Take wet beds. They’re often obvious from a section of silted ballast or a distinct point at which ballast becomes covered in a light-brown slurry, formed by water contaminated with powdered ballast being pumped upwards as wheels push the track down. They are treated by digging out the ballast and replacing it with new.
However, they can be caused by a variety of track faults, which can include dipped joints, poor quality welds showing dips and humps, ballast or drainage deficiencies, loose or missing fastenings, missing rail pads or rail surface irregularities. Without fixing these problems at source, the track gang will soon be wasting their time digging out clogged ballast once more. High levels of rework point toward inefficiency.
Drivers regularly traversing a route will know whether their train’s performance matches the timetable. They may be consistently late or early at a particular point, which shows that the timetable is inconsistent or less efficient than it might be.
Lateness matters more in some places and at some times than others - late trains in peak hours will naturally delay more people than late trains at quieter times. This is why London Underground measures ‘lost customer hours’, because it’s a combination of delay and passengers. The national network should adopt this measure because it can help concentrate effort to where it will have most effect.
These measures of timetable consistency and lost customer hours both feed into an assessment of a line’s operational excellence. However, it takes staff and effort to find, collate and analyse statistics, and when money is tight it’s all too easy to cut such posts. If NR is to cut its central functions as it devolves control to its routes, then it must ensure it allows those routes the freedom to employ analysts so that they can direct scarce resources to where they will have most benefit.
How efficiently NR and train operators use the network is hard to ascertain. NR publishes annual route plans, and these contain maps that show capability in terms of linespeed, axle load (as route availability), gauge and electrification. They do not contain maps that show capability in terms of train paths per hour or per day. Nor do they contain maps that show how much capability is already consumed.
Granted, this can be difficult to calculate, but it would show where pinch points exist along a line or at a junction. Such a map would show where the network is being used efficiently and where it is not. It would show where capacity was at or approaching its maximum, and thus where reliability was most important for the service.
At ORR, Rail Safety Director Ian Prosser is taking an interest in how performance is managed and benchmarked in order to give a better view of rail’s efficiency. He argues that measurement should incorporate customer service, asset reliability, operational excellence, staff (absenteeism, training days per year and turnover) and safety. The latter has benefited from much measurement and focus over the past few decades, such that in February 2017 the railway marked the tenth anniversary since a passenger was killed in a rail accident.
Customer service is measured twice a year in Transport Focus surveys. It’s also measured by the complaint rate figures that ORR publishes. Yet as the graph on page 59 shows, since the turn of the century complaints have fallen sharply while satisfaction scores have remained broadly constant.
Another measure of customer service could be ‘on-time, in-full’ delivery. If you order something from a supplier, you expect your order to be delivered on time and in full. If you buy a ticket from a rail company, you expect that company to transport you from the right place to the right place at the right time. If you order a seat reservation as well, you don’t expect to be standing. The railway already holds this information.
Process industries measure asset reliability through overall equipment effectiveness (OEE). It compares actual output with that which could be produced if the process runs flat out, always produces a perfect product, and never breaks down. These three elements are product rate, quality rate and availability.
Prosser argues that for rail, the product rate could be the percentage of a route’s maximum passenger or freight capacity. For passenger trains this would be the combination of maximum number of trains multiplied by the maximum length multiplied by the number of seats per coach (some routes might also account for standing capacity). The maximum number of trains depends on the headway (time between trains) that the signalling provides, and the maximum length of train by the shortest platform at which it stops.
For quality rate, the measure should be punctuality to the minute. And availability would be the time the line is open for traffic, including planned and unplanned closures.
These calculations will not be simple for lines with several tracks - those with a mix of fast and slow trains. To illustrate the principles, take the Hexham-Carlisle line. It’s largely twin-track (save for a short section of single line approaching Carlisle, which is discounted for ease of calculation here). It’s an absolute block line, so the overall headway depends on the longest block section, which is Haltwhistle to Low Row.
A typical passenger train takes 10½ minutes, to which NR’s timetable planning rules add two minutes to calculate a headway of 12½ minutes. This gives a capacity of 4.8 trains per hour, or 806 per week. (Freight takes slightly longer, which cuts capacity. Although a handful of freight trains run every day, the calculations here assume no freight because it makes them easier.)
Northern typically runs two-car Class 156s with 150 seats per train, which would deliver 120,900 seats per week. However, the stations can accommodate a four-car Class 142 (they are too short for a four-car ‘156’), which seats 242. That would be 195,052 seats per week maximum.
