GDLS to build new light tank for army

[bojan]

8 hours ago, Damian said:

Its the same bustle the M1 have. M1 had 44 105mm rounds in total in the bustle. 22 in ready rack and 22 in semi-ready rack.

 

Sorry, but unless this atrocity is even larger than it looks, I just don't see a place for 44 rounds in this bustle (look at the width of blow-out pannel for a real size of the bustle w/o external boxes and racks):

Edited July 4, 2022 by bojan

[Rick]

18 minutes ago, bojan said:

No in either case. 120mm gun mortars don't have separate propellant charges. This translates in faster loading time (if human loader is used) or less complicated mechanical loader. Russian 120mm gun-mortar ammo*:

High capacity spin stabilized shell x 2, guided round, 2 x regular mortar shells.

120mm gun-mortars shells (especially high capacity ones) also have higher efficiency than 105mm howitzers, having more HE payload as their shell walls are thinner, due the lower pressures involved.

*All rifled 120mm gun-mortars and rifled mortars (Soviet/Russina, French and Euro) ammo is compatible.

Thank you, did not know this.

[Junior FO]

1 hour ago, sunday said:

120mm HE load is on par with 155mm conventional, and the mortar also has a vastly simplified recoil absorbing mechanism. We are talking here of a HE thrower on par with WWII-era ISU-152/Sturmpanzer IV, only with less penetration.

HE filler for 155 is ~6kg, the 120mm has about half that.

[Hellfish6]

I just wanna know why/how this beat out the BAE submission, which was smaller, lighter, more mature, had a 120mm prototype, had a hybrid-electric drive prototyped, and didn't require an M88 or a HET to move around. 

Edited July 5, 2022 by Hellfish6

[Damian]

5 hours ago, bojan said:

Sorry, but unless this atrocity is even larger than it looks, I just don't see a place for 44 rounds in this bustle (look at the width of blow-out pannel for a real size of the bustle w/o external boxes and racks):

Bustle is looking narrower because there are no, thick special armor modules protecting it from the sides. Internal volume wise, this turret is identical with M1 series.

[DKTanker]

5 hours ago, bojan said:

Sorry, but unless this atrocity is even larger than it looks, I just don't see a place for 44 rounds in this bustle (look at the width of blow-out pannel for a real size of the bustle w/o external boxes and racks):

The blow out panel is just about the same size as the two, or three, on the M1s.  Need to look at the two hatches, on the M1 the loaders hatch is just in board of the outer edge of the blowout panel, just as it is on this vehicle.  Also, the windsensor comes just about to the edge of the blowout panel when laid down, just as it does on the M1.  Caveat, the M1 turret side slopes outboard which is mirrored internally allowing more rounds lower in ammo rack (note the squareness of this turret).  However if the bulkhead dividing the two sides of the bustle rack is eliminated the number of rounds should be able to be increased.  Along those lines, a new type of ammo rack has been developed for the M1A1 which does away with the large sliding doors and the dividing bulkhead.  Ammunition, which is on an automated conveyor is accessed through a small hatch.  The M1A1 turret loadout with this system remains at the original 34 rounds.

[lucklucky]

12 hours ago, urbanoid said:

Not enough range? 

Can it get one hit one kill? the issue with those vehicles is they need to be resupplied often or even continuously.

[bojan]

9 minutes ago, lucklucky said:

Can it get one hit one kill?

On what?

Quote

 the issue with those vehicles is they need to be resupplied often or even continuously.

Every single vehicle has to.

[urbanoid]

To kill what in one hit? A modern MBT? Most likely not, same as 105 mm. Anything else it can reach and hit? Yeah, probably.

Any vehicle has to be resupplied, and the US military is very good at logistics.

[lucklucky]

Does that mortar have precision to hit and kill at first shot. If it does then it is better than the HV gun. if instead have to spend say 4 rounds it is not so good. The resupply needs will be 4x bigger.

 

  

40 minutes ago, bojan said:

On what?

Vehicle, anti tank team etc.

Edited July 5, 2022 by lucklucky

[sunday]

9 hours ago, Junior FO said:

HE filler for 155 is ~6kg, the 120mm has about half that.

I stand corrected. 120mm mortar rounds have between 1.3 and 4.2kg of filler, while there are 155mm artillery rounds (US M795) with up to 11kg of explosive filler.

That will teach me to write from memory.

[lucklucky]

But 120mm mortar rounds are usually considered as effective as a 155mm because the mortar round due to more vertical trajectory its explosion have more uniform effects.

Edited July 6, 2022 by lucklucky

[bojan]

3 hours ago, lucklucky said:

Does that mortar have precision to hit

Rifled gun-mortars do if supported by FCS.

Quote

and kill at first shot.  

Depends what.

Quote

If it does then it is better than the HV gun.

It does better than HV gun because it has high capacity HE, can hit things (via indirect fire) that HV guns can not, can carry more ammo than 105mm L7 (casings for those are pretty large), has potentially higher RoF.

120mm gun-mortars can have almost as good hit % in direct fire as with HV gun thanks to the FCS, which eliminates most of the ranging errors (range, wind and other variables that affect LV guns more than HV ones), and have indirect fire option if needed.

Quote

Vehicle, anti tank team etc.

I would dare to say that with self guided top-attack rounds it is actually better vs armored vehicles (especially heavier ones) than 105mm. Add BMP-3 like coax 30mm plus external F&F ATGM pack and you have covered vast number of situations in the infantry support role.

Again, as DK noted, if the role for this vehicle is infantry support and not anti-armor, why does it have gun optimized for anti-armor performances that does not even have a proper HE round?

 

[Ssnake]

Strix fires a HEAT jet in its direction of travel, on impact. Manufacturer claims pHit as .75 on static, and .67 on moving targets.

pKill must be lower than that, of course, depending on the hit location.

Given the 120mm caliber and the top attack profile however, even an active protection system may have trouble reducing the warhead's performance to a level that a passive armor array may still be able to stop.

 

Even a pK of just .5 will still seriously disrupt an attacking mech/armor company. Strix sales people will probably argue with a reduced logistical strain for the artillery when dealing with armored formations, and probably not pitch it as a tank substitute. Nevertheless, since Strix can be fired from pretty much any 120mm mortar, I think it has substantial potential.

[Junior FO]

15 hours ago, sunday said:

I stand corrected. 120mm mortar rounds have between 1.3 and 4.2kg of filler, while there are 155mm artillery rounds (US M795) with up to 11kg of explosive filler.

That will teach me to write from memory.

Was actually not aware that latest generation had gone to ~20% filler.

~15% is rule of thumb going back to 30's at least.

15 hours ago, lucklucky said:

But 120mm mortar rounds are usually considered as effective as a 155mm because the mortar round due to more vertical trajectory its explosion is have more uniform effects.

120mm will be less effective vs. vehicles due to smaller and lighter fragments.

12 hours ago, Ssnake said:

Strix fires a HEAT jet in its direction of travel, on impact. Manufacturer claims pHit as .75 on static, and .67 on moving targets.

pKill must be lower than that, of course, depending on the hit location.

Given the 120mm caliber and the top attack profile however, even an active protection system may have trouble reducing the warhead's performance to a level that a passive armor array may still be able to stop.

 

Even a pK of just .5 will still seriously disrupt an attacking mech/armor company. Strix sales people will probably argue with a reduced logistical strain for the artillery when dealing with armored formations, and probably not pitch it as a tank substitute. Nevertheless, since Strix can be fired from pretty much any 120mm mortar, I think it has substantial potential.

Indirect fire with Strix on a moving target is a mugs game. Even if firing at a target directly observed from the vehicle. Target area is 100-150m, the flight time is at least 20+ seconds, then the whole calculation and prep time, which with Strix is comparatively considerable.

Minimum range is about 1.2 km and the charge steps are very small between 1 and 2 km, about 1 every 200m, so you can't really pre prep.

It's very bulky and it's shape means you can't put into the the normal magazine.

[Rick]

On 7/4/2022 at 2:43 PM, urbanoid said:

Not enough range? 

What are those?

[Damian]

3 hours ago, Rick said:

What are those?

120mm autoloaded gun-mortars. Upper photo is AMOS, lower photo is Polish Rak.

[bojan]

7 hours ago, Junior FO said:

....Indirect fire with Strix on a moving target is a mugs game. Even if firing at a target directly observed from the vehicle. Target area is 100-150m, the flight time is at least 20+ seconds, then the whole calculation and prep time, which with Strix is comparatively considerable.

I see that as an additional capability of the (my theoretical) vehicle whose primary idea is direct fire with high capacity HE. LV gun-mortar enables such vehicle to use indirect fire also, but it should not be primary mode of fire.

AT vs moving tanks (self defense IOW) can always be handled by 2-4 pack of external F&F ATGMs.

 

[Walter_Sobchak]

On 7/4/2022 at 12:07 AM, DKTanker said:

Yes, well, thirty years ago we deployed MBTs with two distinctly different main guns and a light tank with a third distinctly different main gun.  As I recall we managed to muddle through that excursion in the middle east.
Are we now conceding that the 120mm offers nothing to the light tank mission that the 105mm can't handle?  As I write this I'm now wondering why they decided on a high velocity cannon when they concede the light tank isn't to take on the anti-tank mission.  So why not dust off the 152mm which offers a lot more HE and cannister bang for the buck?  At almost twice the weight of the M551, this new light tank would more easily absorb the recoil from the 152mm.

Dust off the 152mm gun and make a version of javelin that can be launched from it?  

[DKTanker]

On 7/4/2022 at 9:29 PM, Damian said:

Bustle is looking narrower because there are no, thick special armor modules protecting it from the sides. Internal volume wise, this turret is identical with M1 series.

The FCS is the same, I haven't seen any evidence that the rest of the turret is as well.  Perhaps I'm looking in the wrong places and you could provide links.

[Damian]

30 minutes ago, DKTanker said:

The FCS is the same, I haven't seen any evidence that the rest of the turret is as well.  Perhaps I'm looking in the wrong places and you could provide links.

Turret is pretty much the same as the one in M1A2SEPv2/M1A2SEPv3, but instead of being made from steel, the base structure is made from aluminium and without thick special armor modules.

https://www.armyrecognition.com/january_2020_global_defense_security_army_news_industry/general_dynamics_land_systems_releases_first_picture_of_new_mpf_combat_vehicle.html

Quote

It is expected that MPF’s turret will be a scaled-down version of the M1A2 Abrams turret designed to engage in combat with tanks and other armored vehicles. Some sources reported that the new vehicle will be equipped with 105mm cannon and a 7.62mm coaxial machine gun.

 

 

[DKTanker]

45 minutes ago, Damian said:

Turret is pretty much the same as the one in M1A2SEPv2/M1A2SEPv3, but instead of being made from steel, the base structure is made from aluminium and without thick special armor modules.

https://www.armyrecognition.com/january_2020_global_defense_security_army_news_industry/general_dynamics_land_systems_releases_first_picture_of_new_mpf_combat_vehicle.html

So nothing definitive.

[17thfabn]

5 hours ago, Walter_Sobchak said:

Dust off the 152mm gun and make a version of javelin that can be launched from it?  

Simpler just to mount a remote controlled Javelin launcher or two  outside of the tank. 

[Burncycle360]

Stubby 155

[EchoFiveMike]

I said short 155mm using MACS and automated loading a decade ago.  Nothing has changed except the tax cattle have been leeched near to death.  S/F...Ken M