Centenary celebrations for a British-built railway line in India have been galvanised by a blast from the past.
By Baldev Chauhan
BBC correspondent in Simla
The restored British-built KC520 engine puffs into Simla station
The KC520 steam engine, built to ferry British soldiers, bureaucrats and their families from the sweltering Indian plains to a hilly Himalayan retreat, has been restored to its former glory.
It was flagged off by the Indian railways minister, who was in the mountain resort of Simla to mark 100 years of the Kalka-Simla railway this weekend.
Its reappearance - in full working order - 32 years after being consigned to a museum, has brought hope to India's railway enthusiasts.
They are fighting to preserve the narrow-gauge track and to have its value recognised by the United Nations' heritage body, Unesco.
They have been lobbying Unesco to grant the track official World Heritage status, as enjoyed by the 104-year-old "toy train" of Darjeeling, eastern India.
"A Unesco team was here about a couple of months ago to take a look at the 96 kilometre track," Simla's station manager, Praveen Kumar, told the BBC.
Trouble on the tracks
The track from the town of Kalka, at the edge of the plains, to Simla, the former summer capital of British India, is a marvel of engineering.
The Kalka-Simla track has been recognised as an engineering feat
Work began to lay the lines on steep Himalayan terrain in 1889.
The track rises dramatically from 650 metres above sea level to a breathtaking 2,100 metres, passing through 103 tunnels, 969 bridges, 919 curves and 18 railway stations along the way.
The railway was inaugurated by Lord Curzon, the British viceroy in India, in November 1903.
However, all has not been well with the imperial engineering marvel recently.
"The route is consistently undergoing major losses," said the Mr Kumar.
Tickets on the track are heavily subsidised by the Indian government, which has long been trying to boost Simla's economy with holidaymakers' money.
A one-way ticket on the train can cost as little as $0.50, which leaves it with losses of around $2m a year.
Railing against railways
Conservationists and enthusiasts believe world-heritage status will bring in fresh resources to help fund overdue maintenance work.
Simla-based preservationist Ajit Butail, who is also a member of the Indian National Trust for Art and Cultural Heritage, believes more could be done.
The train passes through stunning mountain scenery
"Unfortunately, the heritage issue hasn't been taken up aggressively enough with Unesco by the Indian railways."
"I hope they will do so now, when the entire nation is looking towards this track," he said.
Mr Butail recently joined fellow conservationists on a walk along the 96 km route, in a bid to draw attention to the need to preserve the track.
Celebrated American writer, Paul Theroux, described his journey along the Kalka-Simla track in his 1974 bestseller, The Great Railway Bazaar.
The BBC's veteran India correspondent, Mark Tully, is another enthusiast - he is now vice-president of the Indian Steam Railway Society.
But despite some friends in high places, India's 63,000 km railway system has been struggling for years.
And the problems facing the Kalka-Simla track are symptomatic of a broader malaise afflicting India's railways.
This year sees the 150th anniversary of the railway network built by the British to control and develop their colony.
It has been losing money for years because of unviable routes and artificially low fares.
Efforts to reform the railway system have met fierce political opposition.
It is the world's biggest employer, with a workforce of some 1.6 million people.
Simla's cool mountain air made it an ideal summer capital for the British
Attempts to update the network could have a serious impact on those whose livelihood depends on it.
So, the authorities have tried other means of raising money.
The Kalka-Simla train, for instance, can now be chartered by hoteliers and film-makers at a cost of $2,000.
Flying spark, flaming hill
One such deal ended in disaster in December 2001.
A stray spark from an antique steam engine, chartered by a Canadian film crew, set alight the dry grass around the track.
A helicopter was brought in to put out the fire, but the gusts of wind it created only fanned the flames.
The fire was finally put out, but not before crops around the track had been destroyed.
The railway authorities must hope a similar misfortune will not befall the KC520 as it returns to the route it began plying nearly a century ago.