KANNUR:
The aerial survey to identify the alignment of Kerala’s ambitious Thiruvananthapuram-Kasaragod Semi High-Speed Railway (SHSR) project got under way today, covering the northernmost 80 km stretch from Kannur in the initial phase of the exercise.
The aerial survey will be completed in seven days for the entire 532 km stretch up to Thiruvananthapuram, marking the first vital step before commencing the work of the project, named Silver Line, which will reduce the end-to-end travel time across the state to four hours.
LiDAR (Light Detection and Ranging) aerial remote sensing method is being used for the survey, conducted on a Partenavia P68 series aircraft that took off from Kannur International Airport (KIAL).
A joint venture of the Kerala Government and the Ministry of Railways, the project had obtained the in-principle approval of the Centre on December 17. The Civil Aviation Director General, and the Ministry of Defence had given clearance for the one-week-long survey, followed by the green signal from the Railway Ministry.
The special permission of the Ministry of Defence was required since the aircraft has to fly over highly-sensitive security zones, and it is also mandatory that Indian pilots should be assigned for duty. The survey is being carried out by Hyderabad-based GeoKno India Pvt. Ltd., which had also conducted LiDAR survey for the Mumbai-Ahmedabad bullet train project.
According to V. Ajith Kumar, Managing Director, Kerala Rail Development Corporation Ltd, the implementing agency of the project, also called K-Rail, this survey will help identify the alignment very fast and start the construction. K-Rail is a joint venture by the State government and the Central Railway Ministry.
“This will enable K-Rail to prepare a detailed project report (DPR) and launch the final location survey soon. Albeit ubiquitous across the world, Silver Line is the second rail project in India to rely on LiDAR survey,” he said.
From Kasaragod to Tirur the Silver Line will run parallel to the existing railway track. From Tirur to Thiruvananthapuram, the line will pass separately from the existing railway line since that stretch has a large number of curves that hamper the speed.
The SHSR corridor is expected to reduce congestion and pollution on the roads, improve safety and considerably save the huge cost resulting from the dependence on imported oil. The airports at Thiruvananthapuram and Kochi will be connected with the SHSR. It will have 10 stations and a proposal to build short-distance feeder links to connect to other stations too is also on the cards. Trains will have a maximum speed of 200 km/h.
LiDAR survey is conducted using the reflection of laser rays and the equipment in the helicopter will have a laser unit, scanner and GPS receiver. The laser rays will scan the surface of the earth and the returning rays are received in the sensor to map the route.
Through the survey, accurate details of the land will be available without disturbing the public life. Moreover, it can precisely identify forests, rivers, roads, wetlands, buildings, electricity line and heritage zones. The high-resolution cameras used in the LiDAR unit can detect tree-covered low lands.
The land that has a width of 600 m is being surveyed for Silver Line, and the line will be set up in the suitable 25 m width land. The ground points for this have already been set up. The LiDAR eye can detect things ranging from buildings, people inhabited areas, forest and bridges to stone benches and bushes, enabling to complete the alignment by avoiding things that are beneficial for people. Silver Line requires space for two lines and it will pass through sky ways in cities.
