Stephen Mawson wrote:
I'm replacing a cast-iron bath (enamel in poor condition) with an
acrylic one. The present bath has walls along both ends and the far
side so it will need to be broken up to get it out, especially as I
hope to preserve the wall tiles above it. I recall from many years
ago that I had great trouble breaking a cast-iron bath -- a sledge
hammer just bounced off it. Does anyone have any advice -- apart of course
from the angle-grinder.
(Actually, would that be a possibility? Slot cut in the edge of the
bath, then cold chisel to split?)

Why not have it resurfaced? Dunno where you are but we used this guy
http://www.radiantbaths.co.uk/ and he did a fantastic job. The bath itself
was, at the time of resurfacing, 53 years old and in fairly poor condition.
Now, 6 years after Nigel worked his magic, it still looks like brand new.