Would this work?

[Bob Weaver]

This reminds me of a problem I've wrestled with on a number of occasions - non-jump tug boats (or dirtside grav cargo vehicles) need high-G M-drives to move their loads, but when unloaded they are capable of ridiculous speeds. Today's tugs/fork trucks are limited by gearing to low speeds - what could limit G-vehicles? I really don't want tugs and fork trucks running around at fighter velocities IMTU. Any ideas?

The other factor to consider besides raw speed is maneuverability or control. For vehicles that reach high speeds, its more important to be able to make small changes in vector. At low speeds, it's easy to avoid running into a tree (or whatever). At aircraft speeds, it's harder since you have less time, and you don't want to throw yourself into flat spins at every obstacle.

For Traveller vehicles, just determine the velocity at which the 'lugger' vehicle becomes uncontrollable, and pile on the negative DMs for operating the vehicle. If your PCs want to go ballistic on a grav-forklift, they'll have to make some very hard task rolls to avoid crashing.

I'd be willing to argue that the "top speeds" listed for most Striker/MT vehicles is not their true maximum velocity, just the fastest they can go without risk of losing control.

Best Regards,

Bob W.

 

[Icosahedron]

Thanks guys, yes it looks like governors of some type and/or stability issues are the only possibilities.

My problem was I'd been thinking myself that it's all about acceleration, Capt, but of course that's Traveller thinking - it's actually all about thrust forces. I didn't see it until you put it in writing. A governor can cut the thrust if the acceleration rises too far, whilst allowing the full thrust to tug large masses at low accelerations. Alternatively, tugs could be 1G craft that operate at VERY low accelerations when loaded.
I use Striker's listed speeds as control limits already, Bob, so loading the stability DMs for certain vehicle types could work pretty well.

Thanks for the pointers.

 

[Captain Midnight]

A governor can cut the thrust if the acceleration rises too far, whilst allowing the full thrust to tug large masses at low accelerations. Alternatively, tugs could be 1G craft that operate at VERY low accelerations when loaded.

My question would then be "what's the reasoning behind the limitation on speed?" If it's just that you as a GM think it's not as impressive for tugs to be able to go as fast as fighters... I'd wonder about why the manufacturers would install governors, and how often they would be bypassed. What would also happen in emergency situations, when a tug might need maximum performance from its drives to perform rescues?

If instead it's a traffic-control regulation, I'd think it would be more reasonable to impose strict penalties for anyone who varied from the flight profile issued by System Traffic Control. STC would be well aware of the speed restrictions in various areas, and could issue permission to go flat-out in cases of emergency.

The penalty should be something that would reflect the potential seriousness of the offense -- 500,000 Cr levied against the ship's master and the ship's pilot, revocation of licenses, and either a period of imprisonment or physical punishment, depending on how strict your local governments are.

In general, I prefer to see administrative penalties, as they can be waived (or moderated, or even increased) to fit circumstances, where technical solutions (like speed governors) are difficult to adjust.

 

[Andrew Boulton]

Maybe they only fit low-rated inertial compensators (to save money/space?)

 

[Icosahedron]

I'm afraid it's just me as a GM. I don't want Acc6 Ag6 tugs zipping around IMTU, I want them limited to a max of 1G whether loaded or not, and if a rescue is needed, you don't launch a tug to do the job of the coastguard cutter. I agree that a rationale is needed, I just can't think of one. Even stability doesn't work very well in space. I like Andrew's inertial compensators solution, but it would mean setting up a pricing structure for compensators versus drives, so at the moment I'm leaning toward 1G tugs operating at fractional G under load. The only problem with this is that they are obviously not as efficient as high-G tugs, so why would they be used?
This is why I've never solved this problem - every time I look into it, it opens into a can of worms.

 

[Captain Midnight]

I don't want Acc6 Ag6 tugs zipping around IMTU, I want them limited to a max of 1G whether loaded or not, and if a rescue is needed, you don't launch a tug to do the job of the coastguard cutter. I agree that a rationale is needed, I just can't think of one. (...)
This is why I've never solved this problem - every time I look into it, it opens into a can of worms.

Solution #1 -- Adopt a ruleset for spacecraft that accounts for mass. Maybe it's MT, or GURPS, or something else, but that's your basic problem right there.

Solution #2 -- Who said anything about "agility 6"?. It's certainly possible to have a high acceleration (like 6G maneuver drives) and yet not have enough spare power to give the ship any agility. In fact, if the ship isn't ever expecting to be shot at, it's wildly inefficient from both a cost perspective and an interior-space perspective to provide that much extra power plant capacity. (If your tugs are expecting to be shot at, then they ought to be high-performance.)

 

[boomslang]

My problem was I'd been thinking myself that it's all about acceleration, Capt, but of course that's Traveller thinking - it's actually all about thrust forces. I didn't see it until you put it in writing. A governor can cut the thrust if the acceleration rises too far, whilst allowing the full thrust to tug large masses at low accelerations. Alternatively, tugs could be 1G craft that operate at VERY low accelerations when loaded.

I've always figured that it was a limit of the materials technology that's employed to create grav thrust in the first place; the 6G limit exists simply because trying to squeeze any more ergs out of a gravitics module -- regardless of the mass you're trying to move, which is a separate issue -- causes the drive "coils" to overheat and/or structurally fail.

Call it "etheric resistivity" or "the Mach Inertial Limit" or some such, but the reason that in BT nothing can be shoved at more than 6Gs using gravitics is simply because we don't have materials tough enough to withstand the strain it would put on them to grapple with the inertia involved.

Thus, no matter how many grav modules you strap on, you can't reactionlessly accelerate yourself faster than 6Gs because the mass of the rest of the universe gets in your way. External forces are the only thing that can further increase your acceleration rate (slingshot orbits, for example). Strap-on booster rockets (How quaint and old-timey!) would be another.

And believe me, IMTU, the military would love to go faster than 6Gs, but is resigned to the current performance envelope.

 

[far-trader]

I've always presumed that the standard maneuver drives (book 2 and 5) included full g comp to the rating of the drive. If you want a simple way to factor in the cost savings for a tug that only needs 1g of comp just figure that uncompensated drives are half (or some other fraction) the cost (but just as bulky). So pay normal for the 1G rating for the actual tug then deduct for the rest of Gs and capacity.

 

[atpollard]

Although when you think about it, it would be an incredible feat of nanotechnology to create a material pliant enough to be collapsible and yet impermeable enough to keep all that hydrogen from leaking everywhere.

Internal fuel tanks and Interior cargo holds are both just large voids lined with hull/bulkhead material. Why not just build compartments in 10% incraments that can be either filled with fuel or (if empty of fuel) filled with cargo. All that requires is a door able to handle LH2 - and the fuel port proves that is possible.

The reason that you don't see it, is that Jump 1 ships barely turn a profit under most trade systems - there is no demand for the large scale production of special designs.

 

[Andrew Boulton]

I've always presumed that the standard maneuver drives (book 2 and 5) included full g comp to the rating of the drive. If you want a simple way to factor in the cost savings for a tug that only needs 1g of comp just figure that uncompensated drives are half (or some other fraction) the cost (but just as bulky). So pay normal for the 1G rating for the actual tug then deduct for the rest of Gs and capacity.

...or buy a copy of FF&S!

 

[atpollard]

...or buy a copy of FF&S!

Not until I can get the entire TNE CD.

For now, Striker and MT both break Compensators out from the Maneuver Drives.

 

[aramis]

J2 can and does turn a profit when using Bk2 and T20 trade systems, if players are careful and make good use of the Trader skill for predicting the first die (or 2 in T20, since it's a 3d AVT roll).

J3 can, but does require that you are truly a "tramp"... buy what's good locally and find out where to sell it with the best odds.

 

[atpollard]

J2 can and does turn a profit when using Bk2 and T20 trade systems, if players are careful and make good use of the Trader skill for predicting the first die (or 2 in T20, since it's a 3d AVT roll).

J3 can, but does require that you are truly a "tramp"... buy what's good locally and find out where to sell it with the best odds.

I agree, but this is only sort of true.

Some of the Speculative Trade Rules (like Bk 2) would allow even a dreadnaught (using an empty 100 dTon bay to transport cargo) to make a profit with enough skill and luck.

A pure 'Cargo Only' ship transporting freight at 1000 credits per dTon (per parsec in many house rules) would have a much harder time.

Passengers are either better or worse than Freight depending on the worlds involved and the ability to fill the staterooms.

 

[Butch Clor]

Drives and compensators/Book 2 and HG

Friends,

IMTU and over the decades in discussions with other players we have come up with a few rules comments /definations.

M drives beyond 6 are possible. We use these mostly for Torpedoes (large 2-5dT missles) the progression stays the same,; 3% larger than the previous drive,ie:M-6= 17%, M-7=20%. these can go to M-11=30%. The controlling factor is that compensator technology maxes out at 6G until TL-18. Using this concept a Ship or boat could have a M-7 drive and the crew would take a -1 to all personal stats, per turn., if M-8, -2 to stats. Of course when any personal stat reaches 0 the player in unconscious; with all the ensuing results. Battle dress could offset this but only for a max of number of turns equal to the crew members B/Dress skill.

Book 2 designs versus High Guard.
Ship designs in book 2 are standard easily available components, these can be used to build and repair ships at any type A starport of the components drives base TL or above. a High Guard designed Civilian ship will have to meet all the High guard qualifiers, Design time and cost, restriction to a Class "A" port of the highest TL component installed. In General only sector wide and larger Megacorps, will build very large ships that will need High Guard design tables. In general these were bulk carriers with some passanger capabilities, in the 20-50ktons size. Generally these ships had M-1 drives and Jump drives no larger than 3. Many, since we played in the Spinward Marches, had J-1 drives. Looking at old notes and records, about 80% had J-1, 15% J-2, 3% J-3, and everything else the remaining 2%.
These bulk ships were a good way to assure that your players could move from Point A to Point B on a working passage. Ever cleaned life support filters on a 20kTton ship, built by the same yard that builds Type "S"

Hope this helps
Butch

 

[Icosahedron]

An alternative is that M-drives (and compensators - which use similar technology) increase by 1 per TL up to M12 at TL15 taking 35% (shouldn't M11 be 32%??), which is fine for missiles, but compensators are not 100% reliable; you get the occasional brown-out.
A compensator brown-out at M1 is likely to give everyone aboard a few knocks and bruises (say 1D6 damage), whereas a brown-out above M6 will most likely spread strawberry jam up the walls (6D6?). High-G ships are possible, but rarely permissible. D'ya feel lucky?

 

[deniable]

Given that fighter pilots can take 9G with assistance, and that as soon as a 'brown-out' occurs you stop thrusting, then sure I feel lucky.

Borrowing the TNE rules where tasks get one level harder for each uncompensated G, you would want to ease off the throttle pretty quick, but a few extra G will be doable. People can take 1G to start with and your seat is worth another 1. It's even easier in the ships where the thrust axis is through the deck.

 

[Icosahedron]

You're picturing a ship with everyone wearing combat armour and strapped to their seats? I was thinking more of the Enterprise with people in pyjamas getting flung down the corridors six times faster than falling, along with a jetsam of chairs, tables, personal computers, clip-boards, wrenches and anything else not tied down.

Yes, it would be easier with a through-deck thrust axis, but they are rare IMTU, so I tend not to think of them.

Whatever works IYTU: it was just a suggestion.