The need to create more capacity on the UK rail network has been reported many times. Clever signalling systems to allow closer headways, longer trains with longer platforms, even more infrastructure – these are all part of this objective and, slowly but surely, things are beginning to happen.
However, increasing capacity is one thing, developing a timetable to fit in all the extra trains with a minimum of conflict is something else, all too easy to overlook.
The London & SE section of the Institution of Railway Signal Engineers (IRSE) had a recent talk on Delivering Better Timetables, given by Kris Alexander, the programmes and support services director of capacity planning within Network Rail. It proved to be fascinating.
Some basic statistics
The relationship between timetabling, signalling and command & control is crucial. Network Rail provides paths for 23,500 trains per day, carrying 4.8 million passengers over 900,000 track miles, passing more than 1.5 million signals (hopefully at green) with 220,000 station stops. The plan is for all trains to arrive exactly on time – to the minute.
Travel patterns are also changing. For the December 2015 timetable change, some 10,000 changes were requested. For May 2019, that number grew to 45,000.
The number of trains per weekday has increased by 6.4 per cent in the last 18 months, excluding freight, empty stock movements and non-franchised operators. At weekends, Saturdays has seen an eight per cent increase and Sundays 12 per cent in the same period.
The current timetable performance is around 94 per cent of trains arriving within a minute of right time, but that general statistic can hide some services which are much worse than this. Incidents are critical as they represent the biggest risk for achieving right time arrivals.
The timetable is not just about passenger train services – it also has to encompass freight and non-franchised operations.
- A ‘good timetable’ might be judged by the following factors:
- Most trains arriving right time;
- Regular timetabled or clock-face departures;
- Easy recovery from any disruption;
- Providing services that impact on economic growth;
- Maximising the assets, primarily crew and rolling stock.
Many of these mean different things to different people.
Timetable compilation and constraints
It takes a long time to assemble a timetable and the process involves consultation with a multitude of interested parties. The current system works to the following schedule:
- Commence consultation on TPRs (Train Planning Rules) and EAS (Engineering Access Statements) – 64 weeks out;
- Issue Notice of Change – 55 weeks out;
- TPRs and EASs published – 44 weeks out;
- Train Operator bids scheduled – 40 weeks out;
- Network Rail offers LTP (Long Term Plan) to Train Operators – 26 weeks out;
- Train Operators make bid for a STP (Short Term Plan) – 18 weeks out;
- Network Rail offers a STP – 14 weeks out;
- Information sent to Traveller Publications – 12 weeks out;
- Timetable implemented – week 0.
If all this looks complicated and time consuming, you are right. It can be adversarial and, at best, is inefficient. Much of the compilation work is still carried out manually.
Challenges in the immediate future
Five areas of improvements have been identified to ease the amount of human effort involved and to create a more robust end product.
Challenge 1 is to automate the production of the timetable and to take account of line speeds, signalling diagrams, stock diagrams, TRUST (train reporting using system TOPS) and TPRs, all of which exist as separate data systems but without effective linkage. A typical example would be validating the data for a junction.
Challenge 2 is to unify the Train Planning Rules and associated values. Currently, there is no agreed methodology for calculating the rules and it takes, as an example, 15 documents to timetable a train from Southampton to Trafford Park. Included within this work will be the inclusion of timing allowances for minimum headways plus measures to minimise the propagation of delays when they occur to other services.
Challenge 3 is to improve timetable performance modelling. This is a data-hungry process which requires considerable manual intervention, with much of the data being uncontrolled and inaccessible. Timetable modelling is not well aligned with other industry planning processes and is not properly understood by the client – the train companies. It does not have a complete suite of tools and the industry has let go much of the skill set that existed 10 years ago. Building-back expertise will be part of the challenge.
Challenge 4 relates to Digital Railway technologies, where a project is underway to define a new set of timetable requirements.
These will include: i) timings to have an accuracy down to one second, ii) increasing the number of timing points across the railway, iii) ensuring that timetable planning rules are commensurate with the introduction of ETCS, iv) having a common infrastructure model across the industry, and v) creating a zero-defect timetable.
Challenge 5 relates to improving timetable planning data to enable improved analysis and optioneering. The current Sectional Appendix is unstructured and is not digitised, with the result that elements may be wrong. Signal Control tables have to be manually transferred into the timetabling process in the production of Station Simplifiers issued to station staff. Elements such as signalling plans, track layout variations and electrification work all impact on timetable production but few engineers recognise this fact and, even if they do, how to input the element of change is not properly understood.
Improvement programme
There is general recognition that a significant advancement in timetable production is urgently needed and £100 million has been allocated for this work to be taken forward. Much of it will take time, with some work building on past projects that have already yielded benefits but which can be improved further. The main thrusts will be:
- To produce a Timetable Technical Strategy. Already in development, involving a complex drawing together of all factors (around 50) into a single integrated data system, this is a major task and may take ten years to complete.
- To produce a method for determining the effect of engineering work. Known as an Access Planning Programme, this will be vital to improve the knowledge and impact of engineering work and associated timetable disruption. Cost is estimated to be £13.5 million.
- To continue the work of producing an Integrated Train Planning System (iTPS). Initially introduced in 2010, it has proved very valuable in automating conflict-detection situations and has produced machine-generated planning values. £16 million is allocated to introduce upgraded versions and to enhance the capability. An example will be assessing the impact of long trains stopping at short platforms.
- As indicated earlier, to produce a Timetable Performance Modelling Programme to improve understanding of the impact of proposed changes and include a machine reading capability that will be capable of alignment with train schedule, crew and stock modelling inputs. Cost is estimated at £18.7 million.
- To create a Timetable Data Improvement Programme costed at £8 million. The aim is the extraction of more value from the data so that this can be shared with stakeholders, both within the rail industry and externally to the travel trade market and social media.
Other interfaces
Since this talk was delivered to a signal engineering audience, it was perhaps inevitable that a plea was made for the engineering data to be modified from its present unstructured forms into a single consumable format. People do not realise that such data can impact on timetable performance but, when timings become critical to the second, knowing everything about the signalling can be very relevant. The timetablers need to know about speed limits, gradients, tunnel bores, curvature, signal overlaps, signal control panel operation, even interlocking types, all of which should have a common data format that can be easily accessed.
Also critical are Traffic Management Systems (TMS) and Automatic Route Setting (ARS). TMS should, ideally, be provided with a perfect timetable, but this is still a long way off. When first considered back in 2014, it was thought that purchasing proven systems, already in use on other railways where advantages were being realised in optimising real time train pathing decisions if disruption were to occur, would produce a quick win.
That concept has proved illusory and it has been difficult to implement the trial systems at Cardiff and Romford. Resonate’s Luminate product, in use on the GW main line, has proven to be the most beneficial so far, but it has taken a lot of work to get to the present position.
On the Thameslink central core, the Hitachi TMS system is uploaded with timetable data each day, so that it can constantly review train movements against the planned operation. When late running is detected, the system calculates a revised train path that will keep disruption to a minimum and offers it to the signallers. However, for this to be fully effective, the timetable data for almost the entire Thameslink area has to be entered, so that constant monitoring of real time running can be achieved. As can be imagined, the amount of data involved is huge and the successful transfer is itself a challenge.
Similarly, whilst ARS has been available in its basic form since the 1980s, the decision-making data has only been used in a localised area without the bigger picture of events being considered. Clearly, if more accurate timetabling and train running is to be achieved, ARS and timetable data will need to be fully integrated.
View from the top
By chance, a recent press briefing by Andrew Haines (chief executive of Network Rail) also touched on timetabling challenges. Under the franchise system, train operators are virtually compelled to run more trains with better performance and at lower cost. This presents many difficulties of running a service when things go wrong.
The May 2018 timetable was a classic example, with both Northern and Thameslink introducing huge timetable changes which could not be delivered. People have blamed the timetable for the ensuing chaos, but it was more the unpreparedness of the train companies to operate the resultant train service that caused the problems. A shortage of rolling stock, as well as a lack of train crew and the rate at which they could be trained, were major factors. Thameslink recovered quite well and, within two months, had a revised and workable timetable in place. It has since been upgraded again and now offers a brilliant cross-London service that has contributed to many new journey opportunities.
For Northern, the misery has continued, with the result that the franchise has now been terminated and effectively nationalised and put under government control. Some experienced operators saw these emerging problems and Network Rail was asked to delay the timetable’s introduction but this was not possible with only 10 weeks left before implementation.
Lessons have been learned and it is now likely that big timetable changes will need to be planned over a longer period, possibly up to two years out. Examples of when things have gone better were the 2008 West Coast main line change and the recent introduction of the new Great Western timetable to take advantage of the Class 800 fleet introduction. In both cases, experienced operators were already in place and were not under any particular financial pressures.
Recent government announcements about possible re-opening of lines closed under Beeching have included the Ashington to Blyth line in Northumberland, which will use a section of the East Coast main line north of Newcastle, where paths are already at a premium.
As a general observation, Andrew Haines felt that the scarcity value of the last remaining path on any route may need to be reflected in the price paid. Equally, if more trains are to be operated over a route, it could mean enforced changes to the stopping patterns and run times of existing train services.
This is already happening to some routes on former Southern Region lines. Some services are now actually timetabled to take longer than they did in times past, in recognition that getting through various pinch-points on the route cannot be guaranteed without having additional recovery time.
One piece of advice is that, when new trains and/or infrastructure are introduced, the service should be bedded in on the existing timetable before attempting to change the service pattern with a new timetable. Trying to do it all at once will court disaster.
So, an eye-opening subject where the relationship between engineers and timetablers is becoming ever more critical. One can only hope that the industry as a whole will be up for the challenge.
