Good catch.

RMV = rail maintenance van. It is a glorified and self propelled trolley used by "gangs".

That's a Ballast Regulating Machine (BRM)

This is probably a Ballast Spreader cum Cess Compactor.The folding plates on the flanks are lowered to give the neat slope to the ballast on the "cess".

All credit for the so called derailment goes to the Gang which was doing the thermit welding, the removal of clamps resulted in the increased width of the track and the inevitable happened. At least it didn't derail when Bizzy Mishra, Pawan Koppa & I were near the truck !!! Dilip Setlur

great shot! how you do you expect drivers to accelerate if tracks look this from this angle.

A high level platform is 760-840 mm high from the rail top. While carrying out track renewals or platform surfacing (or making new platforms), this height often needs rechecking. Maybe that's what is happening here.

This is a Plasser's Quick Relaying System (PQRS) depot and the machine is a portal crane. Interesting to note that departmental crane is working the depot. On NR, mostly contractors work the depots while the actual relaying at site is done by departmental cranes. The contractors have their own portals for the depot work.

Have a look at
http://www.iricen.gov.in/projects/613/DESIGN%20DEVELOPMENT.pdf

Why aren't the two rails at the same level? Would the wheels travelling on the higher rails experience a thud when going over the lower rails? Having both rails at the same level would also potentially eliminate the panto-lowering and re-raising exercise.