Garden railway - the first survey

The garden is pretty much square, about an acre, with the house in the middle and a stable block down one side, with pig-sty/engine shed at one end. I hope that the first phase of building will get a 300 foot run along the Southern boundary, terminating in a run round loop. In the future, there are several options for making a continuous run, subject to negotiation with the domestic authorities. I would like to develop it as a narrow gauge line, run with large (though necessarily short wheelbase) engines along the lines of a recently-acquired Tinkerbell.

r-a r-b r-c
19th century pigsty - soon to be the new
engine shed
The door is just big enough
for a Tinkerbell (if you keep your
head down!)
Looking South from the engine
shed door - the rhubarb patch will
need a little remodelling
r-d r-e r-f
The line will sweep around along the
back wall/fence. The knot weed and
compost are all being dug out with
the digger
Looking East along the back fence.
The old shed is due for demolition,
its replacement will move out a little...
... to provide more space - this gap
is just under two feet, I need nearer
four for safety
r-g r-k r-m
At the far East end there is a small
rockery. A bit of remodelling will
make more clearance round the
back either as a cutting or (ideally)
a tunnel...
...which will come out here. Looking North from the cutting exit,
this will be the end of the first
stage of the line - enough room
for a runaround loop