MGT Only: Seems Insane to use FGMP except in special circumstances

[CaptRet]

It seems insane for any infantry to use the FGMP, even if in Battledress. Standard TL14 Battledress protects against 290 Rads (245 for TL13 suits, and 180 Rads for TL14 Combat Armor). Per canon, even nearby friendlies are within the radiation zone when one of these weapons fires (and so only suited personnel can be on the scene). Even given that the suit will protect against the collateral damage from one such discharge, I would expect that in a firefight there would be multiple weapons firing multiple shots. The user and his friends would quickly be exposed to increasing radiation levels - 3 or more shots would probably deliver to them a lethal dose.
On top of that, the weapon is so inherently destructive that the circumstances in which you could use it (even for one shot) would be limited to those where the users wouldn't care about radiation effects on the surroundings, civilian personnel, if any, industrial/cultural/infrastructure assets, etc. And it isn't just the destruction, it is the half-life of the irradiated. So not used for most boarding actions, hostage rescue, city fighting, etc. I think that Imperial Marines would be principally armed with gauss rifles (and some PGMPs for support), with the FGMPs remaining in the Arms Room for use on uninhabited asteroids or zero-g in deep space (or boarding actions where there will be no survivors/prisoners).

 

[Winged Cat]

It seems insane for any infantry to use the FGMP, even if in Battledress.

Indeed, FGMPs are more specialized tools of destruction than they may seem at first. They are for cases where you really need man-portable maximum destruction because the long-term consequences of letting your target to continue to exist are just that bad.

Per canon, even nearby friendlies are within the radiation zone when one of these weapons fires (and so only suited personnel can be on the scene).

This is one of the major limitations. Only suited - or disposable - personnel can be nearby.

Even given that the suit will protect against the collateral damage from one such discharge, I would expect that in a firefight there would be multiple weapons firing multiple shots.

Each of which is individually protected against. Block one completely, block them all completely.

On top of that, the weapon is so inherently destructive that the circumstances in which you could use it (even for one shot) would be limited to those where the users wouldn't care about radiation effects on the surroundings, civilian personnel, if any, industrial/cultural/infrastructure assets, etc. And it isn't just the destruction, it is the half-life of the irradiated. So not used for most boarding actions, hostage rescue, city fighting, etc.

Pretty much, where you don't care about destroying the surroundings - or where doing so is part of the point. For instance, taking out a battleship when all you have is a boarding party (which you can smuggle aboard).

FGMPs are not primarily defensive weapons. There is good reason why most cities with even low law levels will object to a traveller carrying one.

I think that Imperial Marines would be principally armed with gauss rifles (and some PGMPs for support), with the FGMPs remaining in the Arms Room

Quite possibly.

 

[aramis]

FGMP's are to TL14+ forces as RPGs are to TL7...

Designed to give the infantry anti-vehicular firepower.

The line troop should not have the FGMP. But one or two in a squad is great for taking out hard targets.

 

[mike wightman]

It is a typical example of:
the rule of unintended consequence
alternatively
the rule of the author not thinking through the ramifications of their new kewel idea because it is so kewel.
and finally it is contracted by setting canon:

If the party persists in their investigation, they will be ambushed by the thugs
listed above. All of the thugs are this time armed with auto pistols, and will have surprise. After the first round of gunfire, however, a bright flash of light will literally burn them from behind. The two men who burned them will show themselves briefly to check the bodies, and then leave. These unknown protectors are armed with FGMP-15s.

The author of this was a certain Mr Frank Chadwick.

In the original LBB4 only certain plasma and fusion guns required the user to be wearing battle dress, the others have no such requirements.

Note the idea of plasma and fusion guns requiring radiation protection is not unique to MgT - so I am not being snarky towards MgT. Personally I just ignore any mention of radiation effects for man portable plasma and fusion guns, the way it was done in CT and MT, Snapshot, AHL, Striker...

 

[mike wightman]

FGMP's are to TL14+ forces as RPGs are to TL7...

Designed to give the infantry anti-vehicular firepower.

The line troop should not have the FGMP. But one or two in a squad is great for taking out hard targets.

Not according to LBB4:

Tech level 14: A higher proportion of the infantry is equipped with battle dress, and the standard small arm for such troops becomes the PGMP-13.
Tech level 15: Most infantry is by now equipped with battle dress and has converted to the
FGMP-14. The gauss rifle remains the standard arm of non-powered troops.

 

[AnotherDilbert]

Battledress protects you from X Rads from each attack, not just once.

So, Battledress protects you from the radiation side-effect of FGMPs.

Radiation is a very present danger to many Travellers, whether
in combat or exploration. Some armour provides a measure of protection against radiation, as noted in the Rad column of the armour table. This amount of protection is deducted from the rads a Traveller receives every time he is exposed to radiation.

 

[CaptRet]

I remember old CT (I played in the late 70's, early 80's) where the key factor in use of the PGMP 13 was its weight, bulk and recoil (which then was why you needed Battledress to use it - in fact the early descriptions indicated that there were certain approved positions from which to fire it, which took maximum advantage of the Battledress servos to compensate). The radiation effect has grown up since I last played, albeit it makes sense. That said, the PGMP starts to look like nuclear weapons of the last century - more important for their deterrent effect than for their battlefield effect (a weapon so frightful in its effect that there are limited scenarios for its deployment).

 

[kilemall]

I look at it as an attempt for the rules guy to reign in the Munchkins from running wild with their BFG9000s. Season to taste the way you like for your universe.
IMTU it's not even an issue, TL10 is max and it's the gauss rifle and TL12 plasma weapon that's in the lab now.

Of course I'm very CT/Striker, and so the real man portable god weapon is the TL15 version of the RP-A, with battledress able to carry it AND it's power source, that's the REAL anti-vehicle/MG squad weapon..... Heck it can shoot through unarmored starship hull.
AND light enough for the Combat Armor light inf crowd to use like a heavy MG.


The grav-assisted PG/FGMPs are clearly for the CA people, but the expense is such that you might as well go BD and get the lifting power and endurance, at least for the heavy weapons support, robots for the logistical carry in leg/light grav situations.



Speaking of the Combat Armor crew, I would expect their standard rifle to be the TL13 X-ray laser. Nice and clean in CT/Striker, but arguably it too should be radiological.

 

[mike wightman]

I don't see why a plasma gun or fusion gun need to be emitting ionizing radiation at all.

A plasma is only radioactive if made from an element that is radioactive to start with - shooting a bolt of hydrogen plasma is not going to emit ionizing radiation.

The power pack powers a laser ignition system in the weapon itself which heats hydrogen fuel to a plasma state. The plasma is contained in the ignition chamber briefly and then released through a magnetically focused field along the weapon's barrel.

That bolt of plasma could be moving at up to 100km/s if magnetically accelerated, but there is no source of ionizing radiation.
A fusion gun is described as:

Similar in design and function to the PGMP-13, the FGMP-14 differs only in that it contains the plasma slightly longer until a fusion reaction begins to take place.

Now this is where magic technology must be invoked - perhaps a gravitic containment field to squeeze the plasma, or perhaps damper technology is involved.
The fusing of hydrogen produces deuterium, a positron and a gamma ray; the positron and gamma radiation can be contained within the weapon itself and all you are firing is a bolt of deuterium.

 

[Spinward Scout]

I don't see why a plasma gun or fusion gun need to be emitting ionizing radiation at all.

It doesn't. But Infrared is still radiation. Just not ionizing.

 

[whulorigan]

The fusing of hydrogen produces deuterium, a positron and a gamma ray . . .

And an electron-neutrino, just to be nit-picky .
(Not that it would make any difference).

 

[Timerover51]

I don't see why a plasma gun or fusion gun need to be emitting ionizing radiation at all.

A plasma is only radioactive if made from an element that is radioactive to start with - shooting a bolt of hydrogen plasma is not going to emit ionizing radiation.

That bolt of plasma could be moving at up to 100km/s if magnetically accelerated, but there is no source of ionizing radiation.

A fusion gun is described as:

Now this is where magic technology must be invoked - perhaps a gravitic containment field to squeeze the plasma, or perhaps damper technology is involved.

The fusing of hydrogen produces deuterium, a positron and a gamma ray; the positron and gamma radiation can be contained within the weapon itself and all you are firing is a bolt of deuterium.

Deuterium fuses much more readily than does hydrogen, so the deuterium is going to undergo fusion as well, which produces neutrons and a lot of energy, along with Helium-3. Your bolt is going to be composed of a range of fusion products, not just deuterium. As soon as that bolt is out of some form of confinement, that extremely hot gas is going to be expanding into all directions, very rapidly. Unless you have some magical means of continuing confinement once it leaves whatever incredibly heat-resistant barrel you have to aim it, it is going to turn into a very rapidly expanding ball of extremely hot gas, including a nice batch of very fast-moving neutrons. Basically, the explosion occurs as soon as it leaves the barrel. Scratch the firer and anyone in the immediate vicinity.

Then you have the fact that your "bolt of deuterium" has to be extremely small, as a fusion drive has a specific impulse of around 3.1 Million to 4 Million (based on the figures used in Thrust Into Space. bu Maxwell Hunter). That means a pound of material from a fusion drive produces between 3.1 and 4 Million pounds of thrust. That is the recoil that you are going to have to deal with.

One basic question. How are you confining the material once fusion starts?

 

[aramis]

Not according to LBB4:

AHL shows marines in Combat with a mix of FG, GR, and LR (Fusion, Gauss, and Laser rifles).

the marines in BD have mostly FG's, but some LCs.

The JTAS on the 4518 LIR doesn't specify infantry armament.

There is an article on the Zhodani... JTAS 11...

Teleport Commandos and Jump Troops: BD and PGMP-13's, with 1 FGMP-14 per squad.

Line Infantry: CA and Gauss Rifles, 1 PGMP-14 per squad

Lift infantry in non-infantry units: As Jump Troops.
Lift infantry in pure infantry: transitioning to BD, but not to PGMP/FGMP.​

The TL15 IM's per Loren's JTAS-12 article (clearly later ignored by other GDW staff) are 100% BD, and 100% FGMP-14... even for the support... but that this is abnormal.
... but not specifying what is typical for the Army. The implication is read variously...

Note that the marines generated in all later systems except GT do not meet Loren's prescriptions; if they did, we'd see Vacc Suit and High Energy Weapons as the R&S skills; but no, Vacc Suit and Large Blade (in MT); the T4 marines are too low tech for either; the TNE Marines aren't uniformly TL14+, and aren't Imperial; they represent the RCMC, instead, and it's TL12. T4 is 600 years before.

THe only later support for the all battle dress all the time and all fusion guns all the time is Striker II... which is a bland every imperial troop shown is HBD and 14.7cm FG...

This is a case where the fluff SERIOUSLY mismatches the Char Gen... because the Rules are Genre, and the fluff is exemplar within... a GM can impose those changes... (or run GT)...

It's worth noting that both imperial and zhodani do NOT equip all elite forces with peak TL EXCEPT in Striker II... and that';s a clear case of got lazy and did a quick cut and paste. (Proper thought out would have reduced by 1 page by consolidation because they all are equipped almost identically.

 

[MongooseMatt]

Indeed, FGMPs are more specialized tools of destruction than they may seem at first. They are for cases where you really need man-portable maximum destruction because the long-term consequences of letting your target to continue to exist are just that bad.

Exactly this - they are not just the biggest guns players can get their hands on. They have a specific application, and it is a very limited one.

It would be marvellous (for the players, for a while) if they could board a ship with an FGMP... but that might not make for such a good game. By pushing their destructive capabilities as high as they are, FGMPs do become the Big Gun, but certainly a little too big for all but the most extreme situations.

So, it is kind of an 'event' when they do come out in a campaign. They remain special.

 

[MongooseMatt]

May be of interest, this is what we have in 2300AD for the PGMP:

A plasma gun contains a laser ignition system in the weapon that superheats a hydrogen-telluride fuel pellet to a plasma state. The plasma is contained in the ignition chamber briefly and then allowed to escape through a magnetically focused field along the weapon’s barrel. The high velocity plasma bolt is initially about two millimetres in diameter but begins to dissipate almost immediately. Dissipation is minimised by having the bolt ride a ‘tunnel’ of heated air generated by a laser beam from the weapon.

The ammunition for the weapon consists of photonic core plasma cells, each containing a fast discharge battery to pump the weapon’s laser ignition and pathfinder beam, and a fuel pellet for the plasma bolt. After firing, the spent cells are ejected and are not reusable. Some care must be exercised in the selection of the location of the plasma gunner as ejected cells are extremely hot, with semi-molten centres, and can cause minor burn injuries to other troops (1D-2 damage), or even ignite dry, flammable materials.

 

[mike wightman]

Where does all the hydrogen telluride come from? Tellurium is as rare as platinum on Earth, that's going to make for rather expensive ammunition.

Also hydrogen telluride decomposes to hydrogen and tellurium at room temp, so you are going to have to refrigerate your ammunition.

Since you are handwaving this why not just use metallic hydrogen as the ammo?

 

[Condottiere]

Shock and awe.

Combination flame thrower and light machine gun.

 

[whartung]

Battledress protects you from X Rads from each attack, not just once.

Originally Posted by MgT2 Core, p94
Radiation is a very present danger to many Travellers, whether
in combat or exploration. Some armour provides a measure of protection against radiation, as noted in the Rad column of the armour table. This amount of protection is deducted from the rads a Traveller receives every time he is exposed to radiation.

So, Battledress protects you from the radiation side-effect of FGMPs.

But like any energy, if you have multiple sources of that radiation, you add them up.

If you have twice as many light bulbs, it's twice as bright.

So, if you have something that can protect against X*1.2 of something, and two things emitting X (i.e. 2X), then you don't have enough coverage.

I don't know anything about protecting from radiation beyond using sun block or a "sun shirt". But I don't think that they way the "rads" ratings are expressed, that they can necessarily be a "per source" thing, you have to add stuff up.

 

[McPerth]

From MgT2:CB, page 126:

FGMP (...) and fires what amounts to a directed nuclear explosión. Those without radiation protection who are nearby when a FGMP is fired will suffer a potentially letal dose of radiation

While not specifying it, I guess the same rules should apply to those nearby the FGMP hit. See that nearby is quite an ambiguous term, though...

So, I'd say using FGMP is as insane as using tac nukes. See also this old thread I started about other considerations in OTU...

 

[CaptRet]

But like any energy, if you have multiple sources of that radiation, you add them up.

If you have twice as many light bulbs, it's twice as bright.

So, if you have something that can protect against X*1.2 of something, and two things emitting X (i.e. 2X), then you don't have enough coverage.

I don't know anything about protecting from radiation beyond using sun block or a "sun shirt". But I don't think that they way the "rads" ratings are expressed, that they can necessarily be a "per source" thing, you have to add stuff up.

"But like any energy, if you have multiple sources of that radiation, you add them up.
If you have twice as many light bulbs, it's twice as bright."

Whartung, indeed, the point you make about adding up the rads from the various sources (shots) of radiation is exactly what I was driving at in my initial posting. Even with protective battledress/combat armor/HEV suits, if multiple fusion weapons are firing (or if the same weapon fires multiple times) in the same firefight, then that location will become so irradiated as to overcome the protection of even this armor. So for infantry to use the FGMP, unless there is only one firing very few times, is suicidal. Mkes mor sense for them to use the PGMP, gauss rifles, heavy laser rifles, and tactical AT missle launchers.