We’re sorry to announce …, part 1

Never one to understate the benefits that his pet project will provide, Professor Andrew McNaughton is particularly bullish regarding the punctuality performance that we can expect from HS2 trains (see footnote 1):

“… the bloody thing will be on time every time – not [only] if you’re lucky. If it departs Birmingham Curzon Street at 10.42am, then it leaves at 10.42am, not 10.43am.”

And it appears that he really means every time:

“Whether it is sunny, snowing, raining, sleeting, hailing, those trains will run on time. I am not having the wrong type of leaves or the wrong type of anything holding those trains up.”

Indeed, some support for this claim may be found in the HS2 Project Specification, which requires that the maximum delay per train should be “no greater than 30 seconds on any section” (see footnote 2). Unfortunately, though, the document fails to define what is meant by “section”, so it is not possible to translate this requirement into, for example, a punctuality performance target for the Euston-Birmingham service. Also, this condition can only relate to trains running on new high-speed track sections, so classic-compatible trains must be exempt when running on legacy infrastructure, but I will say more about this in part 2.

If the punctuality performance expected by Professor McNaughton is achieved by HS2 in public operation, then we Brits will, it appears, be doing better than our neighbours across the English Channel are currently managing with their TGV. A baromètre de la régularité e-published by the French national state-owned railway company, SNCF, indicates that at the end of last year punctuality on TGV was running at about 93%. This “achievement” by the French is even less impressive in the realisation that the SNCF definition of on time (à l’heure) includes trains that arrive up to fifteen minutes late (en retard) on the very longest journeys (see footnote 3).

Notwithstanding these unfavourable omens from France, it is surely, you might think, imprudent of Professor McNaughton to assert that HS2 trains will be “on time every time” and perhaps he would be wiser to heed the words of Robert Burns:

“The best laid schemes o’ mice an’ men
Gang aft a-gley.”

For there are many unforeseen incidents, as well as planned temporary operational restrictions, that can occur to thwart those attempting to run a railway with too-optimistic quality of service aims. There is also that most unpredictable of all factors, human behaviour, to take into account, in the person of passengers and railway staff, who will always be capable of defeating the most robust operational plans; acting the iceberg to HS2’s Titanic.

In the early days of the HS2 project the international engineering consultancy SYSTRA was commissioned by HS2 Ltd to undertake a study of the operational criteria for the proposed HS2 railway, in particular line capacity and reliability, and the findings of this study were published in a report in October 2011 (see footnote 4). Whilst this report is almost five-years old, it is, as far as I can tell, the most recent published analysis of HS2 line capacity and reliability (see footnote 5).

The SYSTRA report advises that the French TGV operators “claim to be able to run up to 15 to 16 trains per hour on their northern line between Lille and Paris” and cautions that the expectation that HS2 will support 18 trains per hour and per direction at 360km/hr is a “feat that has not yet been attempted on any existing railway”. Despite this, the report finds that it is able to offer general support to the concept, whilst quibbling about some of the details of HS2 Ltd’s calculations (see footnote 6).

This conclusion is of relevance as the report also illustrates that compromise in the capacity and speed of operation are necessary in order to provide some resilience to service perturbations (see footnote 7).

One item in the SYSTRA report that I find interesting is the “breakdown of delays by cause” for the UK network, which I have reproduced below. Whilst this, of course, relates to the legacy network, it seems to me that there is no reason why we should expect the causes of delays, or the relative occurrence of each, to be markedly different for the HS2 network.

Source: SYSTRA Technical Note: HS2 Capacity and Reliability, page 67

Source: SYSTRA Technical Note: HS2 Capacity and Reliability, page 67

The SYSTRA graphic reveals that by far the most common cause of delays is the knock-on from “delay from previous railway” and, as I see it, HS2 will be particularly vulnerable to this effect. Accordingly, I intend to look at this potential threat to service quality in my next posting.

(To be continued …)


  1. As far as I am able to check, Professor McNaughton is still Technical Director of HS2 Ltd despite, as I reported in A bad deal at any price (posted 28 May 2016), the appointment of an Acting Technical Director. The professor’s quotes are taken from an interview that he gave to the Birmingham newspaper Express & Star, as reported in an article published in March 2015.
  2. See paragraph 5.1 of the HS2 Ltd publication HS2 Project Specification, January 2012.
  3. Clicking on Mèthodologie on the Baromètre de la Régularité reveals that “a train is considered late if it arrives five minutes after its scheduled time for a journey less than 1hr 30min, ten minutes for a journey from 1hr 30min to 3hrs, and fifteen minutes for a journey of more than 3hrs” (translation)”.
  4. SYSTRA was formed in 1995 by the merger of the engineering arms of the two French state-owned transportation companies: Société Nationale des Chemins de Fer Français (SNCF), the national operator; and Régie Autonome des Transports Parisiens (RATP), the public transport operator for Paris. The report, Operational Concept Study, Technical Note: HS2 Capacity and Reliability, as e-published by HS2 Ltd has been redacted, but the link that I have provided is to a complete copy obtained by FOI request.
  5. That no other publications are available appears to be confirmed by the response to the FOI request mention in footnote 4.
  6. The extracts are taken from the preamble to Section 6 of the SYSTRA report and the support for 18 trains per hour in each direction may be found in Sub-section 6.6.
  7. The report recommends that spare capacity is introduced when planning train times, either by increasing the headway between successive trains or by reserving spare train paths for use by late-running trains (see Sub-section 5.3 of the SYSTRA report), and that the timetable is planned on the basis of an operating speed that is less than the maximum supported, to allow late-running trains to speed up to recover lost time (see Sub-section 4.5 of the SYSTRA report).

Acknowledgement: I wish to thank John Marriott for alerting me to his FOI request and the existence of the SYSTRA report.


One response to this post.

  1. Posted by LesF on June 21, 2016 at 2:08 pm

    There are two causes of delay not mentioned in the Systra report: suicide (unless “clearing of the track” is meant to include this) and lineside fires. Neither risk can be eliminated. There are 101 causes of delay and it’s silly to pretend a new railway can be risk-proof. As for leaves on the line, HS2 contradict themselves as they do on other matters, according to what they are trying to prove at the time. One day they proclaim they’ll be planting millions of trees to mask the railway, another day these trees will be evergreen so they don’t drop leaves, but that means their noise absorption will be less than for broad-leaved trees, another day they’ll be small shrubs. And their own research says that noise from a source you can’t see is more annoying than one from a visible source.
    HS2 is a bit like Brexit; we don’t know how horrible it’ll be unless we’re foolish enough to try it.


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