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Re: Jump Bubble diameter and location of Jump Drive

Posted: Fri Oct 04, 2013 7:37 am
by locarno24
Since it wouldn't be from the Hydrogen, it must be some energy around the ship while in jump.
Probably. Although exactly what is anyone's guess. It can't just be straight heat, because any seriously lethal external heat level would probably cook the ship like a bean-can over a week in jump space.

Re: Jump Bubble diameter and location of Jump Drive

Posted: Fri Oct 04, 2013 11:49 am
by Reynard
The jump field is an energy field that breaks down the barrier between normal space and the various jumpspaces. That one meter mark around the ship is the transition between different physics and time/space. It's not an absolute boundary as the Starship Operator's Manual describes the effect to living things occurs several centimeters from it. It doesn't go into detail but references what sounds like neural disruption even within the ship at actual transition with the effects increasing the closer you are the field while the field is active.

Going outside the ship while in jumpspace would have to be a dire emergency such as discovering critical hull damage that can't be handled internally. Only the insane casually take a chance to go even more insane or die.

Re: Jump Bubble diameter and location of Jump Drive

Posted: Sun Oct 06, 2013 4:23 pm
by Condottiere
This makes a hull breach a lot more dangerous than I imagined.

Though having to wait a week before re-entering normal space and disintegrating would make Titanic rather less dramatic than James Cameron envisioned.

Re: Jump Bubble diameter and location of Jump Drive

Posted: Sun Oct 06, 2013 4:37 pm
by F33D
Condottiere wrote:This makes a hull breach a lot more dangerous than I imagined.

Though having to wait a week before re-entering normal space and disintegrating would make Titanic rather less dramatic than James Cameron envisioned.
What is going to breach a super strong hull in the middle of jump? Any internal explosion powerful enough is already going to pretty much trash the ship...

Re: Jump Bubble diameter and location of Jump Drive

Posted: Sun Oct 06, 2013 5:03 pm
by GypsyComet
F33D wrote:
What is going to breach a super strong hull in the middle of jump? Any internal explosion powerful enough is already going to pretty much trash the ship...
Cumulative metal fatigue, long-term exposure to high concentrations of hydrogen at a variety of temperatures and pressures, and "stupid PC tricks" (including combat and wilderness refueling) are all going to lead to long-term degradation of the frame and hull. Annual maintenance may or may not catch something in time.

Just because the average Mean Time to Failure at TL15 is well over four decades doesn't mean something won't fail early.

Re: Jump Bubble diameter and location of Jump Drive

Posted: Sun Oct 06, 2013 5:12 pm
by F33D
GypsyComet wrote:
Cumulative metal fatigue, long-term exposure to high concentrations of hydrogen at a variety of temperatures and pressures, and "stupid PC tricks" (including combat and wilderness refueling) are all going to lead to long-term degradation of the frame and hull. Annual maintenance may or may not catch something in time.
About as likely as a turtle flying.

Re: Jump Bubble diameter and location of Jump Drive

Posted: Sun Oct 06, 2013 5:46 pm
by GypsyComet
F33D wrote:
GypsyComet wrote:
Cumulative metal fatigue, long-term exposure to high concentrations of hydrogen at a variety of temperatures and pressures, and "stupid PC tricks" (including combat and wilderness refueling) are all going to lead to long-term degradation of the frame and hull. Annual maintenance may or may not catch something in time.
About as likely as a turtle flying.
Which is reflected in the misjump and in-jump mishap chances, yes.

An early JTAS described the effects of a rare hull breach event in J-Space that someone lived to talk about. it was noted that they happen so rarely that trends and cause-effect are nearly impossible to study. If it happened more often than the occasional and unfortunate turtle-and-catapult encounter, each Major Race would have designed for it.

Re: Jump Bubble diameter and location of Jump Drive

Posted: Mon Oct 07, 2013 5:29 am
by phavoc
GypsyComet wrote:
F33D wrote:
What is going to breach a super strong hull in the middle of jump? Any internal explosion powerful enough is already going to pretty much trash the ship...
Cumulative metal fatigue, long-term exposure to high concentrations of hydrogen at a variety of temperatures and pressures, and "stupid PC tricks" (including combat and wilderness refueling) are all going to lead to long-term degradation of the frame and hull. Annual maintenance may or may not catch something in time.

Just because the average Mean Time to Failure at TL15 is well over four decades doesn't mean something won't fail early.[/quote.]

A ship in jump space shouldn't be experiencing any sort of stress on its hull. It's not under thrust, it has no pressure upon it. It's essentially floating free in a pocket universe. Even the hydrogen surrounding it is not under pressure.

Any fatigue or stress-related problems would most likely occur entering or leaving an atmosphere and a gravity well. Or, perhaps, if the pilot was going crazy with maneuvers and overly-stressing the hull.

Re: Jump Bubble diameter and location of Jump Drive

Posted: Mon Oct 07, 2013 6:00 am
by GypsyComet
phavoc wrote: A ship in jump space shouldn't be experiencing any sort of stress on its hull. It's not under thrust, it has no pressure upon it. It's essentially floating free in a pocket universe. Even the hydrogen surrounding it is not under pressure.

Any fatigue or stress-related problems would most likely occur entering or leaving an atmosphere and a gravity well. Or, perhaps, if the pilot was going crazy with maneuvers and overly-stressing the hull.
Hulls are *always* under stress from something.

Hulls are maintaining roughly one atmosphere inside against weird physics and/or vacuum outside, or are being pushed by drives, or are under gravity and using their feet to keep the hull off the tarmac, or even reversing the direction of the pressure bottle during a gas giant dive or a water landing. It isn't always a lot of stress, but the last straw before a hull breach does not need to be even under normal physics.

What little has been written about jump sickness suggests some pretty unpleasant things at the chemical level. If that field is reaching the passengers it is coming through the hull and stressing or changing it in ways we cannot identify (given that, to us, jump physics is an imaginary science). It is not a great stretch for anyone who knows any material science to recognize that even that little bit of cumulative wear and tear can lead to failure before it is detected. It does not happen often and it is not the only reason ships vanish during a jump, but it is one of the reasons.

Re: Jump Bubble diameter and location of Jump Drive

Posted: Fri Oct 11, 2013 3:48 pm
by Condottiere
That could be one reason that jump bubbles are still an option, despite the danger of upsetting the mass equilibrium if something unreasonably large gets caught within the diameter at the time of departure. The bubble gives a buffer zone against jump space that the grid can't.

Re: Jump Bubble diameter and location of Jump Drive

Posted: Wed Oct 23, 2013 7:49 pm
by Condottiere
Just to verify: Jump 4 requires a TL13/rating 20. A TL12 3/bis computer has a rating 20 (jump).

Are these compatible, or would I have to import or create a prototype of a TL13 3/bis computer on a TL12 industrial base?

Re: Jump Bubble diameter and location of Jump Drive

Posted: Wed Oct 23, 2013 10:45 pm
by phavoc
Condottiere wrote:Just to verify: Jump 4 requires a TL13/rating 20. A TL12 3/bis computer has a rating 20 (jump).

Are these compatible, or would I have to import or create a prototype of a TL13 3/bis computer on a TL12 industrial base?
The tech requirement tables aren't set up to properly cross-reference. It was either oversight or by design. Depending on what are trying to do you can easily explain it away and just import the necessary tech if you are building a ship, or go with your prototype.

For the most part it shouldn't be much of an issue in your campaign unless you are outside of the Imperium and trying to bootstrap a world into a higher TL to build those ships. Otherwise it's cheaper to import the tech/parts from a higher TL world.

Re: Jump Bubble diameter and location of Jump Drive

Posted: Wed Oct 23, 2013 10:48 pm
by Reynard
Condottiere wrote:That could be one reason that jump bubbles are still an option, despite the danger of upsetting the mass equilibrium if something unreasonably large gets caught within the diameter at the time of departure. The bubble gives a buffer zone against jump space that the grid can't.
I was assuming the bubble was low tech with much less control over the field's shape and subsequent vulnerability to outside factors.

Re: Jump Bubble diameter and location of Jump Drive

Posted: Wed Oct 23, 2013 10:57 pm
by F33D
Reynard wrote: I was assuming the bubble was low tech with much less control over the field's shape and subsequent vulnerability to outside factors.
In the MGT universe, it is the ONLY tech.

Re: Jump Bubble diameter and location of Jump Drive

Posted: Thu Oct 24, 2013 10:01 am
by Condottiere
I am going on the assumption that standard alphabet engines are generic, which should make them available across the Imperium (maybe beyond). That's why they're bigger and more expensive than customized ones.

The limitation has to be elsewhere, astrogation controls, inertial compensation.

There's a standard five ton control panel and/or containment unit compared to a customized one percenter. A high tech luxury mini hundred ton star-yacht could have four tons of drives for an overall performance of 1.

Re: Jump Bubble diameter and location of Jump Drive

Posted: Mon Nov 11, 2013 10:27 pm
by MrBackman
The drop-tanks were mentioned first time in Jornal #3 when detailing the Gazelle class Close Escort and have then grudgingly been added to whatever ship design rules there are. Drop tanks, in my opinion, causes all kinds of canon problems such as whu doesn't X-boats use them? Why are there no big warships with drop tanks? Why doesn't the bulk carrier ships have drop-tanks?
Simpy put; does any of you referees out there actually use them and treat them as canon and therefore common?
My design system doesn't have any provisions for drop-tanks but I have added alternative hydrogen storage systems (water, ammonia, methan all store more hydrogen per cubic meter than LHyd) and that certainly breaks canon.

Re: Jump Bubble diameter and location of Jump Drive

Posted: Tue Nov 12, 2013 12:17 am
by phavoc
Condottiere wrote:I am going on the assumption that standard alphabet engines are generic, which should make them available across the Imperium (maybe beyond). That's why they're bigger and more expensive than customized ones.
From what I know, the reason you had the table for engines was because it required less work to design a ship. All you needed to do was cross-reference performance vs. tonnage. Don't ask how they worked out the math, I can't figure out the pattern... It wasn't till they came out with High Guard and larger ships that they had to come up with formulas. Every version of Trav since the beginning just repeated the original stuff.

MrBackman wrote:The drop-tanks were mentioned first time in Jornal #3 when detailing the Gazelle class Close Escort and have then grudgingly been added to whatever ship design rules there are. Drop tanks, in my opinion, causes all kinds of canon problems such as whu doesn't X-boats use them? Why are there no big warships with drop tanks? Why doesn't the bulk carrier ships have drop-tanks?

Simpy put; does any of you referees out there actually use them and treat them as canon and therefore common?

My design system doesn't have any provisions for drop-tanks but I have added alternative hydrogen storage systems (water, ammonia, methan all store more hydrogen per cubic meter than LHyd) and that certainly breaks canon.
Drop tanks, in their original form, have always been associated with smaller ships. If you bring a real-world version to that, you'll also see that fighters, not bombers, are the ones to take on extra fuel because they don't have the range using their onboard tanks. It's nothing fancy, and they do make sense.

I think you don't see them everywhere because it's a hassle to deal with them. The smaller ships CAN mount them, but as a general rule of thumb do not unless they have no other choice.

Re: Jump Bubble diameter and location of Jump Drive

Posted: Tue Nov 12, 2013 4:13 am
by Condottiere
There's some justification in using them on a tactical and operational level, as they can increase endurance (insystem) and increase range (interstellar), however, below TL14 they can screw up parameter calculations to create a misjump, and most commercial shipping would appear to be built at TL12.

So a Gazelle can use them safely, whereas unless the X-Boat systems upgraded to TL14, they couldn't ensure the reliability of the network.

Re: Jump Bubble diameter and location of Jump Drive

Posted: Mon Dec 16, 2013 10:19 am
by Condottiere
What happens when the power plant dies in the middle of a hyperspace jump?

Re: Jump Bubble diameter and location of Jump Drive

Posted: Mon Dec 16, 2013 10:34 am
by Old timer
Simple answer, a mis-jump with either fatal consequences for the ship and its crew, or immediate dropping out of jump space into the middle of nowhere with all the problems that would bring. The power plant runs all things in the ship, so if power fails the jump drive will fail, at least based of the 'physics' of traveller. I dont know if there is anything like an 'official' answer.