THEY are a symbol of the greatness of Glasgow’s industrial past, some of the last working locomotives built in the city in the Victorian and Edwardian eras.

They have survived mud torrents, landslides and even earth tremors, and now the 100-year-old steam engines built in Springburn, which haul the trains of the world-famous Darjeeling Himalayan Railway (DHR) in India, have been given a new lease of life with the line fully reopening after closures that lasted five years.

There are strong links between the railway and Scotland, because the DHR’s ‘B’ Class steam locomotives, 12 of which survive, were built in Springburn in Glasgow by Sharp, Stewart and Co, later the North British Locomotive Co, between 1889 and 1925.

There are many other north British locomotives still in use around the world, but nowhere else do these narrow gauge engines perform a full working passenger service day in and day out.

Known as the “toy train to the clouds”, the DHR is a Unesco World Heritage Site, described by the organisation as “still the most outstanding example of a passenger hill train”.

It was built in the late 1800s to service the local tea planting industry, of which Darjeeling is a major world centre. The DHR reaches up to Ghoom station, some 7,000 feet above sea level.

The extraordinary longevity of the Glasgow locomotives has been the key to the survival of the DHR but the lack of spare parts is becoming a serious threat to continued use of the engines.

Maintenance is becoming increasingly difficult, not least because the rail line is of a narrow two feet wide gauge and engines and carriages built to suit this gauge are rare.

Conditions on the line itself have often been disastrous. The 88km (55-mile) stretch of line between New Jalpaiguri and Darjeeling has been closed in the past due to landslides, the latest closures for a period of nearly five years.

The full DHR only reopened last month and though the railway operators have tried to introduce diesel locomotives and more comfortable trains, the railway has failed to make a profit for some years.

India’s state railways have been rumoured to be near to closing the line in the past, but local people and an 800-strong band of supporters in 24 countries – they form the UK-based Darjeeling Himalayan Railway Society – have campaigned to keep it open.

The DHR is held in deep affection in India, where it is a major tourist attraction.

The line has featured in numerous Bollywood films and was the inspiration for the American comedy drama The Darjeeling Limited starring Owen Wilson, Adrien Brody, Natalie Portman and Bill Murray.

It also featured in an award-winning documentary series on the BBC which told of the difficulties of keeping the line open back in 2010.

An offer has been made to turn the railway into a private enterprise but the Indian state railway’s trade unions objected and the plan was shelved.

There has been fresh investment and upgrading of stations but the maintenance situation is becoming critical, and that’s where the DHR Society – patron Sir Mark Tully – has stepped in. Paul Whittle, vice-chairman of the society, told The National: “Maintenance standards for the Glasgow-built iconic ‘B’ Class steam locomotives have been, and continue to be, a real challenge.

“The society has been active in supporting the DHR with help and advice and our director of engineering has made several working visits to the railway workshops at Tindharia.

“Signs of tangible improvements are already evident and we will be continuing that support.”

As to the future of the line, Whittle is confident it will survive, perhaps with some private investment.

He said: “The DHR has certainly had some challenges to face.

“In December a timetabled service was once again able to operate the whole length of the 55-mile line which had been blocked by a landslip since mid-2010.

“The very costly repair work was a clear statement that Indian Railways is determined to keep the entire railway in service.

“The DHR is a hugely important contributor to the tourism of North East India and despite its problems we see a positive long-term future for it.

“De-linking it from the mainstream Indian Railways and introducing private sector expertise and enterprise could certainly prove a part of that.”

It would seem that the last narrow gauge working steam locomotives from Glasgow’s industrial heyday are not about to run out of puff just yet.

Delight as the Flying Scotsman takes to tracks once again