david.hill64

Eurostat publishes some interesting stuff: not very historic though. Typical link here: https://ec.europa.eu/eurostat/statistics-explained/index.php?title=Railway_safety_statistics&oldid=326173

A generic learning point here is that it is always a good idea to build up the coupling rods first and use these as a template to check that the axle bearings are in the correct place. It can be easier to make adjustments to the frames (elongate the holes) than to the rods. Use an alignment aid appropriate to the scale you are working in. This is often an issue with older designs where the artwork was hand drawn, but rarely so with modern CAD work.

At Gladiator we are still tying to trade but cannot guarantee being able to post anything. Apologies to all. Dave and Trisha

And even these days 'As-built' drawings for electrical/pipe installations in equipment rooms rely on seeing what is there rather than what the installation drawings say...........

Thanks for the update: just shows how important it is not to rely on old information. Do you know why the change was made? Degrading the performance of something is not done lightly.

We have been here many time before. Since the power car brakes were changed in the 80's from the original two stage brake using Girling brake discs to the single stage brake using (originally) BSI or latterly Knorr discs, the braking capability of the HST power cars has complied with the braking curve over the whole speed range up to 125mph. (Unless there has been a further change in recent years, which I doubt). As the DM&EE engineer managing the change, I was involved in the tests of back to back power cars on the GW main line that proved the calculations and lab tests to be true. Note that nominally 80% of the brake force is set through the brake discs and 20% through the tread brake. The tread brake is provided to keep the treads conditioned and aid adhesion. Getting the WR operations team to agree to the test was difficult: they argued that light locomotives had a speed limit lower than line speed. This being driven by the fact that the braking capability of locos varied from barely adequate to barely noticeable. However, it was pointed out that the HST power car was just that: not a loco, so the tests went ahead. The acceleration of a pair of power cars with an enthusiastic footplate crew curious to see what they would do was impressive. With the original set up the brake force was reduced at high speeds (I think 90mph was the changeover - KenW will remember) and increased below that speed so that a full service brake to rest from 125mph would be done at an average retardation of 0.9m/s/s. At lower initial speeds the average deceleration would be higher (until initial speed was low enough for brake force build up time to be more significant). With the revised set up the average retardation was constant independent of the initial speed and independent of the number of trailer cars. So the only reason for limiting the maximum speed of the short formation will be to give an extra braking distance contingency. This would be eminently sensible as the effect of Wheel Slip Protection activity on even a single axle will be more pronounced on a shorter train as the percentage loss of brake force will be greater. There is nominally 300m contingency on level track for 125mph signalling and full service braking. It isn't excessive for a full formation set.

As a child in the late 60's I once had the pleasure of a school trip to Rev Awdry's house and his version of a model railway based on his books. It was wonderful. I wonder what became of it? David

Actually I think you'll find that although the practical headquarters of Bombardier Transportation is Berlin, the company has its registered HQ for tax purposes in the UK: Bombardier Transportation (Global Holding) UK Ltd. I remember the internal email coming round in 2015 informing staff (including me at the time). It's possible that Brexit might have caused a HQ staff are based in Berlin though. I left BT two years ago.

Not really surprising: a Bombardier-Siemens tie up seemed likely before the Alstom-Siemens merger was attempted. Siemens might have a chance of surviving against the Chinese in a world market, but both Alstom and Bombardier are vulnerable individually. The next question will be whether the EU allows it as it will reduce competition within the EU.

When I read an article that says that Pacers use the same chassis as a Leyland bus from the 70's I despair for the stupidity of journalists and realise that you cannot trust anything you read in a newspaper on any topic...............

There is a German equivalent, the Heberlein brake, still in use on some narrow gauge lines.

Moreover noise mitigation measures become less costly. I remember the head of the aerodynamics team at BR Research telling me that aerodynamic noise (admittedly only a proportion of noise generated) is proportional to the ninth power of velocity. Just think about that for a moment: running at 225mph rather than 186mph (100m/s rather than 83m/s) increases the aerodynamic part of the noise generated by 500%. Whereas noise generated by the wheel-rail interaction can be absorbed by low level barriers, upper body noise is much more difficult to contain.

Be very careful when using Shinkanshen as a yardstick for anything. It is an excellent system but the Japanese have a way of presenting statistics that is quite different to western methods. For example the wiki reference you give refers to the much admired punctuality statistics with average delay 24 seconds including 'natural disasters'. But what it doesn't mention is that JR changes the timetable en-route when 'natural disasters happen. When I was working on the Taiwan High Speed Rail project (essentially Japanese E&M systems) we went on a tour of Shinkansen systems hosted by JR and the suppliers. On one journey from the north to Tokyo it started snowing: speed was reduced because of snow build up around the suspension. Arrival in Tokyo was 40 minutes after the advertised arrival journey time when we boarded. However, officially we were on time: the snow time-table had been invoked en-route. Can you imagine the furore here if we tried that? Sorry no delay payment due: we invoked the 'NR incompetence (insert other cause as you wish) timetable and were actually on time. It applies to other statistics too: you will read that no passenger has ever been killed on the Shinkanshen. True by JR definition where a passenger is descried as somebody who has successfully boarded or alighted from a train at a station. So the student who was trapped in a door and dragged to his death doesn't count (hadn't boarded successfully) and the few people who fell from open doors between stations are in the trespass statistics as they left the train not at a station. The JR signalling system is more than capable of supporting more than 12 trains per hour but they choose to limit the number to ensure system resilience. The Japanese don't use high speed turnouts: one reason is that the overhead line design is limited to 80km/h at turnouts. This adversely affects capacity in a way that would not be an issue with HS2 (assuming a non-Japanese overhead line design). In Taiwan 200km/h turnouts were installed as the original alignment was based on European practice, but these have an 80km/h limit. I have no doubt that 18tph is achievable with ETCS. I make that statement as a chartered engineer (though not an IRSE member) with more than 40 years' experience including high speed.

There is a delay with production of the new Bowen Cooke tenders: a new master is being made as the first had some quality issues. Dave has been hospitalised in Taiwan and will miss the Bristol show this weekend. Trisha will be there. Dave

Interesting comparing the state of these with those from Horton Road!!!:

I thought it had gone quiet: I was expecting that after no posting from you for a week we would see the completed Patriot, three wagons, two carriages and a partridge in a pear tree.............bit of a shock to get this news. Wishing you a full and rapid recovery. David

I think they are platform screen doors in Crossrail not platform edge doors, but I understand your point. On the metros that I have worked on through running (usually of trains returning to the depot after the peaks) has not been a problem. Provided the tunnel ventilation system is designed for it the change in the pressure pulse as the train enters/leaves the station box isn't an issue.

I wasn't suggesting that freight or indeed anything other than Crossrail stock need use the tunnel when in service and it is certainly true that the 1100 mm platforms would present an obstacle to many types of vehicle. However, the TSI effectively allows UK to do what it wants. DfT's list of UK rail derogations doesn't contain any relating to infrastructure clearances. https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/832900/Rail_Interoperability_Derogations_and_Decisions.csv/preview

Quite wrong if we had remained in the EU. I suggest you read the derogation. https://ec.europa.eu/transport/sites/transport/files/modes/rail/interoperability/interoperability/doc/c_2012_73_derogation_uk_ccs_tsi.pdf I agree that it is now moot.

Phil some speculation in your comment I think. You imply that the central core has been built to a very restricted loading gauge!!! We seem to have been able to run construction trains and 345's in the tunnels without problems. 345's apparently cope well with standard UK platforms and those in the Crossrail central section. My assumption is that the civil infrastructure in the tunnels conforms to the passenger train and civil works TSI's which themselves contain an opt out to let UK continue to use the existing gauge throughout the system. The electrification works might even conform to the Energy TSI as the use of PSD's will have mitigated part of the risk. Trainguard: depends on when the choice was made. The argument for the derogation appears to be that the core needed moving block which as you rightly say is not a proven product as ETCS level 3. Hence the moves to allow an ETCS 2/3 hybrid. (Just to say again that Bombardier has supplied a fully functional mixed traffic ETCS level 3 look alike system to Turkmenistan (I think: it's one of the -stans). But it uses TETRA not GSM as the carrier so doesn't count). But Thameslink, which is ETCS level 2 has a 30 TPH design through the central core. Given that if we had remained in the EU, Trainguard would have to be ripped out soon and replaced by ETCS, it would have been more sensible to adopt ETCS level 2 throughout. Although Trainguard is a proven product, every metro signalling system is tailored to its application. The wording of the derogation implies that a 'communications bearer capable of supporting ETCS' ie GSM radio , shall be installed as part of the initial installation. What isn't clear to me is whether the intention is that GSM should be used as the data carrier for the Trainguard system. If it is, then it is a completely new development of Trainguard which typically uses 2.4GHz and 5.2GHz Wi-Fi signals as the data carrier. Moreover in the application of Trainguard that I am currently assessing, the use of twin frequencies is a cornerstone of the safety case. If Siemens has had to move away from this - and being 6000 miles away from Crossrail I have no idea what they are actually using - it would have been a significant development. Hindsight is a wonderful thing, but it seems that Crossrail and Thameslink were unaware of what each other was doing. Otherwise we might have had only ETCS and TPWS/AWS as the onboard systems, and saved a fortune. Finally more comments about the derogation. It permits CBTC to be used until ETCS is capable of supporting ATO (already in use in Thameslink), communications with PSD and auto reverse. The Bangkok skytrain CBTC system is a metro version of ETCS level 2 and already supports both communications with PSD and auto reverse. The conditions for the derogation to end may well exist before Crossrail is commissioned.

The reasons are contained in the European Commission's derogation that permits temporary use of the Siemens Trainguard CBTC system in the central core. The EC determined that Crossrail is part of the UK national rail network and therefore falls under the scope of the interoperability directive which demands compliance with the TSI's. In respect of signalling this means using one of the ETCS levels. I would be interested to understand why TfL thought it necessary to continue with Trainguard rather than using ETCS level 2 as per Thameslink especially since if we had remained in the EU migration to ETCS would have been required.

OK that makes a lot of sense, thanks. Last time I used HEX it was still in the hands of the original HEX units. I recall that ETCS was trying to incorporate modules that allowed the onboard ETCS equipment to read wayside telegrams from legacy ATP systems and drive the ETCS ATP that way. There was even a suitable acronym for the modules but it's slipped my mind. I've been away from ETCS development for a while. If it hasn't been able to work then I am not surprised. I was surprised that the IET's have the Alstom ATP system fitted: they must have dredged the bottom of the spares barrels (or took equipment from HST power cars (???)) to equip the trains. For me, the next interesting thing will be to see if the government decides to let the Crossrail central core CBTC system live out its natural life rather than being replaced by ETCS level 3 when that becomes available.

What happened to the GW ATP system? I thought that HEX used that.

Ken, are the gas tanks brass tube? Cheers Dave

Unlikely and it wouldn’t be sensible to abandon an integrated set of standards too quickly. The short term exception in my view would be the electrification clearances in the Energy TSI. Reverting to the proven safe BR standard would knock hundreds of millions off the cost of electrification.