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1/21 With Summer coming to an end and poorer weather on the horizon, a Train Driver’s thoughts start to turn towards Leaf Fall Season but just how slippery do tiny leaves make the railway? And what can be done to reduce the risks?
2/21 “Leaves on the line” is a perennial favourite of the press for a bit of comedy value but, as any Driver will tell you, the dangers are very real and a professional Driver will look to mitigate the risks as part of his or her driving during the slippery season.
3/21 One of the beautiful things about our country is the wealth of greenery it offers. After all, William Blake didn’t call it a “green and pleasant land” for nothing. Sitting in your seat as you cruise through the countryside, you only have to look out of the window
4/21 to see thousands of trees rushing past you beside the railway line. Of course, come the Autumn, these trees start to prepare for Winter by shedding their leaves – and, in the process, creating some of the most beautiful reds, yellows and browns as they do so.
5/21 Unfortunately, the falling leaves then fall on the railway and this is where the problems start. Liz Bonnin (@lizbonnin) demonstrated the problems perfectly in this Bang Goes The Theory segment, please do take a moment to watch:
@lizbonnin 6/21 It’s worth mentioning that, as a Driver, you can actually see the top of the rails turn colour. If conditions are good, the top of the rail is very shiny but, if leaves have been crushed over them, the shine goes dull and black.
@lizbonnin 7/21 So, what can be done to reduce the issues? After all, we still have to get to our destinations on time. In practice, there are quite a few things that we can do.
@lizbonnin 8/21 The first thing is the “Leaf Fall Timetable”. Railway operators build extra time into each journey to allow for the reduced speeds at which trains will run. If you’re a regular traveller, you will be aware that the timetable can vary by a few minutes at this time of year.
@lizbonnin 9/21 Secondly, in conjunction with Network Rail, who maintain the tracks, a fleet of Multi-Purpose Vehicles (MPVs) will run on the railway, literally blowing the leaves off the line.
@lizbonnin 10/21 They can also lay down a sticky substance called Sandite – a mix of sand, aluminium and an adhesive – on those areas of track known to be at a higher risk of low adhesion.
@lizbonnin 11/21 The Driver also has tools available to reduce the risk of sliding on the railway. The train’s own Wheel Slide Protection (WSP) system works very similarly to anti-slip brakes on a car.
@lizbonnin 12/21 Each axle is monitored and compared to all of the other axles on the train. If one starts to slide on braking, it will rotate more slowly than the others so the WSP system will release the brakes on that axle until its speed matches the others.
@lizbonnin 13/21 Trains are also equipped with sanding systems. On certain axles, a very thin pipe runs from the underside of the train down to end just in front of the wheel.
@lizbonnin 14/21 If the WSP system detects sliding, the train automatically starts to lay a thin layer of sand down on to the rails in front of the wheel, assisting the grip needed to brake effectively.
@lizbonnin 15/21 On braking, this is an automatic process but, on accelerating – particularly when leaving a station – the Driver has an override button in the cab so (s)he can lay extra sand as the train departs.
@lizbonnin 16/21 We can also mitigate against the risks by carrying out regular “Running Brake Tests”. Here, the Driver will test the adhesion near a station well before (s)he actually needs to start braking for it.
@lizbonnin 17/21 This has two benefits: (s)he can see if the area is slippery and also, the speed of the train is brought down so that less distance is required for braking.
@lizbonnin 18/21 Occasionally, of course, the preventative measures might not have the desired effect and the train does slide.
@lizbonnin 19/21 Drivers are all trained to recognise the signs quickly, remain calm and take action accordingly, increasing the braking force and allowing the train to do its work in preventing the slide.
@lizbonnin 20/21 If an area is particularly slippery, the Driver will contact the Signaller who will arrange for tests to be carried out in that area and warn approaching trains of the conditions until the rails can be treated.
@lizbonnin 21/21 Hopefully, this thread will help you to understand why journeys can take a little longer in Autumn, how dangerous leaves actually are to trains and what a professional Train Driver can do to ensure that you reach your destination safe and sound.
