bergen-hohne 1979

[orange.paint]

I was just reading about the glorious bergen-hohne 1977 CAT which the RCD won on rental Leo's.Which I have heard by word of mouth through out the regiment.

Then I read on to the "embarassing" CAT shoot of 1979 with the heat expansion throwing off the linkage between the linkage between the gun and the site.
Just wondering as the book does not go into detail what was done to correct this?What was the problem with?The metal bending or etc.

Cold war vet's carry on. ;D

 

[George Wallace]

Lance can answer this probably better than anyone else on this site, as he was actually there on site.  ;D

The linkage between the gun and sight are affected by changes in temperature.  Changes had to be physically made to the linkage, and also to the program in the FCS to compensate for these changes and changes in temp.  CAT '81 saw quite good shooting done by the Canadian Team.

 

[orange.paint]

Just wondering what was corrected,linkage metal type changed?Heat resistance paint etc.Also was it true that they parked the vehicles in the "shade" to cool the turret downto solve the problem?This sounded rather foolish,maybe one excuse to park and have a few?

You said 81 showed great improvement.Im guessing 80 was the year the fcs mods were taking place?

 

[George Wallace]

Heat resistant paint would have no effect on the linkage.  A different metal with better characteristics would be the best bet.  Also there would have to be programing done to the sight computer programs to take into account expansion and contraction of the linkage at different temperatures.  Lots and lots of Math involved there.

 

[Garry]

I don't believe it was the linkage, and iirc it wasn't '79 that the problem surfaced.

We received the Canadian tanks in '79, and they worked superbly.

While I don't remember the actual distances involved (anyone help out here) we used to boresight and zero the Centurian at (again, iirc) 1,000 metres. When we got the Leopard, for the first time we had to deal with computer aided sites and on board computer generated ballistic tables. The (Sabca) fire control system on our Leopards was designed to be boresighted (again, iirc) at 1500 metres and zeroed at 1,000 metres (although something about 1250 metres keeps slipping in- been 20 years, cannot remember).

Boresighting in the old Centurion days merely got you on to the target, thereby saving rounds. The Leopard boresight did much the same thing, but more importantly it told the computer where it was in relation to the gun. This was really important, as when bringing the gun to bear, the fire control system measured a lot of variables (ammo temo, outside air temp, bore wear, wind, humidity, cant angle, speed, and more) as well as fixed variables (gotta love that) due to ammo type, applied the range, then (and only then) adjusted the graticule.

If you didn't boresight at (X) range, and zero at (X) range, then every single thing the fire control system did after that was flawed, as the relationship between the computer and the gun was based on flawed data.

Problem was, very few folk realised that. Remember, there was no such thing as a personal computer back then. Tanks were sledgehammer techonolgy, and Tankers had adapted to that.

At some point, the method of boresighting and zeroing changed. I will NOT go into why, only that we changed the method. Very shortly afterwards, tank crews noticed that had to adjust way more than normal. The only variable that anyone could come up with was the linkage described above. While awaiting "the fix", range to target was extablished by the laser, and that range was then applied to the secondary site, and the round went downrange fired of of the secondary site. (!!!!!!!!)

Yes, a "little" slower than laze and blaze.

And, imho, a load of ..well, you know.

Cheers-Garry

 

[George Wallace]

The first Leos were at the School in '78. 

Some of our problems were rectified by disconnecting the Cross Wind Sensor, as it was usually different from our loc and that of the Tgt.  A lot of improvements came with the Barrel Reference System in the C2. 

Garry

If I remember correctly, there was a flaw with one of the cards in the 'Brain Box' that had to be rectified.

 

[Garry]

George,

Correct on the cards- '79.

The problems blamed on the position resolver that resulted in lazing, then applying the lased values to the secondary sight and shooting off the #2 site were, iirc CAT 83 and 85. I'd bet my last dollar that the position resolvers were fine, and that our method of boresighting and zeroing was the problem....

Correct on '78 as well for the Leopard arriving at the school- I was thinking when "C" Sqn received the Leopard- I remember it well, as I brought three back, and was left north of the river on a siding with 3 tanks and no food. The river was in flood, took awhile to get me.

Remember "Camp May"...???...man, haven't thought about those times in years......sigh.....

Cheers