Emergency Batteries

[SJWaldock]

If a ship or boat has a power plant failure, I assume there would be emergency batteries to keep life support going. This is mentioned specifically in DGP's 'Starship Operators Manual Vol 1' on p16 where the 'Old Timer' recalls his ship's power plant being knocked out of commission by a Zhodhani missile. They jumped to safety as they had 'batteries to last life support for two weeks'.

Would these batteries be classed for ship design purposes as hull, power plant, life support or what? I'm assuming that artificial gravity grids would be turned off to save power and the rest of the equipment would work on reduced power to say 75% of normal.

What are people's thoughts on this?

 

[JustinThyme]

Power Plant, definitely. I've heard the opinion that it should be Life Support, but life support doesn't function without POWER.
And "SOM Vol 1" giving a power plant being whacked, then the ship making jump...?...I can't remember how it went, but I'm assuming the ships capacitors were already charged.

 

[aramis]

SSOM vol 1 was for MT. Batteries were part of that design sequence (The MT One), and thus it was possible to put 2 weeks worth of LS batteries.

What's more, MT Jump units require no power to operate. (I just checked.)

 

[Antony]

In TNE I assumed they were constructed as part of the power plant system but are included in the Emergency Life Support system. IMTU on emergency power they can provide 7 days endurance for extended life support, minimal lighting, one computer and one radio. There is no power for AG or Grav Compensators. It would theoretically be possible to run the maneuver drive from batteries but if so expect a rapid depletion of power (I'll have to do some calculations). Oh yes don't deplete the batteries completely as they also provide power for the fusion reactors start-up system. Once running of course the power plant recharges the batteries.

 

[mike wightman]

Hmm, according to 2nd edition CT you have to have a power plant equal to the jump drive to make a jump, so this couldn't work in that system.

It would work in CT 1st edition because the jump drive doesn't need a separate power plant.

That "Old Timer" story is the second piece of evidence that DGP were working from 1st edition CT and not 2nd edition for rules interpretation.
Or they were just set in their ways...

 

[mike wightman]

And it wouldn't work in T20 because of the EP requirement of the jump drive.

Of course if someone gives an official conversion rate for vehicle scale EPs to ship scale EPs then it may become possible

 

[Andrew Boulton]

Batteries are pretty big.

I just threw together a TL15 Scout/Courier in FF&S2.

One computer, controls, lasercomm, & life support (total 0.27MW) needs 2.16m3 of batteries per 24hrs.

Adding a radio and gravity (another 3.44MW) puts that up to 29.68m3/day. That's over 2dt.

 

[Psion]

My assumption is batteries are integral to the power plant and won't run any components that matter in ship combat (i.e., drives, weapons, screens). Just life support and minimal lighting.

CT HG (and I think MT, too. Damn DRM... ) assumed that there were some capacitors integral to a jump drive.

 

[korvin]

Originally posted by Sigg Oddra:
And it wouldn't work in T20 because of the EP requirement of the jump drive.

Of course if someone gives an official conversion rate for vehicle scale EPs to ship scale EPs then it may become possible

It is already in there, they just did not come out and say what it was. Look on page 282 under Ship's Computer.

Ben

 

[mike wightman]

Unfortunately that particular conversion factor doesn't make sense.
If 1 ship EP is worth 10 vehicle EPs then it would be better to install vehicle scale power plants in ships.
1 displacement ton is 1400vl
TL8 vehicle fusion plant 450vl, 100EP 150vl of fuel per month.
So 1 dt of vehicle power plant produces 300vEP = 30EP and uses 1 dt of fuel every 3 months
It gets better at increasing TLs

By my reckoning a scale of 500 vehicle EPs to one ship EP is a bit closer

 

[far-trader]

From several refereces it seems when converting "size" from vl (vehicle load?) the actual conversion is more like 1,000vl to 1ton (displacement ton or space vessel ton). And when using kg to find vl it's 1kg to 1vl in examples.

So one tonne (a metric ton, 1,000kg) is 1,000vl which is also 1ton, which kinda works out nice, no?

Of course that doesn't fix the power conversion, or the battery problems, or...

 

[mike wightman]

The only reference I have is the scale conversion rules at the beginning of the design section and I can't find any errata; plenty of discussion but no official ruling
I have noticed in the free intro to the vehicle guide compilation that the conversion scale has been changed, in the "How big is my vehicle" section the main rule book is contradicted, so I wonder if the rulebook needs changing?

 

[far-trader]

Nope, no errata as yet despite mobs screaming at the gates so officially it is still 1vl = 10litres and 1,400vl = 1ton (pg.223)

The vehicle TAs all use 1vl = 5litres which seems to be an accepted change even if not acknowledged.

I'm basing my conversions on such examples as:

The vehicle lowberth (500vl and KCr50) compared to the space vessel lowberth (0.5ton and KCr50).

The vehicle listing for the personal mountable weapons, like the LMG (5.5vl Cr1,200) compared to the LMG from the weapons list (5.5kg Cr1,200)

These examples and the fact that it all clicks with a tonne is a ton is 1,000kg is 1,000vl all makes a lot more sense than arguing if 1 vl is 10liters or 5litres, or 1kg or 10kg, etc. etc.

 

[teinedraig]

WRT EP conversion - If I remeber correctly - there was a discussion around EPv to EPs (under computers) and it ended up with 1 EPs = 25 or 50 EPv, which starts to make the power plants align a bit more. Otherwise, yes, you are better off using the vehicle power plants.

As to emergency power - how about solar panels/sails in conjuntion with batteries

 

[Antony]

Luckily FF&S1 does not use EP at all, but Mw so EP conversions are not relevant

 

[Andrew Boulton]

"As to emergency power - how about solar panels/sails in conjuntion with batteries"

Not much use unless you're close to the star, and they're pretty inefficient.

Fuel cells are better. For the Scout/Courier:

One computer, controls, lasercomm, & life support (total 0.27MW) needs 1.46m3/day (vs 2.16m3 of batteries).

Adding a radio and gravity (another 3.44MW) puts that up to 19.85m3/day (vs 29.68m3).

Still big, but almost useful.

Better still would be a small, backup fusion reactor - a month of power for all that gear for .65m3!

 

[TheDS]

As I recall from MT, they gave power in Mw, so you just figure out what you want powered and for how long, and that's how much battery you need.

TNE DOES work that way, and gives you efficiency of scale to boot (I think MT does this too).

In general, figure out what you want to power (LS, low berths, missile launchers, whatever) and then allocate enough battery to power it for 1000 hours, because that is the peak of efficiency; basically you need the least amount of battery if you drain it over the course of 1000 hours.

Something like that. 1000 hours is about 6 weeks.

 

[aramis]

Yes, MT works that way, too. (Big diffeence betwixt the two is that TNE uses Surface area, MT doesn't, and the Td difference (13.5 MT vs 14 TNE).

a lot of little details also changed, like fuel rates...

But in both MT and TNE, batteries are measured in KWH/MWH, and power draws are in MW... so figure out rate per hour, multiply by hours, then divide by rate to get KG (and L) of batteries.

Since most FF&S and MT designs wind up with fractional kL of cargo space, it is not uncommon for players to dfill that with aew KG of "Emergency Power".

Battery powered starships ARE doable in both.

Lame, but doable.

 

[clair_rand]

most ships i do have three primary power plants and some sort of backup..

plant #1 handles emergency & hotel loads

plant #2 handles the extra power requirements of normal operations, drives etc

plant #3 handles combat loads.

the backup is emergency only

typically i'd allocate fuel for several months of hotel loads, say 2 weeks of cruise and 24 hours of combat.

Think what that does to ya fuel consumption rates, and thus fuel tank capacity.

Batteries are viable, but you have to narrow down what your going to drive from them, say basic life support, extended life support and a few communication devices for *part* of the crafts hull.

Mind you i'm into 'extreme' optimisations, someday i'll post what i did to the 'free trader' that gave it around 20% more cargo volume, dropped the cost and reduced running costs. just by tidying up the design a bit.

 

[Antony]

Emergency batteries IMTU power extended life support, one computer and one radio this is for a period of 1 week.

Cold Berths I have always assumed have a backup power supply independent of the ships. How else (in the TNE era) could people have survived in a Cold Berth for 70 odd years in a ship with no power supply. In FF&S1 Cold Berths are listed as requiring 0.001Mw I assum this is the power at the time of freezing and revivification and that in maintenance mode much less is needed.