I.C.E. and Power Amplifiers

[Sigil]

When I play TT, I don't allow I.C.E. powered vehicles or IndustrialMechs to mount energy weapons other than a small laser (and only then if pushed).  The idea that all a vehicle needs is a "power amplifier" in order to utilize PPCs and high-powered lasers is too much of a stretch for me.  While in terms of game mechanics, it is somewhat offset by the requirement for heat sinks, even this doesn't address the underlying power generation requirements.  In addition, it has always seemed to me that vehicles that mount only missile or ballistic weapons are not required to mount heat sinks anyway, another inconsistency that has long bothered me.  Thoughts?

[Tymers Realm]

Simply put, at least in SW era play, your going against Canon rationale as to the need for Power Amps & Heat sinks for combat vehicles. The fact that fusion engines are needed for Mechs!
Granted it doesn't disallow too many SW era CVs (Goblin, Condor, Drillson, Bulldog, & Ontos). I think though that is rather short-sided. I can also see a balance reason in a sense. By giving ICE CVs a pass on Ballistic & Missile Weapon heat, your also purposely turning them into easier to blow up ammo bombs, if I understand the current CV rules correctly.

[guardiandashi]

I look at the "power amp" as being a combination of generators, additional dedicated alternators etc. and energy storage that makes it feasible to run an energy weapon on the vehicle.

to use a modern example take a car lets say I have a ford escort it comes stock with say a 65 watt alternator, I decide to replace the standard headlights with HID ones, and put in a stereo system with a 200 watt draw, there is no way in hell that that puny little 65 watt alternator will supply the electricity needs so I replace it with a 300 watt alternator, and in addition mount a couple of high output batteries 1000+ cca so I now have a huge "battery reserve" IE in battletech terms a power amp and can now run those high draw components.

the heat sinks are needed to handle the waste heat of those high power systems.

of course the thing that boggles my mind... why doesn't the gauss rifle require power amps just like all the other energy weapons.

[glitterboy2098]

i look at it like the current AN/SEQ-3 Laser Weapon System.. the laser only needs electricity. it would be ideal on a Nuclear powered ship.
but since we don't have many of those, and it is currently onboard a warship that doesn't even have much in the way of built in power generators, they've been powering it through a bit of a lashup.. in addition to the ship's two built in generators, it has a couple more high output portable generators parked on deck.

[Kit deSummersville]

Well, the units you're describing are some of the worst choices available, I think you might be worrying over a whole lot of nothin'.

[SCC]

i look at it like the current AN/SEQ-3 Laser Weapon System.. the laser only needs electricity. it would be ideal on a Nuclear powered ship.
but since we don't have many of those, and it is currently onboard a warship that doesn't even have much in the way of built in power generators, they've been powering it through a bit of a lashup.. in addition to the ship's two built in generators, it has a couple more high output portable generators parked on deck.

The problem with that for BT is that it presumes that a fusion reactor of a given output actually produces for energy then an ICE one.

[Tegyrius]

of course the thing that boggles my mind... why doesn't the gauss rifle require power amps just like all the other energy weapons.

Its base mass includes the capacitors that discharge for the firing sequence. That's why it blows up real good when subject to a crit.

[Natasha Kerensky]

This is very munchy, but it makes some sense technically...

Outside of Succession Wars-era scarcity, mount a small, 1-ton, secondary fusion engine to supplement the tank's primary ICE or fuel cell engine.  The ICE or fuel cell engine mobilizes the vehicle, while the fusion engine powers the energy weapons and provides 10 free heat sinks.

Depending on the tank's energy weapon loadout, a small secondary fusion engine can save the tank tons on "power amplifiers" and heat sinks.  No idea if this would affect BV, but the C-bill bump should be modest.

I don't think anything in the rules specifically forbids this (i.e., "each combat vehicle may mount only one engine"), but there are no examples of it in the TROs, either.  You'd want the agreement of your GM or opponents.

FWIW...

[cray]

When I play TT, I don't allow I.C.E. powered vehicles or IndustrialMechs to mount energy weapons other than a small laser (and only then if pushed).  The idea that all a vehicle needs is a "power amplifier" in order to utilize PPCs and high-powered lasers is too much of a stretch for me.

Hmm. Well, here's my winding, tortuous reply.

To make sure we're on the same page, the physics definitions I'm using are:

Energy: the capacity to do work. Measured in Joules, among other units.
Power: the rate of energy delivered. Measured in Watts. 1 Watt = 1 Joule / second.

Power can be a bit misleading - it's often associated with having lots of oomph and getting stuff done, but it's a really just a measure of how fast you're expending energy. Power by itself doesn't say what was accomplished. Meanwhile, energy says how much work was done, but not how quickly.

For example, rounding Earth's gravity to 10m/s/s because I'm lazy, lifting a 1L bottle of water (1kg) to a height of 1 meter from the ground requires the expenditure of 10 Joules. If you lift the bottle in 1 second, then you've expended 10 Joules in 1 second: 10 Watts. If you spend 10 seconds lifting the bottle, then you only spent 1 Watt lifting the bottle. If you're He-Man and lift the bottle in 1/1000th of a second, then you've expended (10 / 0.0001) = 10,000 Watts. In all cases, you still expended 10 Joules.

This leads to BT energy weapons and power amplifiers.

BT energy weapons need some large amount of Joules in a short time. Fusion engines can deliver that energy with sufficient power to directly meet the needs of the energy weapons. IC engines deliver a lot of Joules, but not as quickly. If they tried to directly power a PPC, it'd just spit and sputter as electricity trickled in from the IC engine's alternator, turbogenerator, hamsters-in-cages, or other electrical generator.

However, if you could accumulate those Joules from the IC engine in something over time and discharge it quickly, you could greatly amplify the power available to the weapon. A classic example of such a power amplifying accumulator is the capacitor, and that's how power amplifiers are described on p. 235 of Tech Manual: capacitor banks.

A fusion engine can power a PPC's microsecond discharge directly. An IC engine can't, but an IC engine with a power amplifier has the other 9.99999 seconds of a turn to match the fusion engine.

So, that's why I tend to be happy with power amplifiers in BT allowing ICs to power BFGs. YMMV. :)

it would be ideal on a Nuclear powered ship.

Interestingly, modern naval fission reactors are not ideal for all electrical weapon applications (lasers, railguns, etc). They're very heavy for the horsepower they deliver and run best at high, constant loads. On the other hand, gas turbines are very light for their power. Since battles tend to be short, you don't need the endurance of a nuclear plant, but rather vast power demands to keep those capacitors charged. Nuclear or gas, the breakthrough the US Navy is hoping to implement (for the second time since 1913) is an all-electric ship where all the engine output is available in electrical form, and not just for propulsion. Being able to shuffle around tens and hundreds of megawatts for different ship needs opens some interesting possibilities.

[Daryk]

*snip*
For example, rounding Earth's gravity to 10m/s/s because I'm lazy, lifting a 1L bottle of water (1kg) to a height of 1 meter from the ground requires the expenditure of 10 Joules. If you lift the bottle in 1 second, then you've expended 10 Joules in 1 second: 10 Watts. If you spend 10 seconds lifting the bottle, then you only spent 1 Watt lifting the bottle. If you're He-Man and lift the bottle in 1/1000th of a second, then you've expended (10 / 0.0001) = 10,000 Watts. In all cases, you still expended 10 Joules.
*snip*

Just one quibble with this otherwise excellent explanation.  As you explained previously, Watts are the rate at which you "expend" energy.  So: "If you spend 10 seconds lifting the bottle, then you only spent them at a rate of 1 Watt.  If you're He-Man and lift the bottle in 1/1000th of a second, then you've expended them at a rate of (10/0.001) = 10,000 Watts."
[/physicist]

[Sigil]

A fusion engine can power a PPC's microsecond discharge directly. An IC engine can't, but an IC engine with a power amplifier has the other 9.99999 seconds of a turn to match the fusion engine.

So, that's why I tend to be happy with power amplifiers in BT allowing ICs to power BFGs. YMMV. :)

Wouldn't that mean that the rate of fire for a fusion powered PPC and an ICE + Power Amplifier PPC would be significantly different?  The same would seem to go for lasers as well.  On the opposite side, ballistic and missile weapons would likely have a similar rate of fire as the limiting factor isn't available energy.

[cray]

Wouldn't that mean that the rate of fire for a fusion powered PPC and an ICE + Power Amplifier PPC would be significantly different?

Shh. BT weapons fire once per turn. Don't look behind the curtain! ;)

Alright, a little more technobabble. Consider the analogy: if you a have 100hp electric motor that's normally working at maxed out at 100 horsepower, what happens if you try to feed it to 200 or 300hp? It doesn't deliver two or three times the work, it burns out.

Likewise, weapons are going to be maxed out to be as powerful as possible and light as possible for their current tonnage. And BT weapons are pretty maxed out: it's been centuries of work to lighten them a bit or extend their range a bit. Look how long it took to get from an Age of War 5-ton large laser to a 4-ton Clan ER large laser.

And power's not in short supply - a fusion engine can easily supply 4 PPCs in one salvo. Heck, you could easily get 6 Clan ER PPCs on a 'Mech or fighter (cooling, though...). In other words, a fusion engine can already easily power an energy weapon more than once per turn. That doesn't happen. Theory: the weapons can't handle it. See motor analogy.

There has been a semi-success in doubling laser damage: the blazer. It's a twin large laser mount that hits in one spot. Toward your point, the blazer is an example of faster firing - it's doubling the power input of the large laser. It has to nearly double the tonnage and double the waste heat to increase damage 50% (still: a 12-point headcapper).

[Daryk]

And don't forget that (at least for energy weapons), waste heat is more energy that had to go into generating the weapon's effect.

[Charistoph]

So Gauss Rifles are operating on a (relative) trickle charge, while lasers and PPCs operate on a burst charge?

I guess that would fit considering how massive they are and how their operation is such low heat.

As a side note, I've always thought that half of the heat of energy weapons was from the discharge itself, and the other half was the fusion reactor going in to higher "gear" to power the weapons.

[Nightlord01]

So Gauss Rifles are operating on a (relative) trickle charge, while lasers and PPCs operate on a burst charge?

I guess that would fit considering how massive they are and how their operation is such low heat.

As a side note, I've always thought that half of the heat of energy weapons was from the discharge itself, and the other half was the fusion reactor going in to higher "gear" to power the weapons.

Waste heat is caused by inefficiencies in a system, resistance in the transmission lines, storage mechanisms, signal generators, you name it, every system has them. A big part of the engineering process is to know how much heat these will generate and ensure that heat is removed from the system as swiftly and effectively as possible.

[Charistoph]

Waste heat is caused by inefficiencies in a system, resistance in the transmission lines, storage mechanisms, signal generators, you name it, every system has them. A big part of the engineering process is to know how much heat these will generate and ensure that heat is removed from the system as swiftly and effectively as possible.

To a point, but those systems can be overwhelmed, such as rapid-cycling an energy weapon which pulls a direct feed from a power plant.

[Nightlord01]

To a point, but those systems can be overwhelmed, such as rapid-cycling an energy weapon which pulls a direct feed from a power plant.

Under general conditions, this should not happen, there should be a safety interlock which holds fire until heat comes back down to acceptable levels. All military equipment will have a battle override, however, which will prevent this effect.

If your system is capable of firing fast enough to overheat under general conditions, without battle override, take your engineer out and shoot him before he kills half your soldiers through incompetence.

[Charistoph]

Under general conditions, this should not happen, there should be a safety interlock which holds fire until heat comes back down to acceptable levels. All military equipment will have a battle override, however, which will prevent this effect.

If your system is capable of firing fast enough to overheat under general conditions, without battle override, take your engineer out and shoot him before he kills half your soldiers through incompetence.

And we wonder why Battletechnology fell off during the Succession Wars.  ;)

[Sartris]

take your engineer out and shoot him

-Plaque above ROM Precentor XXIII Gary Olsen's desk, Primary HPG Facility on New Samarkand, 3014-3025

[SCC]

Crey, two problems with your explanation: 1) It doesn't deal with the fact that an engine of a given rating presumably has a given output, regardless of what type of engine it is. 2) Power amplifiers in this case would presumably be capacitors, so why don't they explode?

[Nightlord01]

Crey, two problems with your explanation: 1) It doesn't deal with the fact that an engine of a given rating presumably has a given output, regardless of what type of engine it is. 2) Power amplifiers in this case would presumably be capacitors, so why don't they explode?

I don't actually see these as a problem, although my mental gymnastics are a little different from Cray's.

I look at it as akin to single phase/three phase electricity. Motive, comm, radar, links, non-energy weapons etc can all run on single or three phase electricity, but energy weapons can only use three phase. As a result a static phase converter needs to be used to convert single phase into all three phases. No more energy out of the engine, just distributed differently.

So no need for capacitors, except maybe in small amounts. (Converters use them after all...) Therefore no gauss style ticking time bomb. :-)

[Daryk]

Cray, two problems with your explanation: 1) It doesn't deal with the fact that an engine of a given rating presumably has a given output, regardless of what type of engine it is. 2) Power amplifiers in this case would presumably be capacitors, so why don't they explode?

I think Cray's explanation works because not all of an ICE engine's output is presumed to go into electricity generation.  A significant portion is assumed to directly drive the wheels/tracks/lift fans/rotors/etc.  BattleTech was conceived before full hybrids were considered practical.  Fusion engines put everything into electricity by definition.

[Von Jankmon]

Hmm. Well, here's my winding, tortuous reply.

Heres my short one, that medium laser can but through steel, but only up to 270m effective range.
There is enough of a disconnect that power amps for ICE is way down the list of things to concern yourself over.
It passes under the shadow of other far greater handwaves.

In my imagination I accept mech lasers and other core CBT technologies, I have a vision of how they operate what they do, helped along by MechWarrior video games.  Most of us are in the same comfortable hole.

Power amps just feel right, vehicles are cruder tech normally mounting autocannon and missiles because its harder to marry up the lower tech base to advanced stuff like energy weapons.  What handwavium there is is comparatively small.

[Nightlord01]

I think Cray's explanation works because not all of an ICE engine's output is presumed to go into electricity generation.  A significant portion is assumed to directly drive the wheels/tracks/lift fans/rotors/etc.  BattleTech was conceived before full hybrids were considered practical.  Fusion engines put everything into electricity by definition.

That's the crux of your issue? Noting that we can remove an ICE and replace with a SFE and, without any further changes the vehicle is ready to rock, I'd suggest that all vehicles are either: 1. Electrically driven, or 2. SFE's are capable of outputting kinetic energy rather.

I'd say it's pretty safe to say that most, if not all, vehicles are driven by electric motors powered by an ICE, rather than through drive shafts etc. Kind of like how the GM Volt runs.

[Daryk]

Except for the fact that ICE engines with the same power output weigh twice as much, and switching power plants requires a Class F (factory level) refit (StratOps, page 188).  If it was truly a matter of simply replacing the source of electricity, I'd think it would be something less than that.  Some of that extra weight makes sense as transmission/gear boxes/etc., and direct drive is more efficient for some applications.  That's one of the reasons electric drive lost out at the beginning of the automotive era.

[Nightlord01]

Except for the fact that ICE engines with the same power output weigh twice as much, and switching power plants requires a Class F (factory level) refit (StratOps, page 188).  If it was truly a matter of simply replacing the source of electricity, I'd think it would be something less than that.  Some of that extra weight makes sense as transmission/gear boxes/etc., and direct drive is more efficient for some applications.  That's one of the reasons electric drive lost out at the beginning of the automotive era.

Really getting out of scope here, but your point is addressed by BTU fluff which states that an ICE cannot output the same power as an FE of the same mass, and thus a larger engine is needed. Since we use output as the yardstick, we tend to forget these little things.

As for retrofitting an engine, if you've ever seen a combat vehicle have the engines replaced, it's an intense undertaking. Hell, replacing the engine in a civilian car is difficult and requires specialised equipment. Replacing a multi-ton engine from the guts of a CV is not going to be an easy task. Of course it's a factory refit!

[Sigil]

When using a fusion engine to power a conventional vehicle, it weighs 50% more than an equivalent fusion engine installed in a BattleMech.  The fluff refers to "additional shielding and the such."  This would help explain why refitting an engine requires Factory (Class F) facilities.

In addition, conventional vehicles cannot by powered by Fuel Cell (or Fission) engines.  Why I can understand the fission restriction, why no Fuel Cell powered vehicles?  By the math, they would seem the ideal choice in many circumstances.

I also note that the maximum armor a vehicle can mount is (3.5 x Vehicle Weight) + 40.  Therefore, a 20-ton vehicle could theoretically mount 110 points of armor, or ~ 7.0 tons while an equivalent BattleMech can mount only about 60% as much.  At the other end, a 100-ton vehicle can mount ~ 24.0 tons of armor while a BattleMech tops out at around 19.0 tons.  Another curious choice.  Why the +40 for conventional vehicles, especially given the armor is generally spread across 4-5 locations as opposed to the 7 found on BattleMechs.

[Daryk]

I think fuel cells for vehicles were fixed in an errata.  At the very least, SAW permits it, so I think it's legal now.

Similar type engine swaps (i.e., different ratings, and yes, they're all "multi-ton" above a 25 rating) are only Class D Refits per StratOps (page 188 again), and don't require a factory.  I think that difference is there for a reason, specifically the reason I outlined above.

[VhenRa]

They were only not allowed for that short gap between Tech Manual (When they really become notable for us in civilian vehicle and industrialmech applications, first appearance rules wise is before tech manual... but it was a small gap between it and tech manual) and Tactical Operations (When the rules for combat vehicle fuel cells became available).


And they in-universe only really took off in popularity during and after the Jihad.

[SCC]

I can now state for a fact that ICE engines deliver electrical power and not mechanical power, how? Quite simple, if they delivered mechanical power 'Mechs mounting them would be required to devote tonnage to generators to convert it into electrical power they could use.