Early in the history of railroads the inadequacy of wooden bridging became apparent; heavier trains required bridges of greater stability. Fortunately, improved techniques of metallurgy permitted the use of iron for bridges. George Stephenson designed and built the first such bridge for the Stockton-Darlington Railroad in 1822. This railroad later became the first to carry passengers.
With this breakthrough, engineers may build railroads through swamps. Foresters, produced in the university, use this technology to provide easier access to more Timber in forests. Timber terrain improves to Level I, producing 2 units of timber per turn.
