Denbigh Hall Bridge (Milton Keynes)
Constructed for the London and Birmingham Railway in 1838, using slightly curved cast iron girders across Watling Street (the A5).
The tracks were quadrupled in 1881, and the bridge was widened using straight iron beams.
The railway crossed the road at a considerable skew, such as to rule out long-span girders. Instead, the deck girders were set square across the road, with a span of just 26 ft 9", and a bridge width of no less than 165 ft.
The majority of the cast iron beams were replaced by concrete beams in 1846, leaving cast iron beams only at the northern end.