Trepida Ammo Gurps vs. TNE

[pzmcgwire]

In the TNE Regency Combat Vehicle Guide, theTrepdia has an ammo capacity of 410 PFC rounds for the main fusion gun, while the Gurps Traveller Ground Forces' Trepida has a 40 round capacity and no ammo capacity is listed in MT 101 Vehicles for the Trepida though it does have a ROF of 80.

Which is the canon ammo capacity? Should there even be an ammo capacity for an energy weapon?

What are PFC's? Are these supposed to be a way to account for power plant usage or some type of actual consumable for energy weapons?

 

[whartung]

Should there even be an ammo capacity for an energy weapon?

TNE changed the energy weapons to use cartridges, so then, indeed, do have ammo.

 

[McPerth]

Trepida has a 40 round capacity and no ammo capacity is listed in MT 101 Vehicles for the Trepida though it does have a ROF of 80.

In MT, energy weapons only neded power, so no ammo was given for them when mounted on vehicles. As long as they had power, the weapon could be used.

Same for ship's weapons, where it was one of the main advantages over missiles, that needed space for ammo (and you had to pay for them).

See that old thred, though...

 

[Rupert]

The MT version assumes that a fusion gun is powered by the vehicles power plant, and thus has effectively unlimited ammo.

TNE changed this so that fusion and plasma weapon use a specialised type of one-use energy cell, and so the Trepdia (and other vehicles armed with such guns) has an ammunition capacity.

GT assumes that energy weapons have too great a power drain to generally be powered directly from a reactor or the like. Instead they are powered by a rechargeable power cell, and thus have a limited ammo supply in the short term. Note that the description lists a recharge rate - the main reactor can slowly recharge the power cell, so in the long term the Trepida has effectively unlimited ammo, even though in the short term it's supply is quite limited. You can see this with the other vehicles armed with energy weapons as well.

 

[kilemall]

The MT version assumes that a fusion gun is powered by the vehicles power plant, and thus has effectively unlimited ammo.

TNE changed this so that fusion and plasma weapon use a specialised type of one-use energy cell, and so the Trepdia (and other vehicles armed with such guns) has an ammunition capacity.

GT assumes that energy weapons have too great a power drain to generally be powered directly from a reactor or the like. Instead they are powered by a rechargeable power cell, and thus have a limited ammo supply in the short term. Note that the description lists a recharge rate - the main reactor can slowly recharge the power cell, so in the long term the Trepida has effectively unlimited ammo, even though in the short term it's supply is quite limited. You can see this with the other vehicles armed with energy weapons as well.

2300 went the ammo route for its personal plasma weapons.

 

[Rupert]

2300 went the ammo route for its personal plasma weapons.

That was the first GDW game for it to show up in, yeah. All plasma weapons required ammo in that game, and the ammo was heavy.

 

[McPerth]

That was the first GDW game for it to show up in, yeah. All plasma weapons required ammo in that game, and the ammo was heavy.

Also lasers, in 2300AD, need ammunition, not able to work on batteries. This takes away one of their main advantages, IMHO

 

[Rupert]

2300AD's small arm lasers used single-use batteries. They needed a lot of power, so the batteries were generally quite heavy for the number of shots they gave. Being single use they were definitely yet another thing for the logistics system to have to manage.

TNE's small arm lasers often used single-shot cartridges because they were chemical lasers and rather than having tanks of exotic (and highly volatile, corrosive, and poisonous) chemicals they had little cartridges that were pre-loaded with the chemicals. They also had suspiciously high energy densities, so they were fairly light for the fire-power they gave. Spaceship lasers just used electricity and were generally directly powered from a reactor.

 

[pzmcgwire]

TNE appears to have nerfed the PGMP and FGMP reducing their ammo to low double digits or even single digits compared to GURP's hundreds. Surpringly for the Trepida, GURPs reverses this where the base ammo for the Trepdia is 40 and TNE is 410.

Yes, a GURPS power plant can recharge the ammo eventually, but 40 seems low for a future tank as seems too directly comparable to a current MBT's ammo load.

Also the TNE 5 and 10 shot PGMPs and FGMPs apparently fed by magazines don't seem correct.

Could a TNE Trepida self produce PFCs to recharge its main gun?

 

[Rupert]

TNE appears to have nerfed the PGMP and FGMP reducing their ammo to low double digits or even single digits compared to GURP's hundreds. Surpringly for the Trepida, GURPs reverses this where the base ammo for the Trepdia is 40 and TNE is 410.

Yes, a GURPS power plant can recharge the ammo eventually, but 40 seems low for a future tank as seems too directly comparable to a current MBT's ammo load.

It's an artefact of Vehicles, GURPS' vehicle design system. The main gun is very powerful, so it eats a lot of energy and the power cells can't hold that much. Thus the GURPS interpretation has limited 'ready ammo', but no logistics tail for it because the on-board reactor can recharge the power cells over time.

The TNE version has a large ammo capacity because it cannot recharge them, and thus what they bring to a fight is what they have.

Also the TNE 5 and 10 shot PGMPs and FGMPs apparently fed by magazines don't seem correct.

They are correct for TNE (and it's 8 shots for the compensated ones and 20 for the battledress-only models, with "Putting the heat back into plasma' changes). Whether one likes the change or not is another matter. I was never a super fan of the CT/MT FGMPs with infinite 'ammo' from a little power pack (technology that didn't seem to reach into other parts of the setting much), so I'm okay with it. TNE high energy weapons are much cheaper than CT/MT ones as another change.

Could a TNE Trepida self produce PFCs to recharge its main gun?

Nope. What's more, if you decided that fusion guns can be powered directly off a reactor, the Trepida I's 74 MJ gun firing five shots per 5-second turn would need 74 MW of power, and at TL-14 that means a fusion reactor of nearly 25 m^3 volume and 74 tonnes mass. So now the tank is about twice the size and mass once the extra armour, C-G, thrusters, etc. to protect, lift, and move that reactor are added. Alternatively, you could re-write FF&S' rules to suit.

Back in Striker fusion guns needed about half that much power, and the guns themselves were very light, so fitting them into a vehicle was easier (though fuel the reactors needed a lot more fuel).

Different rules made different assumptions about how things worked, and these resulted in different end details. Presumably the authors thought these were improvements, or they'd have stayed with the original rules.