52 replies to this topic

[ManDaisy]

thats a rocket launcher in your last pics right? Missiles fire would be like from an apache helicoptor or fighter jet.

Edited by ManDaisy, 09 February 2012 - 11:05 AM.

[Nick Makiaveli]

Kartr, on 09 February 2012 - 08:50 AM, said:

@Makiaveli: The manufactures make the same caliber weapon that can use the same exact ammunition. That's why when you're on the battlefield you can salvage weapons and ammunition and expect them to work when you load them on your 'Mech. Standardization is extremely important on the modern battlefield as it eases the logistics situation. This would be even more true in wars that jump from planet to planet. Also the Master Rules Revised states that AC's are cannons ranging from 30mm to 120mm that fire multiple rounds in succession (not the exact wording as I don't have it sitting in front of me).

Besides even if it was multiple AC/2's that fire 10 times as many rounds, or 5 AC/2s firing in concert you would still have much more recoil than a single AC/2 firing its normal burst. In the first situation the recoil adds up leaving your weapon tracking further and further off target, just like when a Machine Gun is fired the succession of recoils forces the barrel upwards. In the second scenario you'd have significantly more recoil as 5 AC/2s fired off simultaneously.

If the shared ammo concept was a critical concern, I'm sure AKs would use the same ammo as M-16s. That said, The TT didn't exactly go into great detail on such things as salvaging ammo. Was pretty abstract as I remember.

Now if all AC/20s are exactly identical, ie every manufacturer is using the same schematics, then yea my point is pretty much fubar. However I was always under the impression that they differed from manufacturer to manufacturer and the game just glossed over how you could salvage one from a a Hunchback say and stick it on a Atlas and not worry about compatible fittings etc.

And multiple smaller weapons might not add up to the same recoil as one large one. Remember we are abstracting the damage here. And since multiple AC/2 caliber weapons would have the same range as a AC/20, would imply a much lower propellant charge than a typical AC/2.

When it's all said and done, all we've really shown is that unless all the weapons in a class are identical, it's really pointless to speculate how they would work. If all AC/2s are 30mm and all AC/20s are 120mm then sure we can make up some recoil numbers. If however Capellan ACs tend to be different from Kuritan ones, then caliber, RoF, recoil systems etc could all be different.

[Strum Wealh]

ManDaisy, on 09 February 2012 - 11:05 AM, said:

thats a rocket launcher in your last pics right? Missiles fire would be like from an apache helicoptor or fighter jet.

The second-to-last picture is a Carl Gustav recoilless rifle being fired by US Special Forces.
The last picture is an AT4 anti-tank weapon being fired by a US Marine.

LRMs carry 120 missiles per ton (1000 kg), which works out to about 8.33 kg per missile.
SRMs carry 100 missiles per ton, which works out to about 10 kg per missile.

So, I feel that comparisons to clusters of similarly-sized (and typically man-portable) missiles and rockets (like the Carl Gustav and the AT4 and the Stinger missile, for instance) are more appropriate than comparisons to much larger and heavier weapons (Sidewinder and Hellfire missiles, for instance.)

Your thoughts?

[ManDaisy]

I think were getting into the area of SRM vs LRM missile types now. Larger missiles ca store more fuel - travel farther, reach a higher speed. This which changes the launching mechanism. I know that some infantry units in battle tech carry SRM-2s so thats what I'm basing it on.

Edited by ManDaisy, 09 February 2012 - 11:35 AM.

[Rajun]

As stated earlier, the mass of the Mech will also make a difference. The stability of a smaller person firing , say a shotgun, is much less than a large soldier firing the same gun.
Receiving end would naturally be the same. Lighter mech taking a AC20 hit would not absorb as well as a heavy mech getting hit. Shooting a AC20 and getting hit at the same time with one could make some interesting knockdowns

[Strum Wealh]

ManDaisy, on 09 February 2012 - 11:28 AM, said:

I think were getting into the area of SRM vs LRM missile types now. Larger missiles ca store more fuel - travel farther, reach a higher speed. This which changes the launching mechanism. I know that some infantry units in battle tech carry SRM-2's so thats what I'm basing it on.

Which doesn't negate my point:

BT/MW LRM and SRM missile launchers, given the sizes of the missiles being fired, are generally akin to clusters of MANPADS-scale weapons built into boxy frames, and that said frames and the individual missile tubes would include (in addition to provisions for the ammo feed system, fire control system, and so on) a recoil-negating duct/vent system that is likely very similar to what is seen on modern MANPADS launchers and recoilless rifles.

Do you disagree?

[Ranger207]

In the tabletop game, if a 'Mech fires a heavy gauss and moves in the same turn, you have to make a piloting skill roll to avoid falling over. The modifiers get better as the 'Mech gets bigger, so an assault actually has a negative modifier. What's important, though, is not the rule for recoil, but the LACK of a recoil rule for anything else, implying that the fire control system / targeting computer already accounts for recoil.

[Nick Makiaveli]

ManDaisy, on 09 February 2012 - 11:28 AM, said:

I think were getting into the area of SRM vs LRM missile types now. Larger missiles ca store more fuel - travel farther, reach a higher speed. This which changes the launching mechanism. I know that some infantry units in battle tech carry SRM-2s so thats what I'm basing it on.

However LRMS only do 1 point of damage per missile, vs SRMs which do 2 each. (Again, unless my brain is misfiring).

So LRMs have longer range at the expense of damage. So that means they aren't automatically larger.

In other words, smaller warhead, larger engine.

[ManDaisy]

I dunno about that, mainly because most battletech artwork doesn't show missile launchers to have an exhaust exit hole in the back of the launcher with the exception of some "one shot" carrying designs. To be exact I would agree with you for SRM launchers, but disagree with you for LRM launchers. LRM launchers which would ignite outside the launcher so both would have little recoil anyway.

Edited by ManDaisy, 09 February 2012 - 12:03 PM.

[Mason Grimm]

The pictures are pretty?

[ManDaisy]

ANYWAYS the point is Missiles shouldn't have significant recoil. Recoil the topic is recoil not missiles if you may.

Edited by ManDaisy, 09 February 2012 - 12:36 PM.

[Kenyon Burguess]

theres a couple tons between the sizes of the autocannons that could be said to help nullify the recoil. also, looking at the new centurion it looks like it was designed to counter the effects with a compensator at the back elbow and a muzzle brake on the front end.

[Nik Van Rhijn]

As I said earlier, if there is significant recoil you couldn't mount large ballistics in arms or they would tear off. Or are you suggesting the arm goes flying up in the air like a small person firing a Desert Eagle? Maybe they should have special shoulder joints to allow it to spin round a few times?

[Azalie]

HIgher recoil for higher ballistics should also take into account lower recoil for a heavier mech. An AC/20 being fired by a hunchback should throw his shoulder back further than that same AC/20 being fired by an atlas. Also location on the mech should have an impact. This is getting complicated. An atlas with an AC/20 near it's hip (as in the video for "MechWarrior Reboot" which I'm sure most of us have seen 20 times and drooled over) would cause less recoil than it if were on his arm or shoulder as it's closer to the center of gravity.

More specifically the force it generates is the same but the effect that force has on the rest of the mech would be reduced by placement.

[Mason Grimm]

In all seriousness; I was watching a "Top 10s" show on the military channel and they were talking about a new SMG that is almost without recoil. It uses a new concept of having the bolt push a receiver down in the handle to significantly reduce the recoil of the weapon which in turn helps prevent the weapon for climbing off the target.

Surely by the year 3000 mankind has worked to perfect this type of approach whether it be using a similar method or by venting gases out using other mechanics or a combination of both.

[Kartr]

Nick Makiaveli, on 09 February 2012 - 11:13 AM, said:

If the shared ammo concept was a critical concern, I'm sure AKs would use the same ammo as M-16s. That said, The TT didn't exactly go into great detail on such things as salvaging ammo. Was pretty abstract as I remember.

Now if all AC/20s are exactly identical, ie every manufacturer is using the same schematics, then yea my point is pretty much fubar. However I was always under the impression that they differed from manufacturer to manufacturer and the game just glossed over how you could salvage one from a a Hunchback say and stick it on a Atlas and not worry about compatible fittings etc.

And multiple smaller weapons might not add up to the same recoil as one large one. Remember we are abstracting the damage here. And since multiple AC/2 caliber weapons would have the same range as a AC/20, would imply a much lower propellant charge than a typical AC/2.

When it's all said and done, all we've really shown is that unless all the weapons in a class are identical, it's really pointless to speculate how they would work. If all AC/2s are 30mm and all AC/20s are 120mm then sure we can make up some recoil numbers. If however Capellan ACs tend to be different from Kuritan ones, then caliber, RoF, recoil systems etc could all be different.

Well I wouldn't say they all use the exact same designs. My opinion based on what I've read is that all AC/20's ustilize the same round. As for the M-16/AK-47 analogy, you have two nations that were on opposite sides of the Cold War. Thanks to the Star League the Inner Sphere is more like a post NATO environment. The SLDF set the gold standard for all weapons and equipment and would have standardized the types of rounds they used. The Inner Sphere houses would most likely have copied that standard so when they got SLDF hand-me-downs they wouldn't have ammunition compatibility issues. Kind of like how the USA, the UK, France, etc all use the standard NATO rounds: 5.56mm, 7.62x51mm, the 105mm tank cannons and 155mm arty.

My other reasoning for the fact that ammunition has to be standardized, is what happens when you're buying Hunchbacks from Coventry Metal Works and Rommel Tanks from Defiance Industries? Both carry AC/20's and the AC/20s are of different designs, but you want both to utilize the same round so you don't have to buy/carry two completely different types of ammunition.

I agree with you in that we can't make definitive recoil numbers for AC's because we don't know all the different design specs. Plus we don't know how the recoil management works so it doesn't tear 'Mech limbs off when you fire them. However we can ballpark it if we know that AC/20s are 120mm cannons and can figure out a ballpark for what the recoil forces would be for a burst of any number of rounds.

[Halfinax]

Nik Van Rhijn, on 09 February 2012 - 12:56 PM, said:

As I said earlier, if there is significant recoil you couldn't mount large ballistics in arms or they would tear off. Or are you suggesting the arm goes flying up in the air like a small person firing a Desert Eagle? Maybe they should have special shoulder joints to allow it to spin round a few times?

This isn't how physics works. A ballistic round doesn't require that much energy to move. The arm of any 'Mech has significantly more mass than any weapon fired from them. A 10 lb projectile wouldn't send a 1 ton arm spinning like a windmill under any circumstance. Firing a 50 cal weapon doesn't make your arm spin off of your body after all. Having a weapon system mounted to a platform that requires more energy than it's mount can handle would be absolutely absurd from an engineering stand point, and would never happen.

The weight of the projectile doesn't throw the shooter off their feet, and shouldn't throw the target off of their's either.

[trycksh0t]

Kartr, on 10 February 2012 - 10:38 PM, said:

Well I wouldn't say they all use the exact same designs. My opinion based on what I've read is that all AC/20's ustilize the same round. As for the M-16/AK-47 analogy, you have two nations that were on opposite sides of the Cold War. Thanks to the Star League the Inner Sphere is more like a post NATO environment. The SLDF set the gold standard for all weapons and equipment and would have standardized the types of rounds they used. The Inner Sphere houses would most likely have copied that standard so when they got SLDF hand-me-downs they wouldn't have ammunition compatibility issues. Kind of like how the USA, the UK, France, etc all use the standard NATO rounds: 5.56mm, 7.62x51mm, the 105mm tank cannons and 155mm arty.

My other reasoning for the fact that ammunition has to be standardized, is what happens when you're buying Hunchbacks from Coventry Metal Works and Rommel Tanks from Defiance Industries? Both carry AC/20's and the AC/20s are of different designs, but you want both to utilize the same round so you don't have to buy/carry two completely different types of ammunition.

I agree with you in that we can't make definitive recoil numbers for AC's because we don't know all the different design specs. Plus we don't know how the recoil management works so it doesn't tear 'Mech limbs off when you fire them. However we can ballpark it if we know that AC/20s are 120mm cannons and can figure out a ballpark for what the recoil forces would be for a burst of any number of rounds.

Unfortunately, there is quite a bit of canon and 'Fluff' available that supports AC's being of several different calibers, specifically ranging from 30mm to 203mm, and are grouped by damage, not calibre. http://www.sarna.net/wiki/Autocannon

Also - http://www.sarna.net...i/Autocannon/20 .

There are 3 seperate AC/20's listed on these pages, each a different calibre (150mm, 185mm, 203mm).

Now, with that out of the way, I'm not sure how recoil would really play a role in combat. We'll keep with AC/20's for this, specifically the Crusher Super Heavy150mm sited from Sarna. The Crusher is a 150mm weapon that weighs 14 tons (as do all AC/20s). By comparison, the heaviest weapon I could find in a similar calibre is the U.S. M198 155mm Howitzer, weighing 15,772 lbs (7.886 tons). Since the AC's in the BT universe seem universally designed to put all shells on target, my assumption is all that the majority of that extra weight is used to reduce recoil. Also, modern 150mm shells weigh about 50kg, and I doubt that 150mm shells in the BT universe weigh much more than that. A 50kg shell, even a burst of 50kg shells, would have little noticeable effect on a multi-ton 'Mech designed to implement said weapon system.


Edit - Quick math. 150mm shells in BT would have to weigh considerably less than 50kg if the Crusher actually does fire in 10 round bursts as stated. Specifically, if it does in-fact fire in 10 round bursts, in order to 1 ton of ammunition to equal 5 shots, or 50 individual shells, they'd weigh 40 lbs a piece, which is just insane.

Edit 2 - On second thought, I'm just going to stop attempting to define BT in any sort of real-world terms, it just doesn't work at all.

Edited by trycksh0t, 10 February 2012 - 11:38 PM.

[Chuckie]

I wish everyone would quit trying to compare armaments and 21st century tech to 31st century tech..

Technology will be GREATLY improved, everything from materials to power plants and I would assume armaments and hydraulics, etc..

I would assume nanotechnology will be old school at this time, carbon fiber, and all sorts of tech we havent even gotten to yet would have been invented years ago..

Remember they can travel through space faster than the speed of light.. and the Mechs are run on FUSION power plants..

If thats not enough to convince you lets compare a M1A2 to a Summoner

M1A2 - Wgt 61 Tons - Speed 72 KPH, (97 without governor) - Armament 120mm gun (AC 1 at best since rate of fire is VERY low compared to BT Tech)

Summoner - Wgt 70 Tons - Speed 86 KPH - Armament AC10, PPC and a LRM 15 oh and it has Jump Jets so it can fly..

The M1A2 is the most high tech tank to date. Has the lightest equipment and some of the best armament of any tank out there.

So.... really..? trying to compare the two is really quite futile.

Edited by Chuckie, 11 February 2012 - 10:54 AM.

[UncleKulikov]

Either cycle time or recoil depending on the rate of fire. If it's single shot then recoil wouldn't matter nearly as much for a full auto AC20.