1970s Pilsator decoction mash

As you read this, I should be sipping a beer in a bar in Copacabana. Flash bastard that I am. Far away from the freezing cold of Amsterdam. 

More fun from behind the iron curtain. In the form of another decoction scheme.

It's been a while since I went on a decoction mash binge. Such a fascinating subject. Who would have guessed that there were so many different methods? And this is another new one to me.

The source is a brewing record image for a Pilsator. I can't remember where I got it, nor which brewery it is. Dead interesting, thougfh.
It's a type of single deoction. But with a twist.

It's mashed in at 50º C, then has rests at 64º C and 74º C. Weirdly, it's cooled back down to 64º C. Thn warmed back up to 76º C. Only then was the wort boiled. But only for ten minutes. Which seems pretty short. It can't have been very much wort that was boiled, as it only raised the temperature of the mash by 2º C.

What's odd about this method? Usually any boils are earlier in the process. And are used to raise the temperature of the mash considerably. For example, from 50º C to 64º C.

1973 DDR Pilsator mashing scheme
operation	time
	start	end	temp. º C	hl
3,500 kg pilsner malt mashed in	06:20	06:40	56	120
drain 1st mash	06:55	07:05		110
raise to 64º C	07:00	07:15
saccharification rest	07:15	07:45	64
raise to 74º C	07:45	07:55
rest 20 min	07:55	08:15	74
move to mash tun	08:15	08:25
cool to 64º C	08:25	08:35	64	140
drain 2nd mash	08:35	08:40		60
saccharification rest	08:40	08:55	76
raise to boil	08:55	09:25
boil	09:25	09:35
move to mash tun	09:35	09:45
saccharification rest	09:45	10:00	76
mash out in lauter tun	10:00	10:25
Source:
a random DDR brewing record I have