History of US Tanks.

[Maj.Hans]

On 2/1/2019 at 5:52 PM, Ssnake said:

Ah. THAT YPG. And I was thinking, the Kurds?

Ditto, had to go back and carefully re-read.

[kgb613]

Hello there, I'm complaining about that not so new video. I watch it again and we can see at around 0:35 "white" smoke coming from left transmission exhaust. Is it smoke coming from transmission over heating, smoke coming from auto filter cleaning or a new smoke generator (?) ? 

 

 

[Assassin 7]

2 minutes ago, kgb613 said:

Hello there, I'm complaining about that not so new video. I watch it again and we can see at around 0:35 "white" smoke coming from left transmission exhaust. Is it smoke coming from transmission over heating, smoke coming from auto filter cleaning or a new smoke generator (?) ? 

 

 

Pulse Jet System, for cleaning Vee-Packs. Air system

[kgb613]

that what I thought, thank's (:

[Assassin 7]

15 minutes ago, kgb613 said:

that what I thought, thank's (:

No Problem, during that video it was in low clean mode, If it switched to high clean there would be dust and dirt coming out constantly.

[Ssnake]

How often would that happen?

Once a day, every hour, every other minute?

It is an automatic filter cleaning, I suppose?

[Assassin 7]

1 minute ago, Ssnake said:

How often would that happen?

Once a day, every hour, every other minute?

It is an automatic filter cleaning, I suppose?

Is an automated system for prolonging the life of the engine, by maintaining a free flow of air; this is accomplished by sequentially back-flushing the air cleaner assembly intake filter elements. The PJS consist of an Air Supply Line (used when the engine is running, to provide air from the engine), an air pressure accumulator (located in the plenum), a vacuum switch (located between the intake filter elements and the engine), nine PJS solenoids attached to the air pressure accumulator installed in the engine intake plenum, element dividers, the scavenger duct and fan, and a PJS Pulse Control Unit is located in the hull near the hydraulic reservoir. When vehicle master power is turned on, the PJS Pulse Control Unit (PCU) begins to monitor engine RPM. The first time engine speed exceeds approximately 1500 RPM, the PCU will start a timer. When the accumulated engine run time above 1500 RPM reaches two minutes, the PCU will activate the PJS. This two-minute timed initialization period occurs only once per PCU power up. Engine bleed air is used to charge an accumulator, located inside the plenum, to approximately 200 psi. Attached to the accumulator are nine PJS solenoids. Three solenoids are used for each intake filter element. Each solenoid is sequentially activated for a period of 100 milliseconds at approximately 10 second
intervals. Upon activation, a solenoid directs a high pressure air pulse into an intake filter element. Activating all nine solenoids in sequence is consideredone cycle of operation. These high pressure pulses of air cause a momentary reverse air flow through a portion of the intake filter element in line with the solenoid. This blows out dust or dirt accumulations from that portion of the intake filter element. Any dust or dirt blown out falls to the bottom of the air box and is scavenged out through the scavenge ducts. The system initially starts in the low clean mode. The low clean mode consists of three cycles of pulses (27 total) repeated at approximately 15 minute intervals. Any time the PCU monitors an engine speed below 1410 RPM for longer than 10 seconds, pulsing will cease. If the engine speed goes back above 1500 RPM, the PCU will resume operation at the point in the cleaning cycle where it left off. During operation, the PCU monitors the level of flow restriction through the use of a vacuum switch located between the intake filter elements and the engine. Whenever the vacuum level reaches approximately 19 inches of water, the vacuum switch will open. At this signal, the PCU will switch to a high clean mode. The high clean mode will be maintained until the flow restriction decreases to the point where the vacuum switch closes. The vacuum switch will close at approximately 12 inches of water. The PCU rechecks the state of the vacuum switch each time two cycles of pulses are completed. During the high clean mode, the PCU will continuously pulse all nine solenoids sequentially at approximately 10 second intervals. There is no 15 minute delay intervals between every third cycle in the high clean mode. When the high clean mode signal is no longer present, the PCU will end the high
clean mode with three final cycles (27 pulses).

[Ssnake]

So, in low clean mode, 27 puffs of dust every 15 minutes?

Or are the solenoids fired so rapidly that it appears as a single puff (as seen in the video)?

 

And after 30 minutes, a high clean interval could be triggered (if in a high dust environment), with nine puffs of dust in 10-second intervals, if necessary continuously until you're out of the dust?

I presume that this comes with a loss of average engine power output, as it would alternate between 1500 and 1400 rpm?

[Assassin 7]

22 minutes ago, Ssnake said:

So, in low clean mode, 27 puffs of dust every 15 minutes?

Or are the solenoids fired so rapidly that it appears as a single puff (as seen in the video)?

1 solenoid fires every 10 seconds, which there are 9 solenoids for 3 times a cycle. Then the cycle starts again after 15 minutes.

And after 30 minutes, a high clean interval could be triggered (if in a high dust environment), with nine puffs of dust in 10-second intervals, if necessary continuously until you're out of the dust? Until the vacuum reaches a safe operating level.

I presume that this comes with a loss of average engine power output, as it would alternate between 1500 and 1400 rpm? No power is lost from the engine.

 

[Ssnake]

SOME power loss appears inevitable if you reverse the air flow...

[Assassin 7]

38 minutes ago, Ssnake said:

SOME power loss appears inevitable if you reverse the air flow...

Its just extra air that the compressors do not need, The air is reverse through the bleed valve then would be compressed back through if needed. BTW that butterfly valve is a pain to replace

 

[EasyE]

On 1/3/2019 at 6:55 PM, Damian90 said:

These were not done in Sweden, this is first thing, and neither Swedes exactly knew what was inside these models. And as you can see it clearly says about "Swedish armor" in these test modules, not US armor, be it Heavy Armor Package or something else.

 

The claim has been made that the Swedes had planned to have a wedge type armor on the turret of their M1A2. That the Export Armor package which is also claimed to be the equivalent to HAP-2 was not able to get sufficient protection over 700mm across the frontal arc with out the addition of the wedge type armor.

 

I don't see any evidence of this.  Is there anything to support this claim.

 

IMHO It doesn't appear to be the case as the protection profile of the M1A2 with the Swedish armor was worse then the Leo-2 with it, with greater LOS on the passive armor 860mm vs 930-950mm LOS.

 

 

[Damian90]

3 hours ago, EasyE said:

 

The claim has been made that the Swedes had planned to have a wedge type armor on the turret of their M1A2. That the Export Armor package which is also claimed to be the equivalent to HAP-2 was not able to get sufficient protection over 700mm across the frontal arc with out the addition of the wedge type armor.

 

I don't see any evidence of this.  Is there anything to support this claim.

 

IMHO It doesn't appear to be the case as the protection profile of the M1A2 with the Swedish armor was worse then the Leo-2 with it, with greater LOS on the passive armor 860mm vs 930-950mm LOS.

 

 

As far as I know, Swedes never actually got real data from US, nor from France. Heck Frenchmen claims that Swedes just madeup armor data on their own, at least for Leclerc.

And no, Export Armor Package definately is not equivalent to Heavy Armor Package, neither 1st, 2nd or 3rd generation.

But yeah it seems that the entire thing is very, very fishy... I would say extremely fishy.

[EasyE]

On 2/9/2019 at 5:24 PM, Damian90 said:

As far as I know, Swedes never actually got real data from US, nor from France. Heck Frenchmen claims that Swedes just madeup armor data on their own, at least for Leclerc.

And no, Export Armor Package definately is not equivalent to Heavy Armor Package, neither 1st, 2nd or 3rd generation.

But yeah it seems that the entire thing is very, very fishy... I would say extremely fishy.

 

I think too much certainty is being drawn from it. It gives us some good insight into German armor packages against monoblock rounds (also the T-80U).  However if that is vague. B-level and C-Level are rather clear armor inserts.  Where I find confusion is the nature of the D armor packages. D-1/2/3, what exactly are these referring to? Are these inserts? Or Inserts plus NERA Wedge armor. Or differnt combos of each. D-1 say is B-Level plus wedge D-2 C level plus wedge, and D-3 a new insert plus wedge? Or different inserts more optimized more against CE? 

 

Seems to be that B-level tech is rough equal to  about BRL-1,  C is BRL-2,  HAP-1/2 around D-2./3... EAP around D-2. 

 

Seems to be a rush for answers by those on the internet.. rather then to figure out what questions to ask first..

 

[Damian90]

23 minutes ago, EasyE said:

 

I think too much certainty is being drawn from it. It gives us some good insight into German armor packages against monoblock rounds (also the T-80U).  However if that is vague. B-level and C-Level are rather clear armor inserts.  Where I find confusion is the nature of the D armor packages. D-1/2/3, what exactly are these referring to? Are these inserts? Or Inserts plus NERA Wedge armor. Or differnt combos of each. D-1 say is B-Level plus wedge D-2 C level plus wedge, and D-3 a new insert plus wedge? Or different inserts more optimized more against CE? 

 

Seems to be that B-level tech is rough equal to  about BRL-1,  C is BRL-2,  HAP-1/2 around D-2./3... EAP around D-2. 

 

Seems to be a rush for answers by those on the internet.. rather then to figure out what questions to ask first..

 

First and foremost, people that draw absolute conclusions from Swedish documents, rush in to them, and do not even question, how accurate these documents are, and on what they are based on.

But hey, it's typical for the internet.

[Grenny]

2 hours ago, Damian90 said:

First and foremost, people that draw absolute conclusions from Swedish documents, rush in to them, and do not even question, how accurate these documents are, and on what they are based on.

But hey, it's typical for the internet.

Well said.

[Maj.Hans]

On 2/8/2019 at 8:54 AM, kgb613 said:

Hello there, I'm complaining about that not so new video. I watch it again and we can see at around 0:35 "white" smoke coming from left transmission exhaust. Is it smoke coming from transmission over heating, smoke coming from auto filter cleaning or a new smoke generator (?) ? 

 

 

I just came here to say WOW is that CROWS mount mega tall!

Also, WOW if I were a tank commander I would utterly HATE having that in front of me!

 

Why not move the M2HB down to gun mantle mount for the gunner to blast stuff with and get a low profile mount with a TC's M240 or something?

[Ssnake]

4 hours ago, Maj.Hans said:

Why not move the M2HB down to gun mantle mount for the gunner to blast stuff with and get a low profile mount with a TC's M240 or something?

I have yet to come across a remote weapon station that is both functional and significantly smaller. They pretty much all come in sizes like this.

Now, of course it's obstructing so much field of view, it's a no-brainer to hate such a decision. But at the end of the day it's a question of trade-off - do you want the crew to be able to observe and fight (under armor protection) especially in high elevation areas that the main gun simply can't reach?

Apparently the US Army expects its tanks to fight more and more in urban terrain where fighting the vehicle unbuttoned is orders of magnitude more risky than in wide open terrain where snipers are pretty much forced to engage only at their max range. In urban areas, there's so much cover and concealment possible, nearly every opponent can get a shot at exposed tank crew at rather comfortable ranges even for mediocre shooters. At least, that's what I'm reading from this design decision.

[Grenny]

16 minutes ago, Ssnake said:

I have yet to come across a remote weapon station that is both functional and significantly smaller. They pretty much all come in sizes like this.

Now, of course it's obstructing so much field of view, it's a no-brainer to hate such a decision. But at the end of the day it's a question of trade-off - do you want the crew to be able to observe and fight (under armor protection) especially in high elevation areas that the main gun simply can't reach?

Apparently the US Army expects its tanks to fight more and more in urban terrain where fighting the vehicle unbuttoned is orders of magnitude more risky than in wide open terrain where snipers are pretty much forced to engage only at their max range. In urban areas, there's so much cover and concealment possible, nearly every opponent can get a shot at exposed tank crew at rather comfortable ranges even for mediocre shooters. At least, that's what I'm reading from this design decision.

US has developed a new CROWS (II? or III?), that is low enough for the TC to look over it.

It may be tricky to get the same elevation as with the Kongsberg variant.

[Damian90]

All M1A2SEPv2's have the M153 CROWS-2 variant being replaced with new CROWS-LP variant that is +/- 50% smaller. Also new M1A2SEPv3/M1A2SEPv4 will use this new CROWS variant.

 

 

[Damian90]

Yuma Proving Grounds presented M1A2C (M1A2SEPv3) with Trophy HV APS mounted... but there is something more interesting on that photo. Turret front seems to receive addon armor plates, these are around ~100mm thick. We can assume that hull front could receive similiar addon armor.

[kgb613]

the question is what are made of those armor plates

[stormrider_sp]

3 hours ago, kgb613 said:

the question is what are made of those armor plates

Made of the best armor type available for sure.

[Maj.Hans]

About the CROWS / RWS thing...

 

I think what my solution would be to that, would be to go back to something akin to the A1's CWS as fitted with the stabilized CWS equipment and IR camera, and call it a day.  Maybe replace the M2HB with an M240 and go with additional ammo capacity rather than big gun, move the M2 down to a position above the main gun.

 

Maybe by going with an M240 you could get more elevation while keeping the mount low profile?

[Assassin 7]

https://armyupdate.com/index.php/2019/05/22/lima-army-tank-plant-to-deliver-m1a2-sepv3-abrams-to-u-s-army/amp/