Does the Scout come with weapons?

[AnotherDilbert]

"The jump drive is powered by the battery, which is recharged during the normal refuelling operations."
So that means any ship with enough HEBs can also charge the jump that way.

Agreed, a jump drive only needs energy, but wast amounts. In a fusion economy it needs both a bit of energy and a lot of fuel (to be turned into energy).

Only antimatter power or other exotic power systems can provide the needed energy without large amounts of fuel.


Let's estimate:
Take a 1000 Dton ship with J-1 at TL-12. It needs a 20 Dt power plant producing 300 Power to power basic systems (200 Power) and either the M-drive or the J-drive (100 Power). It uses 2 Dt fuel over 4 weeks, or 1 Dt per two weeks.

In two weeks the PP would produce 300 Power for 2 × 7 × 24 × 10 = 3360 turns or about 1 000 000 PowerTurns = 1 MPowerTurn from 1 Dt fuel.

A J-1 would require 100 Dton fuel or about 100 MPowerTurn energy.

One Dt of HiEfficiency Batteries holds enough energy to produce 60 Power for 1 turn so 60 × 1 = 60 PowerTurns/Dt.

100 MPowerTurns required / 60 PowerTurns/Dt ≈ 1.7 million Dt batteries required.

So roughly a 1 000 Dt ship would require 1 000 000 Dt batteries to power a jump-1. Obviously that is not happening...


Estimate Two:
At very roughly 1 Power = 10 MW, 100 MPowerTurn (one jump) would be 100 000 000 PowerTurn × 10 [MW/PowerTurn] / 10 [turns/hour] = 100 000 000 MWh = 100 TWh = 100 billion kWh.

That is roughly what ten nuclear reactors of 1000 MWe each produces in a year. Or twenty Hoover dams. Or about 100 large wind power parks with a total of tens of thousands wind mills covering 7800 km² (≈Delaware) (Shepherds Flat Wind Farm).

For one jump...

 

[Condottiere]

As I recall, when alternate methods of energy production became options, it was made quite clear that only custom made shipboard fusion power plants could activate the jump drive, as they were inefficient when compared to normal fusion power plants, but specifically designed to overclock in order to deliver the requisite power draw from the jump drive.

As far as I can tell Mongoose First doesn't mention it; it's certainly conspicuous by it's omission in Mongoose Second.

 

[Sigtrygg]

Have you ever read MWM's Jump space article which clarifies this, or T5?

Within the OTU it is well documented, for a referee's homebrew setting then it is for the referee to make it up.

 

[Reynard]

"So roughly a 1 000 Dt ship would require 1 000 000 Dt batteries to power a jump-1. Obviously that is not happening..."

Just so I'm clear on this, the X-boat tender produces 450 pp per round [6 minutes]. Basic ship power uses 200 pp per round while either Maneuver or Jump uses 100 pp/round and 6 pp go to Sensors and Fuel Processors. That leaves 144 pp for recharging. An X-boat has 40 pp in HEB which can be recharged in one round (as hinted at on HG page 38 "They (HEBs) can be recharged in any round by excess Power not being used by other systems.") and power it's Jump 4 drive no trouble. That should mean 3 x-boats can get a full charge at a time. I'm going to assume Maneuver is also shut down allowing a full compliment of 6 X-boats to be charged at a time.

Now the Tender is purpose built to charge X-boats. Very few ships have any excess power at all. A Free Trader, if it 'dimmed the lights' to produce 10 unused power points, after buying a ton of TL 10 High Efficiency Battery, it could charge the battery in 4 rounds.

Something seems to be missing from the equation such as all that Jump fuel.

 

[AnotherDilbert]

Something seems to be missing from the equation such as all that Jump fuel.

There is no mystery: You need a bit of power and a lot of fuel to jump.

The X-boat needs 100 Dt × 4 [jump-4] × 10% = 40 Power and 100 Dt × 4 [jump-4] × 10% = 40 Dt jump fuel. Note that the X-boat has 1 Dt batteries (40 Power) and 40 Dt jump fuel as expected.

The needed power is supplied by batteries, charged by the tender, but you still need the jump fuel too.


The jump fuel is turned into energy before it is used, so pure energy can be substituted, but you need vast gobs of energy, much more than realistically stored in the ship at Imperial TLs.

 

[Sigtrygg]

I haven't got access to my MgT books at the moment due to computer issues.

Something that bugs me about this batter thing. You need to know the total energy capacity of the battery, ie EP x time.

A tender doesn't just charge the batteries for one turn of operation it has to charge the batteries for a full week if not longer. So just how many joules of energy are being stored in these batteries and how can the tender not take a week to transfer a week's output from its pp to charge the x-boat batterie?

And as i said earlier, batteies are not capacitors...

 

[Linwood]

I haven't got access to my MgT books at the moment due to computer issues.

Something that bugs me about this batter thing. You need to know the total energy capacity of the battery, ie EP x time.

A tender doesn't just charge the batteries for one turn of operation it has to charge the batteries for a full week if not longer. So just how many joules of energy are being stored in these batteries and how can the tender not take a week to transfer a week's output from its pp to charge the x-boat batterie?

And as i said earlier, batteies are not capacitors...

I’ve been wondering about that too. The quickest way would be to make the battery pack module and then simply swap out the depleted pack for a fully-charged (or near-full charge) one. It’s likely that could be done in an hour.

 

[Reynard]

"Note that the X-boat has 1 Dt batteries (40 Power) and 40 Dt jump fuel as expected."

*Squints again at the black on grey fuel stat line for the X-boat which is blurry without my glasses."

AH! You're right! Thank you. I was jumping between the x-boat, the tender and other references and somehow missed that one piece of info. Now it all make perfect sense and why other ships can't pull the same trick.

 

[Reynard]

Maybe the term High Efficiency Battery is another term for a capacitor since it performs like a capacitor for some functions.

 

[AnotherDilbert]

Something that bugs me about this batter thing. You need to know the total energy capacity of the battery, ie EP x time.

Quite, but the jump drive only needs Power for one turn, so it is easy to power from batteries.

Any system that needs power for days or weeks are much better off powered by a power plant.

 

[AnotherDilbert]

Now it all make perfect sense and why other ships can't pull the same trick.

Good, I was suspecting we were talking about different things...

Maybe the term High Efficiency Battery is another term for a capacitor since it performs like a capacitor for some functions.

I don't think we should take that too literally, it just means "HiTech device that stores energy".

 

[Condottiere]

A battery's capacity is the amount of electric charge it can deliver at the rated voltage.

Never been specified: therefore, you can assume transfer could be all the energy currently stored in one turn, though possibly not in one dog fight round.

Ironically, black globe capacitation discharge is more clearly defined.

And solar panelling.

 

[Linwood]

IRL, a battery’s capacity is usually expressed in terms of amp-hrs (current per unit time at its rated voltage) or watt-hrs (power per unit time). The charge/discharge rate is usually defined as a multiple of C (charge capacity) per hr. So at a 1C discharge rate means the battery will go from full to 0 charge in an hour. The way HG describes batteries seems consistent with that - X power points discharged in an hr.

I agree, the way HG is written you could dump the full rated power in a single turn. But if we were talking real-world behavior (OK, granted, it’s a game and we certainly don’t have to see it that way) I would expect an efficiency loss due to overheating if the rate goes very far above 1C as well as a significant long-term degradation in battery life if this occurs frequently. So if you want YTU to be a bit grittier you might work that in (“Sure, captain, we can dump all our battery power into one more burst - but we’ll have to scrap them after.”)

 

[Condottiere]

They're cheap enough to be disposable.

I did explore the possibility of exchanging the jump capacitors with batteries, but couldn't identify a hook with which to do so.