05.02.19
Flying Banana reaps the fruit of its labour
Source: RTM Dec/Jan 19
Steve Quinby, Network Rail’s head of data collection, gives us the rundown on the state-of-the-art ‘Flying Banana’ train.
Managing a railway stretching 20,000 miles – from Wick to Penzance, Lowestoft to Aberystwth, and the hundreds of cities and towns in between – is a considerable challenge for Network Rail. Quite rightly, the 4.7 million passengers who use the railway every day expect a safe and punctual service. Our New Measurement Train (NMT), known more affectionately as the ‘Flying Banana’ because of its distinctively yellow appearance, helps us provide just that.
Travelling at speeds of up to 125mph, the NMT uses a combination of track geometry, laser scanners, high-resolution cameras, overhead line inspection systems, and plain line pattern recognition (PLPR) technology to detect infrastructure faults as the train passes over the tracks. It covers an average of over 2,000 miles a week – or 115,000 miles a year – meaning we can discover track defects before they become a safety issue or affect performance as part of our shift towards a ‘predict and prevent’ strategy.
The NMT offers a number of benefits to Network Rail. The ability it gives us to target our maintenance more effectively saves us millions of pounds in what would otherwise have been spent on unnecessary work. It also represents a safer method of track inspection by reducing unnecessary track defects and helping to get boots off the ballast. The NMT and our other monitoring trains slot between timetabled trains, meaning there are no delays or disruption as they carry out their work.
There are many types of faults that the NMT helps us to find. These include a twist, which is when two tracks are no longer parallel and which, if left undetected, risks causing a train derailment. The NMT can detect cyclic tops, where a dip in the rail surface causes a wheel to bounce, potentially leading to damage elsewhere on the rail. It also monitors the gauge of the track to prevent it becoming too wide or too narrow. If a serious fault is found, on-train technicians on the NMT have the authority to close railway lines and order an immediate fix if required.
The NMT has the capability to carry out shifts of up to 1,000 miles at a time and captures around 10TB of image data every 440 miles.
Track geometry: how it works
A laser sensor gives information about the position of each rail. Meanwhile, transducers and accelerometers mechanically measure the up and down movement of the train as it travels along the rails. This data provides information on track geometry – key in ensuring the track adequately supports and guides rail traffic.
PLPR: how it works
Our PLPR system uses a series of cameras and lasers to detect faulty track components. Image analysis software uses an algorithm to compare what the cameras see with an image of what the track should look like. For example, it might identify missing clips which secure rails to the sleepers. The NMT takes high-definition photographs at 125mph speeds, with one photo taken every 0.8mm. All faults found are sent to inspectors for further examination in our PLPR facility in Derby, who can ensure local track section managers are informed of any relevant track faults on their patch.
Not ‘new’ – but as effective as ever
Despite its name, the NMT can no longer be classed as ‘new,’ but it is constantly updated with the latest equipment to retain its status as the most technically advanced train of its kind in the world. Fifteen years after it was first introduced to our fleet, it continues to help us reduce delays and provide a safer railway for the millions of passengers who depend upon it.
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