The Soviet Tank Thread: Transversely Mounted 1000hp Engines

[Collimatrix]

Xlucine, Mech, T___A, The_Warhawk and I did some compare and contrast on cross-section of Ob 277 and Ob 770.

-Whereas Ob 277 appears to have a conventional powertrain layout for a Soviet heavy tank (it's a bit like a leo 1), Ob 770 has a freakishly compact powerpack and transverse engine.  Seriously, it only looks a little bigger than the powerpack in a T-55.  The engine is weird; it appears to be a ten-cylinder design with two straight rows of five cylinders and two crankshafts.  We're pretty sure it was turbocharged.  This design frees up an enormous amount of space in the rear hull for ammo stowage.  Transmission in Ob 770 is automatic with a manually selected overdrive.  It sounds like it incorporates a torque converter (transmission is described as "hydraulic" per machine-translation, and only has 4 forward gears).  Steering mechanism is unremarked upon, but I suspect it was two-layer planetary geared with reserve clutch and brake as in earlier IS-1/T-55, if only because I can't imagine anything more complicated fitting in that dinky little powerpack.  I suspect that the transmission in Ob 277 was a derivative of the planetary triple differential seen in IS-4, but I'm awaiting further confirmation because I was wrong about this being in IS-7.

 

-Both Ob 277 and Ob 770 solve the torsion bars under the turret basket problem.  Ob 277 is similar to AMX-30 in that some of the road wheel swing arms face forward, and some face backwards so that the torsion bars (compound bars-in-tube type ala T-64/IS-7 IIRC) are not underneath the basket.  Interestingly, the plane of the turret on Ob 277 is tilted forward by a few degrees.  Ob 770 uses in-arm hydropneumatic suspension.

 

-The autoloader in Ob 277 appears to be a refinement on the IS-7s.  Instead of storing both projectile and propellant in the bustle racks, it only stores propellant charges; six on top, eight on the bottom (as opposed to IS-7's six total rounds in the bustle).  AP projectiles are stored in a magazine to the side of the gun, and HE is stored in a rack on the turret floor.  I suspect the ammo in this rack could be rotated ala Ob 416.  The way we think this worked is that Ob 277 would have had eight shots of AP that it could get off very quickly without the loader having to do anything.  To fire HE, it looks like the loader would need to get an HE shell out from under his seat, plop it in the tray, and then select the bustle loader to put in a propellant charge from the top of the bustle rack (the HE and AP probably had different propellant charges).  So, for shooting at other tanks with AP, Ob 277 could reload very quickly for range bracketing, but for lobbing HE against, say, bunkers, it would be a bit slower.  The combination of fast-reloading AP rounds, stereo rangefinder and backup 14.5mm ranging gun would have given Ob 277 very good ability to get rounds on to target quickly for the era.

[T___A]

Object 770 only had 3 forward gears and one reverse. DAV isn't exctaly clear on the subject but the Object 770 is noted as having good turning characteristics so I'm not convinced it has the same as IS-1/T-55.

 

E: According to DAV both the Object 770, and Object 277 share that stereo rangefinder, which is two plane stabilized, and independent of the gun. In addition to the radar range finder, which according to testing worked quite well for them.

[Sturgeon]

Many people know this photo:

 

 

26-27 October 1961, part of the so-called "Berlin crisis".

 

Here is same event from other side, a series of photographs taken in the location of the 3rd Tank Battalion of the 68th Guards tank regiment of the Soviet Army:

 

 

http://477768.livejournal.com/1709628.html

 

Walt, I'm going to write a post about the last Berlin Crisis, and how it spelled doom for the M14. Look for it on TFB, but I'll cross-post it here when it goes up.

[Meplat]

Walt, I'm going to write a post about the last Berlin Crisis, and how it spelled doom for the M14. Look for it on TFB, but I'll cross-post it here when it goes up.

It damn sure was one of the bigger nails in it's casket, that's for sure.

[LoooSeR]

T-62 with KPVT 14.5 mm HMG.

[Sturgeon]

It damn sure was one of the bigger nails in it's casket, that's for sure.

 

That, and the rifle looks like it was designed by the unholy offspring of a drill sergeant and an accountant.

[T___A]

T-62 with KPVT 14.5 mm HMG.

 

Reminds me of the T-54M model 1953

[Meplat]

That, and the rifle looks like it was designed by the unholy offspring of a drill sergeant and an accountant.

That is closer to the truth than many want to admit.

[T___A]

The UTD-40 meant for the Object 770:

[LoooSeR]

Somewhere in Kubinka:

 

 

 

 

 

 

[Tied]

T-62 with KPVT 14.5 mm HMG.

 

thats a Nork T-62 if i have ever seen one

 

they love slapping those 14.5mm on their tanks and i know for a fact a decent amount of Nork Igla's and MRLS have shown up in the middle east as of late 

[Collimatrix]

When was Best Korea exporting hardware?  I would assume before the collapse of their economy.

 

T___A, would you mind posting the pictures of the cross sections of Object 770, so everyone can gaze at its glorious powerpack design?

[Tied]

When was Best Korea exporting hardware?  I would assume before the collapse of their economy.

 

 

they are still doing it today

 

180mm Chuch'ep'o "Koksan"

 240mm ''M-1985'' [1984] 

[Xlucine]

hehe, "koksan". It's like they're overcompensating for something! The "nodong" missile is also an example of this

[T___A]

 

 

T___A, would you mind posting the pictures of the cross sections of Object 770, so everyone can gaze at its glorious powerpack design?

[Tied]

[Meplat]

Gotta admit, that is a good looking chunk of steel.

[Priory_of_Sion]

When did the USSR finally give up on heavy tanks? 

[T___A]

Officially in 1960 when Khurschev unilaterally canceled the heavy tank program however, the army fought on for about 5 more years.

[Collimatrix]

And at least one of them survives in Kubinka!

 

 

I think it's riding lower in its suspension in the museum than it would have in service, ditto UFO tank to it's left.

[Walter_Sobchak]

the website Russia Today keeps running articles on the history of Soviet tanks, and they keep getting stuff hilariously wrong.  For example, did you know that the difference between a T-54 and a T-55 included:

 

The main improvement over the T-54 was the successor’s comprehensive anti-nuclear defense system, insulating the crew against the effects of radiation. The armor thickness remained the same, as did the weaponry, although the main gun and coaxial machine gun was now stabilized in two planes. The tank’s profile was also reduced by almost one meter.

 

Also:

 

By the end of the hostilities, the Israeli tank crews had seen how the L7 tank cannon not only outgunned the 100-mm D-10T2S cannon fitted to the T-55, but also the more advanced 115-mm U5-TC on the Soviet T-62s. The Centurion’s main gun had a greater maximum elevation than its rivals, which often allowed the Israelis to destroy enemy tanks while staying out of reach of return fire.

 

- http://rbth.com/defence/2015/06/01/the_t-55_tank_from_the_school_of_hard_knocks_to_local_conflict_vetera_46539.html)

[LoooSeR]

Object 187. Kubinka.

 

 

one tank have interesting frontal armor layout. Futher one have UFP which externally reminds me T-14's UFP.

[Tied]

the website Russia Today keeps running articles on the history of Soviet tanks, and they keep getting stuff hilariously wrong.  For example, did you know that the difference between a T-54 and a T-55 included:

 

The main improvement over the T-54 was the successor’s comprehensive anti-nuclear defense system, insulating the crew against the effects of radiation. The armor thickness remained the same, as did the weaponry, although the main gun and coaxial machine gun was now stabilized in two planes. The tank’s profile was also reduced by almost one meter.

 

Also:

 

By the end of the hostilities, the Israeli tank crews had seen how the L7 tank cannon not only outgunned the 100-mm D-10T2S cannon fitted to the T-55, but also the more advanced 115-mm U5-TC on the Soviet T-62s. The Centurion’s main gun had a greater maximum elevation than its rivals, which often allowed the Israelis to destroy enemy tanks while staying out of reach of return fire.

 

- http://rbth.com/defence/2015/06/01/the_t-55_tank_from_the_school_of_hard_knocks_to_local_conflict_vetera_46539.html)

 

what a bunch of Russophobes 

[Collimatrix]

Uralvagonzavod wins again.

[Tied]

classic Boroda

 

RUSSIA STRONK