M-Drives as a weapon

[whulorigan]

I'm not sure there's a functional difference between a Traveller turret and a Traveller barbette. It's just labeled differently, in certain sources, because of its size.

I do not remember if it is explicitly the case in CT or MT (where the turret only needs a hardpoint and 1.0 ton allocated for fire control in the ship design), but ISTR in some later editions of Traveller at least, the Barbette required the additional allocation of the 5.0 dton of space for the Barbette in the ship-design in addition to the hardpoint requirement (i.e. it had to be accounted for in the hull-displacement, just like a bay).

In other words, you couldn't just swap-out a turret for a barbette on a given hardpoint.

 

[sabredog]

My take on the barbette thing is that it is a large emplacement with limited movement. It is longer than a turret and looks like those barbettes we originally saw on the Gazelles when they first showed up in the JTAS article - which was when barbettes first showed up and the JTAS article explained was a sort of "heavy laser" as far as using it Traveller games, but a PAW otherwise. They get +2DM to hit and damage is to be skewed towards crew and computer casualties to reflect the radiation hit.

The barbette's weapon can elevate and yaw 45 degrees off the center axis on its front, but the structure cannot rotate like a turret. Barbettes are long and built the way they are because of the PAW design, and this is why they are not used for high energy weapons or lasers, since those don't require a long, heavier structure.

All that is pretty much taken from looking at the pictures and reading the descriptions from the Gazelle article in JTAS #4, but your mileage may vary.

I'm OK with the description and limits, though. The name is just odd since the weapons are not sitting out in the open with the crew behind a gunshield or something.

 

[Carlobrand]

I do not remember if it is explicitly the case in CT or MT (where the turret only needs a hardpoint and 1.0 ton allocated for fire control in the ship design), but ISTR in some later editions of Traveller at least, the Barbette required the additional allocation of the 5.0 dton of space for the Barbette in the ship-design in addition to the hardpoint requirement (i.e. it had to be accounted for in the hull-displacement, just like a bay).

In other words, you couldn't just swap-out a turret for a barbette on a given hardpoint.

CT High Guard II has a particle accel barbette. Only difference seems to be it's a lower tech level, larger and less accurate version of the TL15 PA turret. MT has no barbette, just turrets of different masses and volumes. All weapon volumes including turrets must be accounted for in the hull displacement in CT and MT, with the standard missile/laser/sandcasters taking 1 dT per turret, the plasma/fusion guns taking 2, and the PA weapons taking 3 or 5 (and TL 16+ PAs in MT taking less). CT does not specifically prohibit you from switching out something smaller with a PA (as might occur during a TCS refit); you just have to compensate for the increased tonnage by cutting elsewhere, which is a bit odd but there it is. MT, I haven't found the refit rules, so I don't know. Perhaps there's something in GURPS or Mongoose that treats it differently.

 

[sabredog]

TCS has refitting rules and says any changes to weapons would be considered a "minor change" and so long as the size of the bays isn't changed, and the overall tonnage of the weapons installed doesn't change, then there is no rule regarding what get's swapped with what.

I would offer that barbettes and 3-ton PAW turrets are probably fine for swapping from a 1-ton turret because the larger part of the installation would be the weapon mount outside the hull. Like the picture of the Gazelle. In strict interpretation of "barbette" that would also be the case. In any case, that's how I've always done it IMTU.

When doing this, though, it is important to consider increased mass if you stick a barbette on a ship. Because that might happen it becomes a self-limiter for anyone looking to up-gun their Type S. Also, energy points limits weapons, too.

 

[aramis]

CT High Guard II has a particle accel barbette. Only difference seems to be it's a lower tech level, larger and less accurate version of the TL15 PA turret. MT has no barbette, just turrets of different masses and volumes. All weapon volumes including turrets must be accounted for in the hull displacement in CT and MT, with the standard missile/laser/sandcasters taking 1 dT per turret, the plasma/fusion guns taking 2, and the PA weapons taking 3 or 5 (and TL 16+ PAs in MT taking less). CT does not specifically prohibit you from switching out something smaller with a PA (as might occur during a TCS refit); you just have to compensate for the increased tonnage by cutting elsewhere, which is a bit odd but there it is. MT, I haven't found the refit rules, so I don't know. Perhaps there's something in GURPS or Mongoose that treats it differently.

You really should look up the meaning of "barbette" some time.

The MT 5Ton TL14 PA turret is a barbette.

 

[mike wightman]

IMTU for PC scale ships:

1t - internal fire control, limited by hardpoint restriction (1 per 100t)
5t - barbette, includes fire control - allows extra turret beyond the hardpoint limit

 

[sabredog]

5t - barbette, includes fire control - allows extra turret beyond the hardpoint limit

Does that mean they effectively get another hardpoint for weapons? A 400 ton ship would have four turrets on four hardpoinst, and adding a barbette gets them another weapon for a total of 4 turrets and a barbette?

 

[mike wightman]

Yup - there is the added complication that the power plant has to be one letter higher than the maneuver drive (the double fire rule) to power the extra weapons, and I put a cap of no more barbettes than you have regular turrets.

So the 400t ship could have 4 hardpoint turrets and 4 barbettes.

To integrate HG2 weapons I add a 1t extra surcharge for energy weapons, and a 2t surcharge for PAs (only available at TL15).

The barbette can mount up to a triple turret's worth of laser/missile/sand, two energy weapons (no surcharge for the barbette) or one PA (at TL14 and 15, no surcharge).

I figured these rules are reasonable since you can always upgun a ship by carrying fighters as mobile extra turrets.

 

[robject]

Yup - there is the added complication that the power plant has to be one letter higher than the maneuver drive (the double fire rule) to power the extra weapons, and I put a cap of no more barbettes than you have regular turrets.

That's handy, in that it makes the Gazelle "canonical".

 

[aramis]

I'd agree with this.

The whole language used around turrets, barbettes, bays and spines is very imprecise.

For turret I think = Small trainable mount.

For barbette I think = Large trainable mount.

And the bays are very large trainable mounts (save for missiles)... see the plans and drawings of the AHL...

 

[sabredog]

I figured these rules are reasonable since you can always upgun a ship by carrying fighters as mobile extra turrets.

Except that fighters are not the ship itself. The ship with all the barbettes has to have the structure to carry them, so I thought the whole point of hardpoints was to reflect that limitation in a hull's structure.

Wouldn't adding barbettes just be the same as the fixed weapons rule in the Solomani rulebook? In which case, you could either mount fixed weapons or turrets (or barbettes) per hardpoint?

 

[Carlobrand]

You really should look up the meaning of "barbette" some time.

The MT 5Ton TL14 PA turret is a barbette.

Since the barbette in Traveller clearly has no relationship to the barbette on a castle or the barbette on an ironclad or pre-dreadnought battleship, I fail to see how looking up the meaning in any way affects my quite accurate remarks on how CT and MT words things.

Unless of course you're suggesting that the particle accelerator's being fired over a parapet.

 

[selunatic2397]

Anf I thought a trebuchet in a castle was a menace!

 

[rancke]

Anf I thought a trebuchet in a castle was a menace!

You're just as dead if you're squashed by a big rock as you are if all the water in your body is boiled away in a split second.


Hans

 

[sabredog]

Since the barbette in Traveller clearly has no relationship to the barbette on a castle or the barbette on an ironclad or pre-dreadnought battleship, I fail to see how looking up the meaning in any way affects my quite accurate remarks on how CT and MT words things.

Unless of course you're suggesting that the particle accelerator's being fired over a parapet.

Not all the barbette mounts on ships (or even on shore batteries for that matter) had shields or retracted. A barbette could merely be a circular platform for the gun to rotate on and the gun is exposed. If you look at the main gun mounts on the HMS Benbow, for instance, the guns are merely mounted on an elevated, circular platform. Same with this mount here:

http://commons.wikimedia.org/wiki/File:Re_Umberto_13.5_inch_gun_barbette_right_elevation.jpg

So looking at these barbette mounts, and then at the barbettes on a Gazelle, the connection is easy to see.

 

[Frankymole]

Aren't barbettes often a chunk of hull that rotates, so they'd presumably have the same armour protection as any other part of the ship?

 

[aramis]

Aren't barbettes often a chunk of hull that rotates, so they'd presumably have the same armour protection as any other part of the ship?

Specifically, they're oversized turrets in removable mounts.

 

[Carlobrand]

Not all the barbette mounts on ships (or even on shore batteries for that matter) had shields or retracted. A barbette could merely be a circular platform for the gun to rotate on and the gun is exposed. If you look at the main gun mounts on the HMS Benbow, for instance, the guns are merely mounted on an elevated, circular platform. Same with this mount here:

http://commons.wikimedia.org/wiki/File:Re_Umberto_13.5_inch_gun_barbette_right_elevation.jpg

So looking at these barbette mounts, and then at the barbettes on a Gazelle, the connection is easy to see.

Because ... it's just a gun on a circular platform with no armor protection? Near as I can tell, neither High Guard II nor MegaTraveller make a barbette any easier to damage than a turret.

Your image of the Re Umberto main gun appears to show some sort of parapet wall over which the gun fires, protecting the gun's lower works. If I read the image correctly, it appears to have enough width to serve as an armored defense. There's a groove in it to allow room for what I think is the rammer to work. As to the Benbow, I presume you're referring to the Admiral-class Benbow. Benbow also seems to show some sort of wall over which the gun fires, described as a 14" plate forward and a 12" plate aft.

http://en.wikipedia.org/wiki/HMS_Be...25_inch_Elswick_naval_gun_Right_Elevation.jpg

At any event, that's ancient history so far as Traveller is concerned. The barbettes shown in Supplement 7 are identical in appearance to turrets except for their large size. The barbettes mentioned in High Guard II take a single hardpoint like any other turret and take damage the same way any other weapon does - they're just very large. And, MegaTraveller Referee's Manual does not appear to have the word "barbette" in it anywhere: hardpoint-mounted particle accelerators are dealt with under the heading, "Particle Accelerator Turrets", and all are referred to as turrets including the 5 dTon TL14 model. As near as I can tell, "barbette" in CT just means "big turret".

It's quite interesting that the AHL bays are capped with mega-sized turrets. I hadn't noticed that before. I guess you could call that the bay's tower or garret, maybe bartizan. Interesting.

 

[Reban]

I think when it comes to three dimensional space combat on vessels that can rotate on any axis we're stretching naval terminology a bit when it comes to the physical appearance and operation of barbettes and turrets.

Barbette and turret are good shorthand for Large mount and Small mount respectively.

Bays I've always understood to be a large area within the hull that contains the bulk of the weapons system with a firing aperture or "muzzle" protruding from the hull (in the case of the AHL that's the whole "turret" structure outside the hull).

If we want to imagine what turrets, barbettes and bays look like wouldn't we be better looking at warplanes? :CoW:

 

[sabredog]

Because ... it's just a gun on a circular platform with no armor protection? Near as I can tell, neither High Guard II nor MegaTraveller make a barbette any easier to damage than a turret.

Your image of the Re Umberto main gun appears to show some sort of parapet wall over which the gun fires, protecting the gun's lower works. If I read the image correctly, it appears to have enough width to serve as an armored defense. There's a groove in it to allow room for what I think is the rammer to work. As to the Benbow, I presume you're referring to the Admiral-class Benbow. Benbow also seems to show some sort of wall over which the gun fires, described as a 14" plate forward and a 12" plate aft.

http://en.wikipedia.org/wiki/HMS_Be...25_inch_Elswick_naval_gun_Right_Elevation.jpg

At any event, that's ancient history so far as Traveller is concerned. The barbettes shown in Supplement 7 are identical in appearance to turrets except for their large size. The barbettes mentioned in High Guard II take a single hardpoint like any other turret and take damage the same way any other weapon does - they're just very large. And, MegaTraveller Referee's Manual does not appear to have the word "barbette" in it anywhere: hardpoint-mounted particle accelerators are dealt with under the heading, "Particle Accelerator Turrets", and all are referred to as turrets including the 5 dTon TL14 model. As near as I can tell, "barbette" in CT just means "big turret".

It's quite interesting that the AHL bays are capped with mega-sized turrets. I hadn't noticed that before. I guess you could call that the bay's tower or garret, maybe bartizan. Interesting.

You're right that the language is loose. Classically, in naval definitions the barbette is the circular platform or tower the turret is mounted on and protects (as you say) the lower works that rotate the weapon. The barbette may or may not have some kind of shield to protect the gun(s), but even land-based barbette mounts don't always have that. It seems to depend on the size of the guns and the larger ones of ships don't usually have the shields. Some of the land-based barbettes use the energy from the recoil to lever the guns down into a pit for protection while reloading.

My point was only that the most common and logical explanation is gained by actually looking at the things and drawing the conclusion that the barbette in space can't be an exposed mount. It could be what appears on the Gazelle drawings, though, a long turret-like (though I take it to be non-rotating given the overhang on the sides that would bang into the hull of the Gazelle) mount with a limited-arc weapon in it. Since they are limited in all versions to PAWs I assumed it is something about how a PAW is configured that requires a long, semi-rigid turret at that stage of PAW development. Like maybe the racetrack design which would allow turret mounting doesn't work at lower TL?