Simulating Battletech's spaceflight elements

[grimlock14]

First order of business, I know it won't map all that well.  I know Battletech rules and Kerbal physics are going to develop a Hattfield/McCoy relationship.  

This is mostly an exercise to see just how BAD the Battletech's space ship rules really are.  If I stay with Zenith Nadir entry points for jump ships, and assume infinite fuel, Just what kind of flight profiles would it take to get to and from a planet?

First off, I'm just ignoring fuel consumption.  I'm taking that mulligan right away.  But I don't feel like trying to Rather than building a 10,000 ton dropship, with an obscene number of engines, is there an easy way to throw a Terrier and FLT-T100 under a Command Pod then hand edit the mass and TWR?

[NathanKell]

Woo! (Points at name.)

 

Brachistochrone trajectories are real things. Indeed, pretty much all of BT's space physics are legit, except for ludicrously impossible Isp (on a straight-up calculation, the exhaust velocity of those drives is over lightspeed...) and of course the KF drive.

[Ten Key]

The physics is on the level. The engineering behind it will tie your brain in a knot if you look too closely. But FASA tried a lot harder than most other game designers did.

[Guest]

4 minutes ago, NathanKell said:

except for ludicrously impossible Isp (on a straight-up calculation, the exhaust velocity of those drives is over lightspeed...)

Not to mention the thrust their engines put out.

Something else interesting is armor thickness calculation.  Most BT warships have armor that is paper thin.  A Battlemech itself has armor less than an inch thick.

Battletech is straight up science-fantasy.  Much like Star Wars, I love it for that.

[NathanKell]

Cray/Mike Miller calculated it at as a millimeter or so for most WarShips, yeah.

 

As for fantasy...well, I'd argue on that one. If you get rid of the step functions and old "simplified for pen and paper" stuff it works reasonably, space-wise. But on the ground things are fantasy, yeah. 95 ton robots that run at 86kph aren't scary, they're targets.

[grimlock14]

1 hour ago, NathanKell said:

Woo! (Points at name.)

 

Brachistochrone trajectories are real things. Indeed, pretty much all of BT's space physics are legit, except for ludicrously impossible Isp (on a straight-up calculation, the exhaust velocity of those drives is over lightspeed...) and of course the KF drive.

I figured that such transitions are doable, and I could certainly run the numbers on paper, but I wanted to play with it a bit.  

To my original question, is there a way to hand edit a ship file?

[Wolfos31]

I'm a huge fan of the Battletech video games (read: Mechwarrior) but I always found it amusing that the pinnacle of human warfare tech in this canon were hugely impractical, slow, expensive machines with offensive capabilities barely beyond that of a real world heavy battle tank. A couple of modern day ground attack aircraft would absolutely decimate a lance of mechs. 

A fun universe for reading and playing in though. And the myomer (spelling? it's been a while) muscle technology was interesting and not entirely implausible. 

[FungusForge]

31 minutes ago, Wolfos31 said:

I'm a huge fan of the Battletech video games (read: Mechwarrior) but I always found it amusing that the pinnacle of human warfare tech in this canon were hugely impractical, slow, expensive machines with offensive capabilities barely beyond that of a real world heavy battle tank. A couple of modern day ground attack aircraft would absolutely decimate a lance of mechs. 

A fun universe for reading and playing in though. And the myomer (spelling? it's been a while) muscle technology was interesting and not entirely implausible. 

 A stable bipedal machine that can carry the armament of a modern tank would still have its uses. No, it wouldn't entirely replace them (especially if they were slower), but the mobility advantage of having legs is very real. Boston Dynamics (I think anyhow) has been developing a dog-like robot that could be used to carry supplies across terrain where wheeled and tracked vehicles of a similar scale would have difficulty. Also, as someone who uses the Kerbal Foundries mod, I can tell you that having the wrong suspension/torque settings for whatever world you are landing on sucks, and for tanks would require a bit of tinkering to accomplish, where with a bipedal machine it would merely be pressing a button.

Real facts done, all I can say is that the Battletech wiki says that some of the guns in play are 203mm (the M1 Abrams uses 120mm), and the 100-ton Atlas Assault mech moves at 54km/h (the M1 Abrams has a top speed of 75km/h). Since MWO seems to be pretty accurate to the lore, I think its worth noting the Adder moves at nearly 90km/h and still manages to pack in a pair of ER PPCs, and still bests the power and range of most ballistic weapons.

E: Also, real tanks are just as much a target to a ground attack aircraft as a battlemech is. They are all just fodder to the glorious air-to-ground missile, or the glorious GAU-8 Avenger 30mm autocannon. Chances are a brush up against that for either mech or tank is going to leave them crippled, if not destroyed.

Edited January 15, 2016 by FungusForge

[Wolfos31]

@FungusForge

Yeah, I agree they'd have their uses. I think small scale battlesuits like human power armor or even just humanoid robots will play a role in war and industry twenty years from now. And the eventual uses of Boston Dynamic's dog robot thing would be pretty awesome. I know right now one of the big problems with the thing is it's loud as hell, as in chainsaw running next to your ear loud. 

 

I feel like mechs would be more commonly used for industry in real world applications if they become a reality on the scale battletech describes. I just struggle to imagine a battlezone where their cost could be justified by the advantages they provide. Actually, provided humans ever get off world they would probably be fantastic on airless bodies. Flight would be pretty ineffient as you'd have to use VTOL of some sort so the battlemech's biggest threat would be gone or regulated to short hops from a central hub. Terrain is likely to be unimproved and treacherous and a bipedal design is better than just about anything at traversing that. And since they're powered by a nuclear reactor they could be out about as long as the life support systems on board can care for the pilot. 

[Guest]

2 minutes ago, Wolfos31 said:

Actually, provided humans ever get off world they would probably be fantastic on airless bodies. Flight would be pretty ineffient as you'd have to use VTOL of some sort so the battlemech's biggest threat would be gone or regulated to short hops from a central hub. Terrain is likely to be unimproved and treacherous and a bipedal design is better than just about anything at traversing that. And since they're powered by a nuclear reactor they could be out about as long as the life support systems on board can care for the pilot. 

On an airless body why would you bother with the complicated and expensive machinery of a humanoid form, with all its failings and problems to overcome, when you could just use the elegant simplicity of rocket nozzles to get around?

Mecha are romantic war machine stand-ins for Our Hero, nothing more.  You could justify their use in certain edge cases, most likely certain industrial applications as noted, but there are simply too many problems for them to overcome.

[Workable Goblin]

2 hours ago, regex said:

On an airless body why would you bother with the complicated and expensive machinery of a humanoid form, with all its failings and problems to overcome, when you could just use the elegant simplicity of rocket nozzles to get around?

Rockets are Really Expensive. Less the machinery itself (though obviously that is expensive), but the propellant cost of ballistic travel on airless planets is much higher than you might think, especially if you want to travel long distances. Not to mention that to use rocket propulsion you have to pop up really high and become even more of an obvious target than a mech.

[Fearless Son]

The anime Gasaraki had a plausible use of mecha, being comparatively small, and equipped with grappling hooks and powered winches to allow themselves to occupy positions that conventional armor would be unable to.  Analyzing some night footage of tanks being attacked from a nearby rooftop it is explicitly noted by a character that the armament they deploy is the same grade as mounted on armor, but the tactics employed around it are closer to that of infantry.  They made more sense in urban warfare than tanks, and not just for going to rooftops, they could enter narrow alleys or subway tunnels where otherwise infantry would be able to entrench and tanks could not fit.  

[NathanKell]

You'd have to hand-edit the part cfgs, not the savegame or craft file, but yes, you certainly can do that editing. Edit the pod's, the tank's, and the engine's part cfg files and there you go.

[grimlock14]

::facepalm::

There isn't any need to mod parts.  At the end of the day, it all comes down to acceleration. As per Battletech rules, a "thrust point" is half a G, 4.9m/s^2.  So if I want simulate something with say, 3 thrust points, put a Rhino and an Oscar B on a Command Pod, turn on Infinite Fuel, and use MechJeb to cap acceleration at 29.4 m/s^2.  That should be fine for a 1st order approximation. 

[Scotius]

If anyone is interested - Stanislav Lem novel "Fiasco" describes exploration of Titan's surface with mech-like walking machines.