The absolutely unmistakable form of the Forth Bridge towers over the Firth of Forth, silhouetted by the twilit sky and lit from below and within by spotlights. This bridge didn't take shape by mere happenstance; over 130 lives were lost before the structure we know today hosted its first train.
The original plan for a crossing of the Firth of Forth was designed by Sir Thomas Bouch, engineer of the nearby Tay Bridge, to be similar to his previous work. Tragically, the Tay Bridge collapsed under high wind loads in December of 1879, killing 75 passengers and crew on a train crossing the viaduct at that critical moment. The failure of the Tay Bridge led to Sir Bouch's removal from the Forth project and a halt to construction.
Design work was renewed under the leadership of Sir John Fowler and Sir Benjamin Baker, who performed extensive research into the behavior of cantilevered truss spans and, after numerous iterations, eventually derived the famous, massive superstructure that was intended to both withstand any force nature could present and bolster public confidence that this structure would not fail as the Tay Bridge had. Their incredible design stretches 8,296' between abutments, has two 1,710' spans over the firth (two 680' cantilevers supporting 350' trusses), carries two main tracks 151' above high tide and tops out at 330' tall. The engineers have been vindicated in both of these goals: the bridge has remained in service for over eleven decades and today hosts nearly 200 daily trains. (Unfortunately, prior to its opening in 1890, 63 lives were lost during seven years of construction; safety requirements in those days weren't nearly as stringent as in modern times.)
Arching across the firth beyond the rail bridge is the 48-year-old Forth Road Bridge's 3,301' suspension span. Although originally designed for a 120-year service life, traffic has far exceeded its planned capacity, leading to congestion and exacerbating structural degradation issues caused by corrosion. A second road bridge is currently being built to replace the suspension bridge and is due to open in 2016; construction activities for the cable-stayed bridge's central tower are visible at water level below the apex of the suspension span. The original Forth Road Bridge will be retained for use by pedestrians and transit, extending its effective service life by reducing live loads upon the deteriorated structure.
Note from the photographer:The following paragraph is in response to J. Moller's comment below.
The tale of rings made from the remnants of the Tay sounds like an urban myth that's crossed paths with Canada's "Iron Rings" presented to graduating engineering students, which were long (and falsely) rumored to be made from discarded components of the collapsed Quebec Bridge. (As it happens, I'm a member of the Order of the Engineer here in the USA and wear a steel band on my right pinky for precisely the reason Mr. Moller describes; separate from that, I'm also a licensed professional engineer.) With regard to the location, RP does not list Scotland as a separate country, and since all prior database submissions also refer to the UK I stayed with that for consistency.
