WEBVTT Kind: captions Language: en 1 00:00:00.200 --> 00:00:03.320 - 140 years ago, the Callander and Oban railway, 2 00:00:03.320 --> 00:00:04.550 in the south-west of Scotland, 3 00:00:04.550 --> 00:00:06.570 set up a rockfall detection system 4 00:00:06.570 --> 00:00:10.370 along four miles of remote hillside railway track. 5 00:00:10.370 --> 00:00:11.542 The astonishing thing is: 6 00:00:11.542 --> 00:00:15.650 that system is still in operation today, 140 years later. 7 00:00:15.650 --> 00:00:19.600 And so far no one's been able to come up with anything better. 8 00:00:19.600 --> 00:00:22.870 - The West Highland lines travel hundreds of miles 9 00:00:22.870 --> 00:00:25.140 along natural mountainsides. 10 00:00:25.140 --> 00:00:26.915 There are different hazards depending on where you are 11 00:00:26.915 --> 00:00:28.800 on the Scottish rail network. 12 00:00:28.800 --> 00:00:31.240 Through the Falls of Cruachan, the hazards there 13 00:00:31.240 --> 00:00:34.760 are definitely rockfall and boulder fall. 14 00:00:34.760 --> 00:00:37.690 We're now at Bridge of Orchy on the West Highland line 15 00:00:37.690 --> 00:00:40.700 and the hazards here are much more natural landslides 16 00:00:40.700 --> 00:00:43.410 and debris flows down the steep-sided mountains. 17 00:00:43.410 --> 00:00:46.950 Rocks that are very small can pose a risk to the train operations. 18 00:00:46.950 --> 00:00:50.820 So something as small as a microwave can cause a train a problem. 19 00:00:50.820 --> 00:00:53.587 Something as big as a washing machine could lead to derailment 20 00:00:53.587 --> 00:00:55.300 so it is a really serious issue. 21 00:00:55.300 --> 00:00:58.690 Definitely stopping the hazard at source is the best option for us. 22 00:00:58.690 --> 00:01:01.230 In a typical year we will spend somewhere in the region 23 00:01:01.230 --> 00:01:03.700 of £40 million, and that's on things 24 00:01:03.700 --> 00:01:05.890 that prevent landslides or improve the resilience 25 00:01:05.890 --> 00:01:09.390 of our infrastructure to extreme weather. 26 00:01:09.390 --> 00:01:10.550 - Thank you very much! 27 00:01:10.550 --> 00:01:14.090 - So Scotland's railway is about 3,500 track-miles. 28 00:01:14.090 --> 00:01:16.100 So we can't protect that whole length, 29 00:01:16.100 --> 00:01:19.150 so we need to look at other ways of keeping the trains safe, 30 00:01:19.150 --> 00:01:21.830 which is where the rockfall detection comes in. 31 00:01:21.830 --> 00:01:24.190 - By modern standards, it's a really basic system. 32 00:01:24.190 --> 00:01:25.023 There's no electricity. 33 00:01:25.023 --> 00:01:27.930 Just these wires along the track, held under tension, 34 00:01:27.930 --> 00:01:29.670 mechanically linked to the signals. 35 00:01:29.670 --> 00:01:32.930 If a big boulder falls down, it hits a wire, the wire snaps, 36 00:01:32.930 --> 00:01:34.057 the tension's released, 37 00:01:34.057 --> 00:01:38.110 and the signal at each end of that bit of wire changes to show danger. 38 00:01:38.110 --> 00:01:41.500 Repeat for 17 signals over the four miles of railway. 39 00:01:41.500 --> 00:01:44.494 The system was nicknamed Anderson's Piano after its inventor 40 00:01:44.494 --> 00:01:45.680 and after the humming noises 41 00:01:45.680 --> 00:01:47.890 that the wires sometimes make in high winds. 42 00:01:47.890 --> 00:01:50.890 - Anderson's Piano is a very old system, 140 years. 43 00:01:50.890 --> 00:01:53.990 Keeping something like that going in a modern environment, 44 00:01:53.990 --> 00:01:55.430 it is quite challenging. 45 00:01:55.430 --> 00:01:57.780 Firstly, I guess there's the knowledge. 46 00:01:57.780 --> 00:02:01.280 There's not a user manual or a downloadable book 47 00:02:01.280 --> 00:02:02.970 on how to maintain Anderson's Piano. 48 00:02:02.970 --> 00:02:06.340 We need to pass that down through generations 49 00:02:06.340 --> 00:02:07.940 of technicians and engineers. 50 00:02:07.940 --> 00:02:10.120 And then there's just getting hold of the kit. 51 00:02:10.120 --> 00:02:13.960 A lot of it was bespoke, made in foundries in the Victorian era. 52 00:02:13.960 --> 00:02:15.720 Some of it we've had to improvise. 53 00:02:15.720 --> 00:02:17.720 Some of it is just availability of material. 54 00:02:17.720 --> 00:02:20.830 So getting hold of some of the wire can be quite challenging. 55 00:02:20.830 --> 00:02:23.010 And we think we've managed to find a reasonable source 56 00:02:23.010 --> 00:02:24.240 that is a good enough match. 57 00:02:24.240 --> 00:02:27.580 The kind of rural fence that will use that kind of wire, 58 00:02:27.580 --> 00:02:30.110 the manufacturers are striving to make it stronger and stronger 59 00:02:30.110 --> 00:02:32.690 and we don't need it stronger for Anderson's piano. 60 00:02:32.690 --> 00:02:34.840 We need it to break when there's a rock comes through it. 61 00:02:34.840 --> 00:02:37.920 It's not perfect detection in terms of screening out. 62 00:02:37.920 --> 00:02:40.430 So vegetation can trip it off, 63 00:02:40.430 --> 00:02:42.850 animal movements if they do get inside the boundary. 64 00:02:42.850 --> 00:02:44.120 Very manual to reset. 65 00:02:44.120 --> 00:02:47.320 It's a physical task that involves lifting weights 66 00:02:47.320 --> 00:02:49.870 and repositioning counterbalances 67 00:02:49.870 --> 00:02:53.010 and manually moving signals back into place. 68 00:02:53.010 --> 00:02:55.600 So we can't do that when the trains are running, 69 00:02:55.600 --> 00:02:57.570 so that's disruptive to our network. 70 00:02:57.570 --> 00:03:00.040 It's a physical job that involves human beings. 71 00:03:00.040 --> 00:03:02.240 There's not a big reset button that we can push. 72 00:03:02.240 --> 00:03:05.260 The first we know there's a problem is when the signal goes up 73 00:03:05.260 --> 00:03:07.910 and normally the first person to see that is the train driver. 74 00:03:07.910 --> 00:03:11.603 We are not able to respond someone to the problem when it occurs. 75 00:03:11.603 --> 00:03:13.130 We need to wait until after it's occurred, 76 00:03:13.130 --> 00:03:15.880 because the first time we know about it is when a driver tells us. 77 00:03:15.880 --> 00:03:18.090 - Modern rail safety rules mean that ideally, 78 00:03:18.090 --> 00:03:21.460 no one should ever drive a train past a signal that's set to danger. 79 00:03:21.460 --> 00:03:23.540 If that is ever needed because of a fault somewhere, 80 00:03:23.540 --> 00:03:26.890 it requires checking and double checking with central control. 81 00:03:26.890 --> 00:03:29.670 If a train goes past a danger signal without permission, 82 00:03:29.670 --> 00:03:31.650 there's always an investigation. 83 00:03:31.650 --> 00:03:34.130 If it was because the driver was negligent, 84 00:03:34.130 --> 00:03:36.130 it can end their career. 85 00:03:36.130 --> 00:03:38.280 But the rules for these signals have to be different, 86 00:03:38.280 --> 00:03:41.350 and they go against everything that a modern train driver learns. 87 00:03:41.350 --> 00:03:42.790 If these signals are at danger, 88 00:03:42.790 --> 00:03:44.885 you slow the train down to walking pace, 89 00:03:44.885 --> 00:03:49.020 to a speed where you will be able to stop before you hit any obstruction, 90 00:03:49.020 --> 00:03:51.260 and you radio it into central control... 91 00:03:51.260 --> 00:03:53.000 but you do continue. 92 00:03:53.000 --> 00:03:55.710 And that would never be allowed on a new system. 93 00:03:55.710 --> 00:03:57.620 - It's offering us a level of protection, 94 00:03:57.620 --> 00:04:03.390 so there's a line of defence there that works quite a lot of the time. 95 00:04:03.390 --> 00:04:05.250 It would be less safe without it. 96 00:04:05.250 --> 00:04:07.200 Prevention is better than detection, 97 00:04:07.200 --> 00:04:09.960 so stopping the rocks falling is definitely better 98 00:04:09.960 --> 00:04:11.940 than detecting them when they have occurred. 99 00:04:11.940 --> 00:04:14.690 So we put a great deal of effort into containing 100 00:04:14.690 --> 00:04:16.368 some of the rocks on our cuttings 101 00:04:16.368 --> 00:04:19.960 and into catching boulders through high-strength, 102 00:04:19.960 --> 00:04:23.160 high-capacity catch fences that are anchored into the rock. 103 00:04:23.160 --> 00:04:25.870 We employ all sorts of techniques like netting, 104 00:04:25.870 --> 00:04:28.890 and meshing, and doweling to hold all the rock in place. 105 00:04:28.890 --> 00:04:33.060 We're constantly looking for technology to improve safety on the railway. 106 00:04:33.060 --> 00:04:36.130 Satellite technology that looks for ground movement from space, 107 00:04:36.130 --> 00:04:37.920 and does change detection on that. 108 00:04:37.920 --> 00:04:41.620 We've tried "listening fibres" through fibre-optic cables 109 00:04:41.620 --> 00:04:44.370 that listen for an acoustic signature of a rock falling 110 00:04:44.370 --> 00:04:45.810 or a tree falling on the railway. 111 00:04:45.810 --> 00:04:48.240 The cost of that equipment is starting to come down. 112 00:04:48.240 --> 00:04:49.910 We're starting to see advances in technology 113 00:04:49.910 --> 00:04:52.100 which is making it more affordable to deploy. 114 00:04:52.100 --> 00:04:54.410 But one of the big issues is actually power. 115 00:04:54.410 --> 00:04:56.440 These things will either need a power supply, 116 00:04:56.440 --> 00:04:58.900 which in remote places can be hard to come by, 117 00:04:58.900 --> 00:05:01.460 or they'll run off batteries and solar panels 118 00:05:01.460 --> 00:05:04.620 which need to have sufficient capacity to keep them up all year round. 119 00:05:04.620 --> 00:05:06.500 Scottish winters can be quite dark. 120 00:05:06.500 --> 00:05:09.770 Some of our trials have been hampered by false alerts and false alarms 121 00:05:09.770 --> 00:05:12.100 and too many false alerts to run a railway. 122 00:05:12.100 --> 00:05:15.670 At Bridge of Orchy we've got some detectors in place 123 00:05:15.670 --> 00:05:17.200 to capture any movement. 124 00:05:17.200 --> 00:05:21.150 Now, they're the wireless tilt meters that tell us if the ground's moving. 125 00:05:21.150 --> 00:05:24.610 Like your spirit level on your iPhone that moves about, 126 00:05:24.610 --> 00:05:26.150 they will detect a bit of movement 127 00:05:26.150 --> 00:05:29.700 and we will get an alert or an alarm remotely from that. 128 00:05:29.700 --> 00:05:32.530 We've then got a camera on site that we can see the site 129 00:05:32.530 --> 00:05:35.630 to see whether it's a false alarm or not, so we're not needlessly stopping trains. 130 00:05:35.630 --> 00:05:38.760 We've got some infrared kit on there so that we can see at nighttime. 131 00:05:38.760 --> 00:05:40.750 Then infrared reflectors to see if there's been a problem 132 00:05:40.750 --> 00:05:42.060 during the hours of darkness as well. 133 00:05:42.060 --> 00:05:43.590 It's all remote back to base 134 00:05:43.590 --> 00:05:47.120 and it only requires a technician in our control centre 135 00:05:47.120 --> 00:05:48.730 to watch that and monitor that. 136 00:05:48.730 --> 00:05:51.380 It's also less prone to false alarms 137 00:05:51.380 --> 00:05:53.270 and we can reset it at the touch of a button. 138 00:05:53.270 --> 00:05:55.870 So we know about it before the train comes, 139 00:05:55.870 --> 00:05:57.190 we can capture the problem 140 00:05:57.190 --> 00:05:59.430 before it manifests itself on the railway, 141 00:05:59.430 --> 00:06:02.830 and we can remotely reset it and remotely monitor it. 142 00:06:02.830 --> 00:06:05.920 We do an awful lot, but it's not enough to go everywhere. 143 00:06:05.920 --> 00:06:08.910 And, you know, we can't physically protect every mile of railway. 144 00:06:08.910 --> 00:06:10.400 It's just impracticable. 145 00:06:10.400 --> 00:06:11.650 - From talking to the folks here, 146 00:06:11.650 --> 00:06:13.750 I'd say that the best description of these signals 147 00:06:13.750 --> 00:06:17.070 is that they are a frustrating, imperfect system 148 00:06:17.070 --> 00:06:18.880 that's still better than nothing. 149 00:06:18.880 --> 00:06:20.930 Back when I was researching this video, I figured 150 00:06:20.930 --> 00:06:24.011 that there must be a better solution, and with all the confidence of 151 00:06:24.011 --> 00:06:26.610 someone in the YouTube comments who's only watched half the video, 152 00:06:26.610 --> 00:06:28.710 I thought, "Hey, couldn't they just?..." 153 00:06:28.710 --> 00:06:32.922 And no. They can't, at least not yet. 154 00:06:32.922 --> 00:06:35.672 [train rumbling] 155 00:06:40.810 --> 00:06:43.773 How's that for timing?!