What shall we do with a railway line like Dawlish?

Over the past two months, there have been numerous articles, speeches and discussions about the railway line at Dawlish, on the Devon coast, just a short way from Exeter.

There has been so much discussion on the internet that Google's auto-complete feature suggests "Dawlish railway" as soon as you enter "Dawlish".  In the first week in February, during a series of severe storms, the sea wall at Dawlish was destroyed and the railway track left suspended over a void.
(c) Getty images
Needless to say, no trains could run along the track.  And as a result, no through trains could run from Plymouth, Torquay and Cornwall to London - or anywhere else in mainland Britain.  The line through Dawlish is the only railway link between western Devon (and Cornwall) and the British railway network.

It wasn't always like this.  In the great days of railway travel, there were other routes that linked  the western end of the peninsula with the rest of the UK, but in the cutbacks of the 1960s, only the one line was left.

Dawlish has always been a problem for the railway line.  In winter storms, waves frequently wash over trains on the line, and services may be interrupted.  But the damage last month is far more serious than ever before.  It will be April 4th when the first trains can run again, after intense engineering work on the line, the sea wall and sea defences.  With eight weeks without a rail link, businesses all over Devon are counting the cost, with estimates of £5million lost per day. 

Proposals for alternative routes have been put forward.  The BBC report gives a very good summary of the five alternatives, of which three are essentially variations of the same concept.  Emotions are running high for some action, and several commentators draw a parallel between the investment in the infrastructure of Devon and the money that is planned to be spent for the high speed rail link between London and the north of England.  Why not invest in links to the west of England as well (or instead)?

So where can O.R. help?  Let's call the three alternatives A, B and C.  A is a line from Exeter to Plymouth, via the towns of Okehampton and Tavistock.  That would follow a former route, closed in the 1960s.  It would be the "easiest" to build.  However, it would link Exeter and Plymouth but bypass Torquay and south Devon.  It would be inconvenient to use as trains would have to be reversed in Exeter and Plymouth because of the track layouts.  B uses an old line from Newton Abbot to Exeter, which has been closed for fifty years, and whose tunnels would need to be reopened, possibly rebored.  C would be close to B, following one of three routes to bypass Dawlish by going through new tunnels. 

Engineers and economists can produce costs for each of these.  O.R. can produce models of demand for train services along the lines, and can help bring some rationality to the emotive atmosphere about possible decisions.  Here are some considerations

(1) Should the line at Dawlish be closed completely in favour of a new route?  That is not on anyone's agenda; the route through Dawlish is (a) picturesque and popular with holiday visitors (b) fast (c) a good link for the urban areas of south and south-west Devon

(2) If any of the options is chosen, will there be regular services all year round on that line, or will it simply be kept as a "Spare part" in case the line at Dawlish is broken?

(3) How much will it cost to keep a line in reserve "just in case"?

(4) If a line is used regularly, how often should trains run, and should they be through trains to other parts of the UK?  What would the demand be for such services?

(5) ... and more difficult ... what is the expected time before the line at Dawlish is broken again?

(6) What would cost-benefit show for each of A/B/C in the absence of emotion about "being cut off"?  Can one justify any of A, B or C on the basis of regular use?

Currently, the main line between Exeter and Plymouth/Torquay is well-used.  It is not used to full capacity - more trains could be run along it if there were sufficient demand.  So one cannot justify having two lines to Plymouth on the basis of demand for train services.  Potential demand from communities that would be served by A/B/C is small and thus there is only a slight economic case for those lines in the absence of the problem of Dawlish. 

I fear that the rational discussion may be drowned (pun intended) by hysteria about "remember Dawlish in 2014". 

Meanwhile, a "2014 Railways of Dawlish" calendar is still on sale here


Popular Posts