A project is under way to reinstate the narrow gauge Welsh Highland Railway between Caernarfon and Porthmadog in North Wales. Progress to date has seen the railway opened for 19·4 km between Caernarfon and Rhyd Ddu. The remaining 20·3 km section between Rhyd Ddu and Porthmadog is due for completion in 2009, which when connected with the existing Ffestiniog Railway at Porthmadog will result in the longest heritage railway in Britain by far, with a total length of nearly 62 km. Bryn-y-Felin Bridge forms a prominent landmark where the railway crosses over the Glaslyn River near Beddgelert in the heart of the Snowdonia National Park, near to the popular and much photographed beauty spot of the Aberglaslyn Pass. The structural form of the bridge is a steel half-through Warren truss, replicating the style of the previous bridge on the site. The aim was to produce a cost-effective design that reflected the heritage of the railway, and that could be readily constructed and maintained.

This paper describes repairs to two 1906-built riveted steel plate girder bridges owned and maintained by the Gloucestershire Warwickshire Steam Railway (GWSR). Stanton Bridge carries the de-trunked former A46 main road over the railway on a 57?38˚skew, and had extensive corrosion to the main and secondary girders. Gretton Bridge, which carries the railway over a minor road, needed repairs to the bottom flange and a web stiffener as a result of impact from an over-height road vehicle. GWSR is a volunteer-run organisation operating passenger trains hauled by restored steam locomotives.

A largely volunteer-run project to reinstate 40 km of the Welsh Highland Railway between Caernarfon and Porthmadog in north Wales will be completed in 2009. It will link with the existing Ffestiniog railway to create a through route of nearly 62 km – the longest heritage railway reconstruction in the UK. This paper describes the historical context, planning, construction, operation and finance needed to reinstate one of the country's steepest and most scenic railway routes. A culmination of dogged persistence in the face of political indifference will result in an environmentally sustainable transport facility through the heart of Snowdonia National Park and is likely to bring significant economic regeneration to the area.