Good news for Nagpurkars as Mahametro has announced the dates of trial run track laying completion. The tracks will be laid out by August 25 for the trial run between Mihan depot and Khapri depot. The electrical traction system will be installed simultaneously.
According to a source in Mahametro, there are two types of grade section. "One is the ballasted (gravel) track which covers most of the stretch and the other is ballast-less (concrete) track that covers the viaduct over Concor siding. About 90% work on ballasted track is over and 25% work on ballast less track remains. We will complete both by August 25 and then the coaches will be able to travel from Mihan depot to Airport South station," he added.
The work of placing ballast had started in mid-January. Approximately 300mm long cushion was created and sleepers were laid at an interval of 60cm, after which, 18-metre long rails were fixed upon them.
The distance between two rails is 1,435 millimetres, which is the specification for a standard gauge track. Instead of using fish plates as in the past, they were joined by flash butt welding or AT welding.
While he head hardened rail is manufactured in Russia by a Swiss company, the other components are produced in India. The specification of the rail is 1080 UIC 60.
The rails are fixed on a concrete plinth beam in the ballast-less section. It has no sleepers and double resilient base plate fastening system is used. Every base plate is placed at a gap of 60cm, just like the sleepers.
The grade section has seventeen horizontal curves having a radius from 391 mts to 18kms. The Metro viaduct in this section has 25 piers. There are two scissor crossovers located near Khapri and Airport South stations having radii of 190 m and 4.5 m. The crossovers will help facilitate change of lines and reversal of coaches.
Information source: timesofindia
Title image: metro-report