After Mussoorie based author Bill Aitken and former BBC south east Asia correspondent Mark Tully, British author Terry Martin has termed the move as foolish, saying, ``Replacing the steam engine with a diesel locomotive is to prise the diamonds from the crown (of the DHR) and replace them with glass.'' Aitken and Tully and other avid lovers of the vintage steam railway had earlier expressed their displeasure at the change after diesel locomotives were introduced on the narrow gauge line.

The 19th century engineering marvel was declared a World Heritage Site by the United Nations Educational Scientific and Cultural Organisation (UNESCO) last year for being the world's first hill railway system that's still in active use after over a century, and also ``served as a model for similar developments in various parts of the world''.

The author of Halfway to Heaven, a complete encyclopaedia of the DHR toy train system published recently in the UK, Martin is acknowledged as an authority on the subject for producing the only research work of its kind. In an e-mail sent to this newspaper, strongly reacting to the news of the DHR's dieselisation, he dismissed the Indian Railway's argument that the diesel locomotives provided better speed.

The Railways had contended that using the 70-111-year-old steam engines on the 55-mile journey from New Jalpaiguri in the plains to Darjeeling at 2,200 metres above sea level was no longer feasible as the antiquated engines were taking over eight hours to make the trip. The engines needed to stop frequently for water, refuelling or repairs. The diesel locomotives, on the other hand, but the journey time by two hours.

``The records show that the DHR was able to comfortably maintain a service between Siliguri to Darjeeling in 1930 that took a little more than five hours-with four bogey carriages and at least one freight wagon. The coaches then were heavier than they are today. Even during the Second World War when the train was jam-packed with soldiers, the 1942 timetable shows the `mail' was still able to depart from Siliguri at 6.40 hours and arrive at Darjeeling by 12.12 hours. This demonstrates what the properly maintained steam engines were capable of,'' Martin said.

The technology, he said, was now available to build highly efficient oil fired steam engines that would not need to frequently stop for refuelling and water. Replacing the old steam engines with new ones would at least preserve the basic character of the train system, he explained.Meanwhile, UNESCO has demanded an explanation from the Indian authorities on their intentions of replacing the steam engines.

In a letter addressed to Neelam D Sabharwal, India's permanent representative at UNESCO, with a copy to the director general of the Archaeological Survey of India (ASI), the director of the UNESCO World Heritage Centre, Mounir Bouchenaki, said: ``In order to ensure that the value of the site is fully preserved and to prevent any decisions which could negatively affect the site in the future, the (Indian) authorities should immediately inform the World Heritage Committee of their intentions.''The gradual replacement of a very essential character of the site, he reiterated, could undermine the world heritage value of the DHR in the future.

D P Tripathi, secretary in the Railway Board, in his explanation to the UNESCO's south east Asia office, has however referred to the Asian Institute of Transport Development for recommending partial dieselisation of the DHR. ``In its report on `Evaluation and Rehabilitation of the DHR', the institute had recommended partial dieselisation of the long distance service between New Jalpaiguri and Darjeeling and restricting steam services to shorter sections between Darjeeling-Ghoom and Darjeeling-Kurseong... to provide a reliable service to the passengers,'' Tripathi said, while adding that Rs 6.49 crore were being spent for the renovation of the tracks and bridges on the DHR.