I vaguely remember my Dad replacing the catenary supply to his garage
some 20 years ago with an underground supply, but a comment about long
distance feeds and seperate earths rang a bell when it appeared
somewhere here recently and has made me be a bit concerned about the
security of this supply.

The details are that I can work out is that it is a 2.5 T & E that runs
I reckon some 25 m from the CU to a shed en route to the garage which
is some 8 m further on - at least the outer wall of it is. The CU fuse
is 15A. There's a fused splitter in the shed (brick !), one feed
supplying the lights and sockets in the shed and attached lean to
greenhouse, and the other the garage, both I think are 15A.

The old man's memory isn't as good as it used to be - or more likely he
is suspicious that I am going to condemn his work(!) as he is not being
that forthcoming on how the cable runs underground from the house, but
as far as I can see it is in a plastic pipe about 25mm dia. with an 8m
u/g run to the brick shed from the house.

The loading on this possible guddle is light - some lights, a deep
freeze, beer fridge and a wood turning lathe are the only things in
regular use; the workshop is elsewhere and seperately fed (6mm, etc)
and that's where the heavy loading is.

Condemning this garage supply would be met with severe objection, so
how can I make it safer ?

Rob