Sand Casters

[Old_Dr_Skull]

I've started a CT campaign using Book 2 and Mayday for starships and Striker for ground combat (more or less).

In a recent adventure, some mercenaries discharged a Sand Caster from a ship's boat into a loading bay on an asteroid ship. There were a dozen or so guards inside and they were instantly shredded. In Striker even troops in the highest tech level battledress have virtually no chance of surviving being caught in the danger space of a sand caster, and anyione in less armor than that has absolutely no chance.

I'm a little puzzled at the physics. In the Striker rules it seems that the sand caster discharges with significant energy and momemtum. Yet in the Mayday system the sand tracks with the ship as long as the ship doesn't change vector. I would think that the energetic discharge of the sand would cause it to depart on its own vector and leave the ship's vicintiy relatively quickly.

 

[Otto Harkaman]

I'm a little puzzled at the physics. In the Striker rules it seems that the sand caster discharges with significant energy and momemtum. Yet in the Mayday system the sand tracks with the ship as long as the ship doesn't change vector. I would think that the energetic discharge of the sand would cause it to depart on its own vector and leave the ship's vicintiy relatively quickly.

I was thinking of this also and agree with you. On the other hand in pure gaming mode it makes an interesting tactic for a ship to maintain the same vector and velocity and so obtain this protection.

 

[BytePro]

I'd assume the damage to personnel is in the initial deployment and dispersal of the 'sand' and not simply running into it later?

 

[Old_Dr_Skull]

I'd assume the damage to personnel is in the initial deployment and dispersal of the 'sand' and not simply running into it later?

Yes that's true. So the initial dispersal should be pretty powerful to shred all those guys. But in space the sand should continue in the direction of the dispersal forever and I would think it would rather quickly leave any area that would protect the ship. Unless I'm greatly underestimating the size of the sand cloud in space.

 

[BytePro]

The only way it could hang in position with reference to a moving ship in space is with some active force. I.e. independent acceleration, or, more likely, some sort of gravitic traction field from the ship.

If its fired from a ship it will retain the sum of its initial velocity (speed and direction) from the turret and the ship till acted upon by some other force (like gravity, or, very marginally, a solar wind...)

 

[BlackBat242]

I would expect that, given the two statements, there is a "variable ejection-speed" function on the sandcaster fire controls, which allows the gunner to choose "high-speed eject" or "protective cloud deployment"... and possibly settings between.

 

[BytePro]

Yeah - and a 'release' option which would abandon a cloud to its own trajectory. Which then raises the question of capturing an enemy's cloud :devil:

 

[Whipsnade]

I'm a little puzzled at the physics. In the Striker rules it seems that the sand caster discharges with significant energy and momemtum. Yet in the Mayday system the sand tracks with the ship as long as the ship doesn't change vector. I would think that the energetic discharge of the sand would cause it to depart on its own vector and leave the ship's vicintiy relatively quickly.

Here's a hint: Compare and contrast the scale of a typical Striker battlefield with the scale of LBB:2/Mayday battle.

One uses measurements in hundred of meters and the other uses measurements in light seconds...

 

[Icosahedron]

You beat me to it, Whipsnade.

Yes, it's a matter of scale. On the PC scale that sandcaster is powerful, but on the scale of starship combat, no matter how much of a push the canister gets, it's going to remain 'in the vicinity of' the ship (in the same million km hex or whatever they are) for a very long time.

Whether or not the pinpoint cloud of sand would remain directly between the pinpoint ship and the pinpoint enemy, is just a handwave.

 

[Whipsnade]

You beat me to it, Whipsnade.

It's usually the other way 'round...

Whether or not the pinpoint cloud of sand would remain directly between the pinpoint ship and the pinpoint enemy, is just a handwave.

Yup, it's a handwave for ease of play more than anything else. Ships aren't deploying a single canister of sand against potential weapon strikes, it's just modeled that way to make things easier during play.

As usual there's a perception roll failure at work here. (And Ghu knows how often I fail that same roll everyday!) Folks looked at the model rather than looking "beneath" or "beyond" at what is actually being modeled. Another example of this involving sandcasters is the seemingly magical ability of ships in HG2 combat sand against lasers after those light speed lasers have been fired. Of course, sand isn't really deployed after lasers are fired, it's just modeled that way in the HG2 combat procedure for ease of play.

 

[Carlobrand]

Here's a hint: Compare and contrast the scale of a typical Striker battlefield with the scale of LBB:2/Mayday battle.

One uses measurements in hundred of meters and the other uses measurements in light seconds...

Uh, differences in scale don't actually resolve the problem. Book-2 describes its scale as 100km per millimeter and features 1000-second turns. If we assume the sand is projected at bullet speeds, then the sand will have an initial velocity roughly 10mm per turn different than the craft launching it. My guess is it has an initial velocity quite a bit higher than the average bullet, since this stuff carries a lot more punch than your typical shotgun pellet. The craft could boost a bit to match vectors, but this stuff is not quite your granddaddy's leisurely lingering Mayday sand.

There's actually not much in Book 2 describing the behavior of sand aside from a mention of a -3 DM per 25mm cloud applied on the to-hit roll. It's not even clear that Book 2 sand has any effect on missiles, since missiles in Book 2 explode and do damage on contact rather than rolling to hit.

On the other hand, a cloud of fast-moving grains with penetrations of 20 might be a bit more effective at killing missiles than a cloud floating leisurely around the target. Perhaps the Striker designers were thinking about High Guard and weren't familiar with Mayday and Book 2.

 

[aramis]

Uh, differences in scale don't actually resolve the problem. Book-2 describes its scale as 100km per millimeter and features 1000-second turns. If we assume the sand is projected at bullet speeds, then the sand will have an initial velocity roughly 10mm per turn different than the craft launching it. My guess is it has an initial velocity quite a bit higher than the average bullet, since this stuff carries a lot more punch than your typical shotgun pellet. The craft could boost a bit to match vectors, but this stuff is not quite your granddaddy's leisurely lingering Mayday sand.

There's actually not much in Book 2 describing the behavior of sand aside from a mention of a -3 DM per 25mm cloud applied on the to-hit roll. It's not even clear that Book 2 sand has any effect on missiles, since missiles in Book 2 explode and do damage on contact rather than rolling to hit.

On the other hand, a cloud of fast-moving grains with penetrations of 20 might be a bit more effective at killing missiles than a cloud floating leisurely around the target. Perhaps the Striker designers were thinking about High Guard and weren't familiar with Mayday and Book 2.

MT implies agreement - player's manual page 80 IIRC...

 

[Whipsnade]

Uh, differences in scale don't actually resolve the problem.

Yes, it does because...

If we assume the sand is projected at bullet speeds...

... that assumption is mistaken.

Why is the assumption mistaken? Because if sand were projected at the "bullet" speeds sand wouldn't work and, because sand obviously works, sand must not be projected at "bullet" speeds.

The people in the setting are at least as smart as we are and they routinely install sandcasters aboard ships to defend those ships from lasers and missiles. They'd have to be pretty ⌧ing stupid to continue to install sand over thousands of years if it didn't work, right? So, because the people in the setting aren't ⌧ing stupid and because sand wouldn't work if it were deployed as you suggest, the fact that sand works and the fact that people in the setting aren't ⌧ing stupid means sand is not deployed as you suggest.

Mr. Miller has repeated stated that sand canisters "work" something like depth charges. The canister is ejected from the vessel, moves off a certain distance, and then deploys it's cargo of anti-laser prismatics. MT further elaborated by suggesting that improvements in sandcasters by TL involved a mixture of improvements in the sand itself and way the sand is deployed.

Sand is deployed in a "cloud" between the ship and potential threats. Don't forget that in the more detailed LBB:2 rules, sand effects both incoming and outgoing fire.

 

[Carlobrand]

MT implies agreement - player's manual page 80 IIRC...

Player's manual page 80:
Sandcaster: penetration 20, damage 10 (which puts it on a level with the VRF Gauss Gun and the recoilless rifles), penetration drops by half every 2 range bands (which is rather quick), range very long (up to 500 meters), danger space 15 meters with a caveat:
"A Sandcaster has a diverging danger space: the danger space shown is for short range. Triple it for each subsequent range band."

In other words, by the time it reaches very long range, the danger space has increased to 27 times that value! We have a cone effect 500 meters long and a bit over 400 meters wide at base. On the positive side - if you happen to be standing in front of one - that quick attenuation rate means it's only at full power within 5 meters (Close and short), dropping to penetration 10 for the next 250 meters (medium and long) and then finishing at penetration 5. (One assumes this is in atmosphere.)

All I can say is that sand "grain" must be, like, golf-ball sized! Big hurt, like to kill about half the people it hits even at very long range, way nastier than a 50-cal round - but it drops speed real quick in atmosphere, so there's quite a bit of drag going on. Suggests something rather big or tumbly or both.

So, as far as MT (and therefore Striker) are concerned, this is definitely not your grand-dad's tame cloud meekly following your ship. It's more like a shotgun for shooting down incoming missiles.

So - how does it affect lasers? My guess is that the "grains" evaporate rapidly under vacuum, creating a large (but temporary) cloud of laser-obscuring fog between the ship and the attacker. Or perhaps the golf-ball-size "grains" explode into clouds of tiny fragments on impact or after travelling a certain distance - might explain why their effect on bodies is so much like the HE rounds. Must make them look remarkably like fireworks. I can't see any other way something that spreads that quick would interfere with any laser blast that happened through over a 20 minute turn.

Add: can we kindly dispense with the unnecessary expletives? I have kids who read over my shoulders from time to time. Thanks.

 

[aramis]

Also note that atten goes up by 6 bands in zero-G vacuum.

 

[Carlobrand]

... that assumption is mistaken..

No, the assumption is game-specific:
Mayday clearly describes sand as a semipermanent cloud - it's there as long as you stay in it, disperses when you alter course.

Book 2 does a terrible job of explaining sand, but it's generally accepted to be a variation on Mayday, so again a cloud around your ship.

High Guard gives us one-turn sand: he shoots, you respond, he shoots again, you respond again. The game assumption seems to be you're using agility (not using agility makes you an easy target), and course changes under Mayday would disperse the cloud - but then there's no exception for ships who chose not to move. No, he shoots, you respond, and if you start losing sandcaster batteries, you start losing the ability to respond - no lingering evident in that. Leaving an opening for ...

Striker, which made a right royal mess of things by giving us sand which, on ejecting from the launcher, explodes "like a sort of giant shotgun" in a CONE with devastating impact on anyone downrange of it. Very much not what Mr. Miller described. Hard to explain that devastating impact when the thing is described as, "... small particles ... similar to ablat personal armor". One is left reasoning that the small particles MUST have tremendous velocity to accomplish that much penetration - that's basic physics. Once that step is taken, one begins to wonder how a cloud of such high-speed particles could manage to linger around a ship without the ship having to speed up to match vectors - and then one wonders how a cloud that expands to 120 meters while traveling 2000 meters downrange with lethal speed manages to linger at all, given more than one 20 minute turn to expand in. One reflects on the one-turn nature of the High Guard sandcasters and concludes it is a very different beast from Mayday sandcasters.

Which is perhaps not surprising. In a discussion elsewhere, we've already pretty well agreed that Book 2 and High Guard are very different games, as the fate of my 6g boat illustrated in another post.

Which also answers the expletive-laden bit. As for Mr. Miller, he can blame his Striker crew for getting us into this confusing mess - and as I pointed out, MegaTrav simply perpetuates the Striker/High Guard model - or maybe makes it worse. Now the sand is expanding 400 meters over a 500-meter downrange move, still penetrating with impossible power though over much reduced range, and NOW it damages like a decent-sized HE round hit you.

Someone in the Striker/MT team didn't get the memo.

 

[Icosahedron]

I've always seen a sandcaster as more of an onager than a cannon - maybe because its called a sand caster rather than a sand cannon.
I can see two possibilities - either the sand incorporates some short-lived grey goo - nanite dissemblers that destroy incoming missiles and other stuff that gets in their way, or, less controversially, the firework effect - the sand canister is hurled away from the ship, then explodes to release a caseload of golf balls in all directions, (which may again explode to release a mass of bullets), which again explode to release prismatic sand. You really don't want to be in the way of that beaten zone of HE projectiles. Sand canisters are effectively 15cm? cluster bomblet munitions fired from a low velocity mortar...

 

[Carlobrand]

I've always seen a sandcaster as more of an onager than a cannon - maybe because its called a sand caster rather than a sand cannon.
I can see two possibilities - either the sand incorporates some short-lived grey goo - nanite dissemblers that destroy incoming missiles and other stuff that gets in their way, or, less controversially, the firework effect - the sand canister is hurled away from the ship, then explodes to release a caseload of golf balls in all directions, (which may again explode to release a mass of bullets), which again explode to release prismatic sand. You really don't want to be in the way of that beaten zone of HE projectiles. Sand canisters are effectively 15cm? cluster bomblet munitions fired from a low velocity mortar...

Onager? A kind of catapult?

I'm not seeing where cannons are mentioned. I visualized the original Mayday sandcaster as a canister pushed out of a launch tube by a puff of air, then bursting in front of the ship to release a slow cloud of sand which the ship maneuvers into for protection. Wouldn't take more than a touch of maneuvering jets to do it, irrelevant in game terms, and the cloud would take a very long time to disperse at the game's scale - too long to be considered. At, say, a meter per second, the cloud could be big enough to cover the ship in under a minute yet take a hundred turns to expand to 1 millimeter on the map.

Then Book 2 decided it was a 25mm (2500 kilometer) cloud. Okay, but if you create a 25mm cloud in one turn, then - unless there's something to decelerate the grains - you have a 50mm cloud of 1/8 density in 2 turns, and a 75mm of 1/27 density in 3 turns, and ... Well, it wasn't the only oddity in the game, so we just HYNAP'ed it (Hold Your Nose And Play). Then Book 5 did something else. Then Striker threw in a complete monkey wrench. Then MegaTrav gave the monkey wrench its stamp of approval and added a complication of its own, and here we are.

And, yes, MegaTrav sand is behaving very much like some mutant kind of CBM. I really, really think some of the writers had never played Classic - or else the directive was forget Classic and focus on evolving the Striker system into a nifty role-playing game for the gearhead set.

 

[Icosahedron]

Onager? A kind of catapult?

Yes, a stone-thrower, pretty much what I pictured 30 years ago from LBB2.

I'm not seeing where cannons are mentioned.

They weren't, I was just following what you said:

If we assume the sand is projected at bullet speeds, then the sand will have an initial velocity roughly 10mm per turn different than the craft launching it. My guess is it has an initial velocity quite a bit higher than the average bullet, since this stuff carries a lot more punch than your typical shotgun pellet.

I visualized the original Mayday sandcaster as a canister pushed out of a launch tube by a puff of air,

Which is essentially another version of a catapult - some device that lobs a canister rather than shoots it. Then the canister explodes into a cloud of sand and the explosion can damage physical objects.

Just handwaving fit to take off here. You can't fix something that wasn't scientifically based to begin with.

 

[tater]

2500km wide... assume it is a disk 1250km radius, 1 m thick. That means the "sand" density is 0.00000001 grams per cubic meter (assuming a 50kg reload, 100% "sand"). A less perfect disk or sphere (more realistic, in other words) will lower particle density further. Clearly B2 is wrong on the size for any hope of sand being plausible (it's not plausible, but it's canon so we have to make it work somehow).

BTW, for the sand to expand to that width in 1 B2 turn, it moves at over 8000 feet per second. Rifles are less than half that, and M1 tank a little more than half that. Sounds like a cannon to me. That or it lobs slowly out, then explodes, sending particles laterally at cannon speeds. Which is it?