Sensors and Engagement Ranges

[warwizard]

How fast can the ships go in that system?

Assuming you mean how much acceleration can the crew withstand...

G-comp starts at TL 10 at 1g and proceeds +1g per +1 TL if seated a general crew person can withstand an additional g with no restrictions, fighter pilots can of course take up to gcomp + 7g's for a few seconds so you could design fighters that have 12 to 13 g's for emergency evasion at TL 15

G-tanks appear at TL 8 and immerse the space suited crewperson in water and provide an additional G of resistance.

So G-comp TL15 + g-tank + 1 g natural tolerance gives you 8g's with some periods at higher g's.

 

[warwizard]

the really scary thing about the TL 15 , 50 g missiles is that they can do that for 2+ hours and remain near 1m3 volume.

500 meters per second acceleration for 7200 seconds gives us 3600 km/s velocity or about 8 seconds per .1 LS or 1.2% light speed, and yes direct contact at these velocities is indeed nuclear explosion type of energy release.

Edit:This 2 hrs of thrust gives the missile a 43 LS powered envelope.
For space combat I would have a variable time scale, the approach and cat and mouse phases could be done in 1/2 hr turns, but the actual missile attack phases would be done in snapshot scale (6 seconds) allowing the point defenses the chance to make the last second hits on the approaching doom.

 

[kilemall]

Hmmm, think that 43 LS figure is a mite under.

I had g-comp baked into IMTU, very similar, TL9 1-G + per TL, with the difference that many ships operate with a vertical deck plan tailfin down, using the constant accel for a 1-G effect.

So sustained 'high speed streamliners' will be Buck Rogers/Space Angel craft at 2-G/3-G sitting, with compensation taking off the 2-G edge.

Warships regularly push it to 2-G on the crew in pursuit/escape burns, with decreased functionality especially in engineering/damage control rolls.

Mercury and Gemini astronauts did the 7-G thing for quite a bit longer then combat pilots doing ACM, and the shuttle was designed for 4-G, so it can be done for a bit, but the Mercury astronauts were top pilots in peak physical condition, this isn't a realistic crewing expectation most navies can have outside their fighter cockpits.

Otherwise, they go faster for longer periods of time, I start rolling damage on the crew. My overriding theme is Space Hurts, and G-damage is a big part of it.

A really desperate maneuver is walking up the Frozen Watch to take over when the current crew is too hurt to continue on.

Water tank? I dunno, that one I don't buy. The issue is blood circulation and pressure, I fail to see what a tank is going to do that a pressure suit can't. Micropumps serving liquid/gas pressure bladders on a suit seems more realistic and economical.

The Expanse has a possibly practical solution, drug pumping for high-G burns.

Another is nanites to maintain blood flow.

Ultimately for those polities that allow it, genetic engineering for humans designed for space. The genetic limitation treaty to avoid 20-G spacecraft gaps?

All of which would be good stuff for making for a sci-fi feel to things, but definitely a IYTU type decision and not something I would want to bake into rules for everyone.

 

[warwizard]

Yes I've read your previous thread on that and agree with the setting, I've got something similar planned for the 20 years after first contact before the 1st interstellar war. My players use a lot of hot sleep (Fast drug) and load the ships with 60X the life support limit putting the colonists in cramped budget airline seats for the duration of the outbound trip, even the airline seats are offloaded and become resources for the colony to recycle. One colonist in 480 rides in normal un drugged state and acts as steward for 8, 60 person groups.
9 colonists per displacement ton in the cargo hold (.5m3 allowance for personnel items stowed per 9 colonist) really brings to mind the concept of cattle car. Instead of bringing fast antidote on the 2nd trip out, they have the colonies build a "reception hall" filled with the seats from the first trip and the fast travelers wait out the remainder of their 60 days to save the YUAN 150 per person for the antidote. and yes the player doing that runs the PRC (People's Republic of China) faction, and is playing his population card to the max, with the EU, USSR and USA factions setting up colonies with more resources and fewer people. When the Russians tried something like that , it ended badly for them when they tried to do it without the fast drug, there is now a colony where Russian colony ships land and the ships offload their colonists and supplies, loads up the trade goods and then after the ship jumps back some 3 to 5 percent of the new colonists die suddenly.

 

[mike wightman]

Sorry for the slight aside - either of you ever see the GDW game Double Star by a certain MWM?

“The Epsilon Cetus system, containing an M8 red dwarf and a G0 yellow star, was originally colonized by two independent relocation missions. The first to arrive, and thus to claim the better G0 system, were those of Islamic origin. The second mission, of Chinese origin, arrived some 50 years later in a crippled colony ship, found the G0 system jealously guarded by a handful of Islamic ships, and had to crash-land instead in the far poorer quality red dwarf system. This early incident left a lasting animosity between the two cultures. Over two centuries, the Islamic culture established itself in its system, exploiting its mineral and ecological wealth to the fullest, and developing a thriving interplanetary society. The Chinese colony, on the other hand, was forced to spend the past 150 years in a spartan struggle for survival against marginal environments and the unpredictable flares of the red dwarf. Now, however, the pressure of population on the Chinese and the pressure for additional resource supplies on the Islamic has brought these two cultures into direct conflict.”

 

[mike wightman]

Some good ideas in this thread, some of which I already use, some which I am considering giving a try.
1. different scales for sensor phase and cambat phase - I've never tried a 6 second ship combat phase, hmmm
2. smart missile and drone swarms - consider designing an escort class vessel with max armour, screens and point defence to go along with the swarm to act as forward controller
3 - railguns and lasers for point defence - can't help it but I still think ship lasers need their range reduced (would make the missile swarm a bit more effective)
4 - have you considered that if both sides are shooting swarms at each other, and using fighters and anti-missile missiles, the swarm will start to have their own mini-battle somewhere in the space between the two fleets...

 

[warwizard]

Yes I have a copy of double star.

 

[warwizard]

Some good ideas in this thread, some of which I already use, some which I am considering giving a try.
1. different scales for sensor phase and cambat phase - I've never tried a 6 second ship combat phase, hmmm
2. smart missile and drone swarms - consider designing an escort class vessel with max armour, screens and point defence to go along with the swarm to act as forward controller
3 - railguns and lasers for point defence - can't help it but I still think ship lasers need their range reduced (would make the missile swarm a bit more effective)
4 - have you considered that if both sides are shooting swarms at each other, and using fighters and anti-missile missiles, the swarm will start to have their own mini-battle somewhere in the space between the two fleets...

Yeah that's where the 6 second turns come in , lots of dying as the furball happens between the fleets. You get star wars like ship battles where you have all sizes of ships doing their own thing, fighters shooting fighters and once the big ships close in shooting whatever is next in front of their guns. You never saw the fighters killing the big ships, just shooting surface features like bridge shields and turbo laser batteries, like what I've been saying you don't need to kill it just degrade it's sensors weapons and defenses with itty bitty hits.

 

[kilemall]

Pretty close to a time/space/action scale-

• 10,000 seconds, 100,000km per hex for moving to detection and determining initial contact vee, a HUGE determinant for what happens next.

• 1,000 seconds, two scales 100,000km per large movement hex, 10,000 km per hex nav plotter for each ship/fleet group in the same 100,000 km area.

Each nav plotter map has 4 10-hex wide megahexes corresponding to a 100,000km hex, arranged in a diamond to allow for whatever radical moves. Each move happens at the same time for all ships for simplification.

This is the default time scale for HG-style resolution. I could even go for a simplified Imperium/FFW squadron resolution, or maybe one ship result stands in for the state of it's whole CruDiv.

• 100 seconds for character action/drama/energy allocation/firing/damage control. This is the default time scale for ACS or HG fighting drama once they are at weapons range.

Weapons fire when they are charged, and can be fired multiple times if there is sufficient power to charge them multiple times. EP generation is divided by 10 and parceled out. Ships can go to full burn or agility or drop it and switch to weapons charging.

Movement is proportional impulse ala SFB if at least one ship is moving fast enough to cover more then 100,000 kms in 1000 seconds.


No generic batteries bearing rule, ships roll to expose/aim direct fire weapons, specific sides of the ship get battered in and potentially expose inner systems prompting captains to roll them away from fire and dealing with consequences of that decision.


I have a mechanism for dealing in range and effects on probability and firepower decrease/increase which would apply to both the HG version and ACS/drama version, but my gut check and RFC is twofold-

1. SHOULD there be a more dramatic difference in TL performance then default incrementalist HG and the (IMO) associated difference in currency pricing?
2. What SHOULD the extreme range of Spinal Weapons be?

Really looking for commentary here.

 

[warwizard]

Well they have it somewhat backwards on the cost, lower tech is usually bigger , heavier, and more expensive. As far as the sensor go, an antenna is an antenna, but the signal processors get smaller and lighter and use less power.

Jammers do not affect higher tech level sensors, but penetration aids like stealth , EMM masking, and extra radiators are TL dependent for extra levels of signal reduction, where a -1 reduction is an order of magnitude improvement in how close you can get before getting target locked by a given sensor. There are NOT similar order of magnitude gains in the sensors as you improve technology. A TL 15 force vs a TL 14 force should enjoy a 4:1 range and time to impact advantage in missile combat, along with better stealth and the ability to use jammers that is denied to the TL 14 force. All this added up leads me to reach the conclusion that TL 15 should have an order of magnitude advantage in missile combat. And resupply? a single free trader can carry over 1000 reloads in box launchers (1042 box launchers in 82 dt cargo)

The analysis of beam combat finds no such great advantages, and the graduation there is one of incremental improvements instead of one of clear advantage. The laser systems can pack 150 Mj instead of 140 Mj big woop so you can penetrate a few more CM of armor, no big deal, being able to build a tunable X-ray laser gives you a great advantage in either range or size, but it's not order of magnitude better.

There is not a lot of difference on the maneuver drives other than the crew's ability to withstand the g's, and when you run out of energy/reaction mass.

Now the question of what range should a spinal weapon be? How stable is the weapon platform? Do crew moving around or ship maneuvering cause vibration or flexing of the tube that generates errors of shot placement in the 100's of meters at short ranges become thousands of meters at 100 times the range? Do you have a beam pointing system that provides useful feedback as to where the beam is actually going to go if fired? And is the range so long that the beam pointing information is 10 seconds old by the time you get it?
Maneuvering targets, likely extreme range would be no more than a light second due to agility of the target. Stationary, or orbital targets with predictable path... well as far as you can focus your beam then. I would allow ships in the reserve to fire spinal weapons at drifting cripples.

Given that missiles become so good at TL 15 my T4 designed fleet would likely not have any spinal mounts, as I would expect to never reach that range. (google what happened to Taffey 3 and the Gambier bay)

 

[kilemall]

The harsh Striker currency conversion and the less harsh but still serious conversion rate of TCS is predicated on I think the desirability/value of goods produced by X TL.

And, I'm guessing their capacity for import/export by starport facility is about the level of economic stimulation/activity brought on by a higher interstellar interaction level.

There is a LOT of interesting discussion to be had over the juxtaposition of those two tables that merit it's own thread, later.

But that should not be taken as some ratio of TL vs. bigger/clunkier. HG is FILLED with higher tech being smaller/cheaper/better. It's more about desirability, availability and inability to support higher tech levels natively that counts.

Would you rather have a 100 MCr TL9 or TL14 ship? In most cases the answer is obvious for fighting purposes.

But if you have a commercial and/or frontier support situation, and just stupid lift is required no extra needs, if currency differences are in play that TL9 craft is all the ship you need and at 50% off it's 'good enough'.

Do you really need a high tech grav assist AI screwdriver? In most cases, no.

This isn't so far fetched- TCS only does the conversion of naval tax to the higher tech worlds when it is being remitted to build higher tech ships, it does say you can build the ships natively at the full tax collected.

To make that tax dollar stretch to get support level ships that don't need the latest in armaments and drives, and generate activity locally for planets that need the stimulation given the less desirability of their goods, that would be a facet of most multi-world navies. You could even have the higher tech worlds convert into lower tech credits and buy a LOT of tanker/lift capacity.

Of course, ugly ugly questions arise, such as 'are all passenger and freight fees denominated in the interstellar polities' top currency?'

Like I said, a whole other thread, but for ship design VERY relevant when looking at incrementalist vs. radical tech differences.




Secondly, I do not take for granted in any way shape or form that missiles are 50 G at TL15, because I am working CT:HG2 and am not looking to work outside that system nor really learn another version, CT MgT and T5 are plenty.

If one disregards CT/SS3/Mayday one could assign whatever value one likes to missile speed, which I am open to, but being a game and players being the min/max weasels they are, one should not give them 80% of the combat value at 50% of the cost.

Space Hurts.




Third, of course spinal weapons should have limits based on multi-LS ranges even if somehow they maintained power and coherence that far out and target ship maneuver considerations.

Since this is ultimately game art and not weapons engineering ala our one world low TL outlook, we can assume a lot of solutions that would boggle us and go with things that are much more capable but have limits that 'feel' right.

15LS and no drop in power or hit probability as Mayday:HG has it seems outside of that feel.

I'm asking more for about what 'feels' right given the speed/time/firing/maneuver scale I have outlined.


Fourth, T4's beam combat assumptions would seem to be just as arbitrary as HG's (and largely predicated on the dynamic of the x-ray laser's improvement), if nothing else the same power and computing improvements baked into a lot of the tech increases should allow for more precision/power/efficient input conversion/cheaper etc.

Not terribly relevant as I am satisfied with the laser's jack of all trades multirole function, just venting about how we shouldn't kid ourselves that these things are game decisions, not necessarily realistic extrapolation.

 

[kilemall]

Just to give you an idea of how badly these things can go, the Traveller CT computer system of course aged VERY badly.

However the various Cyberpunk related games did not age well either, particularly with storage capacities that seemed obscenely huge when the games were written.

We blew by and left those 'advanced hardware' values in the dust a decade or more before the putative 2013/2020/near future dates they portrayed.

Yet we also don't have the direct neural sensorial UI of cyberspace as presented in novels and games and that remains advanced out of the average person's reach, although we certainly do have the low life hackers, data ripping, financial shenanigans and underworld data market in abundance.

 

[warwizard]

Point is valid on the 50 g rockets there is a major fudge on the input power needed for the Heplar. if someone would care to convert 2000 kN to watts we'd see that the energy of the input power exceeds the energy of the thrust produced.

http://www.translatorscafe.com/cafe/EN/units-converter/power/1-57/watt-newton_meter/second/ "A watt (W) is a derived unit of power in the International System of Units (SI) defined as one joule per second. Power measures the rate of energy conversion or the rate at which work is done. One watt is the rate at which work is done when an object’s velocity is held constant at one meter per second against constant opposing force of one newton. In electromagnetism, one watt is defined as the rate at which work is done when one ampere of current flows across a potential difference of one volt.
Example: A small LED lamp consumes several watts of energy."

1N.m.s = 1W, so 2000 KN for one second for 1 meter = 2MW, HEPLAR requires 10 MW for this level of thrust, Thruster plates need 20 MW so our super physics breaking futuristic rockets are only 10% to 20% efficient at converting electrical power to thrust, yet the VASMIR rocket is 70% efficient.

https://en.wikipedia.org/wiki/Variable_Specific_Impulse_Magnetoplasma_Rocket

So if we were to apply VASMIR efficiencies to the Heplar we'd need only 2.8 MW for our 2000 KN. with the minimum size of the heplar at .1m3 you would need 560 kw from a .1 m3 fusion plant (minimum size at TL 15) to power a .2m3 heplar for 400 KN of thrust with a mass of .3 mt giving a max acceleration of 133 g's, with 40 kw excess power for sensors and communicators.

 

[kilemall]

Some good ideas in this thread, some of which I already use, some which I am considering giving a try.
1. different scales for sensor phase and cambat phase - I've never tried a 6 second ship combat phase, hmmm

Others may find play value in that, I don't, else I would have likely moved this more in the direction of CT resolution tracking each individual shot with HG weapons or gone with some of the wonkier Traveller ship combat versions.

2. smart missile and drone swarms - consider designing an escort class vessel with max armour, screens and point defence to go along with the swarm to act as forward controller

Now that is a neglected facet of the combats and may make for very long range engagements and a whole lot more scouting.

Makes defining HG missiles re: range/speed and ability to drift while being powered and ready to respond imperative. You would also need to have some means of quantifying what computer model/sensor fit/TL allows how much missile swarm handoff. You don't want the spectacle of a Type S bringing down the hammer of the fleet with a Mod 1/b computer and one gunner at the console.

3 - railguns and lasers for point defence - can't help it but I still think ship lasers need their range reduced (would make the missile swarm a bit more effective)

Oh, that.

Antimissile mode is 10% of the power of a full shot, can't do damage like a full shot against ships except at less then 10,000 km, can therefore fire 10x in a 1000 second turn against incoming every 100 second phase.

Target ship has agility and countermeasures to help with basic to hit (which I take to mean is the ECM roll baked into the table), and can have dedicated escort ships for anti-missile work (treated as one ship for batteries bearing).

Pitch that against missile advantages- -3 to hit - agility/evade - penaids/countermeasures when shots are long range and maybe just attack value reduction, at AM range something like the beam table is in play no gunner skill (too fast), missile agility now a plus to hit.

And missile bays can empty their VLS cells in one turn.

4 - have you considered that if both sides are shooting swarms at each other, and using fighters and anti-missile missiles, the swarm will start to have their own mini-battle somewhere in the space between the two fleets...

Well, more like the forward missile controller ships allocate their leading swarms to destroy the enemy forward missile controllers and thus get long range dominance.

I don't think one wants to outlaw such tactics, or see them dominate battles consistently, so one ought to look to something like extreme missile direction range should be about the same as extreme spinal weapon range, so there is a mix of weapons and ship types that have scissors/rock/paper/lizard/spock interactions.

I see anti-missile missiles as being like Sprint and the other nuclear ABMs, high-G short range one turn weapons that close fast against missile swarms and detonate. Perfect sort of role for turret missile racks, leaving the big missile bays for attack.

Remember, higher tech ships can carry nuclear dampers, missiles can't.

 

[mike wightman]

Back to the drawing board.
CT LBB2 ranges:
0.25ls..civilian ship vs stealthy target
0.5ls...civilian ship sensor range (passive perhaps?)
0.8ls...weapons at -2Dm to hit
1.0ls...military ship vs stealthy target
1.7ls...weapons at -5DM to hit
2.0ls...military ship sensor range
3.0ls...maximum tracking range (active sensors perhaps? lasers can not get a weapon lock beyond this range)

 

[mike wightman]

Sensor tasks:
civilian:
attempt to obtain a weapon lock on target
0.5ls-0.8ls no DM
0.8ls-1.7ls -2DM to sensor roll
1.7ls-3.0ls -5DM to sensor roll

military
attempt to obtain weapon lock
2.0ls-2.3ls -2DM to sensor roll
2.3ls-3.0ls -5DM to sensor roll

 

[kilemall]

Sensor tasks:
civilian:
attempt to obtain a weapon lock on target
0.5ls-0.8ls no DM
0.8ls-1.7ls -2DM to sensor roll
1.7ls-3.0ls -5DM to sensor roll

military
attempt to obtain weapon lock
2.0ls-2.3ls -2DM to sensor roll
2.3ls-3.0ls -5DM to sensor roll

Not sure where this is from- TTB? MT?

Certainly looks in line with CT type values.

 

[kilemall]

Back to the drawing board.
CT LBB2 ranges:
0.25ls..civilian ship vs stealthy target
0.5ls...civilian ship sensor range (passive perhaps?)
0.8ls...weapons at -2Dm to hit
1.0ls...military ship vs stealthy target
1.7ls...weapons at -5DM to hit
2.0ls...military ship sensor range
3.0ls...maximum tracking range (active sensors perhaps? lasers can not get a weapon lock beyond this range)

This of course is the baseline I was originally going to work in, but even then it seemed a bit constraining for the spinal weapons which I think we can presume are significantly more powerful and/or are firing a multi-second beam in the case of the PAs and likely a 'flak pattern' of detonations in the case of Meson Guns.

And for the latter, who knows how long they can go before decaying? Although the short range +2 bonus suggests a clue that MGs really like to work in shorter time frames, I suppose because they have to be in the 'right place at the right time' detonation wise rather then 'just' hit the hull.

 

[mike wightman]

Not sure where this is from- TTB? MT?

Certainly looks in line with CT type values.

I made them up - by using the weapon to hit DMs to 'fill in the sensor gap' so to speak - as in the range given to autodetect is a bit boring so I decided there is a chance to obtain a weapon lock once a target is within the 3ls tracking zone.
Note that if you open fire you grant your opponent automatic sensor success.

 

[kilemall]

I made them up - by using the weapon to hit DMs to 'fill in the sensor gap' so to speak - as in the range given to autodetect is a bit boring so I decided there is a chance to obtain a weapon lock once a target is within the 3ls tracking zone.
Note that if you open fire you grant your opponent automatic sensor success.

Oh ya, I had that intent to be sure, its the ultimate in 'going active'.