Safety
Permissive society
On 27 February 1989, a rear-end collision occurred at Warrington, killing the driver and a rolling stock
inspector.Greg Morse takes a look at one of the elements – permissive working – and asks if there are any lessons for the modern rail industry
I
n 1989, all eyes were on the SPAD question, the timing of the fatal accidents at Bellgrove and Purley ensuring their consideration in Anthony Hidden’s analysis of the multi-train collision at Clapham the previous year. Though it was right for British Rail to focus on the issue and move towards adopting an automatic train control system, there seemed to be another problem looming – lower down the risk ranking, but there all the same: permissive working. And in the February of that year, two staff members lost their lives because of errors around it. Permissive working is a useful operational tool, which (where authorised) lets trains proceed (with caution) into a block section, signal section or dead-end platform road already occupied by another train. While ‘breaking’ the golden ‘one train, one section’ rule of railway safety, this can clearly increase capacity and aid efficiency. It’s just that when things go
Under permissive working, trains are allowed to proceed with caution into a block section, signal section or dead-end platform line already occupied by another train. Permissive moves are signalled by bringing a train to a stand (or almost to a stand) at a red protecting signal, and then ‘calling it on’ by illuminating the position light signal (or semaphore subsidiary signal) associated with it. The driver must then drive ‘on sight’ and be prepared to stop short of any obstruction. A shunting move can also be allowed to enter a portion of line that is already occupied, even though permissive working is not authorised, providing this is for the purpose of attaching, detaching or removing vehicles.
wrong, they do go wrong – usually on the freight side. Indeed, the permissive working of freight trains was in the causal chain of at least nine staff fatalities between 1968 and 1989. Many occurred on freight-only lines, but on 3 February 1984 a driver and his guard were killed when a Speedlink service was ‘called on’ into an occupied section at Wigan North Western and struck the rear of a container train whose tail lamp had gone out. Readers can find out more in a forthcoming issue of Rail, but in brief this led to the replacement of the traditional oil lamp with (essentially) the battery powered design we have today. Not that it was all about tail lamps, as an accident on 27 February 1989 would demonstrate. It happened in the darkness outside Warrington Bank Quay station. Just before 21:30, the guard of Doncaster- bound 6E26 checked his consist in nearby Walton Old Yard. All being well, and the position light signal (PLS) being clear, the driver eased the train over the points and onto the Down Helsby line, bringing it to a stand at WN216 signal. Soon after, red became green, but before the driver could open up, he felt a severe bump. He quickly climbed down from the cab and went back to investigate. What he
found filled him with horror: the Dover– Mossend service had struck the rear of his train, sending two wagons laden with lorries down the embankment, and badly damaging the cab of the locomotive. Inside, a 32-year-old rolling stock technician was already dead; the 56-year- old driver, a veteran railwayman of some 42 years’ service, died later in hospital. The investigation recognised that the ‘Mossend’ had been signalled by a ground PLS (rather than one mounted beneath a main aspect), noted that there were
February 2014 Page 91
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148 |
Page 149 |
Page 150 |
Page 151 |
Page 152 |
Page 153 |
Page 154 |
Page 155 |
Page 156 |
Page 157 |
Page 158 |
Page 159 |
Page 160 |
Page 161 |
Page 162 |
Page 163 |
Page 164