Well it was on two poles actually. Supported on metal supports across the two poles. It was a type of transformer thingy but not one that I recognised. A grey metal box, quite small down a long country lane. It appeared to be fed by three phase 400 Volt overhead aerial bunched conductors, no 11kV in sight. Could it be a step up thingy to compensate for the long run to the remote houses? I must learn how to post pictures. It was in Watery Lane in Beechampton near to Stony Stratford in Bucks M.K. It was interesting to see that the stream had mostly dried up, but at the lowest point that is where a pole had its P.M.E. earth electrode. Do you think that the installers deliberately chose that spot as it was likely to remain damp during very dry weather?