Thank you for your
explanation, Michael ... the
thing is - as I had mentioned on Simon's thread - I'm not a driver
myself, and ...

... know
even less about the "mechanics" of
ANY kind of vehicle, to be frank. But I
do remember my dad fitting
chains to the wheels of his Austin travelling shop for delivering groceries to customers in outlying farm areas during the
heavy snowfalls of the
1950s & early 60s and wondered whether the practice continued into
modern times.