The key there is it’s a official rule so anything you want Published in say the JTAS need to not ignore the ruleAnd you’re not ignoring the rule the nerfs the maneuver drive out there.
Excel Ship Designer v2025.05.31
- Thread starter Arkathan
- Start date
Terry Mixon
Emperor Mongoose
Thankfully, my publishing is in non-Traveller science fiction, and I don't have to worry about it.
Matt did say they were open to the idea of moving the 1000D limit out a ways, which would address my major complaints. Finger's crossed.
Well if you expand the DSMS to TL 17 it’s 45% efficient and takes no extra space combine that with 3 levels of energy efficiency in the M-Drive and it’s really not a problem. At that point you essentially just pay more energy and lose some of you efficiency if your outside the 1000D limit
Arkathan
Emperor Mongoose
Oh. Crap. I did go formulaic instead of table... and didn't put a limiter on it. Which means at some point, including a DSMS makes the M-Drive smaller than it would be without one. And you'll eventually reach 100%.
Don't do that. The implementation is valid only up to TL 15. Until I get time to NERF it.
I still think that, if you absolutely must have a drop-off in M-drive efficiency, tying it to the stellar system's heliopause is a good benchmark. (A good approximation for a system's heliopause would be about 120 AU divided by (the square root of the system's luminosity) - it fits our one real-life data point without letting things get completely out of hand at the extremes. And use some sort of compounding efficiency drop at each multiple of the distance, so that the drive never falls all the way to zero.
Personally, I don't like the idea of the M-drive losing all effectiveness unless the players deliberately do that to themselves. But that's an objection based on my own biases. Although if they insist on doing something suicidality non-intelligent, I won't make it impossible - just obviously a bad idea.
Personally, I don't like the idea of the M-drive losing all effectiveness unless the players deliberately do that to themselves. But that's an objection based on my own biases. Although if they insist on doing something suicidality non-intelligent, I won't make it impossible - just obviously a bad idea.
I think you can safely estimate it out to TL17.
Arkathan
Emperor Mongoose
I agree on the heliopause being a better cut off, but I still maintain that if there were no stellar gravity well, you would not have an Oort Cloud. But, the inclusion in the spreadsheet is easily ignored and doesn't specify a point at which the need for it kicks in. People had asked for it a couple of times and I could no longer use the dodge that I didn't have access to the rules.
For black holes, I would suggest keeping the heliopause of the star prior to its death.
Terry Mixon
Emperor Mongoose
What about the gravity from Sagittarius A*? All stars are caught up in that. Are we ever truly out of a gravity field?
??? Where did the Oort cloud come into this?
For that matter, if there were no stellar gravity well, there would be no stellar system at all. The (stellar) gravity well is what allows the planets et cetera to orbit the stars... and to form in the first place, for that matter.
As for the "heliopause" of a black hole, well, technically if the black hole has an accretion disk, then the emissions from matter falling into the event horizon provide some radiative energy, allowing for a level of luminosity and thus a heliopause of sorts - I'd have no idea how to estimate it, though. I can't think it would amount to much, though. Maybe something on par with the heliopause of a lower-end red dwarf.
Terry Mixon
Emperor Mongoose
I’m not talking about the heliopause of a black hole. Just the basic 1000 diameters calculation. Yes, it’s off because the black hole is a singularly but Sagittarius A* masses 4.3 million suns. That doesn’t even count the masses of the other 10 million stars within one parsec of Sagittarius A* or the rest of the galactic bulge’s 10 billion stars.
Traveller simplifies things by using diameters from the star/planet/whatever, but it’s really a function of mass and the distance from it. I submit that Charted Space is just a caught in “deep space” as a planet would be to a star.
Last edited:
Sigtrygg
Emperor Mongoose
537km/s - that is how fast you have to be going to escape from the milky way's gravitational effect, otherwise you are still in orbit around its centre. That would take ~15 hours at 1g and you would have moved ~14,420,000 km, a bit over the 1000D.
Perhaps the m-drive efficiency drop off is due to velocity rather than distance...
Perhaps the m-drive efficiency drop off is due to velocity rather than distance...
Last edited:
Arkathan
Emperor Mongoose
You may have missed the relevant part of the discussion, some of which went on in another thread.
DSMS is an in-game work around for the M-Drives being all but useless outside 1000d of the local star.
People wanted to include it for designing ships.
I am among those who think the 1000d rule is asinine. There is enough of a galactic gravity well to keep stars in line. The local stellar gravity well is sufficient to maintain an Oort cloud out to a light year. So why would there not be gravity to push against?
The 1000D limit doesn't work so well for stellar black holes, having a huge mass, but a very small diameter. Thus your suggestion about using the heliopause as the boundary would need to use the stats of the original star before it became a black hole. That heliopause radius would better approximate the standard you suggested for the limit of M-drives.
Terry Mixon
Emperor Mongoose
Perhaps I have explained it badly. The thought really has nothing to do with escape velocity. The gravitational effect of a body drops off with distance. If the effect of gravity is what we are looking at for the 1000 D limit, then there will be something similar for the galactic bulge. My hypothesis is that Charted Space falls inside the same distance where a maneuver drive could push against the gravity of the galactic bulge.
EccentRick
Banded Mongoose
I know it has never been part of the text for either and gets brought up more for Jump drives than M-Drives, but I've always wondered if the gravitational 'slope' (gradient, derivative, Tidal forces, pick your term) was a major factor in the performance. A 3rd (4th? more?) banked idea for a thread.
Terry Mixon
Emperor Mongoose
Okay, I ran into an error (or something) while trying to recreate the Valiant Light Cruiser from High Guard 2022. In specific, the number of required gunners.
The entry in the book calls for 203 gunners. Well and good. The spreadsheet called for 410 in the military column. I went to the book for clarification. Adding it up for the military column in the book, I should have a whopping 532 gunners.
The ship only has 265 cabins + 1 high for the captain. Double stacking everyone in double standard staterooms (it doesn't mention a barracks for the 20 marines) means everyone fits with the numbers provided in the ship's description but falls way short for a full military compliment.
I realize the presented numbers have the be way off in some way. I suppose my question is why the spreadsheet numbers under military don't match the whopping larger number in the book for military. Unless, as I somehow suspect, I'm screwing something up.
The entry in the book calls for 203 gunners. Well and good. The spreadsheet called for 410 in the military column. I went to the book for clarification. Adding it up for the military column in the book, I should have a whopping 532 gunners.
The ship only has 265 cabins + 1 high for the captain. Double stacking everyone in double standard staterooms (it doesn't mention a barracks for the 20 marines) means everyone fits with the numbers provided in the ship's description but falls way short for a full military compliment.
I realize the presented numbers have the be way off in some way. I suppose my question is why the spreadsheet numbers under military don't match the whopping larger number in the book for military. Unless, as I somehow suspect, I'm screwing something up.
AndrewW
Emperor Mongoose
Did you take into account the 67% crew size for a ship that size? (Updated High Guard page: 22).
Terry Mixon
Emperor Mongoose
I was just about to come back and say I found that. That drops the number to 356. Still off from all the rest.
Geir
Emperor Mongoose
Maybe the designer thought that if you only have one gunner for a small bay having two for turrets and barbettes was silly, even if that's what the rules say... (wasn't me, pretty sure. I only did a few of the designs...)I was just about to come back and say I found that. That drops the number to 356. Still off from all the rest.
That's the thing though, having 160 missiles turrets might not have been the best call.... but let's see, a 50 ton bay with crew (let's give them a full stateroom, just to account for common space and stuff) is 54 tons, each turret is 1 ton weaponry, 8 ton crew, so that's 9 tons or 1/6 of a bay and the bay can fire 12 per round or 4 times as many missiles as one turret - so you do get a 6 extra missiles per salvo for the tonnage... okay, I suppose it was a good call. Though the bay holds 144 missiles and 6 triple turrets still only hold 12 each or 72. Hmm. Tradeoffs. Might save dtons by cranking up bandwidth for Virtual Gunner or something. Still doesn't explain the gunner shortage you've identified.
Terry Mixon
Emperor Mongoose
It's a mystery. Something there got hosed real good. If you guys decide to tweak it to make it work, I'd love to hear the new details.
Last edited:
Arkathan
Emperor Mongoose
Hg1 calculations appear to be still in there for some weapons.
I'm changing the way military crew is added. Will test before posting... but not tonight.
Tried inserting it in the hardpoint table, thinking tables would adjust automatically, and it borked the whole page.
I'm changing the way military crew is added. Will test before posting... but not tonight.
Tried inserting it in the hardpoint table, thinking tables would adjust automatically, and it borked the whole page.
