Using High Efficiency Batteries for Jump Drives

[Terry Mixon]

I give you the Improved Express Boat built at TL13 for wide compatibility. This improved version delivers all the same capabilities and adds a thrust 1 maneuver drive, improved civilian-grade sensors, and a common area for the pilot at only a 1% increase in cost.

 

[Condottiere]

Don't forget to have extra batteries to cover a week in jump space, though.

Otherwise who knows Watt would happen...?

Only if you happen to be Scrooge.

At default, you run out of power for life support.

Very, very careful management, possibly a very loose interpretation of the asphyxiations rules.

 

[Geir]

They are correct on the X-Boat example. The battery bank is rated at 40. The power plant at 20.
The basic requirements are 20. The jump drive is 40.
The batteries power the drive, because there is no other source onboard capable of doing so.

Based on that, the batteries will work. But, if that is wrong (wouldn't be the only wrong ship...) then from a design standpoint, you just need enough to power jump, half the hull power (lights dim) and nothing else to actually jump - and even the dim lights can be battery. I think its fairly well established that the jump drive only needs to be powered during jump. If so then minimum requirements are just life support, internal system (med bay, low berths, etc. and more Latin) for the duration of the jump.

 

[rinku]

Time to hit the freezer, guys...

 

[Condottiere]

I do want to point out, that in the medium term, even a prefusion donkey engine is preferable to battery based life support.

 

[rinku]

Based on that, the batteries will work. But, if that is wrong (wouldn't be the only wrong ship...) then from a design standpoint, you just need enough to power jump, half the hull power (lights dim) and nothing else to actually jump - and even the dim lights can be battery. I think its fairly well established that the jump drive only needs to be powered during jump. If so then minimum requirements are just life support, internal system (med bay, low berths, etc. and more Latin) for the duration of the jump.

Well, it's not expected that you'd DESIGN a ship without enough power for the hull basics. But if you find yourself in that situation due to damage or other crisis reasons, that's in "PCs need to make a bunch of quick decisions and skill rolls" territory.

The current X-Boat with it's actual powerplant annoys me as a Classic player, but it's sensible. You could probably rework it to be old school battery powered with only life support and power for one jump, plus 3 days. But really, does it matter? The design is a legacy one from 1977, that needed special pleading as early as 1980. No one is actually mortgaging them, or operating them except a communications organisation. They're not armed or able to go anywhere in real space. They are background colour.

Just accept that this is what this centuries old, long optimised and mass produced government vehicle is and does, and move on to ships that can be designed and bought and built and modified.

 

[AnotherDilbert]

I wish the high efficiency batteries had been called capacitors or supercapacitors instead, then the rapid discharge could be more easily handwaved.

Yet batteries can also do so now.

You need some Power from the batteries AND a massive amount of energy from burning the jump fuel. The batteries does not replace the jump fuel, or the massive power generated from it.

You could just as well run life support off the batteries while the power plant is busy feeding the jump drive.

 

[AnotherDilbert]

Not according to the rules as written.

Oh, yes it is, you need some Power AND the jump fuel converted into even more Power.

Core, p157:
Divert Power: A jump drive requires a tremendous amount of power to function, which must be supplied by the ship’s power plant. On many vessels, especially older ships, the power plant strains to provide this much, leading to the tradition of ‘jump dimming’ where non-essential systems including lighting is shut down to allow for jump. If insufficient Power is available, the jump drive cannot be activated.

JUMP TRAVEL
When making a jump, a ship will use an amount of fuel equal to 10% of its hull tonnage for every parsec jumped. For example, if a 200-ton ship makes a two parsec jump, it will require 40 tons of fuel (10% of 200 tons = 20, multiplied by two parsecs = 40 tons).

 

[AnotherDilbert]

Ah, a house rule. I do it the same way

Yes, the second (clearly marked) part is a house rule, the first part is not...

The rules as written allow you to fire up the jump drive with batteries, no power plant needed.

"This Power can then be used in subsequent rounds as if they were being produced by the power plant; simply add the amount of Power stored within the batteries (they need not be completely drained) to the Power the ship has available that round."

So somehow the jump drive knows the batteries were filled by a fusion or antimatter power plant?

"Jump Drive: In order to use the jump drive, the ship requires an amount of Power equal to 10% of the hull’s total tonnage multiplied by the maximum jump number the drive is capable of. Only fusion and antimatter power plants can generate the intense burst of energy
necessary to operate a jump drive.* In either case, the power plant must be used to inject hydrogen into a jump bubble**, so alternative fuels cannot be used. Note that this Power requirement is only needed when the ship actually initiates a jump – at all other times, the jump drive remains inert."

You glossed over an important part:

Jump Drive: In order to use the jump drive, the ship requires an amount of Power equal to 10% of the hull’s total tonnage multiplied by the maximum jump number the drive is capable of. Only fusion and antimatter power plants can generate the intense burst of energy necessary to operate a jump drive. In either case, the power plant must be used to inject hydrogen into a jump bubble, so alternative fuels cannot be used. Note that this Power requirement is only needed when the ship actually initiates a jump – at all other times, the jump drive remains inert.

This is the process, so in CT, so also in MgT2:

JTAS#2, Jumpspace:
When the jump drive is activated, a large store of fuel is fed through the ship’s power plant to create the energy necessary for the jump drive. In the interests of rapid energy generation, the power plant does not work at full efficiency and some of the fuel is lost in carrying off fusion by-products and in cooling the system. At the end of a very brief period (less than a few minutes), the jump drive capacitors have been charged to capacity. Under computer control, the energy is then fed into appropriate sections of the jump drive and jump begins.

Collectors don't break the rules, they have their own rules:

HG'22, p83:
COLLECTORS
These are accumulators, sweeping up exotic particles captured by a canopy and removing the need to carry separate fuel for the jump drive. This charge is released in a single spike to power a jump drive; collectors cannot be used for normal ship operations.

This is not just a battery, it cannot provide regular Power. It only replaces the jump fuel.
The jump drive still need some Power from a power plant (or battery).

 

[Vormaerin]

Yes, Mongoose reprinted Marc's article in JTAS and then wrote completely different rules in the actual rule book. That's been the point of the entire conversation. That's why the explanation of what the hydrogen is for differs between the two quotes in your last post.

That said, there's no reason to believe that collectors require anything from the power plant to trigger jump in any edition. "This charge is released in a single spike to power a jump drive". They can't do sustained power distribution, so can't be used for anything else. This is consistent with T5, where Collectors are classified as a type of power plant, just with limited applications.

 

[AnotherDilbert]

And I could swear that some earlier Traveller version let you use black globe capacitors to power a jump drive without using jump fuel... but that's probably a Chat-GPT-level hallucination.

CT HG, p43:
If a ship absorbs enough energy to make a jump, and is supplied with sufficient fuel, it may jump at the end of the turn.

This made jump faster, it didn't replace the jump fuel.

 

[AnotherDilbert]

Yes, Mongoose reprinted Marc's article in JTAS and then wrote completely different rules in the actual rule book. That's been the point of the entire conversation. That's why the explanation of what the hydrogen is for differs between the two quotes in your last post.

I don't see the basic contradiction. You need a jump drive, a power plant, and a massive amount of fuel. A part of the jump fuel is burned to produce power, and a part is ejected, as the JTAS article describes.
The descriptions are from different perspectives, but are not contradictory.

That said, there's no reason to believe that collectors require anything from the power plant to trigger jump in any edition. "This charge is released in a single spike to power a jump drive". They can't do sustained power distribution, so can't be used for anything else. This is consistent with T5, where Collectors are classified as a type of power plant, just with limited applications.

The jump drive needs Power points in MgT, the Collector does not provide Power points, hence a power plant (or battery) is needed in addition to the Collector.

As you can't effectively power a ship for a week in jump by batteries, so you need a power plant. Batteries can only regulate the power delivery a bit.

 

[Sigtrygg]

You need some Power from the batteries AND a massive amount of energy from burning the jump fuel.

Not according to the rules as they are written in High Guard.

The batteries does not replace the jump fuel, or the massive power generated from it.

The power generated is calculated in the power plant section and is only used when the jump drive is switched on, a batttery may provide these EPs. The jump drive then using fuel to generate even more energy is not in High Guard, it is fluff text (that I agree with) in other books.

You could just as well run life support off the batteries while the power plant is busy feeding the jump drive.

You could, except when the jump drive needs more energy than the power plant can output...

 

[Vormaerin]

Yes, you need power for the ship. The point is that you don't need power for the jump drive itself when using a collector. The collector apparatus provides everything necessary for the jump drive to function. What it does not have is the ability to feed sustained energy to the rest of the ship.

 

[AnotherDilbert]

Not according to the rules as they are written in High Guard.

HG isn't the only rule book... Core describes the basics.

The power generated is calculated in the power plant section and is only used when the jump drive is switched on, a batttery may provide these EPs.

Agreed, only the turn the jump drive is activated.

The jump drive then using fuel to generate even more energy is not in High Guard, it is fluff text (that I agree with) in other books.

The Core rules chapter on Spacecraft Operation isn't fluff:

Core, "Spacecraft Operations", p153:
JUMP TRAVEL
When making a jump, a ship will use an amount of fuel equal to 10% of its hull tonnage for every parsec jumped. For example, if a 200-ton ship makes a two parsec jump, it will require 40 tons of fuel (10% of 200 tons = 20, multiplied by two parsecs = 40 tons).

Fuel mean it is "burnt" for power:

Fuel: a substance that is used to provide heat or power, usually by being burned:

https://dictionary.cambridge.org/us/dictionary/english/fuel

You could, except when the jump drive needs more energy than the power plant can output...

Agreed, that is a (hopefully) rare corner case, that is inconsistent with the fluff and some previous editions.
But, the XBoat says it's OK, with a regular power plant in the background.

 

[AnotherDilbert]

Yes, you need power for the ship. The point is that you don't need power for the jump drive itself when using a collector. The collector apparatus provides everything necessary for the jump drive to function. What it does not have is the ability to feed sustained energy to the rest of the ship.

Disagree:

HG, p17:
Jump Drive: In order to use the jump drive, the ship requires an amount of Power equal to 10% of the hull’s total tonnage multiplied by the maximum jump number the drive is capable of. Only fusion and antimatter power plants can generate the intense burst of energy necessary to operate a jump drive.

HG, p83:
COLLECTORS
These are accumulators, sweeping up exotic particles captured by a canopy and removing the need to carry separate fuel for the jump drive. This charge is released in a single spike to power a jump drive; collectors cannot be used for normal ship operations.

Collectors can't provide Power points.
Collectors don't obviate the need for Power points for the jump drive, just the jump fuel.

T5 is different, sadly. The separate Power and fuel requirement for jump is presumably taken from T4, like many other concepts in MgT2.

 

[Sigtrygg]

HG isn't the only rule book... Core describes the basics.

It does indeed, what am I missing? Where does it say the power plant feeds energy to onitiate jump and then the jump drive or power plant then generates even more?

page 157 states:
"Divert Power: A jump drive requires a tremendous amount of power to function, which must be supplied by the ship’s power plant. On many vessels, especially older ships, the power plant strains to provide this much, leading to the tradition of ‘jump dimming’ where non-essential systems including lighting is shut down to allow for jump. If insufficient Power is available, the jump drive cannot be activated."

The Core rules chapter on Spacecraft Operation isn't fluff:

Where does it state the jump drive requires a larger burst of energy than that required by the drive?

Fuel mean it is "burnt" for power:

https://dictionary.cambridge.org/us/dictionary/english/fuel

Traveller uses the term fuel to refer to the hydrogen used during the jump process, it is not burnt as fuel. As far as I can tell it is only used to maintain the jump bubble.

Agreed, that is a (hopefully) rare corner case, that is inconsistent with the fluff and some previous editions.

And yet it is now MgT canon.

It could so easily be fixed. MWM's article gives the underlying principles and should be adopted.
1. power is required to initiate jump, as per MgT rules
2. the jump drive then works in combination with the power plant, the ship uses the vast majority of its fuel to generate an extreme burst of energy
3. some of the liquid hydrogen is used as coolant

Which brings us back to collectors...

No hydrogen filled jump bubble, a requirement that a fusion or antimatter reactor is available for step 2...

 

[Sigtrygg]

T5 is different, sadly. The separate Power and fuel requirement for jump is presumably taken from T4, like many other concepts in MgT2.

T4 is where the hydrogen filled bubble comes from, there is no mention of it in T5 that I have found.

 

[Condottiere]

I thought Tee/Five gave three options, including localized field.

As regards Collectors, I'm thinking a dry bubble, if exotic particles are being sidetracked.

 

[Vormaerin]

T5 is one the clearest explanations of the overclocking the power plant mechanic that is the actual justification for the fusion/anti-matter only rule. T5 doesn't even require a jump bubble, having clear rules for both jump bubbles and hull grids, with differences in the performances of the two.