Work begins on 10 year programme to modernise the famous Snowdon Mountain Railway

On Easter Monday 1896 the ribbon was cut on the Snowdon Mountain Railway's inaugural ride – but all did not run smoothly.

On the way back down the mountain (at 3,560ft the highest in England and Wales) the steam locomotive LADAS derailed and plunged off the edge of a cliff. The driver and fireman leapt to safety.

Even though the carriage being pulled behind ground safely to a halt, two passengers also jumped out. One, Ellis Griffith Roberts, sustained fatal injuries in the fall.

The railway – which runs five miles up the side of the mountain from the village of Llanberis to within 60ft of the summit – was mothballed while a safety review ensued.

Eventually it was decided to refit the rack-and-pinion track (based on a design pioneered in the Swiss Alps) with an additional safety feature: a steel girder running the length of the track to lock trains in.

The new design was completed in 1897 and has remained in place ever since – the only one of its kind in the world.

This winter, though, the railway has embarked on a 10-year £2.6m project to rip up the old Victorian track and replace it with a modern design which does not rely on the safety girder.

Over the past few months engineers have battled through blizzards, fog and hill snow to lay 280m of the new track, known as an ypsilon sleeper because of the Y-shaped design.

The first trains will run this weekend and despite the calamity which befell the railway’s last grand opening, senior engineering manager Mike Robertshaw insists there are no jitters.

“I’m not worried,” the 57-year-old says. “The new tracks we are putting in are now the best on the railway.”

Some 120,000 passengers take a ride each year on the Snowdon Mountain Railway which has four steam locomotives (three of which have been there since its inception) and four diesel engines.

Ever since that first fateful crash there has never been another accident.

The railway has remained open every March to November except for the war years when it was commandeered for use as a radar base.

Compared to the inability of the mainline rail network to cope in adverse weather, Robertshaw says it takes winds of 50mph before they will stop running trains to the summit and 70mph before they cancel them altogether. Leaves on the line?

“We don’t have any trees on the mountain so that’s not a problem,” he says. Gwyn Jones, 57, is the longest serving member of the railway’s 28 professional staff who joined as an apprentice 41 years ago.

It has been a hard winter, he admits, but nothing like a decade or so ago when he was once rescued from a hurricane near the summit.

“Still not everybody gets to go up Snowdon for a living,” he says.

The steepest point of the mountain is 1:5.5 and the steam locomotives gobble up 300kg of coal and 400 gallons of water per trip. The railway is a proudly Welsh operation.

The coal comes from the Ffoss-y-fran mine and ballast for the new track from a granite quarry nearby. Even the timetable is based on when the gas lamps used to be lit in nearby Caernarfon.

Elizabeth Partridge, 28, is part of the younger guard working on the railway. She is employed as a fireman, stoking the engines with water and coal, and is one of only a handful of women in the country to do the job professionally.

“I love the fact these locomotives come alive,” she says. “I suppose it is a passion which just gets passed on through the generations.”