Thread: M256 Smoothbore / Rheinmetall 120mm L/44

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

Our loading time was based on MJ? At first I couldn't figure out what you
meant by MJ, because MegaJoule didn't make sense with loading time, but
that appears to be what you're saying. If that's the case, then I
definitely am not remembering enough to give you a good rationale. We were
certainly aware of what a good manual loading time in a tank was, so I can
only conclude that rule was intended for some other application, and we
didn't think it through adequately when it got applied to loading tank
guns.

I like your use of the skill to reduce loading time, which takes me back
to one of the other things I wished we could have had time to do: bring
skills and tasks more fully into the game. Starship skills is what I
thought about a lot, but this tank example would be another. Rather than
the design sequence being abstracted from skills, it should have been
interwoven with it. So you could build a smaller, better, more efficient
widget, but only if you had a person of Engineer-2 or Gunner-2 running it,
or actually rolling a difficult task each time.

All I can say about the round-per-MJ is that it had to have been derived
from some datapoint somewhere, but then was not adequately scaled across
its entire range.

Sorry, I don't think I can answer the mail on this one, except by saying
that I like your house rule.

> 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
>

Oh dear, Dave won't be happy. You've highlighted some of the major issues in FF&S CPR gun design!!

Yes, the reload time always was screwed. Dunno what the reason was for using MJ for so many things in FF&S, but it gave results that aren't even in the ballpark of reality. Most of us houserule it. Or, if you mainly use ETC autocannon like me it isn't an issue because autocannon use a different design sequence.

We could go through the other major issues as we did on a thread a few years back. Such as the penetration of the advanced rounds (APFSDSCI, etc) getting crazy good at high TLs (houserule that too, thanks Rupert Boelyn wherever you are now). The fact that the tracked suspension always makes AFVs too heavy. The fact that receivers and bipods for firearms are wildly overweight (MJ problem again). The way streamlining a grav craft doesn't give you sloped armour (seems to assume you still have a box) so you have to pay volume twice if you want a streamlined, sloped armour grav vehicle. The fact that the turret volume rules for vehicles seem to be more concerned with the amount of space required outside the vehicle to turn the turret without hitting anything than the actual volume of the turret. The missing scale efficiencies for powerplants. And so on.

Despite all that - I still think it is one of the best single RPG books I've ever seen. The scale of the challenge it takes up, and the closeness within which it comes of pulling it all off is breathtaking.

--- 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
>

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
>

Definitely possible. I'll double check when I get home today.

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
>
>

I saw in my notes from 97'ish when I did the first design that it was
wacked (I put an "?!") next to the time but don't ever recall discussing it
on TML or TNE-RCES, etc. I remember the penetration "issue" but don't
really have a problem with it. Exotic rounds get expensive fast, which is
the real limiting factor - it's not an issue so much for players or small
groups as much as it is for, say a government that needs to procure and set
up a logistics train to support hundreds, if not thousands of them. It's
the reason that while an M1A2 and Leo II A5/6 are a better individual tank,
the number of M1A1 brigades in the US Army (maybe with a USMC Tk Bn or two
;) would roll over their more advanced brethren, though admittedly most
likely with some lopsided casualties for those at the tip of the spear. ;)
Logistics and industrial base would just move beyond CPR rounds even
though it would be well within their technical capability. This partially
"answers" the issue for some of the canon proclivities towards certain
techs IMO (Zhos and their heavy lasers... well they're probably still an
oddball but we've seen all sorts of strange in the history of military
procurement here on Earth, many of which defy battlefield logic and have to
due to the politicians either being naive or corrupt and/or just having a
non-military interest to their military-industrial decision (if not a
mixture).

Speaking of sloped... Reminds me of an issue I'm seeing with the Abrams
design. Not so much the abrams but I loved that it captured the basic
concept of adding additional armor as well as the slope. Slope should be
more detailed or at least have one more category if not be relatively open
for AFV designers to choose their own angle and plug it into the
appropriate calculation. I am taking the Abrams to be the more aggressive
slope and not "moderate?" Where would that put the Merkava? I would think
WWII tanks would be largely unsloped and something like the M60 or
Chieftain would have the moderate. Maybe Merkava should be 'radical' and
Abrams/Challenger, are "moderate?"

I think the flow be better if it designed the turret as a separate sub
vehicle than with the standard assumption. I'll have more on this line
when I present the Abrams. I'll probably do the Rheinmetal L/55 next when
I'm done doing all the rounds for the M68/L7

On Thu, Jul 12, 2012 at 2:01 AM, Jake <> wrote:

>
>
> Oh dear, Dave won't be happy. You've highlighted some of the major issues
> in FF&S CPR gun design!!
>
> Yes, the reload time always was screwed. Dunno what the reason was for
> using MJ for so many things in FF&S, but it gave results that aren't even
> in the ballpark of reality. Most of us houserule it. Or, if you mainly use
> ETC autocannon like me it isn't an issue because autocannon use a different
> design sequence.
>
> We could go through the other major issues as we did on a thread a few
> years back. Such as the penetration of the advanced rounds (APFSDSCI, etc)
> getting crazy good at high TLs (houserule that too, thanks Rupert Boelyn
> wherever you are now). The fact that the tracked suspension always makes
> AFVs too heavy. The fact that receivers and bipods for firearms are wildly
> overweight (MJ problem again). The way streamlining a grav craft doesn't
> give you sloped armour (seems to assume you still have a box) so you have
> to pay volume twice if you want a streamlined, sloped armour grav vehicle.
> The fact that the turret volume rules for vehicles seem to be more
> concerned with the amount of space required outside the vehicle to turn the
> turret without hitting anything than the actual volume of the turret. The
> missing scale efficiencies for powerplants. And so on.
>
> Despite all that - I still think it is one of the best single RPG books
> I've ever seen. The scale of the challenge it takes up, and the closeness
> within which it comes of pulling it all off is breathtaking.
>
> --- 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
> >
>
>
>

That MJ thing kept me thinking. All I can think of is that it was
benchmarked at a very low TL, or benchmarked in a different section of the
rules. Because clearly loading a round into a breach is based only on the
size and weight of the round, not how much energy it contains, otherwise
there would be NO advantage whatsoever in TL improvements. Carrying MJ
across too many locations results in double-bookkeeping type issues
because it is tech independent, and you have to bring tech in twice. All I
can say is that it is in there because it made a lot of other things work,
just not everything that it touched.

However, to the extent that what you say later is true, that overall it is
remarkably accurate and workable in doing what it tried to do, that's
realistically all that I can ask. If you were to take all of the
real-world concepts in that book and put all of their real-world design
sequences into the book, it would be hundreds of thousands of pages long
and still wouldn't work, because real-world JSF and FCS and LCS are still
broken.

> Oh dear, Dave won't be happy. You've highlighted some of the major issues
> in FF&S CPR gun design!!
>
> Yes, the reload time always was screwed. Dunno what the reason was for
> using MJ for so many things in FF&S, but it gave results that aren't even
> in the ballpark of reality. Most of us houserule it. Or, if you mainly
> use ETC autocannon like me it isn't an issue because autocannon use a
> different design sequence.
>
> We could go through the other major issues as we did on a thread a few
> years back. Such as the penetration of the advanced rounds (APFSDSCI,
> etc) getting crazy good at high TLs (houserule that too, thanks Rupert
> Boelyn wherever you are now). The fact that the tracked suspension always
> makes AFVs too heavy. The fact that receivers and bipods for firearms are
> wildly overweight (MJ problem again). The way streamlining a grav craft
> doesn't give you sloped armour (seems to assume you still have a box) so
> you have to pay volume twice if you want a streamlined, sloped armour grav
> vehicle. The fact that the turret volume rules for vehicles seem to be
> more concerned with the amount of space required outside the vehicle to
> turn the turret without hitting anything than the actual volume of the
> turret. The missing scale efficiencies for powerplants. And so on.
>
> Despite all that - I still think it is one of the best single RPG books
> I've ever seen. The scale of the challenge it takes up, and the closeness
> within which it comes of pulling it all off is breathtaking.
>

On Thu, Jul 12, 2012 at 8:32 AM, <> wrote:

>
>
> That MJ thing kept me thinking. All I can think of is that it was
> benchmarked at a very low TL, or benchmarked in a different section of the
> rules. Because clearly loading a round into a breach is based only on the
> size and weight of the round, not how much energy it contains, otherwise
> there would be NO advantage whatsoever in TL improvements. Carrying MJ
> across too many locations results in double-bookkeeping type issues
> because it is tech independent, and you have to bring tech in twice. All I
> can say is that it is in there because it made a lot of other things work,
> just not everything that it touched.
>
I think MJ actually DOES correlate to the size of the bore and thus the
size of the round so it's not preposterous. Just use seconds instead of 5
second combat rounds as the baseline. Works great with the autoloaders.
The problem, as it were, is FFS treating autoloaders as the same speed
(when they've always been slower for big bore direct fire weapons).
Integrating skill/task in retrospect seems obvious but that's hindsight
for you.

>
> However, to the extent that what you say later is true, that overall it is
> remarkably accurate and workable in doing what it tried to do, that's
> realistically all that I can ask. If you were to take all of the
> real-world concepts in that book and put all of their real-world design
> sequences into the book, it would be hundreds of thousands of pages long
> and still wouldn't work, because real-world JSF and FCS and LCS are still
> broken.
>
>

They're working through the "prototype" bugs. :D I think the JSF problem
is interesting because it's a problem of too much mission and too many
chiefs and not enough indians. Perspective is a bit lacking, too. The
teen series had a bunch of issues, too, that they had to work through
before they earned their reputations. I think JSF is a great replacement
for the F-16. It can carry as much internally as a Viper can with external
stores and if the JSF goes to external stores it approaches Strike Eagle
packages. I just think asking it to also fill the shoes of the AV8, A10,
F117, F-15, F-18, etc is pushing it.

>
> > Oh dear, Dave won't be happy. You've highlighted some of the major issues
> > in FF&S CPR gun design!!
> >
> > Yes, the reload time always was screwed. Dunno what the reason was for
> > using MJ for so many things in FF&S, but it gave results that aren't even
> > in the ballpark of reality. Most of us houserule it. Or, if you mainly
> > use ETC autocannon like me it isn't an issue because autocannon use a
> > different design sequence.
> >
> > We could go through the other major issues as we did on a thread a few
> > years back. Such as the penetration of the advanced rounds (APFSDSCI,
> > etc) getting crazy good at high TLs (houserule that too, thanks Rupert
> > Boelyn wherever you are now). The fact that the tracked suspension always
> > makes AFVs too heavy. The fact that receivers and bipods for firearms are
> > wildly overweight (MJ problem again). The way streamlining a grav craft
> > doesn't give you sloped armour (seems to assume you still have a box) so
> > you have to pay volume twice if you want a streamlined, sloped armour
> grav
> > vehicle. The fact that the turret volume rules for vehicles seem to be
> > more concerned with the amount of space required outside the vehicle to
> > turn the turret without hitting anything than the actual volume of the
> > turret. The missing scale efficiencies for powerplants. And so on.
> >
> > Despite all that - I still think it is one of the best single RPG books
> > I've ever seen. The scale of the challenge it takes up, and the closeness
> > within which it comes of pulling it all off is breathtaking.
> >
>
>
>

See, and people say that only GDW makes mistakes.

But here is a larger issue. Anything like FF&S that attempts to do what it
does is going to be inevitably so complex that it will result in a large
number of honest errors just like the one you found. There is no getting
around it. And the reason it does that is because it is so complex, and
the reason it is so complex is that is what the players say they want. As
you've seen in the past day, there have been suggestions that we should
have added details on the wheels in the tracked suspension, or more detail
to allow the different type rounds to mass different amounts. Okay, but
remember that each and every one of those additional layers of detail is
another place where players will inevitably make honest mistakes.

>From a design standpoint, I will tell you that GDW was stupid to put out a
system like FF&S because it is inescapably prone to error due to its
complexity. Design 101, you don't put out a system that people will
inevitably make significant errors in. Bad design. But that is what our
players said and still say they want. In fact, they keep saying they want
it to be made more detailed. So we made the effort to give the players
what they say they want. So we're both in this together. Good designers
would never have given you FF&S, it's just a Bad Idea. But if you really
want it, here it is, limited by all of iron laws of Mass of Complex
Concepts divided by Design Time Available.

So when you get down to it, we're right back to, "only GDW makes
mistakes," by agreeing to put the thing out.

> 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.
>>

The thing that jumps out at me again here is the turret issue, which came
up a couple of weeks ago. I had thought we had solved that, but that could
be another case of where I remember all of the course of action
consideration and mental energy better than I do the discharge of energy
when you actually put it to paper.

> I saw in my notes from 97'ish when I did the first design that it was
> wacked (I put an "?!") next to the time but don't ever recall discussing
> it
> on TML or TNE-RCES, etc. I remember the penetration "issue" but don't
> really have a problem with it. Exotic rounds get expensive fast, which is
> the real limiting factor - it's not an issue so much for players or small
> groups as much as it is for, say a government that needs to procure and
> set
> up a logistics train to support hundreds, if not thousands of them. It's
> the reason that while an M1A2 and Leo II A5/6 are a better individual
> tank,
> the number of M1A1 brigades in the US Army (maybe with a USMC Tk Bn or two
> ;) would roll over their more advanced brethren, though admittedly most
> likely with some lopsided casualties for those at the tip of the spear.
> ;)
> Logistics and industrial base would just move beyond CPR rounds even
> though it would be well within their technical capability. This partially
> "answers" the issue for some of the canon proclivities towards certain
> techs IMO (Zhos and their heavy lasers... well they're probably still an
> oddball but we've seen all sorts of strange in the history of military
> procurement here on Earth, many of which defy battlefield logic and have
> to
> due to the politicians either being naive or corrupt and/or just having a
> non-military interest to their military-industrial decision (if not a
> mixture).
>
> Speaking of sloped... Reminds me of an issue I'm seeing with the Abrams
> design. Not so much the abrams but I loved that it captured the basic
> concept of adding additional armor as well as the slope. Slope should be
> more detailed or at least have one more category if not be relatively open
> for AFV designers to choose their own angle and plug it into the
> appropriate calculation. I am taking the Abrams to be the more aggressive
> slope and not "moderate?" Where would that put the Merkava? I would
> think
> WWII tanks would be largely unsloped and something like the M60 or
> Chieftain would have the moderate. Maybe Merkava should be 'radical' and
> Abrams/Challenger, are "moderate?"
>
> I think the flow be better if it designed the turret as a separate sub
> vehicle than with the standard assumption. I'll have more on this line
> when I present the Abrams. I'll probably do the Rheinmetal L/55 next when
> I'm done doing all the rounds for the M68/L7
>

> On Thu, Jul 12, 2012 at 8:32 AM, <> wrote:
>
> I think MJ actually DOES correlate to the size of the bore and thus the
> size of the round so it's not preposterous. Just use seconds instead of 5
> second combat rounds as the baseline. Works great with the autoloaders.
> The problem, as it were, is FFS treating autoloaders as the same speed
> (when they've always been slower for big bore direct fire weapons).
> Integrating skill/task in retrospect seems obvious but that's hindsight
> for you.

MJ is definitely proportional to size of the weapon (energy it must
contain) and recoil system (energy it must dissipate), so it's good there.
But when you convert MJ into its storage medium (the round) which has
other inputs, you need to be careful about retaining MJ instead of its
storage medium. It looks like that one bit us.

> They're working through the "prototype" bugs. :D I think the JSF problem
> is interesting because it's a problem of too much mission and too many
> chiefs and not enough indians.

You caught me. I really changed the subject on that. Here's the real
problem: PPT slides. "Economies of scale," and "if we build just one
system that does everything for everyone, it will be much cheaper in the
long run," look really good on a PPT slide, and everyone falls for it. The
problem is that PPT does not have a built-in laws of physics checker to
throw those phrases out, or mark them with a little squiggly colored line
underneath. "One size fits all" never does. And it's never cheaper, it is
always more expensive, exponentially so, so that the economies of scale by
getting multiple people using it will never make up for the increase. When
you bring more players to your "one size fits all" table, they ALWAYS
bring more cost increases in requirements that must be integrated than
they bring cost savings in terms of the number they will buy to increase
the production run and lower costs.

US DoD procurement is comprehensively destroyed, broken, fraudulent,
criminal, stupid, asleep-the-wheel, the-lights-are-on-but-no-one-is-home.

But I won't let myself go any further on that one.

Dave

On MJ conversion to storage - interesting hmmm
On DOD procurement sad but true, not likely to get fixed this side national annihilation ... then it'll just move somewhere else
Tim

>________________________________
Sent: Thursday, July 12, 2012 10:08 AM
Subject: Re: [Traveller_TNE] Re: M256 Smoothbore / Rheinmetall 120mm L/44
>
>
>
> 
>
>> On Thu, Jul 12, 2012 at 8:32 AM, <> wrote:
>>
>> I think MJ actually DOES correlate to the size of the bore and thus the
>> size of the round so it's not preposterous. Just use seconds instead of 5
>> second combat rounds as the baseline. Works great with the autoloaders.
>> The problem, as it were, is FFS treating autoloaders as the same speed
>> (when they've always been slower for big bore direct fire weapons).
>> Integrating skill/task in retrospect seems obvious but that's hindsight
>> for you.
>
>MJ is definitely proportional to size of the weapon (energy it must
>contain) and recoil system (energy it must dissipate), so it's good there.
>But when you convert MJ into its storage medium (the round) which has
>other inputs, you need to be careful about retaining MJ instead of its
>storage medium. It looks like that one bit us.
>
>> They're working through the "prototype" bugs. :D I think the JSF problem
>> is interesting because it's a problem of too much mission and too many
>> chiefs and not enough indians.
>
>You caught me. I really changed the subject on that. Here's the real
>problem: PPT slides. "Economies of scale," and "if we build just one
>system that does everything for everyone, it will be much cheaper in the
>long run," look really good on a PPT slide, and everyone falls for it. The
>problem is that PPT does not have a built-in laws of physics checker to
>throw those phrases out, or mark them with a little squiggly colored line
>underneath. "One size fits all" never does. And it's never cheaper, it is
>always more expensive, exponentially so, so that the economies of scale by
>getting multiple people using it will never make up for the increase. When
>you bring more players to your "one size fits all" table, they ALWAYS
>bring more cost increases in requirements that must be integrated than
>they bring cost savings in terms of the number they will buy to increase
>the production run and lower costs.
>
>US DoD procurement is comprehensively destroyed, broken, fraudulent,
>criminal, stupid, asleep-the-wheel, the-lights-are-on-but-no-one-is-home.
>
>But I won't let myself go any further on that one.
>
>Dave
>
>
>
>
>

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
> >
>
>
>

Yeah, I know that the correction made your original complaint even worse,
sort of.

And I'm fresh out of anything remotely useful to say about "here's how we
would have fixed that," or "here's why it is that way," or whatever.

> 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
>> >
>>
>>
>>
>

I actually think it's very possible to put a few House Rules in to "fix
it." Enough for my own personal satisfaction, anyway.

As a generic round it's fine, but getting complex never scared me away.
I'm translating most of my stuff into new php back end web site, but check
out what I did for Jump rules. This is obviously intended to be linked
into the technobabble. Getting that digitized is proving a head scratcher
since I'm most inclined to do some simplistic ASCII art rather than
scanning. I might whip out GIMP or MSpaint, etc...

http://masteruxi.net/traveller/phpTNE/ is the WIP test dir. Everyone
please feel free to preview/critique. I have thick skin, though I'll
caution about a bunch of broken links. Most of the design links haven't
been translated yet since I'm still pondering the best way to bring in the
vanilla txt files I was using in the early HTML days (before I converted to
a stylesheet around '07).

I have everything from the COTI thread on the Turin Consolidation there
with the most current edits.

On Thu, Jul 12, 2012 at 10:30 PM, <> wrote:

> **
>
>
> Yeah, I know that the correction made your original complaint even worse,
> sort of.
>
> And I'm fresh out of anything remotely useful to say about "here's how we
> would have fixed that," or "here's why it is that way," or whatever.
>
>
> > 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
> >> >
> >>
> >>
> >>
> >
>
>
>