BattleTech - The Board Game of Armored Combat

BattleTech Player Boards => Fan Designs and Rules => Topic started by: Cowdragon on 15 February 2018, 10:12:11

Title: Micro-Fighter Fuel Consumption
Post by: Cowdragon on 15 February 2018, 10:12:11
They could use a rework for how to power them through space. As the rules stand, they can propel themselves to fantastical speed... and then they are out of gas.

Thoughts on a workaround?
Title: Re: Micro-Fighter Fuel Consumption
Post by: Maingunnery on 15 February 2018, 13:26:38
You could rescale the fuel points based upon the maximum mass, that should increase the number of point by a factor of 10.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Daryk on 15 February 2018, 19:53:35
I think that's by design...  relativistic speeds are bad for game balance at any tonnage.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Maingunnery on 16 February 2018, 11:52:34
I think that's by design...  relativistic speeds are bad for game balance at any tonnage.
Not applicable in this case, were are long way from that.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Alsadius on 16 February 2018, 12:26:09
Not applicable in this case, were are long way from that.

Less than you think. If you ignore the Lorentz transformations(i.e., relativistic effects), it's only 354 G-days to get to the speed of light. A WarShip can easily carry that much fuel, and a specialized fighter might be able to as well.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Maingunnery on 16 February 2018, 12:45:55
Less than you think. If you ignore the Lorentz transformations(i.e., relativistic effects), it's only 354 G-days to get to the speed of light. A WarShip can easily carry that much fuel, and a specialized fighter might be able to as well.
Lets take a worse case scenario, a 19 ton ASF with 16 tons of fuel:
1G burn/days: 8.7
Refactoring for ultra-light (100/20)=x5
8.7x5=43,5

So we would be an order of magnitude in de safe zone.
Title: Re: Micro-Fighter Fuel Consumption
Post by: I am Belch II on 16 February 2018, 13:19:15
A micro fighter.....like a ProtoMech??

I like it.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Daryk on 16 February 2018, 16:27:22
Lets take a worse case scenario, a 19 ton ASF with 16 tons of fuel:
1G burn/days: 8.7
Refactoring for ultra-light (100/20)=x5
8.7x5=43,5

So we would be an order of magnitude in de safe zone.
That's over 10% the speed of light... that counts as relativistic speed...
Title: Re: Micro-Fighter Fuel Consumption
Post by: Maingunnery on 16 February 2018, 17:10:07
That's over 10% the speed of light... that counts as relativistic speed...
This what I can do with legal level 1 tech:


Mass:              100 tons
Equipment:                                                              Mass
Power Plant:  100 Fusion                                                 3,00
Fuel:                                                                   93,00
Cockpit & Attitude Thrusters:                                            3,00
Armor Type:  Standard  (16 total armor pts)                              1,00

And that is 50.54 1G Burn/Days.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Daryk on 16 February 2018, 17:28:21
That's also useful for planetary bombardment if you're looking for extermination of all life on a planet.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Maingunnery on 16 February 2018, 17:37:27
That's also useful for planetary bombardment if you're looking for extermination of all life on a planet.
Refactoring fuel consumption for ultra-lights doesn't add anything truly special to the setting. I can get more burndays out of an 100 ton ASF, and existing DS should be far more practical for this (life-support & such). But it doesn't happen in the setting so it isn't a concern.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Daryk on 16 February 2018, 17:58:25
Except that once you're tweaking the fundamentals of the system, what's to stop players from taking advantage of existing weaknesses in the rules set?
Title: Re: Micro-Fighter Fuel Consumption
Post by: Maingunnery on 16 February 2018, 18:01:20
Except that once you're tweaking the fundamentals of the system, what's to stop players from taking advantage of existing weaknesses in the rules set?
???
I took a proposed houserule to its most extreme limit and showed that it was less severe then what is already possible.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Daryk on 16 February 2018, 18:07:37
The proposed house rule enables almost-missiles to be as dangerous as dropships pressed into the purpose of planet killing.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Maingunnery on 16 February 2018, 18:16:49
The proposed house rule enables almost-missiles to be as dangerous as dropships pressed into the purpose of planet killing.
Not really, as the life-support systems on ASF are limited, and their small mass will make sure that they can't survive any collision (be it air or a bolt of orbital debris).
And last and not least, that scenario doesn't seem to happen in BT, its a non-existing problem. 
Title: Re: Micro-Fighter Fuel Consumption
Post by: Daryk on 16 February 2018, 18:20:44
The relative costs are the key there... it's much cheaper to kill a planet with micro-fighters (that could be easily automated) with that rule than dropships (the horror!) you would never use under the current rules for fluff reasons alone.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Maingunnery on 16 February 2018, 18:27:09
The relative costs are the key there... it's much cheaper to kill a planet with micro-fighters (that could be easily automated) with that rule than dropships (the horror!) you would never use under the current rules for fluff reasons alone.
UL fighters might not even reach the surface, they are simply too fragile. In theory Dropships could do it, but they are used as such. Costs can't be the reason as a relativistic DS is far cheaper then the nuke carpets that are actually used to kill planets in BT.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Daryk on 16 February 2018, 18:29:52
And relativistic ultra-light fighters can be had for a tiny fraction of the cost of a single dropship (under the proposed house rule).  I'm just trying to point out an unintended consequence of said rule.  It simply puts yet more burden on fluff reasons as to why it's not done regularly.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Maingunnery on 16 February 2018, 18:35:10
And relativistic ultra-light fighters can be had for a tiny fraction of the cost of a single dropship (under the proposed house rule).  I'm just trying to point out an unintended consequence of said rule.  It simply puts yet more burden on fluff reasons as to why it's not done regularly.
They will also have only a fraction of the yield (lower mass and lower end velocity) and far lower chance of actually reaching the surface. The cost argument doesn't work, as I have shown with nukes. This leaves a possible practical problem with relativistic projectiles in BT, and ultra-light fighters aren't going to bypass that.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Daryk on 16 February 2018, 18:41:14
Do you have a link for the nuke argument?  I don't remember reading that one...
Title: Re: Micro-Fighter Fuel Consumption
Post by: Maingunnery on 16 February 2018, 18:49:47
Costs can't be the reason as a relativistic DS is far cheaper then the nuke carpets that are actually used to kill planets in BT.

Also please feel free to offer any examples in BT of where relativistic projectiles are used to kill planets.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Daryk on 16 February 2018, 18:51:24
Canon doesn't enter into house rule discussions.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Maingunnery on 16 February 2018, 19:14:03
Canon doesn't enter into house rule discussions.
In the setting there is clearly something that makes relativistic projectiles either non-practical or non-functional.
It is the way it is.
And the proposed ultra-light ASFs are inferior candidates to that is already available (fragility and low yield).

So please show that there is an actual problem and that the house role will make it worse. If not, then please agree to disagree.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Daryk on 16 February 2018, 23:04:57
The problem is simple exploitability.  If you don't think that's a problem, then we simply disagree.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Liam's Ghost on 16 February 2018, 23:26:37
There are a few potential complications with using relativistic dropships or fighters.

One deceptively big one is aiming. While you can calculate vectors with extreme precision even using pen, paper, and calculator, getting a ship in the vacuum of space to be pointed in exactly the right direction when basically you change position by it shoving itself in different directions with a rocket is a lot more complicated. Over the course of months of burning, even tiny errors in course can become huge. And things moving at a significant fraction of c have much less time to correct for it. Depending on how significant that C fraction is, maybe a WHOLE LOT less because of relativistic affects. So accuracy may be a question.

Space dust is also probably a problem. Maybe a small one, but the longer you take to run your projectile up, the higher that risk becomes and the more potentially catastrophic it becomes to your projectile.

Also, you have to commit to this sort of thing well in advance. We're talking a lead time of months to a year before your shot lands. It's not very practical in a fluid geo-political situation when you can accomplish most of the same thing with a bunch of nukes with less time.

Also, cost. With all those space rocks floating around for free, there's gotta be a cheaper way of doing this sort of thing.

It's kinda the grandest of grand gestures. Even the most super-villainous of super villain factions doesn't really have much of a reason to C-fraction a ship into people when there are more efficient means of mass destruction.

Though I will point out that the Word of Blake loved to throw space rocks at people, and the Taurians did use dropships as kinetic impactors during the Jihad. So it's not strictly unprecedented.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Cowdragon on 23 February 2018, 00:06:59
LOL while it is an extremely interesting read... I really just wanted some way to make smaller fighters a viable option. A ton or two of fuel on such a small fighter SHOULD last a little longer.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Giovanni Blasini on 23 February 2018, 01:30:55
Why even give micro fighters better fuel efficiency?  That's like the opposite of every other Battletech spacecraft, where specific impulse gets better as they get bigger.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Maingunnery on 24 February 2018, 13:59:15
Why even give micro fighters better fuel efficiency?  That's like the opposite of every other Battletech spacecraft, where specific impulse gets better as they get bigger.
To make them playable? Also there should be a bottom to the specific impulse just to make it believable that it concerns BT fusion torch engines.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Cowdragon on 25 February 2018, 20:46:10
To make them playable? Also there should be a bottom to the specific impulse just to make it believable that it concerns BT fusion torch engines.

This.


Also, I'm partial to making lighter gear for lighter platforms. Sort of the Protomech approach.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Giovanni Blasini on 17 March 2018, 22:04:04
It occured to me we actually have a published example: the 8-ton Imperial T-Fighter from Nebula California, which had two tons of fuel and 160 fuel points.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Liam's Ghost on 17 March 2018, 22:13:18
If we go back far enough, we actually have another. The original escape pod in dropships and jumpships was created as a five ton fighter (albiet using fractional accounting and some weird half size engine). It received the same fuel efficiency as the fighters of the time (which was 15 points per ton in those days).
Title: Re: Micro-Fighter Fuel Consumption
Post by: Giovanni Blasini on 17 March 2018, 22:22:37
Do You recall if they used full-sized cockpits for those? This is literally relevant to something I'm working on right now.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Daryk on 18 March 2018, 05:56:14
The escape pod did, but it's not clear on the life boat.  Neither listing completely accounts for the five tons, but I think the 0.5 ton missing on the escape pod is internal structure.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Cowdragon on 20 March 2018, 14:33:38
It occured to me we actually have a published example: the 8-ton Imperial T-Fighter from Nebula California, which had two tons of fuel and 160 fuel points.

What is this? Can you point me in the direction? I've never heard of that. Also, I'm a huge huge huge TIE Fighter fan, and tend to make my aerospace fighters around that same concept.
Title: Re: Micro-Fighter Fuel Consumption
Post by: Maingunnery on 20 March 2018, 15:24:00
What is this? Can you point me in the direction? I've never heard of that. Also, I'm a huge huge huge TIE Fighter fan, and tend to make my aerospace fighters around that same concept.
It is in Welcome to the Nebula California "CAT35APR23".