After a couple of serious accidents the RAF retro-fitted their Bulldogs with escape hammers/belt cutters. TBH, I didn't rate these hammers very much.
I would not have thought they needed belt cutters as you had the strap knife on the flying suit. For the canopy I thought the brief was to get rid of it just before landing if there was any chance of turning over, the front canopy frame plus bone dome was supposed to be enough protection.