high acceleration designs

[clair_rand]

I know thrusters and agrav plates for standard starships go upto 6G. but other drives can go higher..

I did a small 10 ton fighter with angi-grav drives (limited range), gave it 12 hour endurance, managed to get 9G out of it..

Reckon with that as its 'emergency agility' its gunna be hard to hit as it closes in on ya.

Mind you with only a couple of 25MW lasers requiring a high pen result to stand a chance, it needs all the help it can get...

Plan on trying a larger design that can actually carry proper weapons.

the limiting factor is the number of CPs required for the drives vs the psace for the control computer.

Anyone else tried maxing out acceleration on smaller ships as a defensive measure? if so what ya got out of it.?

Also high speed racer anyone.. could get around 11G from one of these things stripped out

 

[Malenfant]

How are you building these things (ie what book, what technology)? I thought 6G was the highest acceleration drive you could get? (though really, it's going to be down to how must thrust the drive produces compared to how massive the ship is, isn't it?)

 

[mike wightman]

IIRC grav vehicles designed in MT, TNE and T4 can have thrust rated at higher than 6G.

In Striker they could go to 7G couldn't they?

 

[aramis]

In MT, with the one small step drives, one can easily get to 20G... if one has limited endurance and no cargo.

FF&S1 has rules for handling the stresses of >6G on the crew...

More than 6 uncompensated G's are a serious short term health risk.

 

[mike wightman]

So take out the pilot

 

[graden1]

Has there ever been a sound rationale for the 6G limitation on maneuver drives in Traveller, aside from "Marc Miller said so."?

XO

 

[hunter]

Originally posted by Xavier Onassis:
Has there ever been a sound rationale for the 6G limitation on maneuver drives in Traveller, aside from "Marc Miller said so."?

XO

No inertial dampers...

Hunter

 

[Falkayn]

Originally posted by hunter:
No inertial dampers...

Hunter

Really? I have always thought that artifical grav gives you very nice dampers ... but that it was limited in Gs. Otherwise all of those nice passenger liners should have their floors aligned perpendicular to their direction of thrust, and should never have greater than 1G maneuver.

Of course it is a slippery slope ... if it can negate even 2G of acceleration then why can't military ships go to 8G (assuming that 6G is a resonable level to tolerate)?

 

[Malenfant]

Originally posted by hunter:
No inertial dampers...

Not officially perhaps - but there is obviously gravitic control technology in Traveller. It'd not hard to imagine that someone invented a way to compensate for acceleration.

In fact, I thought someone did - that's how ships can go up to 6g without crushing everyone inside for as long as they accelerate, isn't it?

 

[hunter]

What I should have said was because of very limited inertial dampers. Yes inertial dampers of some type must exist, but I put the 6G limit down to the limitations on damping capabilities.

Hunter

 

[TheDS]

IIRC, FFS1 lists TL15 dampers at a maximum capacity of 6G, so that means your ship can do 6G and it feels like you're floating. I believe it also goes higher at higher techs.

FFS1 also lists other means of Gee compensation, and it is probably possible, if you are willing to submerge your crew in water, to have virtually unlimited accelleration. (Ok, limited to the power of your drives and your mass.)

The other major limitation is in getting enough thrusting power for the mass you're moving. If it takes up 20% of your hull to get 1G, well, you're not going to reach 6G. So 6G is primarily a practical limitation as well.

 

[Malenfant]

FFS1 also lists other means of Gee compensation, and it is probably possible, if you are willing to submerge your crew in water, to have virtually unlimited accelleration. (Ok, limited to the power of your drives and your mass.)

That bugs me, now I think about it. I mean, sure, water is relatively incompressible, but you inside the tank are not. The water is not magically shielding you from gravity - the acceleration is stil going to apply to your body, which will still be more than 6 times heavier than it ought to be because of that (except now it's got some water pressing down on it too)

 

[Jeff M. Hopper]

I dunno, 6G inertial dampers and G-tanks for the crew would make for a fast, but not easily controlled or damage controlled, ship in a fight.

What would be the max G-protection using both of those methods? (I don't have my books handy.)

 

[TheEngineer]

Well, the main problem of high g for the human body is, that blood is prevented from flowing like it has to do. Thats why pilot use pressure suits to keep blood from accumulating in some limb and leaving the brain under-supplied.
Anyway at higher g-rates inner organs start to move around, which is increasingly unhealthy.

Real-world pilots can still do their job at about 6 or 7 g and are able to cope with g peaks of about 11 g.

So, assuming that those G-Tanks do a similar job as the g-suits and that internal compensation is able to cut away up to 6 g, the system could get along with up to 12 or 13 g.

 

[clair_rand]

I'll have to tidy the design up and post it.. but essentially..

10 ton USL open frame hull, armour 40G, a pair of 25MW B-Laser-13 *GUNS*, one pilot, 3 mod 5 computers.. couple a radios, sensors, life support for 24 hours, 12 hours fuel, Fusion reactor and anti-grav drives from the vehicles section..

works out around 9G

Designs pure MT as published.. nothing fancy.

Figured the 9G is probably going to hamper the pilot a bit, so the cockpit *only* has intertial dampers.

was trying for a small, cheap fighter.. got one out of the three but at least is fast.

Next step is to add a missile turret, since anyhting else adds to much mass with the additonal power plant.

Speacking of which.. there ever been anything published about *non-turret* mounts? thinking a pair of UCP B-Laser-13's mounted hard to the hull and maybe a few missiles, none of it in a conventional hardpoint mount?

 

[graden1]

Originally posted by Malenfant:
</font><blockquote>quote:</font><hr />
FFS1 also lists other means of Gee compensation, and it is probably possible, if you are willing to submerge your crew in water, to have virtually unlimited accelleration. (Ok, limited to the power of your drives and your mass.)

That bugs me, now I think about it. I mean, sure, water is relatively incompressible, but you inside the tank are not. The water is not magically shielding you from gravity - the acceleration is stil going to apply to your body, which will still be more than 6 times heavier than it ought to be because of that (except now it's got some water pressing down on it too) </font>[/QUOTE]The original version of Joe Haldeman's Forever War has lots of information on this subject; they used a system based on this concept to compensate for really high accelerations. The new, re-written version has much of that material dumbed-down or outright removed, so get the original if you can.

XO

 

[TheDS]

Can you perhaps give us a glimpse at what he says, XO?

 

[graden1]

Originally posted by TheDS:
Can you perhaps give us a glimpse at what he says, XO?

Sure, I'll have to review those sections of the book; it's been awhile since I read it. Spending a weekend at home so I should have some time.

XO

***following exhaustive research into his library of musty old out-of-print paperbacks***

In The Forever War, Haldeman's idea was to take the g-suit to its ultimate extreme, with a form-fitting body suit around the occupant providing outside pressure, and an incompressible fluid providing equal pressure inside the body cavity. (Similar to the 'fluid breathing system' from The Abyss, I think.) The internal/external pressure reached thousands of atmosphere's in Haldeman's novel, to compensate for violent maneuvers at over 25g's.

If that sounds extreme or implausible, I agree. I think he was trying to make a point about technology, but I'm going to stop short of writing a whole book report here.

XO

 

[Badbru]

I could be wrong but my understanding of the water filled G-Tanks from FF&S-1 is that they only negated 1 g of thrust. Therefor you could use them instead of G-compensators on any vessel up to 2 g thrust (2 g due to a human being capable, indeed "used to", withstanding 1 g)
In theory then as humans are used to 1 g ie earths 1 g field, 6 g G-compensators should allow a 7 g vessel. If you were then to add g-Tanks aswell; 1-g normal conditioning, + 6 gees from the 6 g G-compensators, + 1g from the G-Tanks should allow you 8 g thrust. FF&S then suggests that each g of thrust beyond that compensated for adds a +1 difficulty mod to tasks. If you pushed this 8g example ship to 9 gees then all pilot tasks that were "average" would become "difficult".

That all said I've never used G-Tanks in any of my designs and have only produced 2 ships out of lots of ships designed that had greater than 6 g acceleration.

 

[aramis]

Realistically, hummans can't operate safely in more than 2-3 sustained G's.

So you can safely add 1 G to compensation rating, for safe operations on-axis, and limmited movement when off-axis.

2-3 G's uncompensated means limmited crew moving about, for sustained ops.

2-3 uncompensated G's for short thrusts means warning before and no body moving during those ops.

4-6 uncomepnsated G's for short bursts are able to be tolerated and remain operable. They are not, however, likely to be able to be sustained for more than a few minutes (These levels, BTW, and the "stamp zone" for WWII high-performance fighters...) sustained operations of any kind result in crew immobility, and inability to reach for controls reliably.

6-10 uncomensated G's are only survivable for short periods or with assistive technologies... and even then, crew immobility is nigh required. Modern jet fighters stamp zones are in the 10-15G range... most have computer restrictions to prevent blacking pilots out...

IIRC, the Apollo-Saturn hit 11G's... for a short while... the crew were essentially non-functional during this. The shuttle peaks at about 4 G's, and usually is only throttled for about 3.5...

The compensation limit by TL is for a standard kit, if you use FF&S1... you can exceed it at rapidly increasing costs.

Now, for short accellerations, the compensation can be safely ignored for the first 6 G's... but for the sustained thrust provided by T-plates, able to span over days, the need for compensation becomes particularly relevant, if not for comfort, then for maintenance and personal hygene.