187 replies to this topic

[CrashieJ]

DavidHurricane, on 14 September 2013 - 08:46 AM, said:

For clarification the jump jets compress the atmosphere and then super-shot it with electricity. So in effect it is a plasma gun.

which is funny because in the Battletech books, Jumpjets use MERCURY. which is not a good fuel source

Mercury Hydride on the other hand CAN be used as a fuel source, is solid, and when heated and turns into Hydrogen and Mercury (liquid).

[Skylarr]

Mindstormer, on 26 September 2013 - 08:37 AM, said:

I thought maybe the BattleTech TechManual might have some insightful information into K-F Drives but unfortunately it only covers the components of aerospace units and dropships not jumpships or military vessels.

Supposedly K-F Drives can only establish a hyperspace window in the areas of or outside the Zenith and Nadir of a star's gravity well. What I find hard to understand is why, if one is traveling at FTL speeds (especially if hyperspace is actually an adjacent dimension), does the endpoint of a hyperspace jump need to be outside the sphere of influence for bodies of gravity as well? I mean, other than potentially ripping something off your ship from the sudden stress of instantly entering a gravity field, what prevents ships from jumping into an atmosphere or just above it?
And does hyperspace in the BattleTech universe exist in an adjacent dimension like it does in the Stargate universe, or is it just a way of referencing FTL travel in normal space?

BTW if anyone wants any information on proper mech, vehicle, or aerospace unit construction feel free to ask me. I can always reference the TechManual for the construction rules.

Quote

The driving force behind the initial colonization of the Inner Sphere, the Kearny-Fuchida Drive was named after the two professors, Thomas Kearny and Takayoshi Fuchida who theorized of the ability to warp space to allow for quick travel over more than two dozen light years.

K-F Drives do not use FTL Technologies. They warp space between two points and then "Jump" through to he other side.

Quote

Space travel

Faster-than-light travel across interstellar distances is common in the BattleTech universe and depends on an advanced space-warping technology known as the Kearny-Fuchida Drive. Interplanetary and orbital space travel is also common practice, generally conducted by fusion-powered dropships and various smaller aerospace craft.
Principles

The theoretical underpinnings of the Kearny-Fuchida (or K-F) hyperspace drive originated in the early 21st century with Stanford physicists Thomas Kearny and Takayoshi Fuchida, whose experiments revealed that particles exposed to a hyperspace energy field jumped almost instantaneously between two points. Though originally dismissed, the effect was confirmed in the early 22nd century and a drive subsequently developed by the Terran Alliance to exploit the principle.

In a K-F jump, an initiator produces a hyperspace field which is then magnified and focused by a large, superconductive mass of titanium/germanium. The amplified field envelopes the ship and pushes it through a hole in normal space called a "jump point", through which it enters hyperspace. Depending on the distance to be traversed, the ship spends up to 15 seconds in hyperspace before reemerging into normal space through another jump point at the destination. The opening and closing of jump points destroys large numbers of subatomic particles and produces a pulse of electromagnetic energy that can be detected at considerable range.

Jumps are normally made to and from points far above a solar system's ecliptic, usually where the gravitational influence in the system is most stable; however, so-called "pirate points" exist where local gravitational pull is stable enough to used; though quicker, using such points is also more dangerous due the random appearance of so-called "Lagrange points". Most Jumpship crews are left stranded in most cases of an emergency.

Jumping requires copious amounts of energy, usually gathered from the nearby star over the course of approximately a week by large solar collectors similar to solar sails and stored in giant capacitors. Recent advances have dropped this to around 14 hours. A quicker but less common technique is to draw the energy from a fusion reactor, or to take advantage of recharge stations in the vicinity of major jump points. Jump failures can result from charging the drive too quickly, poor drive maintenance or spatial anomalies.
Spacecraft

BattleTech spacecraft range considerably in size and function, but generally fall into three broad categories – jumpships, dropships and small craft.

Vessels equipped with K-F drives are known as jumpships and range in mass up to 500,000 tonnes, though warships, a subclass of jumpship hardened against attack and fitted with naval weapons, may mass up to 2.5 million tonnes. The size and delicacy of a jumpship's K-F drive and the danger of jumping while in a gravitational well limits such vessels to deep space and precludes planetary landings. Jumpships often use sail-like collectors to gather solar energy and fusion engines for sub-light maneuvers, and normally travel with a small retinue of dropships.

Dropships are fusion-powered craft built to transport people and cargo between space-bound jumpships and planetary surfaces, or between jumpships. Dropships lack faster-than-light engines and instead use fusion motors for covering short interplanetary distances, for orbital and atmospheric maneuvers, and for takeoffs and landings. They mass anywhere between 400 and 100,000 tonnes, and are usually of either aerodyne (aerodynamic) or spheroidal configuration. Dropships in the BattleTech universe are used for both military and civilian/commercial transportation.

The smallest vessels capable of space travel are known simply as "small craft", or as aerospace craft if capable of planetary landings. They may serve military functions (as fighters or bombers) or civilian purposes (e.g., transportation)

Jump Point

[990Dreams]

Skylarr, on 26 September 2013 - 07:37 PM, said:

K-F Drives do not use FTL Technologies. They warp space between two points and then "Jump" through to he other side.






Jump Point

Exactly what I thought. But not even an antimatter drive could make THAT much power to warp space (maybe to jump). And you'd need more gravity for longer distances

[YourBusDriver]

The fusion power source is not the issue, the fact it uses hydrogen is the problem. Fusion derived from hydrogen produces too much heat and wear on the reactor. When hydrogen undergoes the process to form helium, high density particles in the form of free neutrons are given off. These resultant particles tear the reactor apart, thus the reaction can only be sustained for short periods of time. Helium-3 is a much more stable fuel; being a stable isotope of helium that is missing a neutron, with this missing neutron allowing for the production of clean energy. It gives off negligible levels of neutron radiation, thus making it a more sustainable reaction.
Of course cold fusion and antimatter reactions are probably even more realistic, considering the time period. Technologies such as theses should be like building campfires by the time humanity progresses past the year 2100… long before the setting of this game. Cold fusion and antimatter reactions have power densities nearly one hundred times greater than fusion, and there is zero radiation. They produce close to no waste material, and are almost 100% energy efficient. Also, these reactions are very sizable. Conventional cold fusion reactors are the size of cargo containers and the only hurdle facing antimatter is the stabilization of the anti-particles.

Edited by YourBusDriver, 01 October 2013 - 03:57 PM.

[dal10]

science fiction, stop thinking so hard about it.

[Pht]

Marack Drock, on 01 October 2013 - 08:05 AM, said:

The longest range of a Machgun is one mile. A laser can litterally hit the moon NASA has them. A missile is capable of going over 100 miles without running out of fuel. In World War 2 Missiles from Germany were launched and hit England.

Not sure if Nef has posted the ranges, but BT lasers can reach out to over sixty miles in space and on planet can shoot at things that have "popped up" over the horizon.

Of course missiles can go 100 miles ... but those are a lot larger than the 'mech lrms. Not sure on the range of the ballistic/homing missiles in bt that are of the same class as our larger missiles, but I'm pretty sure the arrows and such are rated in "maps" instead of hex range.

I would guess that the "machine guns" that 'mechs mount are almost purely built to put out scads of fire very quickly, instead of with any precision/accuracy.

[Karl Streiger]

Marack Drock, on 01 October 2013 - 08:05 AM, said:

The longest range of a Machgun is one mile. A laser can litterally hit the moon NASA has them. A missile is capable of going over 100 miles without running out of fuel. In World War 2 Missiles from Germany were launched and hit England.

.. the longest range of a 50cal in BattleTech is 625m (TimeofWar RPG) at this range it is more as capable of hurting most humans even with heavy body armor. (5B/5B) - and it will hardly be only one shot that will hit.

A support Laser - same as a BattleMech Small Laser has a range of 1500m

portable SRMs may hit target up to 740m, portable LRMs up to 2100m (don't forget that are really small missiles)

Next I should at that these values reflect that even average persons are able to hit targets at such distances.

The next is BT magic - there armor and weapon are more advanced. a todays ballistic vest and assault rifle will have a value

RHA for example will have a BAR Rating of 5-6 - that means the armor is capable of reflecting a Medium Laser - but will simple be penetratetd by a Large Laser Mech Armor is always BAR 10 - nearly invulnerable to penetrating attacks.

Thats why the best way to defeat a Mech is to remove its protection - for example using APCBC-HE shells or large iron bullets instead of thiny long rods of Tungsten

Same go for body armor - a archaic bullet proof vest is more as capable of stoppin a slug of a achaic assault rifle - but a Zeus or even the Gunther MP will cause serious injuries.


At least its only a game...

[990Dreams]

YourBusDriver, on 01 October 2013 - 04:22 AM, said:

The fusion power source is not the issue, the fact it uses hydrogen is the problem. Fusion derived from hydrogen produces too much heat and wear on the reactor. When hydrogen undergoes the process to form helium, high density particles in the form of free neutrons are given off. These resultant particles tear the reactor apart, thus the reaction can only be sustained for short periods of time. Helium-3 is a much more stable fuel; being a stable isotope of helium that is missing a neutron, with this missing neutron allowing for the production of clean energy. It gives off negligible levels of neutron radiation, thus making it a more sustainable reaction.
Of course cold fusion and antimatter reactions are probably even more realistic, considering the time period. Technologies such as theses should be like building campfires by the time humanity progresses past the year 2100… long before the setting of this game. Cold fusion and antimatter reactions have power densities nearly one hundred times greater than fusion, and there is zero radiation. They produce close to no waste material, and are almost 100% energy efficient. Also, these reactions are very sizable. Conventional cold fusion reactors are the size of cargo containers and the only hurdle facing antimatter is the stabilization of the anti-particles.

Antimatter: http://www.designntr...imes-faster.htm
And sustained fusion is possible. The ITER is set to go online in ten years or so. We'd just need to scale it down for a mech . As for cold fusion, well... I'm not sure. Perhaps those photonic molecule things could help.

[Nebfer]

Well lets see B-tech fusion reactors use standard hydrogen, to do this one can use Proton chain reactions or the CNO cycle. Both provide the same amount of energy but Iv'e been told that the CNO cycle is easier to get at, but it's not stated which one B-tech uses in any case. Though I have been told that pure hydrogen reactions is one of the harder reactions to do, B-tech seems to have mastered this by around the 2200s, making this a fairly impressive accomplishment.

B-tech sub light drives are absurdly efficient and powerful, Tactical movement is effectively the equivalent of 300m/s of Delta V effectively a typical ASFs fuel tank has enough Delta V to pull a Apollo moon shot three times before needing to refuel. a single thrust point is equal to half a gravity of acceleration (or 4.5m/s/s). As such a your typical ASF (a 6/9 craft) has 4.5 Gs of acceleration, far surpassing any real world craft (most real world fighters have under 1.5Gs). Also B-tech engines are so efficient any B-tech craft over 500 tons is braking the laws of thermodynamics, and likely a few other "laws" along the way, as the engine out put is far greater than whats going in. In an atmosphere an ASF with it's typical 5 tons of hydrogen fuel has a range of 14,400km, conventional fighters are far more impressive, getting double that if not quadrupled the range. B-tech craft also seem to be able to super cruse at their maximum speeds for much of their flying time, which per some novels can be hypersonic as low as 500 meters off the ground.

Ranges for the humble small laser in space is 108km, as is the medium laser, large lasers have 216km (like with the ground theirs oddity's that indicate that theirs more to these ranges than meets the eye). Even so using the dogfighting scale these weapons have a range of 3 and 6km respectively. Note ranges in these scales are done a bit differently than in regular B-tech weapons have a fixed range scale, as such short range is 6 hexes, medium 12, long 20 and extreme 25 hexes, small and medium lasers have a short range (as such only fire out to that range). the size of the hexes at dog fight scale (or aerospace/fighter scale) is 500m and 18km for capital scale (capital weapons use capital scale but 2x the range).

B-tech Gauss rifles I believe are often stated to be related to coil guns, and not railguns, though either way their fairly impressive being able to fling a 250 kilogram slugs at hypersonic velocity's (Mach 5+), this being the Heavy Gauss rifle.

One of the most commonly stated calibers for vehicle scale machine guns (i.e. the ones they put on mechs and tanks) is 20mm, though 50 cals are mentioned at times, theirs even mention of 30mm based MGs.

A few things to note on Early B-tech history, or pre B-tech history (backstory)
1. Many units that existed in the 1980s and early 1990s exist as such in B-tech, though B-tech USA it seems to have built far more Sea Wolf Class Subs than we did.
2. It seems B-tech spent a bit more on orbital life capability's than we ever did, as from the mid 1990s to 2007 B-tech Earth built a space station with orbital construction capability's (not to mention Anti missile systems), that had a population/crew of 2,000. The ISS has a crew of 6ish and a mass about 450 tons, in roughly a decade B-tech earth built a space station that mass's easily over 10,000 tons. Or more than 30 times the lift capability's...

[parman01]

Colby Boucher, on 18 September 2013 - 02:24 AM, said:

Here's a puzzle: how does the stalker stay upright? That thing should fall flat on it's face.

To be honest. Any bipedal, 50-100 tonn vehicle would probably fall on its face. This is part of Mechwarrior I'd rather leave alone.

[dal10]

get the center of gravity low enough, you could make it more stable than some wheeled vehicles.

[990Dreams]

parman01, on 16 October 2013 - 05:29 AM, said:

To be honest. Any bipedal, 50-100 tonn vehicle would probably fall on its face. This is part of Mechwarrior I'd rather leave alone.

Gyro and neurohelmet. The neurohelmet allows for humans to control the balance (which we are better at than a gyro), and the gyro does it when the human can't (i.e over heating, which the crouch helps)

[dal10]

actually the neurohelmet tells the gyro, you know what, don't work for a second, i know what i am doing.

[Loganauer]

Missile range because they're smaller and more compact I can buy, lasers not being effective against the armor at that range I can buy, but machine guns should definitely have a larger optimal range having personally fired modern weapon systems with an optimal range up around 300m.

I'd like to hear you guys talk about the physics of the games heat system. Shouldn't it because less effective at cooling off the hotter it gets?

[Pht]

Loganauer, on 30 August 2014 - 04:12 PM, said:

I'd like to hear you guys talk about the physics of the games heat system. Shouldn't it because less effective at cooling off the hotter it gets?

That's there. Its in the advanced rules, where the other time-eating stuff is.

Severe overheating can break down the coolant itself, NM the fact that it can literally make heatsinks explode.

PS. The ranges aren't exactly what most think they are - re: extreme range and LOS rules. Btw, the machineguns aren't really machineguns like we think of ... the things are over 20mm in size, at the very smallest, and they're built almost purely for ROF in the fiction, not range. So, yes, the rounds they spit out do go past their rated range... but they don't concentrate like they need to do their battlefield rated damage vs mech scale armor past their rated range.

[Loganauer]

Could you share the numbers of it? I read a thread where someone suggested that for every 5% of heat, cooling dissipation would slow down by 3%, so at 100% heat it would be cooling off at 40% efficiency. This was mentioned as a method to discourage high alpha builds.

I also seem to remember that in Mechwarrior: Dark Age, which I played heavily as an adolescent, you could "vent" the 'mech to make it lose a click of heat. Is that anywhere in canon? Physical pilot actions to cool the mech down?


*edit*

If both of these are true and in canon, an excellent balance mechanism for the game would be for heat to dissipate slower (encouraging heat neutral builds) and powering down to "vent" would drastically improve dissipation despite the high heat by giving it circulation.

(related thread for dissipation)
http://mwomercs.com/...aid-of-no-heat/

As I understand it, thermodynamics would dictate that an object would dissipate heat to heat sinks slower as it heats up in an environment with little circulation, as the engine reaches thermal equilibrium with the heat sinks. That's what's going on in my mind with dissipation, the engine is getting hotter and dispersing the heat to heat sinks. "Venting" would give a lot of circulation to help dissipation.

In this thread
http://mwomercs.com/...ussion-on-heat/
Strum Wealh explains these are not similar to modern heat sinks and that external heat sinks pump heat -out- of the 'mech and internal heat sinks use a regenerative cooling mechanism. So I'm not certain if the same principle would apply.



Also while trying to find info on venting, I came across this

http://mwomercs.com/...ttletech-fluff/

"Flamers - A weapon that draws the heat straight from the fusion reactor and vents it! How it should work is obvious: The hotter your reactor is running, the more potent the damage that can be fueled through your flamer is. Since it's venting heat, it should cause either no heat, or actually lower it. .. except it doesn't. It spikes your heat to dump heat out of your 'mech into the atmosphere. What?

Any thoughts on that?

Edited by Loganauer, 31 August 2014 - 02:44 AM.

[kosmos1214]

on the flamer bit inside the reactor is a near perfect vacuum a vacuum will not transfer heat but as you are venting it through your mech there is heat exposure that is normally not dealt with in thoughts levels

and on the ac bit its not black powder the world moved away from black powder in the 1910-1930s ish for military use
though some big guns used it longer but that was replacement cost at work and on a side note you need to make a gun barrel different for modern chemical propellents if you used black powder in a modern gun you wold blow it up in your face same if you used modern propellent in a black powder gun

[CN9 ACE PILOT]

Steinar Bergstol, on 14 September 2013 - 11:54 AM, said:

I would advice against thinking _too_ hard about the physics of Battletech/Mechwarrior. Heads have been known to spontaneously explode. Very messy. Should be fun to see the questions and answers though.

Your post saved me.

All i can say, given only some battlemechs variants can load them/have them. Must be something built internally, in addition to just being able to slap on jump jets.

[Loganauer]

I got the flamer question answered in the thread it was found in

• Flamer - Siphons hot plasma from the shielded reactor core, and then pumps it through conduits and then out a nozzle.

"This should most certainly cause your Mech to get much hotter, as the plasma is being removed from the electromagnetically-shielded environment and then sent through non-shielded parts of your Mech. That would cause the chassis of your Mech to accumulate large quantities of heat,and the target Mech would only accumulate the amount of heat that their Mech physically absorbs (whereas most of your Flamer Weapon's output energy is going to be dispersed in the environment as a dissipating cloud).

There is no way for a Flamer to cool your Mech because you're taking heat from a shielded environment where it doesn't cause your chassis to get hot, and moving it through an unshielded environment (the conduits that are part of the weapon system) where it can cause your Mech to heat-up."

Edited by Loganauer, 31 August 2014 - 02:48 AM.

[zortesh]

Why are narc beacons so heavy/massive? 12 per a ton there some 80kg each.

Excessive amounts of glue?