs. My calculations for the mercenary cruiser's cargo capacity works out to be 60 tons versus the listed 80 tons.

X-Boats aren't towed unless they end up in the wrong part of a system for their next jump. They are already outside any jump horizons, and will likely go back the way they came in once refueled.

You must have had a kind and gentle referee, most of mine had the express boats showing up in the wrong place.

Airlocks and the Ship's Locker have certain unstated default tonnage that is part of Bridge allocation, IMO. Anything beyond that is coming from Cargo, Subcraft, "Standard" Engineering, or Stateroom allocations. The Marava's huge cargo airlocks are cargo space, for example, or in some cases are the Air/Raft bay doing double duty. Unless a Ship's Locker shows up on the deckplans, it it just a collection of Engineering Lockers, closets on the Bridge or in a crew stateroom, and odd bits of bulkhead stow spaces. If a deckplan maker goes so far as to designate a "Secure Cargo" space, it can certainly double as the Ship's Locker (or part of it) and would be part of Cargo, but that is not the only way to approach it.

There is a problem with the unstated default in my opinion when a deck plan has an airlock in the engineering spaces. My common sense tells me that this airlock is part of engineering not the bridge.

I've taken a course in architectural drawing which stressed that one puts the components in the location they will be used in which takes up space. Of the top of my head I don't remember seeing my deck plans with airlocks and/or ship's lockers shown with in the area identified with the bridge. Usually, they are drawn with a bulkhead and a hatch between the bridge and their location.

On the one or two deck plans I actually have done counting the airlocks and ship's lockers as separate parts has gotten me closer to matching the volume of the hull.

Thank you again for sharing with me.

 

[rancke]

Assuming odd hull sizes (e.g. 110T or even 111T) and fractional maneuver drives (say in tenths of Gs), what's the smallest post-revision J4 ship you can make with a 0.1G maneuver drive? That's the size I would make "real" X-boats.

Note: The 100T minimum for a jump-capable vessel remains in force.

EDIT: Sorry, I meant PRE-revision. I.e. 1st Ed. Book 2. We know that a 100T J4, M1 is possible under HG.


Hans

 

[mike wightman]

HG2, TL13 design
20t bridge
model 4 comp 4t
jump 4 5t
j fuel 40t
TL13pp 8t
pp fuel 4t
md1 2t
2 staterooms 8t
total =91t
1t for cargo, 8t extra data storage capacity etc.

 

[snrdg082102]

Hello Mike Wightman,

Let's try to explain this again.

The x-boat is a LBB2 '77 edition design and has no power plant, power plant fuel or manoeuvre drive. It even says so in the text.
The stat block is just misleading hand wavy fluff to try and conform to HG compatibility - but it doesn't work except as a 77 design.

Here is the direct quote from S7:

the express boat is fitted with drives producing jump-4, and nothing else. There is no power plant or maneuver drive installation. Fuel tankage is forty tons, enough for one jump.

Supplement 7 page 9 XBOAT - 51216
Power Plant: None. Jump drives carry power plant capacities and functions.

The deck plan drawing above the data box has the following caption "Jump Drive and Power Plant" with a line drawn to the outline of a piece of equipment.

Since the jump drive carries the power plant capacities and functions. If the jump drive is providing the power to operate the ship then technically there is a power plant.

Looks like we will disagree on the power plant and the need to have enough fuel to keep the electronics running and the pilot and any passengers breathing, fed, and warm.

Note also it has a 1bis computer but under 81 and HG rules it needs a model 4.

The source of the note is found Supplement 7 page 9 XBOAT - 51216 "Electronics does indicate that the computer is an ISMM Model/1bis."

However per the text on Supplement 7 page 10 Express Boat (Type X): "The standard bridge is complemented by a Model/4 computer, massive communicators, and message banks."

Supplement 9 page 12 Electronics Model/4 computer. Extensive message transmission equipment and storage banks.

There is a conflict between page 9 and page 10. The Consolidated CT Errata correct page 9 to Model 4 in keeping with the fluff.

The computer rules as far as I can determine in Book 2 1977 needs 5 CPU space to run the Navigation, Generate, and Jump 4 programs. A Model/1bis has a CPU space of 4.

Book 2 1981 page 14 has the following: "For example, a ship must have a Model/4 computer before it can perform Jump-4, in addition to the proper size jump drive.

Based on all the above the express boat has a Model 4.

You can build a TL13 x-boat using HG2, but not using 81 LBB2

The express boat built using Book 5 HG1 or HG2 must have a power plant which is not what is outlined in Supplements 7 and 9 since they do not have a power plant.

 

[rancke]

The express boat built using Book 5 HG1 or HG2 must have a power plant which is not what is outlined in Supplements 7 and 9 since they do not have a power plant.

Unlike the real world, fictional worlds are subject to revision. That's the basic concept of the retcon. Under the 77 rules the power plant-challenged X-boat was possible. Under the 81 rules and HG, it wasn't. For the OTU that meant that things changed so that it never was possible. It's not that they were possible in 1105 and turned impossible in 1110. They never were possible. Unfortunately, the writers didn't follow through on that logic and failed to retcon the X-boats, leaving them a canker in the OTU from that day until this. There is no way to reconcile descriptions made under the old rules with the new rules, even if the writers pretended that there were. Can't be done, and any attempt to do so is futile. And no amount of quoting unrevised descriptions based on the 77 rules will change that.


Hans

 

[mike wightman]

Just to add fuel to the fire the DGP authors of MT based the core technology on their 77 edition of the rules, hence the jump drive in MT doesn't need a power plant either

So when the rebellion occurred not only did ships suddenly require far less jump fuel, they also could go back to jumping with no power plant, and used their full allocation of jump fuel regardless of jump distance.

 

[aramis]

Assuming odd hull sizes (e.g. 110T or even 111T) and fractional maneuver drives (say in tenths of Gs), what's the smallest post-revision J4 ship you can make with a 0.1G maneuver drive? That's the size I would make "real" X-boats.

Note: The 100T minimum for a jump-capable vessel remains in force.

EDIT: Sorry, I meant PRE-revision. I.e. 1st Ed. Book 2. We know that a 100T J4, M1 is possible under HG.


Hans

Under Bk2... which does NOT allow for fractional sizes in drive size - anything between 101 and 200 uses drives like a 200Td... the only exception is for JFuel.

Fixed Costs: Bridge, 2xSR, Model 4, 5ton JDrive Kicker, 40Td PP fuel, 1 Td PP Kicker
78Td. 20+8+4+5+40+1

Proportional Tonnages: 4x2.5% JD and 4x1.5% PP, 40% JFuel
54% = 10%+6%+40%

78=(1-0.56)X
78=(0.44)X
78/0.44=X=177.3

Since this is under 200, we can presume only 2 crew Pilot, Engineer.

So, rounding sizes up for each...
JD 5+(0.1 * 177) = 22.7 = 25 = D
PP D = 13

So... iteration 2:
_20 Bridge
__4 Model 4
__8 two Staterooms
_40 Fuel P4
_25 JD D (J4 on ≤200Td)
_13 PP D (P4 on ≤200Td)
===
110 Td of a 110=(1-0.4)X Td hull

110=0.6X
110/0.6=X
183.333 = X

Since you are only allowed 1/2 ton rounding under Book 2
184 Td
0.4x184=73.6 = 74Td fuel.

And so, iteration 3

_TD _MCr_
184 _18.4 Hull
_20 __1.0 Bridge (101-200Td)
__4 _30.0 Model 4
__8 __0.5 two Staterooms
_40 __0.0 Fuel P4
_25 _40.0 JD D (J4 on ≤200Td)
_13 _32.0 PP D (P4 on ≤200Td)
_74 __0.0 Fuel J4
=== =====
184 121.9

Note that the hull cost is over double that of a 200Td (MCr18.1 vs MCr8), or or a mortgage increase of Cr42084, but it saves on 1 crewman and stateroom, at around Cr1800+LS per month... or about Cr5800/month, including salary... and on 4 tons a jump on fuel, for only about 8K a month fuel savings.

In other words, it's cheaper to make it a 200Ton 3 crew design.

The other viable option is to give it 8 days of PP fuel, and keep it 100Td


_TD _MCr_
100 __2.00 Hull
_20 __1.00 Bridge (101-200Td)
__4 _30.00 Model 4
__1 __0.25 two Staterooms
_10 __0.00 Fuel P4 for 1/4 month
_15 _40.00 JD B (J4 on ≤100Td)
__7 _16.00 PP B (P4 on ≤200Td)
_40 __0.00 Fuel J4
=== =====
100 MCr89.25