Energy Weapons in Space Combat

[Egil Skallagrimsson]

The range to hit adjustments for space combat have been irritating me for sometime, in particularly those for energy weapons.

Currently we have two varients, one from the errata to the CRB, and one from HG. They differ, but are both based on the idea that a "long" range weapon performs optimally at "long", with reductions at closer and further ranges.

But pulse lasers, beam lasers, particle beams, fusion guns and meson guns are all direct fire weapons that generate a stream of (different types) of energy. Surely such weapons should be most accurate at the shortest ranges, with performance then dropping off at range?

So, I propose the following;
For all energy weapons, maximum effecitive range is the range given in the core or HG, e.g. for a partical beam, long range. Shots beyond that are ineffective (NB range can be increased using a HG enhancement). To hit adjustments for turret and bay weapons firing at ships or small craft changed to the following, adjacent range +4, close range +2, short range +0, medium range -2, long range -4, very long -6. For spinal mounts, the -6 adjustment in HG applies at all ranges, but no further adjustments needed.
Note that the use of lasers or sandcasters for point defence against missiles or boarders remains unchanged, i.e. +0 at adjacent, because such targets are small, especially in the case of missiles that are fast moving and expose a very small profile.
For missiles and torpedoes, effective range by the speed and amount of fuel carried, as HG, to hit modifiers, -2 at adjacent, +0 at close, short, medium long and very long, -2 at distant.

The overall effect will be to make energy weapons much more deadly at close ranges, but less so at long range, where missiles will be more effective.

Any comments?

Egil

 

[rust]

Surely such weapons should be most accurate at the shortest ranges, with performance then dropping off at range?

This is true for the weapon's use against targets which are stationary,
move very slowly or move towards the weapon or away from it, but
much less so for targets which move at high speed across the wea-
pon's field of view, in this case the target is more difficult to hit the
closer it is, because it stays for a shorter time in the weapon's field
of view. However, remotely realistic rules for this would be too com-
plex for a game like Traveller, so one probably has to accept a sim-
plified model of the real thing, based upon an assumption about what
the average target will be like - and then "more accurate at close ran-
ge" seems just as good or bad as "more accurate at long range".

 

[Egil Skallagrimsson]

Surely such weapons should be most accurate at the shortest ranges, with performance then dropping off at range?

This is true for the weapon's use against targets which are stationary,
move very slowly or move towards the weapon or away from it, but
much less so for targets which move at high speed across the wea-
pon's field of view, in this case the target is more difficult to hit the
closer it is, because it stays for a shorter time in the weapon's field
of view. However, remotely realistic rules for this would be too com-
plex for a game like Traveller, so one probably has to accept a sim-
plified model of the real thing, based upon an assumption about what
the average target will be like - and then "more accurate at close ran-
ge" seems just as good or bad as "more accurate at long range".

Ah, but the ranges involved are really quite long, e.g. long range is at least 10000km, even a large space craft will become a very small dot on the screen at that point, I still find it hard to imagine that a direct fire energy weapon doesn't lose accuracy at range.

However, I take your point about a fast moving ship close to the firing platform, the bonuses for adjacent, close and short may well be too generous, so how about amending the energy weapons range adjustments to "adjacent +0, close +0, short +0,
medium -2, long -4, very long -6"?

Egil

 

[2330ADUSA1]

Being a table-top war gamer as well, I just use the rules of those games for combat ranges. I use hex game grid for my resin minis, and depending on the weapon system it has ranges in hexes.

Now I always use Engery Plasma weapons (Beam, Pulse, Bay weapons) and Missiles. I also use some others exotic weapons systems too, but you get the point.

 

[Captain Jonah]

A few thoughts on this to add my 2 Credits/Livre

Anything that isn’t a turret should be at a large penalty for Adjacent. Small and large Bays, small and large Capital Bays, semi spinals and spinals are big lumbering weapons designed for tracking targets at range, they are not designed for tracking a target flashing past at a few hundred Kilometres.

I see Turrets as being point defence rather than weapons, civilians can carry them because they are no threat to the warships of Traveller. They are small, fast moving with a light defensive weapon load.

Then the larger the weapons the more effective they are at range. Scaling of damage indicates that a large bay is not twice as damaging as a small bay. So where does the extra power and size go to.

I see it being longer beam duration. A small bay fires a more powerful beam or pulse stream for a longer time than a turret. Not only does a hit do more damage but the longer stream allows for more time to track the target and adjust the weapons fire to get a hit. A large bay fires for longer than a small, capital bays fire longer still and a spinal will fire for long enough that it can track onto a target a light second away.

Rough numbers:

So Adj is about -4 for bays (+2 for turrets, 0 for barbettes).

Close is 0 for bays (+1 for turrets, 0 for barbettes)

Short is 0

Med -2

Long -4

V long -6

Distant -8

V Distant -10

Adding to the above ranges are the turret or bay types.

Turrets are no modifier other than weapon fitted Pulse, point defence cluster etc.

Small Bays are +2 at short and out

Large bays are +2 at short, +4 at medium and out

Capital small bays are +4 at short, +6 at medium out

Capital large bays are +2 at short, +4 at medium out, +8 at long out

Spinals are -6 at Adj, -4 at close, -2 at short, 0 at med then +4 at long, +6 at V long, +8 at distant and +10 at V distant (note this means a spinal has effectively no range penalty out to 1 light second. Do not mess with anything armed with a spinal mount.

Note that the bonus or penalty for a bay etc adds to the range. So a large bay is net +2 at short, +2 at med, 0 at long, -2 at V long etc.

The larger weapons have a longer firing cycle allowing the gunners more time to adjust fire. The larger weapons are slower to turn making it more difficult to hit closer targets. Under 10,000Km a spinal mount is going to have a very hard job hitting anything as the entire ship needs to be moved to compensate for the limited ability to offset the spinal mounts fire.

The heavier bays are designed for long range firing, the classic fleet slugging matches, fighters and escorts are there to keep enemy small units out of the close range where the Battleships are vulnerable because their heaviest weapons cannot bear. Spinal mounts fire for 10 or 15 seconds giving the gunners plenty of time to track in on a distant target, though the beams sweep across the target and past it so much of the energy is wasted in space. See Mr Bolton’s excellent Traveller battle on You tube for an example of what I mean.

The smaller weapons are accurate at shorter ranges, larger weapons begin to hit more often at longer ranges where the turrets become very inaccurate. This does make many of the Bay weapons within optimum range more accurate than they are now so is probably best done with armour scaling.

 

[Egil Skallagrimsson]

Thank you, and very interesting, Captain Jonah. I like the idea of differntiating between different types of weapon mounts, but, as you point out, the net effect of the modifications would be to substantially increase the numbers of hits, and so damage.

In particular the spinal mounts, able to inflict devestating damage, would become even more dangerous. I feel that spinal mounts, as basically fixed systems, would be more difficult to target as the whole capital ship would have to alingned perfectly to achieve a hit.

Egil

 

[IanW]

Speaking personally, I design Famile Spofulam warships to fight at "real warship" ranges of 2-4 light seconds. At this point speed-of-light-lag dominates combat, with sensor resolution coming a close second.

Secondary batteries are by definition incapable of penetrating main armour, and thus can only do surface damage - basically, forcing redundant sensor arrays and cutting back on the power output of the enemy ship by destruction of their radiatiors.

Civilian ships are ships without main armour, and they are therefore vulnerable to secondary batteries. Their sensor suites are also a long way short of milspec, and they are generally well short of the 3+ gees a military ship needs to be able to maneuver at to have a chance of surviving.

 

[locarno24]

But pulse lasers, beam lasers, particle beams, fusion guns and meson guns are all direct fire weapons that generate a stream of (different types) of energy. Surely such weapons should be most accurate at the shortest ranges, with performance then dropping off at range?

Depends on several factors:

Just like trying to hit a motor torpedo boat with 16" battleship guns - there's no question that if you have the damn thing pointed in the right direction and fire at the right moment, you'll hit it; muzzle velocity is ridiculous, after all, but actually training the damn things on the right position is hard when the target is manouvring faster than your ability to slew the gun accurately.

This is even more pronounced if you can only put out one fraction-of-a-second shot per six minutes! This is why a beam laser (which fires a stream of laser energy you can wave around in the rough direction of the target for a few seconds) is better suited to hitting than a pulse (which either hits or misses).

Fusion guns I can understand being less effective at range than particle beams - the former do some of their damage from the energized state of the matter they're flinging, which can radiate/disperse/decay/whatever, whilst particle beams simply fling (tiny) chunks of matter very fast - essentially a subatomic equivalent to a railgun.

Why in gods name a particle beam has a longer effective range than a laser I'm not quite sure, though. It can, by definition, only be firing at a proportion of lightspeed, and if a laser 'spot' will disperse then surely a particle beam stream will too.

I'm personally a fan of the laser/pulse laser/missile/heavy missile weapons as a 'set' - it gives missiles a feel of importance and it just seems to work nicely; there's a reason it works well for the Honor Harrington and Reality Dysfunction novels.

 

[Captain Jonah]

Egil. Spinals must be capable of a small degree of offset fire simply by fluctuating the containment field at the point of fire. Only a complete idiot is going to build a truly bore sighted weapon than requires the entire ship to turn. B5 I’m looking at you here :roll:

In terms of the one shot every six minutes or every ten minutes or every half an hour from earlier versions. I don’t see that you fire once and sit reading a newspaper for 5 minutes and 50 seconds.

I see it much more as firing sustained bursts of fire, 10 or 20 seconds of a beam or pulses, then recharge and fire again. Over a 6 minute turn weapons shout be able to fire several times.

Given the ranges and speeds involved you are more or less firing ranging shots first then tracking in your fire to try for a good hit.

The bigger weapons can sustain higher energy throughput and hence do more damage but can also sustain longer sustained fire. The downside is they are slower to move to track targets.

Locarno24’s example is exactly what I mean. A 16” turret is not going to be able to engage MTBs at 100’, they will be moving faster than it can track them. On the other hand at 10 miles the relative movement of those MTBs is tiny and the big guns can track them just fine.

Plasma/fusion weapons have a limited effective range because the energy state packets they fire decay rapidly once fired. For most everything else it’s a matter of your sensors and targeting computers/gunners rather than anything else. Beams have an advantage in that they can be tracked onto a target more easily but have less damage per second as they are lower throughput. Pulses have more energy per pulse but its harder to track a stream of pulses onto a target.

I also don’t understood why types of weapons have an optimum range, particularly the Pbeam being longer ranged than the laser when the Particle stream is sub light (it may be high sub light but its still sub light). A weapon system (turret/Bay/spinal) should have a range at which it is not suffering penalties to hit and there is a difference between beams and pulses but that’s about it.

A Pbeam pulse and a laser pulse should be as accurate as each other at whatever range. The same with Laser or particle beams.

Like Locarno24 I feel that there are engagement bands where weapon mounts are effective.

Missiles and torpedoes and recon drones as the furthest engagements out to light minutes for semi AI drones. Spinals out to several light seconds then capital bay weapons then bay weapons then last and up close turrets. A thousand Dton Large Capital Laser beam is going to be perfectly capable of hitting something several light seconds away but needs to hand off its target to a bay weapon or even turrets as enemy escorts close under the range of the bigger weapons.

 

[rust]

Only a complete idiot is going to build a truly bore sighted weapon than requires the entire ship to turn.

Think of the dedicated bow chaser guns of the Renaissance and
the early Age of Sail. They usually had the best fire power and
range of all the ship's guns, but were mounted so that they only
could fire straight forward, and one indeed had to turn the ship
in order to use its best guns against any target which was not
straight ahead of it.

 

[Captain Jonah]

I'll rephrase slightly then. :lol:

Only a complete idiot is going to build starship weapons that are bore sighted.

The bow chasers you mention above are from a time when all cannon were effectively fixed mounts and were fired at the sort of ranges where rifles and muskets were also used. Hollywood films aside the accuracy of a fixed mount weapon against a target at any kind of distance when both firer and target are moving is not high. A lot of the paintings of the age with ships firing into each other from a few hundred feet away are because they couldn’t hit the broadside of a barn at long ranges.

A meson/particle/laser spinal mount is going to use some sort of focusing or containment field which should allow for a degree or more of targeting wobble.

Trying to hit with a spinal meson at a target a few hundred thousand kilometres away when you have to turn the entire ship to get that meson burst inside the target ship is all but impossible.

How precise is the drive field at moving that 100,000Dton battleship one 34th of a degree left to line up with a target at the precise instant the bore sighted meson gun needs to fire to get the meson stream to decay inside the targets hull.

Me I reckon fixed mounts have an arc of fire of a few degrees either side rather than being truly bore sighted, getting a Traveller Dreadnaught or battleship close enough to be able to line up a spinal mount on an enemies hull sounds very 18th century.

I know Traveller is a 1970s game using 1950s ideas of technology set in a 1800s universe but still, Bore sighted :roll: :wink:

 

[hdan]

You don't have to line up with the target, only pass by the target and carefully time your shot. This technique was used by some early Ironclads (specifically the Monitor) which did not have precise turret motor control - set the turret spinning and fire the cannon as the target came into bearing.

Of course in two axes it's a little harder, but not as hard as holding that precise a bearing would be while under thrust, I imagine.

 

[IanW]

Captain Jonah,

Spinal weapons are forced by the technology of the Traveller Universe.

Basically, particle accelerators and meson guns have a maximum range and power defined by their length, and lasers have a maximum megajoulage defined by technology (*).

If you want a weapon capable of penetrating military armour or military meson screens, you need a weapon with length to do that.

As an example, the TL12 Chevalier sans Peur is a 22.5k dton battleship, built to be heavily armoured. Therefore, it's built as a Happy Fun Ball, and is a sphere 84.4m in diameter.

Its Particle Accelerator Weapon main armament is 64 meters long.

Secondary weapons can go into big turrets, which we call bays - but when you need to armour 64m of length so surface hits dont destroy it, it should go into the ship.

By the way, the design of the Chevalier sans Peur is posted below. At 32 GCr, Im damn proud of the design as a M4 J3 battleship.

http://lists.travellercentral.com/pipermail/tml/2011-November/035728.html

Ian Whitchurch, Gearhead


(*) I wasnt around at the time, but my understanding is Lasers horribly overperformed PAWs in FFS1, breaking the High Guard tradition of PAWs and Meson Guns being the main weapons, and Lasers being the lighter "support" weapon.

 

[phavoc]

I'll rephrase slightly then. :lol:

Only a complete idiot is going to build starship weapons that are bore sighted.

Spinal mount weapons are considered 'ship killers', and they will destroy smaller ships with one shot, and can do massive damage in a single salvo. So one would think that the most powerful single ship-to-ship weapon would have some limitations built into it.

For the most part, a spinal mounts only weakness is the fact that you can't shoot at your enemies while running way. So in that case its a truly offensive-only weapon.

Other than that, it's not going to be that big of a deal to target the enemy who is always in front of you, or who at least you are not running away from. Even large ships have thrusters which makes aiming the ship quite easy, especially when you think of just how large a field of fire a ship is going to have at a distance. These are light-speed weapons and their typical targets are quite large and simply don't have the maneuverability to get out of the way of the attack when at a distance (you don't typically use a Tigress's spinal mount on a pesky destroyer. No, you are aiming at their battleships.

What's funny to me is why aren't there more scaled-down spinal-mount class weapons, so that smaller ships might mount them as well? Traveller doesn't use energy output from reactors except in the broadest sense, so there's no reason why you shouldn't have smaller class weapons for smaller ships. Assuming you wanted to build your fleet that way.

 

[IanW]

Phavoc,

A 50 dton bay weapon for a 20 kdton battleship is a spinal mount consuming 10% of ship volume for a 500 dton frigate, and does the job quite nicely on civilian, lightly-armoured ships. Theres a pretty good design posted a week or two back for a Armed Freighter thats got that sort of Civilian Spinal Mount.

In my view, there is a bit of a "dead zone" in weapons effectiveness between lasers and other light weapons that can deal with missiles and lightly armoured civilians, and Honking Big Guns designed to do internal damage at very long ranges on heavily-armoured battleships.

If your traveller universe has a lot of lightly-armoured military ships, then theres a role for intermediate size weapons.

 

[Egil Skallagrimsson]

Just like trying to hit a motor torpedo boat with 16" battleship guns - there's no question that if you have the damn thing pointed in the right direction and fire at the right moment, you'll hit it; muzzle velocity is ridiculous, after all, but actually training the damn things on the right position is hard when the target is manouvring faster than your ability to slew the gun accurately.....

I'm personally a fan of the laser/pulse laser/missile/heavy missile weapons as a 'set' - it gives missiles a feel of importance and it just seems to work nicely; there's a reason it works well for the Honor Harrington and Reality Dysfunction novels.

Looks like another vote for a modifier based on weapon mounts rather than, or additional to, weapon type. I am also a fan of the laser/missile/combat wasp set up in sci-fi, but the Traveller vibe is much more long distance death rays.

Egil

 

[Egil Skallagrimsson]

Egil. Spinals must be capable of a small degree of offset fire simply by fluctuating the containment field at the point of fire. Only a complete idiot is going to build a truly bore sighted weapon than requires the entire ship to turn. B5 I’m looking at you here :roll:

Hang on, would that be true of most fighter aircraft since the Fokker Eindecker as well? Even large ships in Trav are assumed to be very manoeuvrable, all those M-drives dotted around the hull. It might well be easier to point the whole ship at the target, effectively the whole ship is the mount. Why would there be a need to allow the spinal mount to traverse, it would complicate the design, and probably create empty, useless, spaces within the capital ship to faciliate traverse (and presumably elevation).

Egil

 

[Egil Skallagrimsson]

Locarno24’s example is exactly what I mean. A 16” turret is not going to be able to engage MTBs at 100’, they will be moving faster than it can track them. On the other hand at 10 miles the relative movement of those MTBs is tiny and the big guns can track them just fine.

The more I think about this the less convinced I am of the comparison, the 16" gun is mounted of a large but low tech turret which has to be positioned on top of the superstructure. Our MTB will be invulnerable at 100' because the gun cannot depress low enough to engage it. It also assumes that a more powerful weapon,e.g. a particle beam bay, will fire its packets of energy as a single large "shell", whereas a less powerful weapon e.g a particle beam turret, will fire that as a series of smaller "shells" . Remember that in our terms, a 16" gun lobbing a shell 20km is still only just in the "short" range (ok, in a zero gravity vacuum that range will be somewhat increased...)

I think what I am imagining is beam weapons as comparable to enormous torches, projecting an energy beam the accuracy (and power?) of which will decline in direct proportion to range.

Egil

 

[phavoc]

Locarno24’s example is exactly what I mean. A 16” turret is not going to be able to engage MTBs at 100’, they will be moving faster than it can track them. On the other hand at 10 miles the relative movement of those MTBs is tiny and the big guns can track them just fine.

The more I think about this the less convinced I am of the comparison, the 16" gun is mounted of a large but low tech turret which has to be positioned on top of the superstructure. Our MTB will be invulnerable at 100' because the gun cannot depress low enough to engage it. It also assumes that a more powerful weapon,e.g. a particle beam bay, will fire its packets of energy as a single large "shell", whereas a less powerful weapon e.g a particle beam turret, will fire that as a series of smaller "shells" . Remember that in our terms, a 16" gun lobbing a shell 20km is still only just in the "short" range (ok, in a zero gravity vacuum that range will be somewhat increased...)

I think what I am imagining is beam weapons as comparable to enormous torches, projecting an energy beam the accuracy (and power?) of which will decline in direct proportion to range.

Egil

Think about the battleship designs of WW1 & WW2. Lets take the Bismark as an example. The main battery was comprised of 15in guns mounted in three turrets (standard 2 forward, 1 rear). The secondary battery was 12 6in guns mounted in 6 dual turrets. These guns were capable of rapid fire and could depress to engage close-in targets (-10 degrees). Then there was the AA battery of 16 4in guns, and the various 20mm gun mounts (in single and quad) in various places around the ship. So the Bismark was capable of engaging a wide variety of targets with its primary and secondary armaments.

Now the HMS Dreadnought was armed differently. It had 5 dual 12in turrets, and a number of lighter machineguns, but essentially it was built to engage other battleships only. Later on the naval designers put the secondary armaments back on the ships.

So using our naval history, there's precedents for both. With the way Traveller armament is designed, you can't NOT install a large secondary set of armament on warships, because with the execption of the spinal mount, a 5,000 ton destroyer can mount the same size weapons as a 500,000 ton battleship. The weapons really should scale upwards to get away from that.

Can you image a light cruisers of old mounting a 16' cannon in a single turret? It would be putting an awful big hammer in an eggshell.

 

[phavoc]

Phavoc,

A 50 dton bay weapon for a 20 kdton battleship is a spinal mount consuming 10% of ship volume for a 500 dton frigate, and does the job quite nicely on civilian, lightly-armoured ships. Theres a pretty good design posted a week or two back for a Armed Freighter thats got that sort of Civilian Spinal Mount.

In my view, there is a bit of a "dead zone" in weapons effectiveness between lasers and other light weapons that can deal with missiles and lightly armoured civilians, and Honking Big Guns designed to do internal damage at very long ranges on heavily-armoured battleships.

If your traveller universe has a lot of lightly-armoured military ships, then theres a role for intermediate size weapons.

Yes, that's true (about the 50/500 ton example). But its not quite the same (though if you are being chased by a frigate mounting one, it might as well be...).

The problem with the analogy is that it doesn't scale. A 1,000 ton ship could mount a single 100 ton bay, and the analogy remains the same. except that you could also mount 2 50 ton bays. A 5,000 ton ship could mount multiple 100 ton bays, or 2x that number of 50 ton bays. But a ship can only mount a single spinal mount.

What I was looking for was crafting spinals for different ship tonnages, using the roughly 10% volume method. So a 50,000 ton ship could mount a 5,000 ton spinal, while a 35,000 ton ship would mount a 350 ton spinal. Which would allow for scaling of the weapon and you could tailor your ship designs using different tonnages for different tasks.