Five minutes of 'almost total darkness' that changed Wales

A FIVE-MINUTE immersion in almost total darkness represents one of the triumphs of Victorian endeavour in Wales.

- ANDREW FORGRAVE Reporter

A train exits the northern end of the Ffestiniog Tunnel. Inset, the tunnel was a key element of the Conwy Valley line, originally built to service Blaenau Ffestiniog's slate quarries

(WELSH SKIES BY GARETH NATIONAL LIBRARY OF WALES)

It’s an engineering marvel that almost overshadows the incredible scenery through which the 28-mile Conwy Valley line passes.

This year marks the 200th anniversary of Britain's modern railway network. To celebrate the occasion, Network Rail chose to shine a spotlight on the Ffestiniog tunnel, the UK’s longest unlined tunnel.

Puncturing the route from Llandudno Junction to Blaenau Ffestiniog, it was built over six years through solid rock to serve the latter's slate mines. Network Rail said it remains an “extraordinary” achievement that serves as an enduring monument to the men who carved it out.

Blaenau was already served by Ffestiniog Railway, opened in 1832 and the world’s oldest narrow-gauge railway, However this 13.5-mile line to Porthmadog harbour primarily served the area’s slate industry.

Half a century after it was built, the London and North Western Railway (LNWR) saw an opportunity to connect Blaenau directly to the national rail network. As well as improving access for workers, the aim was to open up export routes into England’s industrial heartlands via a specially built quay at Deganwy.

Yet the proposed scheme faced a major hurdle - how to navigate past Moel Dyrnogydd, a 1,719ft mountain overlooking Blaenau, without tortuous climbs. In the event, LNWR engineers decided to tunnel 2.5 miles through it.