I was surprised that Whiteball was closed again for work not that many years after it was last closed for major work. Is there a problem with this tunnel that needs addressing every few years?
When that question was raised two weeks ago (by Timmer, as it happens!) it got half an answer. Poking about a bit more, and trying to pick the more reliable third party sources, it seems that:
- In 2011/12, a third of the tunnel was lined as an emergency measure with RamArch steel mesh to catch the falling bricks.
- During the three-week closure in 2014, at least the crown of that section of the tunnel was sprayed with concrete to form a new lining, and by some reports the rest of the tunnel was lined with RamArch and the crown sprayed with concrete. But reports are contradictory.
- The plan then was for a new clever train-mounted rig to spray one side at a time during overnight closures while the other line was open for trains to run by day. This was from AMCO, now AMCO-Giffen, who made the multiple-head drilling trains for fixing the RamArch and also for the conductor rail in the Severn Tunnel.
- But in 2109 there was a three-week closure to spray the tunnel sides, though other work may have been done as well. So it looks like another of NR» 's clever high-output on-track machines has to be marked as "disappointing".
- It now appears that there is more work that still needs doing after that closure has ended. Presumably this is the in the parts of the tunnel where relining is less urgent. Whether it can be done without a full closure, we'll have to wait and see.
Further reading/pictures from
Cornwall RS, and on P 92 of the
March 2014 issue of The Rail Engineer (Archive).
Click on the map to explore geographics
