Joining gas capes / groundsheets?

I’m trying to work out if my recollection is right.

WWII gas capes / groundsheets issued to Australian troops looked like the one the bloke in the foreground is wearing

Laid flat, they looked like this

My recollection is that they could be joined by top and tailing them side by side and buttoning them together to make a double size for shelter etc, which looks possible from the last picture.

Anyone know?