Re: GURPS Spaceships Design Spreadsheet
 

I'm comparing two unstreamlined SM+3½ craft, so it doesn't seem like the bad streamlining is the reason:
Skirt $6k + Ducted Fan $24k + two reactors (minimum for overground hoverflight), giving Move 3/30.
vs.
Helicopter rotor $20k + one reactor, giving Move 5/40.

Doesn't the ground effect increase efficiency of thrust relative to a 'naked' propeller, leaving more power available for horizontal thrust?

Also, ground speed three times higher than water speed, is that right?

Re: GURPS Spaceships Design Spreadsheet
 

The primary advantage of the ground effect skirt is to increase stability, which helicopters and VTOL Jets have issues with when they get close to the ground or water (the backblast off of the ground causes vortices which make it difficult to control). The Hovercraft speed record is only 85mph on water and 56mph on land (this is, literally, where I got the max speeds from for the Hovercraft in the Optional Rules page); hovercraft are never going to have speeds, or general stats, comparable to Helicopters.

Now, I'll have to look into the actual speeds listed, because I don't think that's right, especially with ground speed being greater than water speed.
Edit: And it looks like I accidently multiplied Hovercraft Ground Speed by x4 across the board (actually, in the formula I doubled it instead of halving it like Water Speed).

Re: GURPS Spaceships Design Spreadsheet
 

Oh, I'm not saying a better top speed is warranted. I'm just puzzled by it requiring twice the number of systems and twice the number of power points to achieve its modest performance. Back before the system was added, I was thinking that a hover+propulsion system would at worst be comparable to a rotor in terms of monetary and energy costs, and I'm curious about the physics/engineering that is the cause of such gross inefficiency (after all, helicopters aren't the most elegant flight system either).

Re: GURPS Spaceships Design Spreadsheet
 

Version 2.0 Release Candidate 28
-Fixed Bug where a ship with User Systems could error on loading.

Version 2.0 Release Candidate 27
-Fixed Bug preventing ships with Structural Reinforcement from loading.

Version 2.0 Release Candidate 26
-Corrected Hovercraft Ground Speed, which was accidently multiplied by x4.

You can download the spreadsheet here:

Excel 2000 (RC28)
http://gurpsland.no-ip.org/zip/SpaceshipsV2.zip (~5.3 MB)
http://gurpsland.no-ip.org/zip/SpaceshipsV2.7z (~2.7 MB)

Excel 2007 (RC28)
http://gurpsland.no-ip.org/zip/SpaceshipsV2-2007.zip (~6.6 MB)
http://gurpsland.no-ip.org/zip/SpaceshipsV2-2007.7z (~6.5 MB)

OpenOffice 3.3.0 (RC9)
http://gurpsland.no-ip.org/zip/SpaceshipsV2-Ooo.zip (~2.1 MB)
http://gurpsland.no-ip.org/zip/SpaceshipsV2-Ooo.7z (~1.9 MB)

Spaceships Optional Rules
http://gurpsland.no-ip.org/pdf/Space...ionalRules.pdf

Re: GURPS Spaceships Design Spreadsheet
 

Just took a look at this and I LOVE, LOVE, LOVE all the crunchy bits with built in calculators for everything. This is everything I adore about Excel. Plus, someone else did it. I am going to use this for my Rifts Robots to see how it works.

THANK YOU!

Re: GURPS Spaceships Design Spreadsheet
 

Hi, I tried saving a design I made, it let me but when I tried to load it again it gave me an error message and wouldn't load. When I ran the debugging thing it seemed to single out this line of code:

TabledSTdHP.Caption = Format(CInt(ShipdSTdHP), "#,##0")

It seems to relate to the design having structural reinforcement as a system. I tried loading a different design that didn't have that and it loaded fine. Using Excel 2007 with Windows 10 btw.

Re: GURPS Spaceships Design Spreadsheet
 

Yes, it does seem to be linked to Structural Reinforcement. I've just uploaded RC27, which corrects this loading bug. If you import the saved ships from RC26 into RC27 they will load just fine in RC27, as this bug only cropped up during the ship reading routines and not the ship saving routines.

Re: GURPS Spaceships Design Spreadsheet
 

Hi, I seem to have a problem where if I save a design I made to Unofficial Ships and it has a user designed system it doesn't want to load the ship properly.

This is what it highlighted when I ran the debug thing:

For i = 1 To NEW_SYSTEM_STATS
If CDbl(ShipUserSys.Cost(i)) <> CDbl(SheetUserSys.Cost(i)) Or _
ShipUserSys.PerformanceOne(i) <> SheetUserSys.PerformanceOne(i) Or _
ShipUserSys.PerformanceTwo(i) <> SheetUserSys.PerformanceTwo(i) Or _
ShipUserSys.PerformanceThree(i) <> SheetUserSys.PerformanceThree(i) Then
UserSystemsDifferent = True


It's the excel 2007 version run on windows 10. If you need me to send all the other stuff it said let me know. I didn't think posting several pages of what looks like computer code on the forum would be a good idea.

Re: GURPS Spaceships Design Spreadsheet
 

It's one of my own designs. When I saved it that's where it wanted to save it to. It's not one of the designs you put there. The ones that I made that just use official systems seem to load just fine.

Re: GURPS Spaceships Design Spreadsheet
 

Yeah, I realized that after I asked (thus why I deleted my question). I'll look into this, but probably not until tomorrow.

The User Systems is an extra level of complexity from the standard systems, since the ship has to save all the data for all the SM's that are defined as well as save from and load into the User Systems sheet. The standards systems are stored as just a system name, and get all their stats as a lookup on a data table.