Kalka (Himachal Pradesh), Sept. 12 : Indian Railways are upbeat about getting their fourth valuable asset listed as a World Heritage site.

United Nations Educational, Scientific and Cultural Organization (UNESCO) officials began evaluating the feasibility of the Kalka-Shimla toy train being included in the World Heritage sites on Tuesady.

"I have done reports for the Darjeeling Himalayan Railway and the Nilgiri Mountain Railway in Tamil Nadu. On both those occasions, the reports were favorable. The sites were inscribed. But I can't say anything about this one yet," said Robert Lee, a UNESCO consultant.

The toy train, so called because of its miniature size and its movement at a snail's pace, are presents an old-world charm.

Introduced in 1903, the train has chugged along to the present times.

"The Kalka-Shimla section, which was opened 104 years back, has got some technologically superior features, particularly in terms of bridges, curves and tunnels. The mechanical rolling stock is the most heavy worked narrow gauge railway on the entire world, not only in India," said H.K. Jaggi, Divisional Railway Manager, Ambala.

The UNESCO team will evaluate the rail network for three days. The final verdict is expected by July next year.

The toy train would have been a strong contender, but for a nearly six-year-old decision to replace classic steam engines with diesel after a fire mishap during a film shoot by a Canadian crew in December 2001.

In 2004, the Indian Railways shelved a similar move to replace the steam locomotive with a diesel engine on the Darjeeling toy train after the UNESCO threatened to withdraw its World Heritage status.

The six-hour journey from Kalka to Shimla takes the train through 107 tunnels and connects to a number of hill resorts, including Dharampore, Taksal, Gamma and Solan.

The journey offers the passengers a picturesque view of the Himalayan range.