Missile Thrust

[wbnc]

Okay, I now that in the original core book Missiles had a thrust of 5, but this was amended in High Guard...In Beta, the missiles are listed a thrust 5 once more...will this be amended in Highguard beta or ill it remain thrust 5....if it will be increased to thrust 10 as in High guard why not change it in the core rules rather than listing it as a change in High Guard.

 

[Annatar Giftbringer]

Well, the new missiles are vastly more powerful, so perhaps 5G is appropriate for these?

 

[wbnc]

Well, the new missiles are vastly more powerful, so perhaps 5G is appropriate for these?

at 5 Gee some starships can simply out maneuver and outrun missiles....most fighters would wave toodles and fly off laughing...Even the basic light fighter in the core book can pull 6 Gees.

now for a torpedo, yeah 5gee is plenty of acceleration..after all those big boys are designed to wreck starships, not fighters, or small craft.

 

[phavoc]

Yeah, a missile has no flesh to worry about. They should be 10G at least. 5G missile is a joke.

 

[Annatar Giftbringer]

Sure, 5G is a bit slow, I agree. However, take a look at these two quotes from the beta rulebook:

2nd edition rulebook, p161:
Note that High Guard introduces missiles that are more accurate, carry more fuel or are faster, but these rules suit all missiles included in this Core Rulebook.


2nd edition rulebook, p162:
Flee: A spacecraft under missile attack may simply turn around and engage its manoeuvre drive, thrusting away from the missiles. Missiles are extremely long-ranged weapons and so it is not normally possible to outrange a missile but this can buy enough time to prolong electronic warfare or perhaps make a jump. This means that ships that dedicate Thrust 5 or 6 to fleeing cannot be caught by missiles at all – they are simply too fast.

They are meant to be slow. It's supposed to be possible to outrun them. But as the first quote says, High Guard will introduce other missile variants, so most likely we will see thrust 10 (or even higher) missiles, that trade warhead for speed, or range.

 

[wbnc]

that make sense, if there are different versions with he base missile being a slow heavy hitter.

 

[phavoc]

Sure, 5G is a bit slow, I agree. However, take a look at these two quotes from the beta rulebook:

2nd edition rulebook, p161:
Note that High Guard introduces missiles that are more accurate, carry more fuel or are faster, but these rules suit all missiles included in this Core Rulebook.


2nd edition rulebook, p162:
Flee: A spacecraft under missile attack may simply turn around and engage its manoeuvre drive, thrusting away from the missiles. Missiles are extremely long-ranged weapons and so it is not normally possible to outrange a missile but this can buy enough time to prolong electronic warfare or perhaps make a jump. This means that ships that dedicate Thrust 5 or 6 to fleeing cannot be caught by missiles at all – they are simply too fast.

They are meant to be slow. It's supposed to be possible to outrun them. But as the first quote says, High Guard will introduce other missile variants, so most likely we will see thrust 10 (or even higher) missiles, that trade warhead for speed, or range.

I saw that. BUT, that violates the basic tenet of Traveller maneuvering. Granted, the game does not keep track of direction and thrust - except when it's calculating travel times and then it's 50% thrust in direction of your target, flip, 50% thrust in the opposite direction).

So the idea that you can do a U-turn, negate all of your thrust and then run away is silly (however, I will grant you it's possible under the rules, if you aren't using the alternate).

But still, missiles are fast. They are supposed to be. They have no little bits of flesh to worry about. The standard missile should at least be reasonably effective against any ship and small craft it's designed to kill. Expanded missile rules should have missiles that are even faster. Torps should be minimum 6G so you can't outrun them.

 

[AndrewW]

Torps should be minimum 6G so you can't outrun them.

Who said you can't outrun a 6G torpedo¿

 

[phavoc]

Torps should be minimum 6G so you can't outrun them.

Who said you can't outrun a 6G torpedo¿

Under the old rules the fastest a ship 100 tons or over could go was 6G. Now if that's being change, the speed of the torp needs to be, at a minimum, the max speed of ship. Should be faster in my opinion, just so you can't outrun them (unless it's fired at max range and the ship is running away from it).

 

[AndrewW]

Under the old rules the fastest a ship 100 tons or over could go was 6G. Now if that's being change, the speed of the torp needs to be, at a minimum, the max speed of ship. Should be faster in my opinion, just so you can't outrun them (unless it's fired at max range and the ship is running away from it).

Using an ordinary Gravitic drive, limits ships of 70 tons or more to 6G, however one could use a High-Burn Thruster...

Either way though you didn't specify what size ship the torpedo was used against.

 

[Anonymous]

You may want to tie in hull structural strength to acceleration and increase the actual size of grav drive per factor.

 

[wbnc]

I saw that. BUT, that violates the basic tenet of Traveller maneuvering. Granted, the game does not keep track of direction and thrust - except when it's calculating travel times and then it's 50% thrust in direction of your target, flip, 50% thrust in the opposite direction).

So the idea that you can do a U-turn, negate all of your thrust and then run away is silly (however, I will grant you it's possible under the rules, if you aren't using the alternate).

But still, missiles are fast. They are supposed to be. They have no little bits of flesh to worry about. The standard missile should at least be reasonably effective against any ship and small craft it's designed to kill. Expanded missile rules should have missiles that are even faster. Torps should be minimum 6G so you can't outrun them.

at first I had the same reaction..then had to rethink the subject..after a few posts.

first off I think these missiles should be seen more like a big Anti-ship missile...at least for now..not as something like a sparrow, or sidewinder,.

A maverick missile..a very heavy missile in modern terms is high subsonic to trans-sonic...714mph, a harpoon anti-ship missile is even slower, 514 mph. In Traveller terms/mechanics, they have lower acceleration than dogfight missiles.

basically these are offensive missiles, not dogfight missiles. long range heavy warheads meant to deal damage to large targets.

you don't have to out run a missile, only out maneuver it....if you laterally accelerate at 6 gees, and a missile can only accelerate at 5 gees then odds are you can force it to miss.

I vaguely remember an 4-4 pilot explaining how they evaded SAMs, when they spotted them they turned hard into them to change rate of closure and force the missile into a tight turn..the missiles couldn't follow and would overshoot.

same principle would apply here, not for most ships, but for ships that can generate 6 gees or better....they just out maneuver the missile forcing it to try and execute 6 gee turns....

also by accelerating away from a missile, you increase the time to impact, basically reducing a missiles thrust by your thrust rating....and since it takes units of thrust to close range, by lowering the missiles effective thrust rating ( not actual rating, but relative to you) it gives you more time to jam it, decoy it, or shoot it down.

this is pretty much how warships evaded torpedoes in naval battles...I distinctly remember that the Yamato was removed from the board at Leyte gulf when it had to maneuver to avoid torpedoes...

 

[phavoc]

Under the old rules the fastest a ship 100 tons or over could go was 6G. Now if that's being change, the speed of the torp needs to be, at a minimum, the max speed of ship. Should be faster in my opinion, just so you can't outrun them (unless it's fired at max range and the ship is running away from it).

Using an ordinary Gravitic drive, limits ships of 70 tons or more to 6G, however one could use a High-Burn Thruster...

Either way though you didn't specify what size ship the torpedo was used against.

True. But the book classifies anything under 100tons as a small craft. I figured using the books definition was appropriate.

at first I had the same reaction..then had to rethink the subject..after a few posts.

first off I think these missiles should be seen more like a big Anti-ship missile...at least for now..not as something like a sparrow, or sidewinder,.

A maverick missile..a very heavy missile in modern terms is high subsonic to trans-sonic...714mph, a harpoon anti-ship missile is even slower, 514 mph. In Traveller terms/mechanics, they have lower acceleration than dogfight missiles.

But you are conflating an AGM with a cruise missile. An AGM doesn't "fly" so much as falls towards the target in a powered state. There are no SSM Mavericks, just air launched. Also the range of the Maverick is about 22km. The range on the Harpoon is 100km beyond that. And Harpoons speed is 10x that of it's intended targets. Yes these are both missiles, but beyond that they aren't equivalent. One is a land-attack (you could I suppose target a vessel with one) air-dropped only, one is a sea/air/land launched effective only against naval targets. Harpoons are autonomous and mavericks are usually guided. It would be better compare the Harpoon to say an SSN-22 Sunburn. 500mph vs. Mach 3. Both have the same sort of launch and targeting profiles, but the Sunburn is much bigger and WAY faster. In Traveller terms the Harpoon might be the standard missile and the Sunburn is the torpedo.

basically these are offensive missiles, not dogfight missiles. long range heavy warheads meant to deal damage to large targets.

you don't have to out run a missile, only out maneuver it....if you laterally accelerate at 6 gees, and a missile can only accelerate at 5 gees then odds are you can force it to miss.

I vaguely remember an 4-4 pilot explaining how they evaded SAMs, when they spotted them they turned hard into them to change rate of closure and force the missile into a tight turn..the missiles couldn't follow and would overshoot.

same principle would apply here, not for most ships, but for ships that can generate 6 gees or better....they just out maneuver the missile forcing it to try and execute 6 gee turns....

also by accelerating away from a missile, you increase the time to impact, basically reducing a missiles thrust by your thrust rating....and since it takes units of thrust to close range, by lowering the missiles effective thrust rating ( not actual rating, but relative to you) it gives you more time to jam it, decoy it, or shoot it down.

All very true. Except that in space there are no limitations on control surfaces. The reason you can outmaneuver a missile in the air is that an aircraft has far superior abilities to change heading and direction with its vastly superior and larger control surfaces. It has wings for lift, aierlons, flaps and rudders to change directions. A missile has a rocket that is always pushing it forward and relatively tiny control vanes to make changes. Also an aircraft experiences energy bleed when making maneuvers, but the pilot can easily counter that. A missiles solid-fuel rocket engine burns at a continuous rate and cannot make those changes.

Which is why aerial missiles have proximity warheads to better their odds to hitting or damaging an aircraft. A modern missile going up against a modern aircraft with a well-trained pilot has a low chance of actually impacting with the aircraft to detonate it. Usually those types of hits are from infrared missiles hitting the engines. I don't know what the percentage of actual real-world strikes against equivalent tech enemies is, though I suspect low (and much attributable to poor pilot training).

this is pretty much how warships evaded torpedoes in naval battles...I distinctly remember that the Yamato was removed from the board at Leyte gulf when it had to maneuver to avoid torpedoes...

Torpedoes in WW2 were fired at long range and, unless they were the more advanced ones that could home, on set paths that could be avoided if the ship had enough warning and was nimble enough on the helm. Which was also why they were often fired in a spread to ensure that the enemy could not evade all of them. It's also why some had magnetic heads set on them to detonate under a ship's keel (it also was the most deadly of attacks), because sometimes the torp passed under the target.

Both the Yamato and Mushashi (and all of the ships of the fleet) were swarmed by aircraft. The Mushashi took over a dozen bomb hits and about 20 torps to sink it, not sure what it took to sink Yamato, though I suspect it was somewhere along the same lines. At one of the first naval battles off Guadalacanal (Battle of Savo Island) the Japanese sank a cruiser with a torpedo spread fired from max range (about 40km). It was sheer dumb luck they were able to hit them, and, of course, it's near impossible to see torpedo wakes at nighttime.

The issue of speed and response time on the helm was the reason that the zig-zag maneuver was invented for slow-moving convoys. Torps had a helluva time of hitting a high-speed target. A little bit of trivia here. The Queen Elizabeth was converted to troop transport during the war, carrying something like 10k troops per trip. They were also very high speed and rarely traveled with escort because u-boats couldn't catch them or really even target them. The Queen Mary even sunk an escort cruiser once when the two ships zig/zagged into each other. The Queen Mary cut the little cruiser in two and sailed on with only minor bow damage (easily done when you are 10x the size of your target).

 

[wbnc]

at first I had the same reaction..then had to rethink the subject..after a few posts.

first off I think these missiles should be seen more like a big Anti-ship missile...at least for now..not as something like a sparrow, or sidewinder,.

A maverick missile..a very heavy missile in modern terms is high subsonic to trans-sonic...714mph, a harpoon anti-ship missile is even slower, 514 mph. In Traveller terms/mechanics, they have lower acceleration than dogfight missiles.

But you are conflating an AGM with a cruise missile. An AGM doesn't "fly" so much as falls towards the target in a powered state. There are no SSM Mavericks, just air launched. Also the range of the Maverick is about 22km. The range on the Harpoon is 100km beyond that. And Harpoons speed is 10x that of it's intended targets. Yes these are both missiles, but beyond that they aren't equivalent. One is a land-attack (you could I suppose target a vessel with one) air-dropped only, one is a sea/air/land launched effective only against naval targets. Harpoons are autonomous and mavericks are usually guided. It would be better compare the Harpoon to say an SSN-22 Sunburn. 500mph vs. Mach 3. Both have the same sort of launch and targeting profiles, but the Sunburn is much bigger and WAY faster. In Traveller terms the Harpoon might be the standard missile and the Sunburn is the torpedo.

basically these are offensive missiles, not dogfight missiles. long range heavy warheads meant to deal damage to large targets.

you don't have to out run a missile, only out maneuver it....if you laterally accelerate at 6 gees, and a missile can only accelerate at 5 gees then odds are you can force it to miss.

I vaguely remember an 4-4 pilot explaining how they evaded SAMs, when they spotted them they turned hard into them to change rate of closure and force the missile into a tight turn..the missiles couldn't follow and would overshoot.

same principle would apply here, not for most ships, but for ships that can generate 6 gees or better....they just out maneuver the missile forcing it to try and execute 6 gee turns....

also by accelerating away from a missile, you increase the time to impact, basically reducing a missiles thrust by your thrust rating....and since it takes units of thrust to close range, by lowering the missiles effective thrust rating ( not actual rating, but relative to you) it gives you more time to jam it, decoy it, or shoot it down.

All very true. Except that in space there are no limitations on control surfaces. The reason you can outmaneuver a missile in the air is that an aircraft has far superior abilities to change heading and direction with its vastly superior and larger control surfaces. It has wings for lift, aierlons, flaps and rudders to change directions. A missile has a rocket that is always pushing it forward and relatively tiny control vanes to make changes. Also an aircraft experiences energy bleed when making maneuvers, but the pilot can easily counter that. A missiles solid-fuel rocket engine burns at a continuous rate and cannot make those changes.

Which is why aerial missiles have proximity warheads to better their odds to hitting or damaging an aircraft. A modern missile going up against a modern aircraft with a well-trained pilot has a low chance of actually impacting with the aircraft to detonate it. Usually those types of hits are from infrared missiles hitting the engines. I don't know what the percentage of actual real-world strikes against equivalent tech enemies is, though I suspect low (and much attributable to poor pilot training).

this is pretty much how warships evaded torpedoes in naval battles...I distinctly remember that the Yamato was removed from the board at Leyte gulf when it had to maneuver to avoid torpedoes...

Torpedoes in WW2 were fired at long range and, unless they were the more advanced ones that could home, on set paths that could be avoided if the ship had enough warning and was nimble enough on the helm. Which was also why they were often fired in a spread to ensure that the enemy could not evade all of them. It's also why some had magnetic heads set on them to detonate under a ship's keel (it also was the most deadly of attacks), because sometimes the torp passed under the target.

Both the Yamato and Mushashi (and all of the ships of the fleet) were swarmed by aircraft. The Mushashi took over a dozen bomb hits and about 20 torps to sink it, not sure what it took to sink Yamato, though I suspect it was somewhere along the same lines. At one of the first naval battles off Guadalacanal (Battle of Savo Island) the Japanese sank a cruiser with a torpedo spread fired from max range (about 40km). It was sheer dumb luck they were able to hit them, and, of course, it's near impossible to see torpedo wakes at nighttime.

The issue of speed and response time on the helm was the reason that the zig-zag maneuver was invented for slow-moving convoys. Torps had a helluva time of hitting a high-speed target. A little bit of trivia here. The Queen Elizabeth was converted to troop transport during the war, carrying something like 10k troops per trip. They were also very high speed and rarely traveled with escort because u-boats couldn't catch them or really even target them. The Queen Mary even sunk an escort cruiser once when the two ships zig/zagged into each other. The Queen Mary cut the little cruiser in two and sailed on with only minor bow damage (easily done when you are 10x the size of your target).

since in space all objects use direct thrust to maneuver, and do not need to fly with their nose, or drive pointed in the direction of travel, a missile can rotate around it's axis and use it's drives as maneuver thrusters...meaning it can apply all 5 gees of thrust in any particular direction at once..not the admittedly feeble aerodynamic lift generated by fins and vanes.


however a vessel with 6Gee thrust can do the same, meaning it can accelerate at 6gees perpendicular to it's direction of travel, at any time by rotating it's nose and pointing it's engines in the direction it wants to accelerate.

I am also fairly certain that by TL-12 someone will figure out how to put a throttle on a missiles drives...so it can adjust it's thrust...however both vessels are limited by their maximum thrust..5 or 6 gees respectively. and since centripetal, and centrifugal force still apply in zero gee.. a missile can only overcome 5 gees worth of either...a 6 gee vessel can outmaneuver it along any axis of travel, generate a Gee of acceleration over it in a turn, and cut a tighter circle in space at full thrust.


nwifa missile has been accelerating at full thrust for several minutes, or tens of minutes it's maximum velocity is going to be high, which means its velocity alone will generate a large amount of centrifugal/centripetal force in a turn...it's main drive can only overcome 5 gees worth of centrifugal, or centripetal acceleration...where the target burning at 6 gees , and if the pilot is smart, lower starting velocity to begin with.

and since energy bleed due to drag is a non factor the only way the missile can slow down to match a turn is to burn Gees from it's drives, which makes it harder to match the maneuvers of the target...

that still leaves a 6 gee vessel, or small craft at an advantage in a maneuver...the odds of a proximity warhead getting close enough to the 6 gee vehicle is slim since even a large SAM has an effective range of 100 meters or less. and since most starship have the rough equivalent of a main battle tanks armor frag isn't going to do much good...


I know the compassion leaves a lot to be desired, when it comes to WWII weapons and vessels, but it's the best analogy I can come up with.... the speeds, distances, and comparative armor ratings are off but the principles are close enough.

Historically out maneuvering, guided or unguided weapons has proven effective..and since we are projecting and predicting future trends by the best analogs we can come up with..with a daskh of science and physics tossed in...it's as good as you get using a very basic framework.

Even in a sci-fi setting I remember a good maneuver in star trek computer games where the computer handled the math, and behavior of stuff...you could out run a missile, at long range, simply by out turning them...the missiles didn't have enough thrust to keep up with a fast ship, or match it's turning ability..of course firing off missiles at close range was more effective..since the ships didn't have time to react, or open up the range far enough to outpace the missiles...

in a modern dogfight the same rules have seemed to apply. About the only time a missile has a good chance is when the reaction times are short, and the other guy isn't trained to exploit the advantages of his craft over the missile.otherwise the missiles usually end up sailing off into the wild blue.

 

[AndrewW]

True. But the book classifies anything under 100tons as a small craft. I figured using the books definition was appropriate.

A ship 100+ tons can exceed 6g using a high-burn thruster.

 

[phavoc]

True. But the book classifies anything under 100tons as a small craft. I figured using the books definition was appropriate.

A ship 100+ tons can exceed 6g using a high-burn thruster.

Not if you haven't bought Scoundrel they can't.

And, to quote from the naval design bible, High Guard (Chapter Small Craft Design, Verse, err, pg 56, Revised Edition)

Definitions
A small craft is any ship from 10 to 99 tons. Small craft cannot
use jump engines.

Praise Miller!

@wnbc - fair enough. You bring up some very valid counterpoints. Traveller doesn't model thrust at all. It's like Star Wars with their etheric flaps and aerilons that you can do barrel rolls and 180 changes without having to account for your existing thrust. Traveller states that ships travel using a very realistic physical method (if you want to come to a zero stop, you must apply an equal amount of thrust in reverse). It's very light on the physics of things and I'm ok with that, as I don't want to be bogged down in minutia every turn.

However, at some point I feel a hand has to be raised and say "whoa, you are starting to completely toss out the movement model you put forth to begin with". I am not particular about things so long as they stay relatively within the same arena. It starts getting a bit silly when you imply one type of movement and then toss it out the door because it's convenient to your current view (the implied you, I don't mean YOU specifically).

Space combat is pretty simple in the main rules, and most rarely even map it out to show movement and all that. I like the minatures aspect, and SOME of the movement plotting things, like thrust, and SOME vector movement. But too much and it's not fun anymore, nor is it Traveller. I might as well go back to Star Fleet Battles or Renegade Legion Interceptor for that.

 

[AndrewW]

Not if you haven't bought Scoundrel they can't.

That option has been brought into High Guard for 2nd edition. Either way, it's there in the existing rules. One could still make use of a ship designed using that without needing to have purchased Scoundrel.

And, to quote from the naval design bible, High Guard (Chapter Small Craft Design, Verse, err, pg 56, Revised Edition)

I'm familiar with it, though it is actually off since a 100 ton vessel can be either a small craft or spacecraft.

 

[phavoc]

And, to quote from the naval design bible, High Guard (Chapter Small Craft Design, Verse, err, pg 56, Revised Edition)

I'm familiar with it, though it is actually off since a 100 ton vessel can be either a space craft or spacecraft.

Hey, I can only quote what's been printed as canon and not fixed with errata. And I think you meant small craft vs. spacecraft?

And then you jump into the differences between jump-capable space craft and non-jump capable. But all this terminology is taking away from the discussion on missile thrust speeds. I do hope that MGT isn't doing another 180 on missile thrust. It started at 5, was fixed and set to 10 in High Guard, now it's back to 5 in the 2nd edition, so should we expect it to be back to 10 in the new High Guard? My neck is getting rather sore from the revision whiplash effect.

 

[wbnc]

@wnbc - fair enough. You bring up some very valid counterpoints. Traveller doesn't model thrust at all. It's like Star Wars with their etheric flaps and aerilons that you can do barrel rolls and 180 changes without having to account for your existing thrust. Traveller states that ships travel using a very realistic physical method (if you want to come to a zero stop, you must apply an equal amount of thrust in reverse). It's very light on the physics of things and I'm ok with that, as I don't want to be bogged down in minutia every turn.

However, at some point I feel a hand has to be raised and say "whoa, you are starting to completely toss out the movement model you put forth to begin with". I am not particular about things so long as they stay relatively within the same arena. It starts getting a bit silly when you imply one type of movement and then toss it out the door because it's convenient to your current view (the implied you, I don't mean YOU specifically).

Space combat is pretty simple in the main rules, and most rarely even map it out to show movement and all that. I like the minatures aspect, and SOME of the movement plotting things, like thrust, and SOME vector movement. But too much and it's not fun anymore, nor is it Traveller. I might as well go back to Star Fleet Battles or Renegade Legion Interceptor for that.

Traveler is good in some ways, it leaves a lot fo the detail tot he REF and plaeyrs to custom tune to their campaign...but sometimes I really wish I had a bit more crunch to the system...usually if I look at a player and tell him..umm that wont work the way you think it does...it's enough. But when a person goes all "but the rules don't say that..it gets tricky..fortunately not many people I game with are that hard to reign in.

I[ve found ways to handle the lack of hard coded rules. and if you take the bare bones combat system and apply a few basic tweaks you can do a fair job with minutures. by using vectors..and tracking thrust.

I'e played both starlfeet paperwork, and book keeping ...and renegade legion..they are very good at modeling the tactical movement of a starship... with a bit more paperwork and number tracking. I'd happily use either to supplement a game if I had players familiar with the systems.

also with a bit of work either victory at sea, or call to arms would work as well...if you want a more detailed combat simulator....it takes a bit more work but its fun, and relatively stable.

 

[AndrewW]

Hey, I can only quote what's been printed as canon and not fixed with errata. And I think you meant small craft vs. spacecraft?

Errr, yup.

I do hope that MGT isn't doing another 180 on missile thrust. It started at 5, was fixed and set to 10 in High Guard, now it's back to 5 in the 2nd edition, so should we expect it to be back to 10 in the new High Guard? My neck is getting rather sore from the revision whiplash effect.

Don't know yet. It may get revised.