British-era Kalka-Shimla rail track facing threat :

1. Chugging its way through history all the way to achieving a Unesco World Heritage tag, the British-era narrow gauge Kalka-Shimla rail track is facing threats - all of them man-made.

2. The massive cutting of the highly fragile mountain for four-laning the National Highway between Parwanoo and Solan towns in Himachal Pradesh has posed a threat to the rail track that was opened by Lord Curzon, the Viceroy of India in 1903.

3. Experts and locals say the maximum threat to the rail track is on a 30-km stretch between Parwanoo and Kumarhatti where frequent landslides and sinking of mountains due to soil erosion and loss of vegetation are high.

4.The hill slope is critical while building a road in the mountains but for the four laning of the 88-km stretch that connects Shimla and Parwanoo, the hills have been or are being cut vertically at most places, making the mountain ecosystem fragile.

5. Geologists blame unscientific cutting of precipitous hills, largely of shell, sandstone and clay, for the frequent landslips.

6. "Most of these mountain slopes are of sedimentary formation and have become destabilised with the reckless cutting by heavy earth-moving machinery. The loose and naked boulders with muck will continue to roll down on the highway for eight to 10 years more.

7. "On the Parwanoo to Solan stretch, most of the hill cutting was done largely vertically than horizontally. At some points, large-scale vertical cutting was carried out,".

8. Some of the stretches along the Parwanoo-Solan stretch have become permanent landslide points like Chakki ka Mor. The risk of driving is aggravated after dusk, say motorists.

9. A staggering 23,785 trees are likely to be cut for the road widening from Parwanoo to Solan, official records say. But the project aims to cut travel time between Chandigarh and Shimla by a mere 17 km.

10. The executing agency, the National Highway Authority of India (NHAI), says it is aware of the threats and taking mitigating steps.

11. NHAI project director added that they are aware about possible threats to the rail track with the construction of the National Highway. We are taking all preventive measures to safeguard the track,". The construction of the Solan-Parwanoo highway will be completed by March 31, except for the overbridges at Jabli, Kumarhatti and Solan.

12. UNESCO  had included the 30-inch gauge Kalka-Shimla rail line in the list of World Heritage Sites in 2008.

Kalka–Shimla railway :

The Kalka–Shimla railway is a 2 ft 6 in (762 mm) narrow-gauge railway in North India which traverses a mostly-mountainous route from Kalka to Shimla. It is known for dramatic views of the hills and surrounding villages. The railway was built under the direction of Herbert Septimus Harington between 1898 and 1903 to connect Shimla, the summer capital of India during the British Raj, with the rest of the Indian rail system.

Its early locomotives were manufactured by Sharp, Stewart and Company. Larger locomotives were introduced, which were manufactured by the Hunslet Engine Company. Diesel and diesel-hydraulic locomotives began operation in 1955 and 1970, respectively.

In 2007, the Himachal Pradesh government declared the railway a heritage property.[10] For about a week, beginning on 11 September 2007, a UNESCO team visited the railway to inspect it for possible selection as a World Heritage Site. On 8 July 2008, it became part of the mountain railways of India World Heritage Site with the Darjeeling Himalayan and Nilgiri Mountain Railways.[12]

On 7 July 2011 Indian Railways opened the Baba Bhalku Rail Museum in Shimla to document the history of the railway line and to display related artefacts.