MT: RM Hulls and Non-standard Extrapolation

[snrdg082102]

I found 7 of 32 UCP values that didn't match the results of the formula UCP x 13.5 = Volume in the vehicle table. Of the 17 entries 8 UCP values, 25, 35, 45, etc, don't match the formula.

Vehicle UCPs in question: 0.007, 0.019, 0.056, 0.093, 0.130, 0.25, and 0.75. Example: UCP 0.007 = 0.10 in the table and calculating the volume, round(0.007 x 13.5,2) = round(0.0945,2)= 0.09

The differences appear to be in how rounding the number off was handless The values appear to rounded to two decimal places. The table shows 0.007 has a 0.10 kL volume while the formula has the vale as .007 x 13.5 = 0.0945

Small Craft has 8 of 17 entries in the table that don't match the calculated value. Again the reason appears to be how rounding was handled. The 8 all end in 5. In this case the values have the ones place rounded to 1 or 5. The result is that the values in the tables are 3 kL off.

I have an Excel spreadsheet, I'm still trying to get used to OpenOffice, that has my results. (I already had to re-type everything since I took too long writing and I lost connection.

Section 2
I discovered, even with the correction by the consolidated errata, that as long as the custom hull UCP falls between two consecutive values, 1000, 2000, works very well. Unfortunately, trying to extrapolate weight and price between values like, 007 and .019 or 50,000 to 75,000, don't work as well. TNE has an interpolation method that appears to work.

Should I submit Section to Donald McKinney, or has someone beaten me that task?

 

[McPerth]

Vehicle UCPs in question: 0.007, 0.019, 0.056, 0.093, 0.130, 0.25, and 0.75. Example: UCP 0.007 = 0.10 in the table and calculating the volume, round(0.007 x 13.5,2) = round(0.0945,2)= 0.09

The differences appear to be in how rounding the number off was handless The values appear to rounded to two decimal places. The table shows 0.007 has a 0.10 kL volume while the formula has the vale as .007 x 13.5 = 0.0945

Small Craft has 8 of 17 entries in the table that don't match the calculated value. Again the reason appears to be how rounding was handled. The 8 all end in 5. In this case the values have the ones place rounded to 1 or 5. The result is that the values in the tables are 3 kL off.

I don't have my RM here to support my own suposition, but I'm afraid you calculated it inversely as they did:

You begin with the 0.007 dton and try to convert to kl, and result is 0.0945, so you correctly round it to 0.09.

My thinking (and I guess that of the designers) is I need a volume of 0.1 kl, how much does that represent in dton? 0.1 divided by 13.5, and result is 0.007474074..., rounded to 0.007.

I'm affraid I can test this with more entries now, but I guess they will work too.

 

[snrdg082102]

I don't have my RM here to support my own supposition, but I'm afraid you calculated it inversely as they did:

You begin with the 0.007 dtons and try to convert to kl, and result is 0.0945, so you correctly round it to 0.09.

My thinking (and I guess that of the designers) is I need a volume of 0.1 kl, how much does that represent in dtons? 0.1 divided by 13.5, and result is 0.007474074..., rounded to 0.007.

I'm afraid I can test this with more entries now, but I guess they will work too.

Morning McPerth,


Thanks for the reply and the most probable solution to the issue. The post I sent was the third attempt and pared down to minimum. Not to mention not well checked, edit coming up.

Here is how I started. MT: RM p. 57 states 1 displacement ton = 13.5 kL. I checked the vehicle table and saw that UCP 1 = 13.5 kL. Looking over the tables you find a progression. Abbreviations: Vehicle = VE, Small Craft = SC, Space Vessel = SV.

VE: UCP 1 = 13.5 and UCP 10 = 135
SC: UCP 100 = 1,350
SV: UCP 100 = 1,350, UCP 1,000 = 13,500, UCP 10,000 = 135,000, UCP 100000 = 1,350,000, and UCP 1,000,000 = 13,500,000

Next I checked to see if there were other UCP values that had a similar progression to UCP 1. The following list is not complete just the first seven matches I found.

Note that errata corrected Vehicle Table entries 0.050 to 0.500 and 0.075 to 0.750.

UCP
0.007(VE), 7.000(VE), 70.0(SC), 700(SV), 7,000(SV), & 700,000(SV)
0.019(VE) & 19.000(VE)
0.130(VE) & 13.000(VE)
0.025(VE), 25.0(SC)
0.500(VE), 5.000(VE), 50.0(SC), 500(SV), 5,000(SV), 50,000(SV), & 500,000(SV)
0.750(VE), 75.0(SC), & 75,000(SV)
1.000(VE), 10.000(VE), 100(SC), 100(SV), 1,000(SV), 10,000(SV), 100,000(SV), & 1,000,000(SV)

Here is the comparison for ("Bond, James Bond") 0.007, I'm very sorry I just could not resist temptation. Anyway here is the list

VE UCP: 0.007 = 0.10 and UCP 7.000 = 94.5
SC UCP: 70.0 = 945
SV UCP: 700 = 9450, UCP 7,000 = 94,500, UCP 700,000 = 9,450,000

VE UCP 0.007 doesn't fit the progression based on the five other data points.

I tried the next value that appears to be a progression which are in VE table as UCP 0.019 and 19.0.

.019 = 0.25 and 19 = 256.50

The two UCPs to volume relationships, at least to me, appear to be inaccurate.

I then looked at the Space Vessel Table checking the UCP to Volume relationship.

Method 1 (M1): Volume ÷ 13.5 and Method 2 (M2): UCP x 13.5
M2 is the one I went with (less math to deal with)

M1: 1350 ÷ 13.5 = 100
M2: UCP 100 x 13.5 = 1350

M1: 121500 ÷ 13.5 = 9000
M2: UCP 9000 x 13.5 = 121500

M1: 1,010,000 ÷ 13.5 = 74814.81481
M2: UCP 75,000 x 13.5 = 1,012,500
Please note that the consolidated errata corrected the entry in MT: RM to 1,012,500.

Of the 32 SV table entries only 1 entry, prior to the errata correction, was out of whack. In the process of the correction the UCP gained 2,500 kL.

Of the 8 SC table entries 6 have lost about 3 kL and 2 gained by about the same amount of 3 kL. I haven't checked the numbers for the VE table to easy

Thanks for the reply and following my long winded verbiage.

 

[McPerth]

Hi, Tom

Now that I have my RM at hand, I see most of those incongruences may be derived (again IMHO, I cannont talk for DGP people) from what they did calculate it.

I guess most of the 'vehicles' under 0.25 dton where designed by taking the volume needed (all of them round numbers, if you see, 0.1, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75 and 2.5) and divided them by 13.5 to find the tonnage, so we have those strange numbers in the dton column (it works, after rounding).

From 0.25 dton on, they seem to have taken the tonnage and multiplied by 13.5, and that'swhy form 0.25 dton on the tonnage are round numbers, while volumes' are quite more strange.

Of course, I repeat, that's my personal interpretation of the table, I don't pretend it to be an official explanation, as I'm not related to DGP.

EDIT: Anyway I've never designed anything smaller than 0.25 dton (this grav bike http://www.travellerrpg.com/CotI/Discuss/showpost.php?p=376972&postcount=30), and I guess most of smaller designs were taken from CT B8 (robots), where volume was given in liters, and no reference to dton was given

 

[snrdg082102]

Hi, Tom

Now that I have my RM at hand, I see most of those incongruences may be derived (again IMHO, I cannot talk for DGP people) from what they did calculate it.

I guess most of the 'vehicles' under 0.25 dton where designed by taking the volume needed (all of them round numbers, if you see, 0.1, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75 and 2.5) and divided them by 13.5 to find the tonnage, so we have those strange numbers in the dton column (it works, after rounding).

From 0.25 dton on, they seem to have taken the tonnage and multiplied by 13.5, and that's why form 0.25 dton on the tonnage are round numbers, while volumes' are quite more strange.

Of course, I repeat, that's my personal interpretation of the table, I don't pretend it to be an official explanation, as I'm not related to DGP.

EDIT: Anyway I've never designed anything smaller than 0.25 dton (this grav bike http://www.travellerrpg.com/CotI/Discuss/showpost.php?p=376972&postcount=30), and I guess most of smaller designs were taken from CT B8 (robots), where volume was given in liters, and no reference to dton was given

Thanks for the reply and the time to check out my findings. Nice to know I'm not totally out to lunch.

Hindsight is 20/20 as they say and after 20 odd years of hindsight changing calculating methods may not have been a good idea. Of course I'm the type who prefers following the same, and often very boring, steps.

Never for a minute thought that you would claim to be making official comments unless you proved you had the authority or right to.

Nice bike specifications.

My MT: RM has GDW, now FFE, stamped on the covers not DGP, but they both seem to have the same inconsistencies in how the conversion between UCP/dtons and Volume were calculated. Any designs I might share will have a note indicating that the volume reflects multiplying UCP by 13.5.

I do have some DGP MT stuff specifically the Starship Operator's Manual Vol. 1, MT Alien Vol.1: Vilani & Vargr, and 101 Vehicles.

I guess I'm going to spend some time on the spreadsheets. Catch you later.

 

[PFVA63]

Hi

Just as an aside, over the years I've found that rounding and such can have a very significant effect on being able to match alot of published stuff.

Specifically I once put together a spreadsheet to do ship designs to the GURPS Traveller: Interstellar Wars rules and one thing that I found was if I rounded each intermediate step of the calcs to just a few significant digits I was able to replicate most (all?) the designs in the book, but if I didn't round at each step sometimes things would cascade resulting in some significant/noticeable differences in the overall designs.

Regards

Pat

 

[snrdg082102]

Just as an aside, over the years I've found that rounding and such can have a very significant effect on being able to match alot of published stuff.

Specifically I once put together a spreadsheet to do ship designs to the GURPS Traveller: Interstellar Wars rules and one thing that I found was if I rounded each intermediate step of the calcs to just a few significant digits I was able to replicate most (all?) the designs in the book, but if I didn't round at each step sometimes things would cascade resulting in some significant/noticeable differences in the overall designs.

Regards

Pat

Howdy Pat,

You are right without knowing how the designer rounds and at which stages the rounding is done trying to replicate a design is nearly impossible. Sometimes you do get lucky, unfortunately 99% of the time the only design I match is the example.

Thanks for the aside.

 

[OjnoTheRed]

Yes, McPerth has it absolutely right - in the Robot designs in both the spreadsheet in my signature and the supplement, the starting point was always the actual volume in litres. The UCP figure, rounded to 3 decimal places, is derived from the volume (= volume in litres / 13,500). For tiny sizes I started rounding to 4 decimal places.

To my mind, the UCP figure for displacement tons are really an after-thought in the design process and allowed existing Traveller fans to readily compare existing classic designs (e.g. the Type S Scout/Courier) to volumes in the new design system. That is to say, it's a rough and ready short-hand for Traveller players. The design system is actually ruled by measurement in litres and kilolitres (although the designs posted here by MajorB show that you can look at this another way, with hull calculated to fit around the desired components and capability of the vehicle).

 

[snrdg082102]

Yes, McPerth has it absolutely right - in the Robot designs in both the spreadsheet in my signature and the supplement, the starting point was always the actual volume in liters. The UCP figure, rounded to 3 decimal places, is derived from the volume (= volume in liters / 13,500). For tiny sizes I started rounding to 4 decimal places.

To my mind, the UCP figure for displacement tons are really an after-thought in the design process and allowed existing Traveller fans to readily compare existing classic designs (e.g. the Type S Scout/Courier) to volumes in the new design system. That is to say, it's a rough and ready short-hand for Traveller players. The design system is actually ruled by measurement in liters and kiloliters (although the designs posted here by MajorB show that you can look at this another way, with hull calculated to fit around the desired components and capability of the vehicle).

Thank you for confirming that the UCP was derived by dividing hull volume by 13,500 l = 13.5 kl = 1 dton. I've been reviewing the tables and concluded that UCP was an afterthought.

I'm not completely satisfied with the extrapolation method, especially for volumes that have gaps between the numbers like 50,000, 75,000, 100,000.

My method, more time consuming, is going to be MT extrapolate, Average the numbers, TNE Interpolate, and then decide which number fits best. As a foot note I'll mention how I came up with the numbers. Of course, I could always keep my work from public view.

Again thanks for the help.

 

[snrdg082102]

Darn my memory. If I'm not mistaken 99%, there could be something being measured in liters, of the MT: RM Craft design system volume is measured in kiloliters. Of course using liters makes more sense for the smaller designs like most vehicles and robots.

Thanks again for helping sort out MT.

 

[McPerth]

My MT: RM has GDW, now FFE, stamped on the covers not DGP, but they both seem to have the same inconsistencies in how the conversion between UCP/dtons and Volume were calculated. Any designs I might share will have a note indicating that the volume reflects multiplying UCP by 13.5.

I do have some DGP MT stuff specifically the Starship Operator's Manual Vol. 1, MT Alien Vol.1: Vilani & Vargr, and 101 Vehicles.

For what I've read (or at least understood) in those forums from people that know better than myself, MT was designed by DGP, even if published by GDW

 

[snrdg082102]

For what I've read (or at least understood) in those forums from people that know better than myself, MT was designed by DGP, even if published by GDW

Apparently I'm missing some forums because I don't recall conversations about DGP designing MegaTraveller. Also, I've been into Traveller, all variations, since the early 1980s starting with CT and my impression when I picked MT in 1989 or 1990 the game was by Marc W. Miller and publisher GDW. Of course my memory could be wrong.

Let me check my copy of The Traveller Bibliography for MegaTraveller. The section on MegaTraveller shows the author to be Marc W. Miller, the publisher as GDW and publishing dates of 1987 and 1988.

Downport.com, http://www.downport.com/, has links to sources that I feel will support the information provided above that GDW and Marc W. Miller originated MT. Of course if I am in error I'd like to know.

DGP also produced MT material, three of which I mentioned since I was able to get my hands on physical copies. Of course I'd really like to purchase the FFE CD-ROM copies for CT, MT, okay all the Traveller variants offered. The problem is I haven't hit the lottery yet to afford them.

Catch you later.

 

[sfchbryan]

Marc's name is all over everything, but DGP was doing all of the work at that time. The parts of MT that were cut & pasted from CT were by Marc, but most of the new material & the task system was done by DGP.

At the time, GDW wasn't very interested in Traveller.

 

[aramis]

Apparently I'm missing some forums because I don't recall conversations about DGP designing MegaTraveller. Also, I've been into Traveller, all variations, since the early 1980s starting with CT and my impression when I picked MT in 1989 or 1990 the game was by Marc W. Miller and publisher GDW. Of course my memory could be wrong.

Let me check my copy of The Traveller Bibliography for MegaTraveller. The section on MegaTraveller shows the author to be Marc W. Miller, the publisher as GDW and publishing dates of 1987 and 1988.

If you look at the actual CREDITS pages for MT, you find the DGP guys: Joe D. Fugate Sr and Gary L Thomas...

From the MT PM:

Credits
Design ..................................................... Marc W. Miller
Additional Design .................................. Frank Chadwick, Joe D. Fugate Sr., Gary L. Thomas
Editing ................................................ Joe D. Fugate Sr. and Gary L. Thomas
Contributions.. ....................................... Loren Wiseman, J. Andrew Keith, John Harshman, Timothy B. Brown​

 

[snrdg082102]

Thanks aramis for the additional data. I'd say that there was a team effort on MT. IIRC GDW was expanding CT, thinking about future projects like TNE, T4, Traveller 2300, er uh, drat I can't think of the name for at least one more game.

I'd like to have a compromise by saying both GDW and DGP worked on MT since I wasn't being a fly on the wall. Kind of hard when I was either at sea on a detergent, oops I mean deterrent patrol in the Pac or in port training.

Thanks again aramis for the information.

 

[aramis]

Thanks aramis for the additional data. I'd say that there was a team effort on MT.

Nice idea, but not born out by the comments of Marc, Loren, Frank, Joe, and Gary over the years. It's been well established that Marc had almost nothing to do with MT once it was initially decided on the rebellion motif and overall plotline; Joe and Gary did the editing and additional development for MT; Frank and Loren did the development during CT (just go look at the credits) and didn't do much for MT; the printing issues were due to entry into the typesetter from DGP's Mac-based drafts; the designers' notes for MT are by Joe and Gary in one of the MTJ's; Frank was busy on other projects at the time MT was developed (including T2K and board games), as was Loren (T2K, 2300), and Marc (board games).

They contracted DGP to do it for them. If my books weren't inaccessible at the moment, I'd provide page references.

 

[snrdg082102]

Nice idea, but not born out by the comments of Marc, Loren, Frank, Joe, and Gary over the years. It's been well established that Marc had almost nothing to do with MT once it was initially decided on the rebellion motif and overall plot line; Joe and Gary did the editing and additional development for MT; Frank and Loren did the development during CT (just go look at the credits) and didn't do much for MT; the printing issues were due to entry into the typesetter from DGP's Mac-based drafts; the designers' notes for MT are by Joe and Gary in one of the MTJ's; Frank was busy on other projects at the time MT was developed (including T2K and board games), as was Loren (T2K, 2300), and Marc (board games).

They contracted DGP to do it for them. If my books weren't inaccessible at the moment, I'd provide page references.

I guess I won't run for political office I can't even pull the wool over some of the peoples eyes;-). Actually, I haven't paid much attention to who did what I have always liked having the design systems, though I've never really been more than average in using them.

Thanks for putting me straight.

(I've just noticed I'm having issues with spelling average for some reason I'm adding an extra a between the v and e. I'm glad for ieSpell.)