Where, as at a double-line junction, one pair of rails crosses another pair, " diamond " crossings (p) are formed.
This may be rectangular in shape (" straight " shed), containing a series of parallel tracks on which the engines stand and which are reached by means of points and crossings diverging from a main track outside; or it may take a polygonal or circular form (round house or rotunda), the lines for the engines radiating from a turn-table which occupies the centre and can be rotated so as to serve any of the radiating lines.
It is situated at one of the most important crossings of the Euphrates, where there was, in ancient times, a bridge of boats, and is now a ferry on the road from Aleppo to Urfa, Diarbekr and Mosul.
Norfolk County Council is trialing an ultra-bright belisha beacon designed to reduce accidents at crossings at two locations in the county.
Apart from designated border crossings, the immediate border area is a military restricted zone.
