Damn you're right, of course. Stopped with the warhead on this go around.
Have corrected it now. I went with BB propellant for my APFSDSDU-8 so
it's indeed 39.24kg and 992.4 Cr apiece. Unfortunately this is almost
double the mass of the Real Life Silver Bullet used by the Abrams. BB
propellant increases short range to 593m for KE and 444 for HE.
Real Life M829 DU Sabot variants ranged from 18.6 to 22.3kg. Ironically
enough both first and A3 model are reputed to have 8.1 kg of propellant
though the M829A3 has much better performance (supposed it would count as
"BB" propellant in FF&S), though the DU penetrator gained length and
apparently density as well as shedding weight in the sabot petals and more
advanced fin designs. One thing that looks very interesting is if I use
the 2.2 multiplier for KEAP and divide that from the mass of the APFSDU
"warhead", it's damned close to the mass of the original M829. Think that
might be my house rule on the issue but want to play with the numbers some,
too
I think a better system would be to let the designer decide on the mass of
the KE penetrator and use a different formula to determine the propellant.
Damage and Penetration should then be determined from the "baseline"
determined in the weapon design. This would follow a more realistic
evolution of ammunition to meet mission requirement and most likely enemy
profiles rather than just tech level progression.
In Real Life, the M829A2 was reputed to be specifically designed to
counter Kontakt-5
ERA, for example.
My biggest beef is that ask any one of my loaders over the years: they
would have much rather been slinging sabot rounds in Tank Gunnery than HEAT
or MPAT rounds. Not that I ever had to shoot at any target more than twice
to hit it. ;) Still, the system gives them all the same dimensions when
HEAT are the heaviest, MPAT the longest (and have a nasty habit of getting
the air/ground switch snagged on one of the lines by the ammo door)...
On Thu, Jul 12, 2012 at 2:07 AM, Jake <> wrote:
> **
>
>
> Forgot to say, your design is correct except for the ammo where you appear
> to have forgotten to calculate for the propellant. APFSDSDU/HEAP mass
> correctly calculated is 39.24kg
>
>
> --- In , Master Uxi <master.uxi@...> wrote:
> >
> > Redesigned this as part of the CPR sequence for doing the M1 Abrams
> series
> > of MBT
> >
> > Some thoughts that have occurred to me over the years (and this time in
> > particular):
> >
> > Ammo is pretty far off and should probably be more detailed. Rather
> simple
> > assumption, regardless of type. The table should adjust for materials and
> > intent, as well as just TL. For example, 120mm ammunition if I'm reading
> > right is 30kg regardless if it's APFSDS, AFSDSDU, HEAT (HEAP, etc). Real
> > Life ... or even Wikipedia. much less my FM-17-12 (aka 3-20) tells us
> the
> > M829 sabot variants ranged from 18.6 to 22.3kg depending on the
> propellant
> > and density of the DU penetrator as well as details like metal vs carbon
> > fiber sabots, etc.
> >
> > Loading times and crew requirements don't seem to fit my experience or
> > understanding of our own MBT. I don't consider the Abrams to have
> > mechanical assist, for example, and default timing is one 5-second combat
> > round per MJ. In the standard crewman skills test, the deadline is 7
> > seconds for the 120mm and my manual says 5 seconds for the 105mm. In the
> > Fleet, a loader is gonna kicked if he can't do it in 4-5 seconds which is
> > about the minimum for the hydraulic door to open enough to grab the
> round.
> > The crew requirements might work for indirect fire as it is, though and
> > would also either be a human loader or an autoloader. Almost ironic that
> > NATO used human loaders and Warsaw Pact nations used mechanical
> > autoloaders given their doctrines on man vs machine.
> >
> > The time/power discrepancy actually seems to be somewhat proportional to
> > the MJ difference, which has a natural correlation to the size and thus
> > weight of the round at the MJ calculated (8.85MJ for the M256 vs 6.90MJ
> for
> > the M68/L7 105mm). Realistically, the proper time to load should be a
> > function of the size of the round and the strength of the loader and
> > experience and familiarity with the task. In a skill system like TNE,
> > basic Task Failure would be accomplished in the speed of the MJ while
> basic
> > success would just beat it by exactly 2 seconds each. Outstanding success
> > would double that by shaving 4 seconds giving realistic times. Critical
> > failure would mean damaging the round, possible causing misfire or
> perhaps
> > striking the combustible case and releasing propellant in the turret! Ref
> > discretion. There, that nit is picked with my House Rule.
> >
> > The Abrams uses safety features that actually slow down the loading,
> though
> > increases crew safety. Lap-loading (holding a round in the lap while
> > waiting for command), etc could be much faster and while I hear it was
> SOP
> > in the old days with the M60 but that was before blow-off panels, etc.
> > Soviet autoloaders are SLOW (they max elevate to eject the round) but one
> > 5-second round per MJ still sounds excessive. 2 seconds per MJ rounded up
> > to the nearest whole combat round is more reasonable for autoloaders.
> Most
> > Soviet/former-Soviet designed tanks are going to take 2-3 rounds or so
> > which is between 150-200% the time a NATO meatbag loader not messing it
> up
> > is going to take . Not sure what the thought process was for this design
> > sequence. I imagine it's indirect fire but maybe Dave can elaborate.
> > anyhoo:
> >
> > *M256 Cannon / Rheinmetall 120mm L/44*
> > TL8
> > 528cm Long (120/44 caliber)
> > Laser Rangefinder (LRF)
> > Optical Rangefinder (GAS)
> > TL8 Digital Ballistic Computer
> > Direct Mount
> > No options
> > 8.85 MJ muzzle energy
> > Crew: 2
> > Range: KE 494m / HE 370m
> > Reloading: 9 rounds* [1-2 rounds per Skill/Task roll]
> > Volume: 2.0204 m3
> > Mass: 2.0204 tonnes
> > Price: 0.048 MCr
> >
> > *Ammunition*
>
> > APFSDSDU (M829)
> > TL8
> > 12cm
> > Damage: 26
> > Burst: nil
> > Penetration: Short: 145, Med: 135, Long:125, Extreme: 105
> > Price: 900 Cr
> >
> > HEAP (HEAT M830)
> > TL8
> > 12cm
> > Damage: 16
> > Burst: 29
> > Penetration: 113C
> > Price:450 Cr
> >
>
>
>
Have corrected it now. I went with BB propellant for my APFSDSDU-8 so
it's indeed 39.24kg and 992.4 Cr apiece. Unfortunately this is almost
double the mass of the Real Life Silver Bullet used by the Abrams. BB
propellant increases short range to 593m for KE and 444 for HE.
Real Life M829 DU Sabot variants ranged from 18.6 to 22.3kg. Ironically
enough both first and A3 model are reputed to have 8.1 kg of propellant
though the M829A3 has much better performance (supposed it would count as
"BB" propellant in FF&S), though the DU penetrator gained length and
apparently density as well as shedding weight in the sabot petals and more
advanced fin designs. One thing that looks very interesting is if I use
the 2.2 multiplier for KEAP and divide that from the mass of the APFSDU
"warhead", it's damned close to the mass of the original M829. Think that
might be my house rule on the issue but want to play with the numbers some,
too
I think a better system would be to let the designer decide on the mass of
the KE penetrator and use a different formula to determine the propellant.
Damage and Penetration should then be determined from the "baseline"
determined in the weapon design. This would follow a more realistic
evolution of ammunition to meet mission requirement and most likely enemy
profiles rather than just tech level progression.
In Real Life, the M829A2 was reputed to be specifically designed to
counter Kontakt-5
ERA, for example.
My biggest beef is that ask any one of my loaders over the years: they
would have much rather been slinging sabot rounds in Tank Gunnery than HEAT
or MPAT rounds. Not that I ever had to shoot at any target more than twice
to hit it. ;) Still, the system gives them all the same dimensions when
HEAT are the heaviest, MPAT the longest (and have a nasty habit of getting
the air/ground switch snagged on one of the lines by the ammo door)...
On Thu, Jul 12, 2012 at 2:07 AM, Jake <> wrote:
> **
>
>
> Forgot to say, your design is correct except for the ammo where you appear
> to have forgotten to calculate for the propellant. APFSDSDU/HEAP mass
> correctly calculated is 39.24kg
>
>
> --- In , Master Uxi <master.uxi@...> wrote:
> >
> > Redesigned this as part of the CPR sequence for doing the M1 Abrams
> series
> > of MBT
> >
> > Some thoughts that have occurred to me over the years (and this time in
> > particular):
> >
> > Ammo is pretty far off and should probably be more detailed. Rather
> simple
> > assumption, regardless of type. The table should adjust for materials and
> > intent, as well as just TL. For example, 120mm ammunition if I'm reading
> > right is 30kg regardless if it's APFSDS, AFSDSDU, HEAT (HEAP, etc). Real
> > Life ... or even Wikipedia. much less my FM-17-12 (aka 3-20) tells us
> the
> > M829 sabot variants ranged from 18.6 to 22.3kg depending on the
> propellant
> > and density of the DU penetrator as well as details like metal vs carbon
> > fiber sabots, etc.
> >
> > Loading times and crew requirements don't seem to fit my experience or
> > understanding of our own MBT. I don't consider the Abrams to have
> > mechanical assist, for example, and default timing is one 5-second combat
> > round per MJ. In the standard crewman skills test, the deadline is 7
> > seconds for the 120mm and my manual says 5 seconds for the 105mm. In the
> > Fleet, a loader is gonna kicked if he can't do it in 4-5 seconds which is
> > about the minimum for the hydraulic door to open enough to grab the
> round.
> > The crew requirements might work for indirect fire as it is, though and
> > would also either be a human loader or an autoloader. Almost ironic that
> > NATO used human loaders and Warsaw Pact nations used mechanical
> > autoloaders given their doctrines on man vs machine.
> >
> > The time/power discrepancy actually seems to be somewhat proportional to
> > the MJ difference, which has a natural correlation to the size and thus
> > weight of the round at the MJ calculated (8.85MJ for the M256 vs 6.90MJ
> for
> > the M68/L7 105mm). Realistically, the proper time to load should be a
> > function of the size of the round and the strength of the loader and
> > experience and familiarity with the task. In a skill system like TNE,
> > basic Task Failure would be accomplished in the speed of the MJ while
> basic
> > success would just beat it by exactly 2 seconds each. Outstanding success
> > would double that by shaving 4 seconds giving realistic times. Critical
> > failure would mean damaging the round, possible causing misfire or
> perhaps
> > striking the combustible case and releasing propellant in the turret! Ref
> > discretion. There, that nit is picked with my House Rule.
> >
> > The Abrams uses safety features that actually slow down the loading,
> though
> > increases crew safety. Lap-loading (holding a round in the lap while
> > waiting for command), etc could be much faster and while I hear it was
> SOP
> > in the old days with the M60 but that was before blow-off panels, etc.
> > Soviet autoloaders are SLOW (they max elevate to eject the round) but one
> > 5-second round per MJ still sounds excessive. 2 seconds per MJ rounded up
> > to the nearest whole combat round is more reasonable for autoloaders.
> Most
> > Soviet/former-Soviet designed tanks are going to take 2-3 rounds or so
> > which is between 150-200% the time a NATO meatbag loader not messing it
> up
> > is going to take . Not sure what the thought process was for this design
> > sequence. I imagine it's indirect fire but maybe Dave can elaborate.
> > anyhoo:
> >
> > *M256 Cannon / Rheinmetall 120mm L/44*
> > TL8
> > 528cm Long (120/44 caliber)
> > Laser Rangefinder (LRF)
> > Optical Rangefinder (GAS)
> > TL8 Digital Ballistic Computer
> > Direct Mount
> > No options
> > 8.85 MJ muzzle energy
> > Crew: 2
> > Range: KE 494m / HE 370m
> > Reloading: 9 rounds* [1-2 rounds per Skill/Task roll]
> > Volume: 2.0204 m3
> > Mass: 2.0204 tonnes
> > Price: 0.048 MCr
> >
> > *Ammunition*
>
> > APFSDSDU (M829)
> > TL8
> > 12cm
> > Damage: 26
> > Burst: nil
> > Penetration: Short: 145, Med: 135, Long:125, Extreme: 105
> > Price: 900 Cr
> >
> > HEAP (HEAT M830)
> > TL8
> > 12cm
> > Damage: 16
> > Burst: 29
> > Penetration: 113C
> > Price:450 Cr
> >
>
>
>