Monday, 3 June 2013

The Earth Moved

Something funny happened over the winter to a length of my track. The sharp (actually, it's 5' radius) curve about to be traversed by the cat in the picture, got longer!

I first noticed that the two rail joints on the curve were getting wider. For a while, it was still passable to trains. But by the time I did something about it, the gap was almost the length of a fishplate.

Mac heads for the affected curve.
What I found on investigation was that the rubbercrete capping had separated from the brick base in this area. Why it had stretched I don't know, but no longer bonded to the bricks there was no stopping it!

The "slipped" curve after corrective work to the trackbed, and before the track was relaid.

On Monday, the track was relaid on the down main line, and trains were running again, single-line, with a 20mph speed limit until the ballasting was complete.

A ballast train approaches the new section of track.

An overhead view of the site.

Ballasting in progress.

The team

You may have noticed that the new track is being laid with some precision on a narrow strip of rubberised cork, whereas the old track was on a wide strip of closed-cell foam. I don't pretend that this is a new method of track construction, but it is new to this railway, and aims at eliminating some of the disadvantages of the old method. Whether it brings with it any new problems, remains to be seen.

Advantages of new method:
  • Curves are made with a series of 100mm straight lengths end to end, allowing curves and transitions to be laid out and adjusted accurately before track is laid.
  • Banking on curves can be set up and measured accurately before track is laid.
  • More rigid than foam, so track pins do not cause sleepers to bend in the middle,
  • Accurate width facilitates a neater ballasting job.

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