Canadian T72 tanks

[Malcolm Towrie]

Hi, we have two T-72’s at the Ontario Regiment Museum now, one a good runner, one a gate guard.
The runner is a Polish tank, from a private owner’s collection, and I believe it came from Poland via the UK.
The second is a Czech tank (I believe) and came across to a Canadian base for testing, before we got it.
Anyway, we have lots of manuals,Polish, Russian, and Bosnian (according to Google translate), and a couple of abbreviated ones in English, but Google struggles to do a comprehensible translation (or the manuals are very poorly written) so technical info is a problem.
My present question is more from curiosity than a need to repair:
- the tank is 24 volt as expected. However, the electric starter is 48 volt, supplied by temporarily connecting the four 12 volt batteries in series using a large relay activated by the start push button.
- slaving is done by another T-72 supplying 48 volts somehow.
- does anybody know how the slaving tank supplies 48 volts while it is running in 24 volt mode? We occasionally need to slave it.
The manuals we have shed no light on this.

Malcolm

[Richard Farrant]

Hi Malcolm,
On the Tank Museum's Youtube channel yesterday was a new video on the T72 and one of the museum's workshop volunteers is a chap who was a T72 commander in the East German army. He is very knowledgable on the workings of it, so maybe you could make contact with him through the museum?
Here is a link to the video;
https://www.youtube.com/watch?v=4XjFKVyXzls

[Grant Bowker]

Originally Posted by Malcolm Towrie

Anyway, we have lots of manuals,Polish, Russian, and Bosnian (according to Google translate), and a couple of abbreviated ones in English, but Google struggles to do a comprehensible translation (or the manuals are very poorly written) so technical info is a problem.

It' not just Google that has problems translating technical material. My parent's first VCR came with both English and French manuals. Trying to do the setup of the programming for channels and recording was virtually impossible using the English manual but rather easier using the French one even though everyone involved was very much "French is our second language". I'm convinced the English manual had been translated from Japanese, probably by by someone who was a very competent translator but had no expertise with using the machine in question. On the other hand, I believe the French manual had been done by someone who had been trained to program and operate the VCR and who had then followed the outline of the original manual (English? Japanese? doesn't matter) to write a French version.


To offer a tiny bit of help on your 12/24 volt question - trucks used to employ a device known as a series-parallel switch to configure batteries to be able to provide 12 volts for most of the truck but 24 volts for the starting system. Higher voltage permits the same power to flow with lower current resulting in less heating of cables and letting smaller cables do the job. The power transmission grid uses the same voltage/current relationship to economically move electricity around the country - huge voltage, lower current.

[James P]

Originally Posted by Malcolm Towrie

Hi, we have two T-72’s at the Ontario Regiment Museum now, one a good runner, one a gate guard.
The runner is a Polish tank, from a private owner’s collection, and I believe it came from Poland via the UK.
The second is a Czech tank (I believe) and came across to a Canadian base for testing, before we got it.
Anyway, we have lots of manuals,Polish, Russian, and Bosnian (according to Google translate), and a couple of abbreviated ones in English, but Google struggles to do a comprehensible translation (or the manuals are very poorly written) so technical info is a problem.
My present question is more from curiosity than a need to repair:
- the tank is 24 volt as expected. However, the electric starter is 48 volt, supplied by temporarily connecting the four 12 volt batteries in series using a large relay activated by the start push button.
- slaving is done by another T-72 supplying 48 volts somehow.
- does anybody know how the slaving tank supplies 48 volts while it is running in 24 volt mode? We occasionally need to slave it.
The manuals we have shed no light on this.

Malcolm

The practice was to do air starts, or a combination of air/electric. Have you do a tow start and do you double suction the transmission for ease of start , and that said don,t stand in front of the tank on start up.