Sand Casters

[BytePro]

I get the feeling we wouldn't be having this discussion if the folks at GDW had worded things in LBB2 ship combat a little differently.

The LBB wording is pretty terse - don't recall anything about sand 'hanging around' the ship, for instance. The most obscure (pun) part is the '(per 25mm)' on the Defender's DMs table.

[IMTU, that was 25mm depth of sand in the canister - i.e. per canister DM ]

 

[tater]

The LBB wording is pretty terse - don't recall anything about sand 'hanging around' the ship, for instance. The most obscure (pun) part is the '(per 25mm)' on the Defender's DMs table.

[IMTU, that was 25mm depth of sand in the canister - i.e. per canister DM ]

B2 has sand and missiles launched during the ordnance launch phase.

All ordnance which is launched has the launching ship's vector, which must be taken into account.

Sand has no propulsion, so it just stays there, unless the ship moves away from it.

 

[BytePro]

Sand has no propulsion, so it just stays there, unless the ship moves away from it.

Exactly - it doesn't 'hang around' the ship as the ship moves.

Sand launched against a target impacts on following turn, but no mention is made for any other turns...

 

[Ishmael]

Breaking lock makes no sense (the chaff idea).

One, it assumes active sensors.

Two, it would have to be as hot as the ship to distract real sensors, then it would have to act like a ship. In the HG sense of shooting after the first beams hit, the shots are already "in the air" and lock doesn't matter.

There is no such assumption in that 'chaff/flares/smoke/etc" should work against all sensors and not just active. I'll assume you are referring to MT's use of active sensors to make a lock. That's something I disagree with because weapons can be guided by passive sensors, a rifle scope or the IR sensor in an AIM-9 missile, for example. MT's rules are for game considerations, I'm sure, but I do things differently IMTU.

The cloud does not have to be as hot as the ship ( although I'd guess that it has the same temperature as the ship from being stored before firing, on the ship ), nor does it have to act like a ship. The purpose of a sand cloud as I use it, is not to fool the attacking sensors into thinking the cloud is a ship, or to try to convince attacking sensors that the actual ship is not there. The sand/chaff/flares' purpose is to hopefully throw off the attacker's firing solution just enough to cause a miss, nothing more.

Coincidentally, on page 80 in MT REf's manual, sandcaster are listed under "Basic Obscuration Devices".
The devices listed range from smoke at tech 5 to sandcasters at tech 12.

Regarding low density stopping a missile, that is actually plausible. Missiles are closing at possibly 100s of km/s. Hitting anything will damage the missile. Warheads on such missiles (short of those to disperse clouds of penetrators) are pointless, usually, as the missile has more KE than explosive energy. Also, the delicate bits (sensors) are pointing towards the target.

It's tougher with the beams because lasers in traveller by definition can damage ships. If sand material was better armor than armor, then they'd use it as armor instead... So beams can ablate sand.

Low density makes it very unlikely. I was meaning the density of the sand cloud, and not the density of each grain of sand, of course.
Using the numbers you mentioned in post #20, and the size of a 'typical' grain of beach sand, I could show that there might be only a single grain per ~900 m^3; it would be likely that a missile or beam might pass through the cloud you described, without ever encountering a grain at all.
If a grain is hit, it would impact with ~250,000 joules. A beam degraded by this amount would not lose much. A missile would experience an explosion equivalent to approximately 60g of TNT, something appropriate shielding can shrug off.... well, high tech shielding.

These are reasons I feel that sand, as described by canon, wouldn't work.

 

[tater]

Exactly - it doesn't 'hang around' the ship as the ship moves.

Sand launched against a target impacts on following turn, but no mention is made for any other turns...

If the ship does not accelerate, the sand "hangs around."

Ie: ship drifting and sand stays there.

 

[Hemdian]

If a grain is hit, it would impact with ~250,000 joules. A beam degraded by this amount would not lose much.

i can't speak to the other problems, but I thought sand was 'prismatic'. Which I thought meant that lasers beams were deflected and scattered (refraction) rather than absorbed.

 

[tater]

There is no such assumption in that 'chaff/flares/smoke/etc" should work against all sensors and not just active. I'll assume you are referring to MT's use of active sensors to make a lock. That's something I disagree with because weapons can be guided by passive sensors, a rifle scope or the IR sensor in an AIM-9 missile, for example. MT's rules are for game considerations, I'm sure, but I do things differently IMTU.

I was saying the idea of sand as chaff, or any sort of sensor block is wrong because, well, it is. Chaff is by definition vs only active. Vs passive it would have to be in effect a decoy, or block the large amount of light (largely IR) coming off the target.

Anyway, what I said regarding all other tasks, is that you are claiming it fools the sensors, but it only fools the sensors right before they shoot beam weapons, but NOT PAWs and MGs? If the PAW and MG can ignore the "fooling" aspect of the sand, I'll use those sensors to do fire control for my lasers, too.

The cloud does not have to be as hot as the ship ( although I'd guess that it has the same temperature as the ship from being stored before firing, on the ship ), nor does it have to act like a ship. The purpose of a sand cloud as I use it, is not to fool the attacking sensors into thinking the cloud is a ship, or to try to convince attacking sensors that the actual ship is not there. The sand/chaff/flares' purpose is to hopefully throw off the attacker's firing solution just enough to cause a miss, nothing more.

How does it "fool" the sensors? The FC solution is the vector of the target, and it's position. Sand moves with the ship, unless the ship accelerates. If the ship accelerates, the sand is no longer between the ship and the shooter. If the ship drifts, keeping the sand, then the FC solution is unchanged. If the target is maneuvering, then the sand is uselessly left behind, and the FC solution is based on the observed acceleration.

There is no possible way it can fool the sensors, sadly.

Low density makes it very unlikely. I was meaning the density of the sand cloud, and not the density of each grain of sand, of course.
Using the numbers you mentioned in post #20, and the size of a 'typical' grain of beach sand, I could show that there might be only a single grain per ~900 m^3; it would be likely that a missile or beam might pass through the cloud you described, without ever encountering a grain at all.
If a grain is hit, it would impact with ~250,000 joules. A beam degraded by this amount would not lose much. A missile would experience an explosion equivalent to approximately 60g of TNT, something appropriate shielding can shrug off.... well, high tech shielding.

These are reasons I feel that sand, as described by canon, wouldn't work.

One, I agree it won't work. I am not defending sand, I hate it I'm trying to think of ANY place where it is not stupid, so if I were to say, write some new combat rules, I could keep sand with SOME utility, even if not at all vs beams.

As for vs missiles, my point was that implausible as sand vs missiles is, it's FAR more plausible than sand vs beams

Also, instead of a vast, low density cloud, vs missiles, I literally mean shooting a tight group of sand into the missile path. Missiles have a 100% known path, as they MUST intercept. I'd think of it as super-fine canister round. A disk maybe 100m in radius, tops. This is shotgun round aimed at a missile. Note that it would target the missile's sensors for the most part.

 

[tater]

i can't speak to the other problems, but I thought sand was 'prismatic'. Which I thought meant that lasers beams were deflected and scattered (refraction) rather than absorbed.

The index of refraction varies with wavelength. A prism for visible light won't necessarily work for other light. You'd need loads of different prisms, just in case of diff wavelengths. Those that don't work for the particular laser wavelength will vaporize. The density is already low, it will be lower by a large factor because most sand will be useless as prisms.

Even optics that work absorb energy, too, and there is a LOT in a short time frame, and "sand" particles have low thermal mass, so even those will vaporize.

 

[BytePro]

If the ship does not accelerate, the sand "hangs around."

Ie: ship drifting and sand stays there.

Ordnance fired has an initial acceleration, which means in space its gonna effectively keep moving at that initial velocity vector. Ship and ordnance keep moving unless acted upon by another force (usually ships M-Drive during combat) - all the LBB rules state is launching ship's vector 'must be taken into account.' A ship would have to very carefully accelerate, then decelerate, to match velocity of sand...

Recall nothing in LBB2 that says or even directly implies that sand 'hangs around' a ship. Notably, no rules for accounting for a sand canister 'explosion' in more than one turn. [Mayday and other rule books differ, of course.]

 

[tater]

1. Regarding OP, I think sand is probably dangerous to stand in front of. Shredded in battledress? Not so sure about THAT, lol.

2. How to make sand work better...

A quick rule change suggestion to try:

Dump the penetrate sand table in HG.

Use sand as a DM vs damage for each hit with sand applied. Use the difference between the attack and sand factors as a +DM for a given sucessful attack's damage roll. If you get at least a +4 for this, there is a chance of "NE."

A factor 9 SC vs a factor 2 laser would have a total DM of 6+7. So on a 9+, there would be "NE."

Vs missiles either the same, or maybe the difference divided by 2 or something.

This is quick and dirty, with minimal changes to HG.

B2 doesn't work since SCs stack. So an already hard to-hit in B2, can easily be made impossible with sand.

Another example of how really bad HG is vs B2. It's not "scale," either. B2 tells us that sand can easily make a ship invulnerable to beam attack. There is no reason why 1 SC vs 1 laser should be any different than 30 SC vs 30 lasers, and that is not counting the B2 stacking of sand.

 

[BytePro]

'Sand' is described in LBB2 as 'particles used are similar to ablat personal armor'. Ablat personal armor [TL9] will '(vaporize) when hit by laser fire' and 'carries away the energy of the laser'.

This doesn't explicitly prevent the 'sand' from being prismatic, just implies its not the primary action. [IMTU - the sand does affect the frequency variations of beams while the 'vaporization' aspect includes fusing... a hack to 'explain' the tremendous energy absorption.]

 

[BytePro]

...B2 tells us that sand can easily make a ship invulnerable to beam attack. There is no reason why 1 SC vs 1 laser should be any different than 30 SC vs 30 lasers, and that is not counting the B2 stacking of sand.

Where - please quote text...

 

[tater]

Ordnance fired has an initial acceleration, which means in space its gonna effectively keep moving at that initial velocity vector. Ship and ordnance keep moving unless acted upon by another force (usually ships M-Drive during combat) - all the LBB rules state is launching ship's vector 'must be taken into account.' A ship would have to very carefully accelerate, then decelerate, to match velocity of sand...

Recall nothing in LBB2 that says or even directly implies that sand 'hangs around' a ship. Notably, no rules for accounting for a sand canister 'explosion' in more than one turn. [Mayday and other rule books differ, of course.]

Everything says it hangs around. The initial acceleration of sand in in the launcher. It is given a velocity to separate from the turret, that's it.

There is no mention in B2 about how it is dispersed, so it drifts radially from the ship at launch velocity. If it is sent out with compressed air, or a spring, it's a few m/s. The ship could easily use a tiny puff of attitude control 180 degrees from sand launch, and correct. It would of course not have to then decelerate. Sand is given 1 m/s velocity away from turret. Ship is given 1 m/s in same direction once sand gets to desired position. They are now fixed in relationship to each other. All this easy to automate from turret, since it knows the velocity give the sand, and direction.

Sand drifts with the ship. Also, B2 allows STACKING sand.

 

[tater]

Where - please quote text...

Each canister makes a 25mm cloud of sand. The combat tables say there is a DM to-hit: "Obscuring sand (per 25mm) -3 "

To-hit is 8+, best attacker DM is predict 5 (+3) and gunner skill. Assuming they add, then +9 with gunner 6. We're at a 1+ to hit on 2d6. 4 sand canisters, and no one can hit you at close range. At long range 3 is enough.

 

[BytePro]

Where?

 

[Carlobrand]

Here is every word that Book 2 (what does LB stand for?) has to say on the subject - except the section that says which boats mount sandcasters:

P15: "Weapons for installation in turrets include pulse and beam lasers, missile racks, and sandcasters. All are used in the space combat system described later in this book."

P16-17: "The four commonly available weapons types are pulse lasers, beam lasers, missile launchers, and sandcasters. ... Sandcasters are defensive weapons; they dispense small particles which counteract the strength of lasers and protect the ship. The specific particles used are similar to ablat personal armor; replacement canisters of this special sand weigh about 50 kg and cost Cr400."

P23 (table, Weapons and Mounts): "Sandcaster 250,000[Cr]"

P.27 (preparing a data card): "After each turret designation, indicate the armament with which each turret is equipped, using the letters B (beam laser), P (pulse laser), M (missile launcher), and S (sandcaster)."

P29, (laser fire phase sequence): "Third, the target player determines all applicable defense DMs and sums them to create a single defense DM to be used against the enemy fire. Defense DMs result from such circumstances as obscuring sand, range, or defensive programs."

P29/32, (ordnance launch phase sequence): "During the ordnance launch phase, missiles or sand or both, may be launched, ... During the ordnance launch phase, missiles or sand which contacted a target in [interrupted by tables] the preceding movement phase now explode or take effect.Ordnance must be specified as launched during the launch phase, and only one missile or sand canister may be launched from a launch rack or sandcaster. The launched item does not actually move until the following friendly movement phase. All ordnance which is launched has the launching ship's vector, which must be taken into account."

P30 (table, Defender's DMs): "Obscuring sand (per 25mm) -3"

P31 (list, game turn sequence): "Intruder Player Turn — A. Intruder Movement. The intruder moves his ships using the movement, gravity, and other applicable rules. Ordnance (missiles and sand) which he has launched in previous game turns is moved at the same time. ... D. Intruder Ordnance Launch. The intruder may launch ordnance (missiles and/or sand) at enemy targets or on specific missions, subject to the applicable rules. Ordnance which has contacted enemy ships explodes in this phase. ... Native Player Turn — A. Native Movement. The native moves his ships using the movement, gravity, and other applicable rules. Ordnance (missiles and sand) which he has launched in previous game turns is moved at the same time. ... D. Native Ordnance Launch. The native may launch ordnance (missiles and/or sand) at enemy targets or on specific missions, subject to the applicable rules. Ordnance which has contacted enemy ships explodes in this phase. ... "

P32 (ordnance launch phase sequence, further): "Reloading: Each launcher (sand or missile) has an inherent capacity for three missiles or canisters. This means that a triple turret with three missile launchers has a total of 9 missiles in ready position.
When a launcher's missiles or canisters are exhausted, it may be reloaded by the turret's gunner in one turn. Reloading three launchers would take three turns. A gunner engaged in reloading is unable to fire other weaponry in the turret.
Missile Detonation: Ordnance which impacts a target in a movement phase, and which then survives anti-missile fire, detonates in the ordnance launch phase. This detonation will inflict 1 to 6 hits depending on the range at detonation. For each missile, throw one die. The result is the number of hits inflicted; determine each resulting hit location separately."

P39 (Computers, software list): "Launch allows missiles to be launched from launch racks and sand to be fired from sandcasters. The target program is also required."

P41 (table, computer software list): "[space:] 1 [MCr:] 2 Launch; allows launch of missiles and sand [skills needed:] [computer-]1, gunnery-2 [throw:] 11+"

That's all. Missiles and sand/canisters are jointly defined as ordnance, but the indiscriminate way the word is used, it appears at times that the sand canister is impacting the ship that's shooting at you, which doesn't make sense. Sand might linger - "All ordnance which is launched has the launching ship's vector, which must be taken into account ... Ordnance (missiles and sand) which he has launched in previous game turns is moved at the same time" - but that 25mm bit really throws a kink in that view. We could argue about it till the cows come home and not come to agreement

A few points: This predates everything else. At this point in the TU, a 50kg HE missile can explode in a blast that riddles the target ship with shrapnel. We don't know how thick the ship hull is. We don't know how much power the lasers draw - in fact, if I recall, you could mount two triple batteries of lasers on a Free Trader if you wanted and still have power for thrust. It was only later that High Guard set power limits, and that was in undefined "energy points". It was even later that Striker gave us ships with hulls like tank armor and lasers that pumped out 250 Mw of energy.

Whipsnade makes a good point, in his special fashion. We should probably consider these games individually, rather than using one to make inferences about another. As I said, the Striker sandcaster is not your grandfather's Book-2 sandcaster. Well, neither is the ship hull or the laser or the missile. High Guard missiles do not do damage like Book-2 missiles, and in fact Book 2 missiles can't do damage at all (at least by shrapnel) in the Striker universe. For all we know, the Book-2 laser is a 1 Mw job and the Book-2 hull a half-centimeter of steel over a metal skeleton. It was, after all, intended as a fairly simple game.

 

[far-trader]

...(what does LB stand for?)

In what context? In this thread I'd guess a slip of the keys and meant to be LBB (for Little Black Book, usually followed by a number, the original Traveller books).

 

[BytePro]

Thanks Carlobrand!

That jives with my read... except I'd include the text referred to be the ellipsis from p29: ... 'provided both launch and target programs are running.'

So, no reference to the (per 25mm) aside from an entry on the DM table and nothing to say sand just arbitrarily stays with a ship (quite the opposite)? Or even a 'cloud'?

'Stacking' works for me - if its 'ablating' energy to the point of making lasers less effective at hitting, then more of it means less effective to the point of not hitting. However, the rules state a requirement for targeting, so I don't see that as a general purpose cloud (like a force shield or armor), rather each canister addresses a particular attack.

[IMTU (based solely on Books 1-8 of CT), since nothing mentions sand hanging around for more than the next turn nor creating a cloud. Further, I specified that 'sand' can't maintain effectiveness in vacuum very long - which jives with this interpretation and also explains it's worthless as ship armor.]

 

[Ishmael]

I was saying the idea of sand as chaff, or any sort of sensor block is wrong because, well, it is. Chaff is by definition vs only active. Vs passive it would have to be in effect a decoy, or block the large amount of light (largely IR) coming off the target.

Anyway, what I said regarding all other tasks, is that you are claiming it fools the sensors, but it only fools the sensors right before they shoot beam weapons, but NOT PAWs and MGs? If the PAW and MG can ignore the "fooling" aspect of the sand, I'll use those sensors to do fire control for my lasers, too.

Okay, in my first post I did say "Chaff" and that it causes sensors to lose lock, I suppose, because that's primarily how I use it myself with variations on MT rules concerning sensors and weapons lock. I also allow it as ECM against detection as I view sand as being used for ECM and not as a point defense mount.
In my last post, I lumped it with "chaff/flares/smoke/etc.". Flares and smoke are against passive.
Should it affect hits by PAWS and MG? of course!, but that's how I do things and which is not canon.
I would have thought that was obvious.

How does it "fool" the sensors? The FC solution is the vector of the target, and it's position. Sand moves with the ship, unless the ship accelerates. If the ship accelerates, the sand is no longer between the ship and the shooter. If the ship drifts, keeping the sand, then the FC solution is unchanged. If the target is maneuvering, then the sand is uselessly left behind, and the FC solution is based on the observed acceleration.

"Fool" sensors means to create a measure of uncertainty about location or vector, not by making the sensor think the ship disappeared. Much like trying to shoot a target through drifting smoke, or near a blinding light.

Also, instead of a vast, low density cloud, vs missiles, I literally mean shooting a tight group of sand into the missile path. Missiles have a 100% known path, as they MUST intercept. I'd think of it as super-fine canister round. A disk maybe 100m in radius, tops. This is shotgun round aimed at a missile. Note that it would target the missile's sensors for the most part.

Then 'sand' becomes a big point defense shotgun which is not what the descriptions say it is.
And it would work against missiles, energy weapons and not much else.

No sane solution will be canon. So just use it however you like.
I just choose to use it as part of ECM instead of a form of point defense that works on some weapons but not other similar weapons. And IMTU, sand still has a pen of 20.

 

[mike wightman]

Which edition of CT do you have?

It's a sad thing but true that every version of CT had some change or other from earlier iterations.

1977 original has imperial units for space combat, 1981 revised edition has metric, but the full space combat rules are spread between the revised 1981 LBB2, The Traveller Book, and the Starter Edition of Traveller.