MT Only: A MegaTraveller Starship Design Example edited by Don McKinney

[snrdg082102]

Morning again from the Pacific Northwest,

The Travellers's Digest Number 13 1988 included the article A MegaTraveller Starship Example by Joe D. Fugate Sr., which was edited by Donald McKinney who made the document available on his web site. Donald updated the article with material from the Travellers' Digest Number 21 Traveller Q&A pages and additional errata not available in 1988. Joe D. Fugate Sr. answered a question with the designer pointer of not installing Basic Life Support and Extended Life Support in the fuel tanks.

From Donald's article:

1. A jump 4 drive requires 253,125 kl of fuel

2. Using the Regal's corrected volume of 1,012,500 kl the calculated Basic and Extended Life Support requirements are:

Basic Life Support: Power = -1,012.5 MW; Volume = -5,062.5 kl; Weight = 5,062.5 tons; Cost = Cr303,750,000

Extended Life Support: Power = -2,020 MW; Volume = -3,030 kl; Weight = 3,037.5 tons; Cost = Cr202,500,000. My calculations have the volume as -3,037.5 kl.

3. The design note is for not installing basic and extended life support in the fuel tanks. From the article in red text "Let's look at what happens when we remove the life support from the Jump fuel space:" which was calculated as 253,125 kl.

The new requirements are:

Basic Life Support: Power = -672.08 MW; Volume = -3,360.40 kl; Weight = 3,360.40 tons; Cost = Cr201,624,120

Extended Life Support: Power = -1,344.16 MW; Volume = -2,016.24 kl; Weight = 2,016.24 tons; Cost = Cr134,416,080.

My recalculations began as follows:

1,012,500 kl - 253,125 kl = 759,375 kl.

Basic Life Support Power = 0.001 x 759,375 = 759.3750 kl which is not a match.

Extended Life Support Power = 0.002 x 759,375 = 1,518.750 kl which is again not a match.

Taking the article's basic life support power input requirement of 672.08 MW and dividing by 0.001 results in a hull volume of 672,080 kl.

Taking the article's extended life support power input requirement of 1,344.16 MW and dividing by 0.002 results in a hull volume of 672,080 kl. (Changed the incorrect value of 0.001 to 0.002)

Checking to see the fuel tankage used I subtracted the total hull volume from the volume of 672,080 of the basic and extended life support requirements. The calculation returns the fuel tankage as being 1,012,500 - 672,080 = 340,420 kl. This is not the jump fuel tankage, however this is the power plant fuel requirement as determined in THE FUEL AND MISCELLANEOUS SECTION.

I hope that my calculation using the real Jump fuel tankage is correct and if I did the process correctly the calculations in the Environment Controls step is probably errata.

Was my approach of subtracting the jump fuel tankage from the total hull volume correct?

If I'm on the right track would this be errata?

 

[AnotherDilbert]

The design example is riddled with mistakes, as far as I can see. I get something like this:

Obvious differences marked in red.

Trying to do differential calculations from that mess is doomed to fail.

He tries to do something smart with fuel purification that I don't understand at a glance, and it seems to give strange results. Note that we don't have to refine all fuel in 6 h, hence we can use a smaller purification plant.

The ship is severely underpowered, since at least locomotion power is miscalculated.


Note that I calculate Basic & Extended Life Support for everything but fuel tankage, which I believe is compliant with TD#21. Since the fuel tankage is miscalculated in TD#13 my calculations will not agree with the example...

Note that I calculate with the full volume, not the rounded down volume from the Space Vessel Hull Table.

 

[snrdg082102]

Hello AnotherDilbert,

The design example is riddled with mistakes, as far as I can see. I get something like this:

Snipping the spreadsheet.


Yes, both the original article and Donald's edited version have what I've found to be math errors, but the basic design process is in my opinion valid.


I made a start of going through the TD 13 article and then switched to Donald's edited version using his MT Consolidated Errata v2.16. I got to the Communications section and found my first difference. IIRC correctly I used the COTI MT Errata sub-forum to contact him on my findings. Unfortunately, my attention was diverted to something else and failed to provide Donald with further updates before his passing.

Trying to do differential calculations from that mess is doomed to fail.

For the most part I've been able to, at least I think I have, recreate the calculations, provided I don't use the wrong modifiers.

He tries to do something smart with fuel purification that I don't understand at a glance, and it seems to give strange results. Note that we don't have to refine all fuel in 6 h, hence we can use a smaller purification plant.

In the Fuel and Miscellaneous section the fuel purification plants are calculated at half the capacity of the fuel tankage.


My method is to calculate the size of the power plant as I go starting with the output power listed on the table and the scale efficiency, modified with the MT Consolidated Errata v2.21.

The ship is severely underpowered, since at least locomotion power is miscalculated.

Joe Sr. and Donald downgraded the JD and MD from the CT TCS Regal design in an attempt to reclaim volume needed for power plant fuel tankage.

Note that I calculate Basic & Extended Life Support for everything but fuel tankage, which I believe is compliant with TD#21. Since the fuel tankage is miscalculated in TD#13 my calculations will not agree with the example...

I have two drafts of a MT spreadsheet based on Donald's version. One draft I've completed and my numbers do not match the ones in the spreadsheet inserted with the reply. I noticed that the spreadsheet with the reply has a JD4 and MD2. Joe Sr. and Donald downgraded the Regal to JD 3 and MD1.

Note that I calculate with the full volume, not the rounded down volume from the Space Vessel Hull Table.

MT Consolidated Errata v2.21 corrected the 75,000 UCP volume from 1,010,000 to 1,012,500 on the Space Vessel Hull table on MT Referee's Manual page 62.


Thank you for your detailed help which I'll be comparing to my results.

 

[AnotherDilbert]

Joe Sr. and Donald downgraded the JD and MD from the CT TCS Regal design in an attempt to reclaim volume needed for power plant fuel tankage.

OK, I looked at TD#13, where J-4 & M-2 is used.

 

[snrdg082102]

Hello AnotherDilbert,

OK, I looked at TD#13, where J-4 & M-2 is used.

Yep, Joe Sr. used JD 4 and MD 2, while Donald's edited version uses JD 3 and MD 1. At least I was only half half baked instead of totally out to lunch.

 

[snrdg082102]

Hello AnotherDilbert,


Looking at the attached copy of a spreadsheet I noticed that you included 75 airlocks. The number of airlocks appears to be equal to UCP tons divided by 1,000.


My research came up with Hull d-tons divided by 100 which I found in TNE FF&S Mk 1 Mod 0 (January 1994).


Can you let me know where you found the 1,000 figure.


Tom Rux

 

[AnotherDilbert]

Can you let me know where you found the 1,000 figure.

It's my own default, probably influenced by the FFS figure.

MegaTraveller allows no free airlocks, and we must have some...

 

[AnotherDilbert]

I took a look at the revised design example (thanks snrdg082102), and it is still a mess.

I get some thing like this (deviations marked in red):

Why would we only exclude jump fuel from life support, but not power plant fuel?

 

[snrdg082102]

Afternoon from the Pacific Northwest AnotherDilbert,

It's my own default, probably influenced by the FFS figure.

MegaTraveller allows no free airlocks, and we must have some...

Thank you for the clarification one the number of airlocks.



Checking my searchable MT PDFs I did not find any mention of "airlocks", which I've equated to CT having one airlock subsumed in the volumes of the bridge and engineering sections that can be moved anywhere if desired.


However, since I am not a fan of that particular CT design rule I opted for the TNE FF&S airlock and I have been considering imported T4 FF&S minimal airlocks and the decontamination addition.

 

[snrdg082102]

I took a look at the revised design example (thanks snrdg082102), and it is still a mess.

The mess is, in my opinion, still mainly math errors which I can understand from my work at creating a spreadsheet using the edited version.

I get some thing like this (deviations marked in red):

snipping the table

1. Looking at the Crew listing at the top of the table there is a red 7 under Maintenance.

From page 82 of the MT Referee's Manual Craft Design Flowchart 9 - Accommodations Step 7 Ship's Troops "Reduce maintenance crew (Cm) by 1 for every 6 ship's troops carried."

With 75 ship's troops the maintenance crew requirement is zero versus seven. Being retired USN the ship's troops, a.k.a. Marines, did not replace any of the ship's crew. However, I'm not overly concerned with the requirements as written.

2. Example HP wrong.

Yes, Donald used the value of the original article and is one of the items I've noted in my errata notes. Considering that Donald was working on the several different Traveller projects, juggling ct-starships, answering questions, juggling other unrelated Traveller hobbies, and real life I'm surprised that there are not more errata.

3. The change to Power Plant fuel consumption rate may not have been in MT Consolidated Errata v. 2.14 (03/05/08). This is also part of my errata notes.

4. EM Masking being calculated for a hull volume of 1,010,000 kl is similar to the hardpoints issue.

5. Passive EMS Array entry for the TL 13 system is more errata and probably was an error made by having to many irons in the fire. I'm not sure if the removal of the TL 13 system was part of MT Consolidated Errata v. 2.14 (03/05/08).

6. High Penetration Densitometer of the TL 15 is another bit of errata caused by reading the wrong table row. I made a similar error on the Extended Life Support's power requirement. The difference is I'm only working on this project and have no dead lines to meet but my own.

7. Neutrino Sensors the only item I see that does not match is the TL 14 system's weight in the edited article is shown as 0.0100 when the table has it as 0.095.

Why would we only exclude jump fuel from life support, but not power plant fuel?

The only explanation I can think of would be that Donald overlooked the need to recalculate the life support to exclude the power plant fuel tankage.

I think that Donald's power plant fuel tankage calculation may have forgotten to take out the fuel purification plants modifier to fuel consumption made in the Power Supply Section.

I've completed one draft spreadsheet that skipped estimating the crew and calculated the power supply section after going through to Step 10 in MT Referee's Manual.

In the example the Jump Fuel tankage is included with the Jump Drive volume while the power plant's fuel tankage is determined in the Fuel and Misc. Section.

My opinion is that the jump fuel tankage should be moved to the Fuel and Misc. Section. Does this suggested change sound reasonable?

Thank you for your help

 

[AnotherDilbert]

1. Looking at the Crew listing at the top of the table there is a red 7 under Maintenance.

From page 82 of the MT Referee's Manual Craft Design Flowchart 9 - Accommodations Step 7 Ship's Troops "Reduce maintenance crew (Cm) by 1 for every 6 ship's troops carried."

Yes, thanks, I noticed that after a while.

I have found a lot of other bugs in my rather primitive MT spreadsheet, that I have now corrected.

My opinion is that the jump fuel tankage should be moved to the Fuel and Misc. Section. Does this suggested change sound reasonable?

Agreed, all Fuel should be in the Fuel section.

 

[snrdg082102]

Evening from the Pacific Northwest AnotherDilbert

Yes, thanks, I noticed that after a while.

I missed the reference to Ship's Troops replacing maintenance crew in my first rough spreadsheet.

Personally, I think that the maintenance crew should be more along the requirements similar to CT LBB 5 HG2 2e Service Crew with the ship's troops replacing the security detail not the maintenance, supply, food service, and other undefined personnel.

I have found a lot of other bugs in my rather primitive MT spreadsheet, that I have now corrected.

To be honest my spreadsheets are primitive since I've found that when the advanced one I've downloaded break or have setting issues they are hard to fix. That is if they don't trip the security level of the spreadsheet application.

Agreed, all Fuel should be in the Fuel section.

Whenever I finish up going through the article I'm hoping to figure out where to put what I believe to be errata. I think the best way to show the errata is in the same format as Donald did, unfortunately I've not been able to contact Joe D. Fugate Sr. to get permission. The next best way I think is to use the format Donald McKinney used in his Consolidated Errata.

Thank you again for your help.

 

[snrdg082102]

Hello AnotherDilbert,

Back on August 13, 2019 I asked for clarification on the Maneuver Drive Thrust which the attached spreadsheet had as 2 and in Donald's edited version the thrust is listed as 1.

I'm going through Joe's original article again this time checking the calculations and the text. During the review of the Power Plant Section on page 44 I found the following:

"The old Regal design in TCS had a maneuver drive 6 - with the new design system, the power and volume requirements of such a maneuver drive are much too large. It seems reasonable that if we drop the maneuver drive all the way from 6 to 1, we might be in much better shape. How could I guess that? Experience; do a few designs of your own and you'll get the knack of it. Here's what we get by downsizing the maneuver capability:..."

This is a bit of errata the Donald caught in and indicated in the edited version.

Update to the information above.

The New Maneuver Drive calculations lists the drive as having 1,500 units which is the required number for a 1G rating not the 2G indicated.

 

[AnotherDilbert]

Back on August 13, 2019 I asked for clarification on the Maneuver Drive Thrust which the attached spreadsheet had as 2 and in Donald's edited version the thrust is listed as 1.

The spreadsheet in post #2 (with 2 G) is based on the original in TD#13.

The spreadsheet in post #8 (with 1 G) is based in Don's errata.

 

[snrdg082102]

A soggy morning from the Pacific Northwest AnotherDilbert,

The spreadsheet in post #2 (with 2 G) is based on the original in TD#13.

The spreadsheet in post #8 (with 1 G) is based in Don's errata.

Yes, the first line of the block on the top right column of TD #13 page 44 does show that the Maneuver Drive = 2. However, below the Maneuver entry the number of units is listed as 1,500. Looking on MT Referee's Manual page 65 5 Maneuver Drive Table cross referencing Hull Displ 75,000
to 1,500 units is in the first column which corresponds to 1G. Cross referencing 2G with Hull Displ 75,000 the number of units would be 3,750.

The text that was cited at the bottom of the left hand column of page 44 states that the Maneuver Drive was dropped to 1.

Neither the original TD#13 text or units shown support Maneuver=2, of course had I not been checking out the numbers and read the text I would not have discovered the glitch.

 

[AnotherDilbert]

Yes, the first line of the block on the top right column of TD #13 page 44 does show that the Maneuver Drive = 2. However, below the Maneuver entry the number of units is listed as 1,500.

Yes, you are correct. I didn't even notice that among the other problems.

 

[snrdg082102]

Hello AnotherDilbert

Yes, you are correct. I didn't even notice that among the other problems.

I missed the connection too and I would have missed the text and entry had I not checked MT Referee's Manual followed by reading the text.

 

[atpollard]

This would probably be why TNE FF&S never surpassed CT High Guard in popularity for Starship Design.

On a serious note, there is a lot to love about MT design (not the errors), but in my opinion it is about 1 decimal place too complex for starships. There are too many little calculations that increase the chance for an error and have minimal impact on the final design.

 

[aramis]

This would probably be why TNE FF&S never surpassed CT High Guard in popularity for Starship Design.

On a serious note, there is a lot to love about MT design (not the errors), but in my opinion it is about 1 decimal place too complex for starships. There are too many little calculations that increase the chance for an error and have minimal impact on the final design.

Add to that that one can simply plug in the values from CT HG into MT ship combat...

 

[AnotherDilbert]

This would probably be why TNE FF&S never surpassed CT High Guard in popularity for Starship Design.

This particular problem is absolutely the same in HG; the author said M-2, but calculated a 2% (M-1) drive.

On a serious note, there is a lot to love about MT design (not the errors), but in my opinion it is about 1 decimal place too complex for starships. There are too many little calculations that increase the chance for an error and have minimal impact on the final design.

Agreed, it's too fiddly to use without computer support.

But the coherent design and combat systems from ground cars to space-ships is a nice idea.