Book 2 Sandcasters

[creativehum]

Hi timerover,

A couple of thoughts about sandcaster technology.

Here is the description of sandcasters from p. 61 of TTB:

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 the material used in ablat personal armor; replacement canisters of this special sand weigh about 50 kg and cost Cr400.

Thus, the technology for the "sand" is TL 9 (when ablat personal armor is introduced). The "sandcaster" TL (as I'm reading it) is essentially the "cannon" technology required to fire the canister. (Note that "missiles" and "missile launchers" are listed as two separate items on the TL Table.) A ship with a damaged sandcaster that dry-docked on a TL 5 world could probably (perhaps with great effort) gather the parts and tech to repair the sandcaster.

As for the volume once launched into space: There's no way really to settle this, but I imagine synthetic particles are quite light so that the weight of 50kg contains a lot of the ablative "sand." For all I know the technology to make effective "sand" for space combat is actually a higher tech level.

As for the volume of the sand clouds: they are not actually stopping the laser... they are stopping the focus of the laser beam. Passing through a "mist" of ablative particles for 2500km, no matter how fine, is enough to break the focus to prevent it from doing harm to the ship even if it should strike the hull. (Just like the personal combat system and missiles, the issue in Classic Traveller is not whether the attack "hits" but is an effective hit that does damage.)

I know this information won't convince anyone of the effectiveness of sandcasters as written. But as written sandcasters do work, and this seems to be the logic.

 

[creativehum]

Sorry, I didn't check the errata...

Not a big deal... but I thought you'd like to know. I reviewed Revised SS:3 two nights ago, so it was fresh in my head.

 

[Timerover51]

Normally, yes. You can also build missiles that can turn their drive on and off.

I would consider the missile to be more like a HEAP anti-tank missile, giving reasonable penetration.

It also attacks at potentially very high speed, adding a kinetic component to the damage. After boosting for 30 min at 5G it would have a speed of 90 km/s, far faster than any gun round.

The following is a quote from Special Supplement 3 Missiles Revised.

For example, the standard missile in Traveller is a 5G6 continuous burn (36 kg, Cr3,600, TL 8), mass sensing (1 kg, Cr1,000, TL 10), proximity detonator (1 kg, Cr500, TL 6), high explosive (10 kg, Cr500, TL 6) warhead missile (all produced at their standard tech level), costing Cr5.600 and massing 48 kg. This price does not take into account tech level effects. At TL 9, this missile costs Cr5,540; at TL 12, it costs Cr4,480.

The fuel for the missile is listed at Tech Level 8, which is about where we are now in the real world. Turns are 16.66 minutes (1000 seconds long), so this fuel is sufficient to last in excess of 80 minutes, weighing only 36 kilograms total, which I assume includes the container that the fuel is burning in, the primary nozzle for propulsion and the secondary nozzles for vector change. For a 5G acceleration to start with, the missile has to generate 250 kilograms of thrust, converting to my English unit mind, that is 551 pounds of thrust. Again, the fuel is Tech Level 8. With very energetic solid propellant, burning at a pressure of about 1000 pounds per square inch and with an optimally expanded nozzle, you might get a bit over 300 pounds per pound of propellant thrust per second. That would be about 0.75 kilograms of fuel per second of boost. The whole fuel package weighs 38 kilograms. Sixty seconds of burn requires 45 kilograms of propellant. This is a slight problem.

I will not comment on the guidance system, as that is theoretically Tech Level 10, except to ask what range this is supposed to be capable of sensing the mass of the target?

As for the warhead, it is rated as Tech Level 6 with a proximity fuze of Tech Level 6, weighing 10 kilograms. Tech Level 6 is a bit behind us, say roughly 1950 or so. A proximity fuze indicates to me that this is a fragmentation warhead, with likely half the weight in explosive and half in controlled fragments In another thread, you claim that the standard merchant ship hull in Traveller is equivalent to 33 cm of hard steel armor. If the warhead is fragmentation, as it appears to be, it will do absolutely no damage to your 33 cm hard steel armor hull whatsoever, if with a contact hit. Now, if it does use a shaped charged hear, I think that is what you mean by your HEAP comment, then you basically have to score a direct hit, in which case you may punch a hole in the ship of about the same diameter of the shaped charge. I say may, because a lot would depend on the configuration of the ship and whether or not the area hit was a fuel tank. Quite simply, the warhead, as described in the rules, is not capable of causing significant damage to any size ship in Traveller.

Now, as the missile, except for the sensor, is basically Tech Level 8 and lower, then it should be able tp be produced now. The problem is that the missile as described in the rules is impossible. If you believe that it is possible to build such a missile, then please demonstrate how it could be done. I believe that I have shown that it is not possible to produce such a missile at the present day.

 

[creativehum]

The fuel for the missile is listed at Tech Level 8, which is about where we are now in the real world.

I have no horse in this particular conversation, but I do want to point out that we're not at TL 8. We are TL 7. (This may not matter to the conversation, but it might... so I thought it was worth bringing up.)

TL 8 consist of air/rafts, GCarriers, weather control, fusion, and laser carbines... none of which we have today.

There might be some confusion due to the listing of years next to the Tech Levels. While TTB lists these years as a general guideline neither edition of Book 3 does this on the TL Table or anywhere in the books. I personally think the addition of the years as a marker is a mistake as it can lead to confusion and somehow staple the technology on different worlds as fulfilling some sort of "path" that the civilization of Earth walked... which isn't at all the use of the table.

The original TL scale was built with 7 as the average, and marking 7 as "most like us today" back in 1977. The fact is not matter what years were placed next to the TL values in TTB TL Chart, we haven't advanced enough in our tech to reach TL 8.

Again, this may have no bearing on the discussion at hand. But I thought it was worth pointing out.

 

[Timerover51]

Hi timerover,

A couple of thoughts about sandcaster technology.

Here is the description of sandcasters from p. 61 of TTB:

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 the material used in ablat personal armor; replacement canisters of this special sand weigh about 50 kg and cost Cr400.

Thus, the technology for the "sand" is TL 9 (when ablat personal armor is introduced). The "sandcaster" TL (as I'm reading it) is essentially the "cannon" technology required to fire the canister. (Note that "missiles" and "missile launchers" are listed as two separate items on the TL Table.) A ship with a damaged sandcaster that dry-docked on a TL 5 world could probably (perhaps with great effort) gather the parts and tech to repair the sandcaster.

As for the volume once launched into space: There's no way really to settle this, but I imagine synthetic particles are quite light so that the weight of 50kg contains a lot of the ablative "sand." For all I know the technology to make effective "sand" for space combat is actually a higher tech level.

As for the volume of the sand clouds: they are not actually stopping the laser... they are stopping the focus of the laser beam. Passing through a "mist" of ablative particles for 2500km, no matter how fine, is enough to break the focus to prevent it from doing harm to the ship even if it should strike the hull. (Just like the personal combat system and missiles, the issue in Classic Traveller is not whether the attack "hits" but is an effective hit that does damage.)

I know this information won't convince anyone of the effectiveness of sandcasters as written. But as written sandcasters do work, and this seems to be the logic.

I understand that the sand clouds are breaking up the focus of the laser, but that also happens naturally, as the laser beam is not totally coherent, even when produced, and will diffuse with distance. What is the range supposed to be of the lasers in space combat? Are we talking tens of kilometers or thousands of kilometers?

As for the sand dispersing, the only way that happens is it you give it a sideways velocity vector, as there is nothing in the vacuum of space to disperse it, as you would have in the atmosphere. As I see it, a cloud of aluminum chaff behind the ship would do a nice job of breaking up the laser beam, which would have to be fired with incredible accuracy to hit a ship several dozens of kilometers away. Just consider the time delay between the time your radar pulse hits the target and returns to you. Your target is no longer where the radar return says it was. How large is the laser beam? A meter or so? What is the configuration of the target ship? For that matter, does the target ship have a coating of ablative material on the exterior. The US was making ablative material for satellite re-entry in the mid-1950s. Are you saying that a laser, at some range of many kilometers, can pack more energy per square centimeter of target than a space capsule re-entering at around 28,000 kilometers per hour?

Side Rant: The Technology Levels for historic technology in the Traveller Book and Traveller in general are a mess, and should be thoroughly reworked. Water Wheels were a major energy source for the Romans, while some of the Roman sailing ships were larger than anything built between about 400 to 1500. Mortars date from about 1600 or so, and hand-carried mortars mortars from around 1690 or so when Menno Coehoorn developed them. No mention of the bow at all, nor of the musket, while the earliest example of plate armor that we have dates from about 1200 BC. End of rant.

 

[McPerth]

Can a cloud be place within a cloud? So that the positioning of the two clouds is the same, the cloud denser, and the DMs doubled.).

I'd say no. The DM is clarly indicated as being per 25 mm of sand clouth, regardless its density.

 

[Timerover51]

The original TL scale was built with 7 as the average, and marking 7 as "most like us today" back in 1977. The fact is not matter what years were placed next to the TL values in TTB TL Chart, we haven't advanced enough in our tech to reach TL 8.

Again, this may have no bearing on the discussion at hand. But I thought it was worth pointing out.

The Spinward Marches Supplement that came out in 1979 has a Tech Level chart with dates added, but is missing Tech Level 8, with Tech Level 7 running from 1970 to 1989.

Starter Traveller has a Tech Level Chart with dates identical to the one in The Traveller Book. As Starter Traveller came out in 1983, and The Traveller Book came out in 1982, both appearing after the 1981 Edition of the Little Black Books, I would argue that they represent the most accurate view of Classic Traveller Tech Levels. As we are nowhere near usable fusion plants in the real world, and any form of contra-gravity equipment looks to be even farther out, if it ever appears, then we are basically stuck at Tech Level 7 forever. Usable personal lasers weapons also appear to be a ways away.

 

[creativehum]

As Starter Traveller came out in 1983, and The Traveller Book came out in 1982, both appearing after the 1981 Edition of the Little Black Books, I would argue that they represent the most accurate view of Classic Traveller Tech Levels.

And I would argue that the addition of the years corrupts the original intent of the TL.

The 1977 edition uses the term "Technological Index" for an easy comparison of the relative technology between worlds and the kinds of goods that can be manufactured on a given world. The point is to have an easy tool that the Referee can use to extrapolate information quickly as Player Characters interact with an entire world he might be making up on the fly.

By tying the Tech Level to dates it is doing exactly what you are frustrated by -- removing it from the realm of a specific (and very smart) RPG tool and trying to turn it into some sort of accounting of technological development. As you note, it fails at this. But since it was never built to do that, I don't consider the table itself flawed in any way but this particular repurposing.

While I understand that most people see each new reworking of the text and rules as some sort of advancement I honestly can't agree. The text and tools of Classical Traveller were there as Referee tools for RPG play and as quick notations for how the Player Characters experience and encounter countless environments. They are brilliantly designed, efficient, and useful.

Later versions of the text tried to make them simulations of actual reality. A completely different goal -- and simply reprinting the the rules and tables and asking them to do something completely different than they were design to do makes no sense. We see the results of this in the countless argument and circles people go through trying to square the rules and tables from Classic Traveller with reality -- when in fact they were there to make the life of an RPG Referee easier.

I understand I might be the only person on the planet who thinks that the later version of the game stretched the intentions of the rules and tables beyond their purpose and capabilities. But the fact is, contrary to common wisdom, whatever comes later is not always an advance, an improvement, or progress.

The test, as far as I am concerned, is simply this: You are frustrated with the TL Table and I am not. And I would argue it is because I expect it to only do what it was built to (provide an aid to a Referee in an RPG game), and you expect it to do something different (provide a map of technological development).

 

[infojunky]

And I would argue that the addition of the years corrupts the original intent of the TL.

The 1977 edition uses the term "Technological Index" for an easy comparison of the relative technology between worlds and the kinds of goods that can be manufactured on a given world. The point is to have an easy tool that the Referee can use to extrapolate information quickly as Player Characters interact with an entire world he might be making up on the fly.

I am going to agree with your point of view, as in the 1977 edition the metric makes sense. But it quickly becomes a morass of expectations with the change to a time accounting.

I would also like to point out the blanks on the Tech Level table where meant to be filled in by the individual referee as it suited their game.

 

[Timerover51]

Your arguments might have more validity if T5.0.9 had not also put dates into its Tech Level Chart.

Edit Note: The above remark was directed at CreativeHum.

As a further note, Marc was responsible for T5, and I am not sure if the author can be charged with corrupting his own work when it comes to later editions. I agree that by putting the years into the chart, he does cause some problems, but he is the one that choose to do so, not anyone else.

 

[aramis]

As we are nowhere near usable fusion plants in the real world, and any form of contra-gravity equipment looks to be even farther out, if it ever appears, then we are basically stuck at Tech Level 7 forever. Usable personal lasers weapons also appear to be a ways away.

Depending on whether you ask the engineers or the scientists, we may have both already.

Note that, as of 2003, there was a guy who was at 99.97% recapture on fusion pulses. The USN nationalized his work around then, with a hefty cash bonus.

And of course, there's the EM-drive. (a bunch papers showing thrust. None explaining why, but several showing that it's more than light pressure.) It might be gravitic...

 

[Timerover51]

Depending on whether you ask the engineers or the scientists, we may have both already.

Note that, as of 2003, there was a guy who was at 99.97% recapture on fusion pulses. The USN nationalized his work around then, with a hefty cash bonus.

And of course, there's the EM-drive. (a bunch papers showing thrust. None explaining why, but several showing that it's more than light pressure.) It might be gravitic...

Is the EM-drive related to the Dean Drive, or is it something new? I know that Jerry Pournelle thought that the Dean Drive was legitimate.

 

[mike wightman]

My explanation of the sandcaster.

It is a re-purposed VRF gaussgun. The rounds it fires are designed to explode into a shower of nanoscale particles the same approximate size as the incoming laser wavelength, which causes further diffraction of the laser reducing its chance to cause damage.
As a point defence weapon when grounded the rounds are fired inert so the sandcaster acts as a giant gauss shotgun.

 

[mike wightman]

The jury is very much out on the em drive, here is a PBS spacetime video on the matter:

https://www.youtube.com/watch?v=hqoo_4wSkdg

 

[aramis]

The jury is very much out on the em drive, here is a PBS spacetime video on the matter:

https://www.youtube.com/watch?v=hqoo_4wSkdg

PBS's commentaeies tend towards "Science as religion". Only one of the 5 I listen to is open to the idea that it might work. Of the three physicists, 1 is, "It breaks known physics, so it must be experimental error," another has stopped just short of calling it fraud, and the third has said, "until we know why it works we can't implement it - which is flat out wrong on SO many levels.

One only needs to know how to make it work, not why it works, to be using something. See also X-Rays, radium watch dials, the "helicopter stick" toys (been around since ancient egypt; king Tut had one).

To Answer Timerover's question...
Resonant cavity thruster.. Pump microwaves into a truncated cone or truncated pyramid, either way made of copper, and get thrust in the direction of the small end.

Pure electric thrust. Efficiency is comparable to ion drives - both mass and power efficiency — save that it's not using reaction mass.

the Chinese claim to be using it for OMS on tiengong 3.
The Chinese space agency has accepted it as valid. NASA has had a comm blackout on it since Dr. White got functional thrust in both air and vacuum, but was unable to null it out as a space warp.

It's been tested repeatedly; it's consistently shown thrust. And no one knows exactly why.

 

[whartung]

For example, the standard missile in Traveller is a 5G6 continuous burn (36 kg, Cr3,600, TL 8), mass sensing (1 kg, Cr1,000, TL 10), proximity detonator (1 kg, Cr500, TL 6), high explosive (10 kg, Cr500, TL 6) warhead missile ...

And now, based on the other thread, these are supposed to poke holes in 33cm of armor -- and that's just on merchant craft.

This is one of the reasons I liked TNE (ref the other thread). They went through and re-thought these problems.

CT has missile "because ships have missile" just like CT has lasers "because ships have lasers" but without any real thought on how they'd actually work. With TNE, they worked out the "reality" and adapted the technologies to fix it.

 

[aramis]

And now, based on the other thread, these are supposed to poke holes in 33cm of armor -- and that's just on merchant craft.

This is one of the reasons I liked TNE (ref the other thread). They went through and re-thought these problems.

CT has missile "because ships have missile" just like CT has lasers "because ships have lasers" but without any real thought on how they'd actually work. With TNE, they worked out the "reality" and adapted the technologies to fix it.

CT missiles are essentially doing what sidewinder (AIM-9 series) do - close up and then shotgun blast the target. UGLY.

44 G-seconds, however, is quite small compared to CT's 18,000...

 

[AnotherDilbert]

Now, as the missile, except for the sensor, is basically Tech Level 8 and lower, then it should be able tp be produced now. The problem is that the missile as described in the rules is impossible. If you believe that it is possible to build such a missile, then please demonstrate how it could be done. I believe that I have shown that it is not possible to produce such a missile at the present day.

I agree that we can't build such missiles, but neither can we build air/rafts or lasers that can destroy manoeuvring targets at 300000 km. As already pointed out we are a bit off TL8, unfortunately.


Once ships were postulated to accelerate at multiple Gs, there was no choice but to postulate remarkably fuel efficient reaction drives. (CT'77 even used reaction drives for ships, not "gravitic" drives.)

If we divide all acceleration by 10 or 100 we might come closer to real performance. FFS had some numbers for supposedly realistic reaction drives, that could probably be used for a low-tech campaign.

 

[creativehum]

I went down a bit of a rabbit hole following up on Aramis' posts. (No links were provided, so I did the best I could.) I'm not knocking Aramis' enthusiasm. I'm only swinging it back around to a simple table used in an RPG game.

Whether or not the technologies referenced above pan out (and even accepting claims by the Chinese government that they are experimenting with the technology in orbit) in the context of the Classic Traveller TL table it is clear that Earth 2017 does not have the "technological expertise, and thus the capabilities of local industry" to manufacture items with these technologies. And that is what matters for the TL table. So at this point we're still at TL 7.

I understand there is a whole sub-theme in later Traveller editions of when technology might be about to jump from one TL to the next. I'm only addressing the TL table as it is addressed in CT books.

Given that ablat technology shows up at TL 9 (and is required for sand clouds) the technology and production of sandcasters as a defense against laser weapons is still two ticks up the scale from our technology today.

 

[AnotherDilbert]

FFS had some numbers for supposedly realistic reaction drives, that could probably be used for a low-tech campaign.

I made a quick calculation with FFS, and I can make a ship with TL7 solid fuel rocket with about 0.1 Ghour using 80% of the ship as fuel. Pushing the design and recalculation for increased performance as fuel is burned off might get us to 0.2 Ghours.

With a few minutes burn time that might get us to orbit, but not much more.