"T i m" wrote in message
news ....
The 'track' was (would be) a single (25') length of thick walled steel
tube (about 25 mm dia) that was tack welded to some steel rectangular
box section with perforated sides that get's set into the ground
(concrete) with the 'track' slightly above the surrounding surface.

There were concave faced nylon wheels set under each end of the gate
to keep it 'on-track'.

The 6" square steel posts are set infront of the track with rollered
guides above the gate to keep the gate upright as it is opened. They
also stop the gate being lifted off it's track when closed.

There was a stop on the gate to prevent it going past the second post
when open and another at the closed end that allows the gate to be
padlocked shut. I would probably also fit a drop bolt in the middle to
help prevent the gate being bent in the middle.

The gate itself would be about 12' wide by 6' high steel box (not
sure what thickness or section would be needed yet) and probably be
constructed to look like two 'gates' from the outside and the 'panels'
infilled on the outside by some suitable wood (floor grade T&G or
thinner cladding stuff over WBP ply for strength).
....

Anyone done similar, any thoughts or reservations etc please?

It sounds not dissimilar to a gate I have, except that the track is an
inverted T section, with twin wheels running each side of the central web
and the span is a bit less - around 3m.

IIRC (I won't be able to check for about a month), the gate section is about
100-125mm by about 50mm. The infil panels are steel, folded slightly along
the diagonals (making extremely shallow pyramids), presumably to keep them
from drumming. My gate closes to a steel post that has a U-shaped piece to
engage with the top of the gate when shut. As it is electrically operated,
using a worm drive, there is no need for a lock.

Colin Bignell