Saturday night I called in to Croydon and West Croydon to check on the progress.

There were two concrete slabs next to the line at West Croydon. Very heavy looking, maybe 300 - 400mm thick.

Having watched a 200T capacity Fleurieu Cranes' Demag set up for an hour or so at West Croydon, we almost missed the first of two slabs being placed at just up the line at Croydon.

Most impressive at Croydon was the careful attention being paid by workers to getting the slab correctly positioned with reference to the rails. Two Laser units were facilitating the measurements. Fine work from the crane driver at one point lifted the slab 20mm to suit the engineers/surveyors.

It looked like the workers will be bolting down rail mounts directly to the slab.

The two shots were taken at Croydon station around 11pm on Saturday the 7th of March 2015.

[img]http://i154.photobucket.com/albums/s264/billd_photo/Croydon_March_2015_0852_small_zpshv0xzhip.jpg[/img]

[img]http://i154.photobucket.com/albums/s264/billd_photo/Croydon_March_2015_0851_small_zpsb8x6pvu9.jpg[/img]

A postscript to this thread.  At West Croydon the subway roof slabs has been covered with ballast and the track installed on timber sleepers, possibly to match the similar construction over the adjacent Rosetta St underpass.  At Croydon the roof slabs are uncovered and the track fixings bolted directly bolted to the slab.

Alex C

A postscript to this thread.  At West Croydon the subway roof slabs has been covered with ballast and the track installed on timber sleepers, possibly to match the similar construction over the adjacent Rosetta St underpass.  At Croydon the roof slabs are uncovered and the track fixings bolted directly bolted to the slab.

Alex C

I think that might be due to the fact that the West Croydon Subway is a lot deeper than the Croydon one so what worked on one did not work on the other! The one at West Croydon is as deep almost as the vehicle subway on Rosetta Street!

PPS. Both subways are now back in use.  At Croydon the unadorned slabs form the roof of the central lowest portion of the subway, while at West Croydon the underside of the slabs has been covered with plasterboard.  At both locations the foot of the main ramp is about 2m below road level and then further short ramps (under the platforms) down to the lowest section, where the headroom is c.2.2m.  The subway floor is 2.5-3m below rail level, being slightly deeper at W. C. by the depth of the ballast bed.

Alex C