While I.K. Brunel was making extraordinarily wide railways towards the west of the U.K. in the nineteenth century, other Engineers were struggling with the balance between first cost and opening date elsewhere, resulting in some interesting compromises. Making things a bit smaller made them a bit cheaper, and if money and time were tight then so it had to be. The line to Hastings was a particularly awkward one, a small tunnel requiring the design of especially narrow rolling stock for that route. Upon recent electrification the line through the tunnel was singled, and the need for the narrow stock disappeared.
Gauging Trials and Engineering Errors
The practice in the U.K. is still to carry out "gauging trials" on lines before new or unusual rolling stock is used. Three recent incidents come immediately to mind with varying degrees of humour and alarm to accompany them:
- The sole surviving class 306 3-car overhead-electric unit was towed over the 3rd & 4th rail electric Metropolitan Line of the London Transport network a few years ago. Metropolitan Line trains are in themselves a bit wider than most regular U.K. stock and the 306 is similar. Imagine the consternation caused at Rickmansworth station, which is sharply curved, when the said 306 cleared the platform canopy valance by only a couple of millimeters.
- Some brand-new Chiltern Line trains had to be restricted from certain routes owing to the outward-opening plug doors fouling the platforms when opening during initial testing and thereby becoming mechanically inoperable.
- And a tall heritage steam locomotive, in steam, caused major panic and emergency action by the crew when its safety valves struck an overbridge on a line where proper gauging trials had not been carried out beforehand, breaking these fittings clean off the top of the boiler…
The TGV in Kent: Mission Impossible
The film "Mission Impossible", starring the US actor Tom Cruise, is excellent cliff-hanger entertainment. It is rather spoilt as far as the purist is concerned by the inappropriate depiction of a French TGV train streaking through what is supposed to be the Kent countryside towards the Channel Tunnel rail route. The TGV, amazing as it is and being the same track gauge, is simply too tall and too wide to operate over Kent's lines, which is why the superb Eurostar trains, shorter and thinner to suit the UK's smaller loading gauge, operate all the way from London to Paris and Brussels over the TGV routes instead while they pass through France. Indeed, when the time is right, they could probably take him over the new high speed network all the way to Madrid.
From Mallard to Bullet
The UK's National railway Museum is located in the city of York, and it has a deserved international reputation. At the time of writing, admission is free-of-charge. Under an arrangement with Japanese Railways, it took delivery of one of the driving-end vehicles from a retired "bullet train". Both of them being painted blue, it stands gloriously and impressively alongside "Mallard" (image at right), still the fastest steam locomotive in the world, at the entrance to the main gallery. Although both are to the same track gauge, what isn't generally known is that the bullet train vehicle is so wide that, as it was being gently propelled into the building, it only cleared the main entrance doorway by about the thickness of a coat of paint.
Editor's Note: CR4 would like to thank PWSlack for contributing this two-part series. (Cheers!) Click here if you missed Part 1.
Resources:
http://en.wikipedia.org/wiki/Track_gauge
http://en.wikipedia.org/wiki/Variable_gauge
http://en.wikipedia.org/wiki/Loading_gauge
http://en.wikipedia.org/wiki/Rollbock
http://en.wikipedia.org/wiki/British_Rail_Class_201
http://www.nrm.org.uk/
http://www.didcotrailwaycentre.org.uk/guide/broadgauge.html
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Re: Load Gauges and Railway Construction (Part 2)
