I've been building armor for quite a while and it just occured to me how do tanks turn? does it have anything to do with the drive sprocket? or is there some other mechanism?

From what I know, I think it's in their transmission. When a tank turns one of the track moves forward while the other one stops or reverses & acts like a pivot. That's just a birds eyeview. Maybe some of our tank experts here could explain it to you more clearly. Regards.

I have to agree to what Cardinal just said. All of the tanks/afv/tracked vehichles I've been on just "brake" on one side to turn. As far as I know this can be achieved in two ways for vehicles with a "simple" transmission and not a very high power plain brakes are applied on the sprocket on the side you want to steer towards. More complex system have a dual action: brakes and progressive "disconnection" of the traction. I've never seen a counter rotating mechanism of the tracks, but I cannot exclude that this exists...
Ciao

The difference in the two tracks turning speed makes the tank turn . By brother in law used to drive M48 MOLF and i have listen to many stories. There are also brakes on the tank and if you step powerly on the you make it stand up !!!!! If you have not listen to a tuned M48 warming up in the morning you havent hear anything !!!!

Most AFVs are driven by a method called "Skid Steering" which is what they do, they basically brake, or skid one track, while the other track is still turning, and the AFV turns in the direction of the Skid.......now maybe that is too generalized, as most of the time the slower track doesn't actually stop and skid....just slows down. An AFV sitting still, with one track in reverse and one track in forward, will sit there and do 360s all day.

There are two basic turning methods for tracked vehicles: Skid or slide turn and neutral steer.

Slide turns can be achieved in two ways: By disc brakes between differential and final drives. These usaually use laterals for steering - The M113 uses this method: Pull back on the lateral on the side to which you want to turn and it slows down the track on the side, causing the vehicle to turn. This method is cheaper and easier to maintain, but it creates a vehicle with a larger turning radius.

Cross-drive steering has brakes built into the transmission, but also has the ability to make one track go foreward and the other backward. All American tanks since the M26 Pershing have had a cross-drive transmission (CD-850 in M-46 thru M60). When the transmission is in either forward or reverse, it steers by slide turns, slowing down the track on the turn side. Place the transmission in neutral and turn the steering wheel one way or other and you have tracks going in opposite direction, turning the vehicle in roughly its on length. This greatly improves the agility of a large tracked vehicle. Cross-drive transmissions are heavier, more costly, but they are woth it.

Hi
Should know this. Ok!

Basic steering like on D6 or D8 Cat is straight Clutch brake system. where when a steering lever is pulled a clutch on one side is disengaged and allowing the other side to drive the tracks there fore turning the CAT. That is the basics. This is SKID steer

Tanks have similar but there are various types.
You have a skid steer type,
Power steer some external of the gear box & some internal.

Lets go deeper.
But because the it is so complicated with the use of Annulus, Sun pinions, Planet carriers I will only touch on basics.
Lets take the Merritt & Brown system in a Centurion. When the right hand steering lever is pulled it acts on the left hand steering brake drum external of the gearbox. Which slows down that side.
Allowing the other side to speed up & cross back over the gear box & drive & speeding up that side & turning the tank.
For instance if you flick your steering lever at tick over you can turn the tank to about 1".
Now netural turn is very complicated but basically when a steering lever is applied at tick over it transfers the drive across the gearbox and powers the other side faster. Harder you pull the stick the tighter the turn.

power steer gear boxes are total different & there are various types but all roughly do the same.

So when the right hand lever or wheel is applied this again slows down the side required to turn the tank. Harder you pull the stick the tighter the turn.

But in natural the opposite happens. When you pull a steering lever on (normally you have to rev the engine to do this) it will drive one side forward & the other backwards.

Some tanks incorporate both types with in a Gearbox and have steering wheel & levers. Like the Leopard having both types of steering.

Now the steering can be used to allow you in a manual tank to change gear at a faster rate than a automatic Gearbox. this is advantage is seen when going Cross country in undulating ground where a manual gear box will always out perform a automatic. Reason is that the manual gearbox does not slow down & wait for a gear change.
Example. Ever tanky knows what a knife edge is. Steep hill both sides. As you drive to the top yop get to the point where you go over now this is done slowly (take my word it seems very quick when driving) when the tank is just about to touch the ground you can stick change the gearbox using the steering lever straight in to top gear & you come down I a rate of knots. In a semi or automatic gearbox you have to go through the range of gears to produce the same momentum.


Now there is an exception. T72 I enjoyed my drive in this beast. Once you have changed gear to 2nd manually with the use of the clutch you can take it out of 2nd & straight into sixth. Now because this has clutches external of the gearbox if you pull the lever hard in sixth you just go straight on. Just lift the steering lever 1” and it turns on a sixpence. Slower & lower the gear you are in the opposite happens.

You have all see the famous picture of a Centurion, Chieftain, Challenger 1 side by side on book covers etc.
Well it was staged.
The reason. Was Jock Beatly & myself were so quick in the gear changes that the Centurion was in Fifth at full speed going past the cameras before the others but once up & running yes they were faster.
So the question is how this work does. Easy.
you dip the clutch, take it out of gear in to the next gear in a swift movement at the same time flick the steering lever which acts like a brake on the gear box allowing you enough time to change gear. By the way we use to have bets on the tank park at Bovington to see who was the quickest.
Remembering you need rpm & momentum to move into higher gears.
1st dead slow to fifth & back including a stall change into first was 1 1/2 lengths of a Centurion tank.

The turning circle of any tracked vehicle especially a tank is determined by the speed & gear you are in.
Example 1st gear the turning circle is 15 feet & in fifth 130 feet in a Centurion.

Try this in your car.
a corner that you would take in fifth gear say 40 MPH. right now take the same corner in 3 rd with more RPM you will find that you can take it at say 50 mph & it will be a tighter turn.

Hope this explains some of the basics. To give you some idea, the teaching practice/lesson on the Centurion Gearbox& Steering is ¾ of a day and is 6 pages in the user handbook. Chieftain is the same.
By the way I was a Driver Mechanic B1 Centurion, Chieftain all variants. & have worked on & drive loads of different tanks. Even now I still look after tanks.

Ossie