With timetable changes, ‘vamp until ready’ is not an option

Just as accident investigations rarely find that a single failure was responsible, so the collapse of the Thameslink timetable in May was exacerbated by multiple contributory factors.

An analysis on the excellent London Reconnections website highlights the impact of the late delivery of the new Class 700 rolling stock fleet on driver training, for example.

However, it is the production of the timetable itself which, when laid out as a timeline, can be seen to lead ineluctably to what can safely be called ‘chaos’ on the affected routes without risking charges of tabloid sensationalism. Table 1 shows the chronology.


In stable times, timetable production starts around 16 months before the introduction date for the next change in December or May. Having the option to make changes in May is a legacy of the time when there was a separate ‘summer’ timetable that would run for 12 weeks at a higher service frequency.

To start the process Network Rail determines the scale, length and dates for the blockades and possessions it will need for maintenance, renewals and enhancements during the currency of the new timetable. Key points in the production process are dated back in weeks from the start of the timetable and expressed as T-x. Effectively, this work starts around T-65.

At 14 months out, train operators give Network Rail prior notification of any significant changes to their current timetable. Having combined these outline requirements with its possession plans, Network Rail provides operators with a Prior Working Timetable at T-45. At this point the bidding starts.

Operators submit their bids for the paths required by their new timetables at T-40. This is known as the Priority Date Notification Statement. Now 420-strong or so, Network Rail’s timetabling team at Milton Keynes starts the task of accommodating as many of the bids as possible. The May 2018 timetable was the most demanding in terms of changes for many years.

What is termed the ‘offer’ is made to the operators at T-26. This is the ‘base timetable’ that enables operators to start translating train services into stock and crew diagrams. Obviously not all bids can be met and differences are resolved through a process of iteration.

At T-18 operators can ‘bid’ for readjustments to their new timetable. For instance, catering for special events or working round engineering possessions. T-18 marks the start of what is known as ‘Informed Traveller’. This is the requirement for the timetable to be fixed at T-12 so that advance tickets can go on sale.

Informed Traveller offers are made at T-14. A week is allowed for the plan to be iterated and at T-12 the passenger operators can put advance tickets on sale. In theory passengers can rely on the trains for which they have bought tickets being in the timetable.


That is how it is supposed to work. And for the May 2018 timetable it all went according to plan, with offers made by T-40. However, Thameslink was already struggling.


‘At the end of the meeting on 4 May, I looked around the boardroom table and asked if there was anything else that anybody felt could get in the way of a successful 20 May launch. Nobody said anything.’ Chris Gibb in evidence to Transport Select Committee

Right away: Class 700 at Bromley South, 25 June 2018. Philip Sherratt
Falling apart: screenshot of the GTR service situation south of the Thames at 21.42 on 5 July 2018. Keith Fender

According to informed sources, Govia Thameslink Railway’s T-40 Thameslink timetable offer in November 2017 came back with ‘hundreds of services’ in the bid rejected. In addition, Network Rail’s Sale of Access Rights Panel is reported to have given GTR a one-year access agreement only, with ‘Contingent Rights’ instead of ‘Firm Contractual Rights’.

Having previously expressed reservations about the Department for Transport’s original Thameslink timetable proposals, it appears that Network Rail wanted to ‘suck it and see’ before signing up to long-term firm rights. Any inherent failings in the timetable would impinge on Network Rail’s performance obligations to the other operators affected by the Thameslink timetable change, notably East Midlands Trains and Inter-city East Coast. Contingent Rights also implied that a vitally important timetable, entering a state of flux following the decision to phase the introduction, would be given lower priority in the timetabling process.

GTR would have to go through each of the rejected services, understand why it had been rejected and rebid. Network Rail then had to see how that fitted into the overall timetable and make a new offer.

Many services would follow this ‘bid-offer cycle’ several times before a path was agreed. Such iteration is a normal part of the timetabling process, but not on such a scale and not with time running out.


There was also an unexpected complication. Chris Gibb had been tasked by Transport Secretary Chris Grayling to investigate the problems with the Southern. His report was delivered in December 2016 and the recommendations included the formation of an Industry Readiness Board (IRB) to monitor and co-ordinate the introduction of the new Thameslink service. For his pains Mr Gibb was asked to chair the Board, which he subsequently described as a ‘very tough job’. The Board’s inaugural monthly meeting was on 13 January 2017.

One of the IRB’s early concerns was the viability of the proposed ‘big bang’ approach to introducing the new Thameslink services. May 2018 would see 20 trains per hour (tph) running through the central core. A lesser detonation would add the remaining 4tph with the December 2018 timetable.

In Chris Gibb’s experience, ‘big bang’ timetable changes were not a good idea. As a result, in April 2017, GTR had recommended to DfT that the implementation of the new timetable should be phased.

By August 2017 (T-40) the ‘big bang’ GTR May 2018 timetable bid had been submitted and was being processed. But it was not until 22 October (T-29) that DfT accepted the recommendation to change to a phased introduction, starting with 18tph in May 2018 and deferring the full service to December 2019.

At the IRB meeting on 17 November 2017, the phasing was discussed and agreed to be achievable. But by now it was T-26 and the offers had come back. So in addition to having to process the large number of rejected bids, the GTR and Network Rail timetabling teams also had to incorporate the new phased approach.


While it was all change at Thameslink, in the North of England Network Rail had finally conceded in January 2018 that the Manchester–Bolton electrification was not going to be ready in time for May. This meant that the Northern and TransPennine Express timetables would have to be reworked. In Scotland, Hitachi was late with the new Class 385 electric trains – an event also requiring a revised timetable.

Thus by T-14 Network Rail did not have a stable working May 2018 timetable for Scotland, London North Eastern, London North Western and South East Routes. Reflecting the overload, it was announced on 11 February 2018 that Informed Traveller could no longer be supported at T-12 and this was slipped back to T-6 – optimistically, as it turned out.


In retrospect, the critical moment for Thameslink came in November when the T-26 offer came back with ‘hundreds’ of services rejected and the IRB agreed that a revised, phased timetable was achievable. In effect, a timetable already in trouble would have to be restructured on the fly.

True, those involved were not to know that in two months’ time changes elsewhere on the network would overwhelm Network Rail’s timetabling capabilities. But as former GTR Chief Executive Charles Horton told the Transport Select Committee ‘The effect of that phasing change was not clearly understood in terms of its impact on Network Rail’s processes. The result was that, combined with some challenges in getting the timetable established, it meant we were into April before we had the timetable finalised’.

Leading participants agree that November was the final moment when the timetable change could have been aborted. Chris Gibb told the Committee, ‘With the benefit of hindsight, it was a challenging thing to commit to, but, back in November last year, nobody said that the system could not cope with it – not Network Rail, GTR or anybody else around the table. They did not say, “Are we not being a bit heroic here?”

Nobody said that. In fact, back in November, if we had said, “We want to delay the whole Thameslink project because the timetable is late,” I do not think we would have been taken seriously at that point’. Also with hindsight, Network Rail South East Route Managing Director John Halsall concedes that the ‘big bang’ change was ‘super-ambitious’, but adds while the phased approach was the right decision, it was still too ambitious. Mr Halsall has described the mood at the time when ‘20 hugely experienced railway people’ on the IRB ‘missed it’.

‘There was a tiny moment in November, when the final decision to adopt a phased timetable was taken, when as an industry we could have put our foot on the ball and said, “No, stop,” and raised a flag at a moment when it would not have caused complete national mayhem. ‘Why did we not, at that point, put our foot on the ball? The answer is that at that point every member of the board and their respective teams believed they could deliver it. When we set up the IRB, it was obviously to make this programme succeed.

There were many challenges associated with it. If the board had adopted the approach, every time a red risk materialised, of saying, “This isn’t going to happen,” we would not have progressed at all.

That “can do and get on with it” approach, which was so helpful up to a point, was actually the problem when we got to the split second when we could have put our foot on the ball: everybody said, “No, we can do this, and we must push on”.’ Even Jo Kaye, Network Rail’s Managing Director, System Operator, who must have been aware of the stresses on her timetabling team, shares the same view. ‘We all believed right up until the very last minute, that the actions we had taken and the mitigations we had put in place would address those risks. That clearly turned out not to be the case.

‘We are very good at identifying and mitigating individual risks. Stepping back and taking a look at those risks in the round, in a different way, would probably have been helpful in this context. That is all within an organisation and an industry acutely aware of capacity crunch and the need for more services. Everyone was absolutely in a spirit of hugely positive forward momentum to make those changes happen. Perhaps something about the culture, of being so keen to deliver, blinded us in some ways to some of the risks.’


All these delays meant that instead of GTR having the Working Timetable (WTT) at T-12, it did not arrive until T-3. According to Charles Horton, while the timetable was being developed GTR had been looking for ways of working round the delays.

However, it was only in the final stages when the timetable was being finalised that the true scale of the resourcing problems became available. When the drivers’ diagrams were overlaid on the individual rosters, the mismatch between route and traction knowledge and the train diagrams became apparent for the first time. Diagrams that would normally be worked out over 12 weeks in an iterative process had to be produced in three. Because of the multiple compromises made to the original plan, the number of driver diagrams had increased by around 50.

According to Mr Horton, rostering did not start until the Thursday night (17 May) before the timetable changed on the Sunday (20 May). ‘That was where we realised that there was a skills mismatch between the assumptions that we had made for the location of the train drivers through the whole project, and which had been in place for over a year, and the actuality of where the work had fallen’.


In his evidence to the Committee, Chris Green put the shortage of time in context. Diagrams had been created ‘in one computer run’, where normally ‘you would do one computer run, then a massive manual iteration to get the errors out and then another iteration to make it more efficient, and the fourth iteration to make it work’.

He confirmed that only with the rosters created was it realised that the rotation of drivers through the roster, each with their own ongoing route training needs, would need more piloting, particularly through the central core and its approaches, than had been assumed. As Charles Horton told the Transport Committee, ‘It was only in that final week, on the Thursday before the timetable came in, that we realised the problem was more serious than we expected’. Chris Green adds, ‘they needed another 50 drivers at that point, at 10 days’ notice, which is the entire establishment of a small train company’.


Yet, when the IRB had met on 4 May, according to Chris Gibb, it had been believed that the new timetable was ready to go on 20 May, with a few cancellations. ‘Tens of cancellations was the scale that we believed it to be. That is what we had been told. Nobody at the board disagreed with that analysis at the time.’ Informed sources qualify this claim. At least one member of the Board thought that the ‘tens of cancellations’ was optimistic based on papers presented at the meeting and suggested that a greater number of services should be withdrawn to provide a buffer. However, with GTR adamant on tens of cancellations, to argue further would have been to publicly challenge the operator’s competence.

That was not the way of the IRB. It was up to Chris Green’s Independent Assurance Panel to do the ‘deep dive’ on-the-spot checks into what was being claimed.

There remains the over-riding question of why all these highly experienced railway managers could not see disaster coming. Perhaps another British Rail veteran, Ian Brown, writing in Rail Future magazine, has got it right. ‘It seems that everyone was so invested financially and reputationally in the May 2018 timetable, and all that it represented for stakeholders, that “group-think” set in. With no-one daring to challenge the project other than to claim mitigation was possible to whatever new risk or problem emerged, the project team sleep-walked to disaster.’ a


The effect of (the timetable) phasing change was not clearly understood in terms of its impact on Network Rail’s processes.’ Charles Horton, former Chief Executive, GTR

‘Perhaps something about the culture, of being so keen to deliver, blinded us in some ways to some of the risks.’ Jo Kaye, Managing Director – System Operator, Network Rail

‘There was a tiny moment in November, when… we could have said, “No, stop,”… when it would not have caused complete national mayhem.’ John Halsall, South East Route Managing Director, Network Rail

‘Back in November, if we had said, “We want to delay the whole Thameslink project because the timetable is late,” I do not think we would have been taken seriously at that point.’ Chris Gibb, Chair, Industry Readiness Board

‘They needed another 50 drivers… at 10 days’ notice, which is the entire establishment of a small train company.’ Chris Green, Chair, Independent Assurance Panel