[train passing] ♪ background music ♪ (Narrator)
This is the Railway Technical Centre in Derby. It’s where we at Network Rail house our fleet of 9 infrastructure monitoring vehicles. We use the vechicles to test pretty much everything there is to test on the network. From the overhead wires, down to the ballast on which the track sits. We carry out monitoring in order to predict and prevent track faults occurring. The workhorse of our monitoring fleet is the New Measurement Train. It surveys our entire mainline network every two weeks covering over 110,000 miles a year. The NMT is a modified high-speed train. Rain or shine it can record track at speeds of up to 125mph, allowing us to work during the day with minimum impact on passenger services. The NMT’s array of sensory technology make it the most technically advanced train of its kind in the world. Transducers and accelerometers mechanically measure the up and down movement of the train as it travels along the rails, giving us information on track geometry. As well as mechanical devices, the NMT also carries optical instruments. This laser sensor gives us vital profile information on the rail head. A new expert system called “Plain Line Pattern Recognition” is currently being developed on the train. It employs a series of lasers and cameras with image analysis software to automatically detect faulty track components as the train passes over them. All the NMT’s sensors, whether mechanical or optical, feed their information into the banks of computer equipment on board which are in turn monitored by our on-train crew. (Carl)
One of the primary objectives of the New Measurement Train is recording the track in a digital format. We’re looking for three main types of defect. There’s “twist”: this is where the two tracks are no longer parallel and one of them has dropped slightly or raised slightly. This would give the train a tilting effect as it goes over. If this was allowed to carry on far enough, you would derail. Next on top of that we’re looking for a defect called “cyclic top”: that is where the train basically starts a small bouncing movement. As this happens and various trains go over it, it gets worse and it gets worse with every train that passes. Eventually you’ll find that a freight train will pass over this and its suspension isn’t as sophisticated as, say, a passenger train. What would happen then is the freight train will go over and, eventually, bounce off of the tracks. Last of all we’re looking for “gauge”: gauge is the width of the track. What you’ll find is, in places, things aren’t quite as they should be and the track might get a little bit wide or a little bit tight. Generally what happens there is we’ll monitor it and we’ll never let that happen. On the New Measurement Train the simplest way of explaining this job is we’re converting all the features of the track into just a digital format: basically ones and zeros. The New Measurement Train covers all of the main routes. These are the main arteries if you like of the railway network. I always find it a constant source of amazement how many miles we can cover in a day. Some of our shifts are up to 1,000 miles long. On this vehicle we’ve got around about 40 sensors. They can range from LDVTs, lasers, giros and accelerometers. They’re constantly feeding information into the computers here behind me. That’s then displayed out on these monitors. What we’ll generally do is, throughout a shift, look for any serious defects. Any other minor defects are also monitored in the background and any defects that are found are stamped with a GPS location making it almost pinpoint accurate for the engineers to come and rectify. At the end of a shift we’ll then package all that data up and send it out to EDC which is the Engineering and Data Centre in Derby where the information is processed further. The train’s capable of testing at 125mph. That’s on all systems. Initially, I got the job about 10 years ago. My previous employment I used to be a non-destructive test engineer. Non-destructive testing is quite simply testing anything without destroying it. It’s non-intrusive methods of inspection i.e. looking through things rather than cutting them in half to see what’s there. With the new measurement train we’re doing a form of non-destructive testing at high speed. Computers make a massive difference to the job. There isn’t a day go by where we don’t look at a screen of some form or another. The automated analysis that the vehicle does on its own allows us to not have to block the lines. It allows trains to run freely in front and behind us. Today we’re recording around about 130 miles. It would take hundreds of men to just record that. The clue’s in the name: New Measurement Train is a testbed for new monitoring equipment. We have two vehicles on the train. There’s the production vehicle which core job is to do the track recording and the development vehicle which we do test out very new systems on. If there was a fault serious enough to block the line we’d instantly tell the driver. He would then stop the train. This would then not only block the line with our presence on the track, we’d then go and tell the signaller what needs to be done and then we will continue testing. Many other faults we find tend to be scheduled into the maintenance regieme. On the front of the train we’ve got HD cameras. It’s such an effective way of monitoring the track without having to come out and investigate in person. The New Measurement Train is definitely the best train we’ve got in our fleet. It’s the fastest, it’s got the most equipment, it covers the largest distance in any shift, it’s somewhat of a legend. I love my job for many reasons. Firstly, the scenery out of my window is always different. It’s far better than turning up to an office every day! Secondly, I’m on the cutting edge of technology. We get to work with systems worth millions of pounds. Last of all, I know that I’m making the railway a safe place to be.