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david.hill64

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    Taoyuan, Derby or a plane in between.........
  • Interests
    Late BR steam period. Like building kits, and having recently got back into the hobby, enjoying it enormously. Built an 0 gauge DJH/Piercy B1 as my first 0 gauge project and now hooked on 7mm. So hooked that I persuaded SWMBO that we should buy Gladiator! Also offering a kit building service now. Finished working for Bombardier but doing some safety assessment work until the mortgage is paid!

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  1. I wrote earlier about the joys for a Gloucester lad of seeing the Scots specials - what were later to be class 06 and 17 plus the different DMU's - but if I think about it there were earlier delights. A trip to Bristol in 1966 showed me warships for the first time, including the original D600 series, and Falcon. Although Gloucester regularly saw Westerns on the London trains and Hymeks on a variety of things, Warships at that time were rare. The regular diesel classes were only Brush type 4 (47) and Peaks (45 and 46) with an occasional 25, 27 and 37. That same year a trip to Birmingham brought me my first Brush type 2 (31) on a Norwich to Birmingham service and my first EEtype 1 (20) outside Bescot yard and my first EEtype 4 (40) on the Euston trains. Later that year a trip to Derby works yielded all sorts of goodies: the original main line diesels (10000/1 and 10201/2/3) on the scrap line plus a variety of small shunters in the D29xx series and strange shunters that were a bit like the standard 08 but with jackshadt drives! Real wonders.
  2. Coming from Gloucester, trips to Scotland in the 70's were very interesting: strange 0-4-0 shunters, claytons, white circle DMUs. All strange beasts.
  3. Not sure what relevance this has to renaming, but perhaps worth noting that trains supplied via ROSCO leasing contracts are still cheaper than those procured directly by DfT. I suspect that those institutions that have invested in new stock which is now off lease might take issue with your assertion that there is little financial risk. According to research by New York University, Financial Institutions (other than banking) have an average profit rate of 65%. Interesting to compare this with returns from green and renewable energy, which are a mere 61%.
  4. Wild guess: noise attenuation. That hollow box is going to be a nice sounding board. Ballast would not impede drainage and muffle sounds.
  5. Aerodynamic effects cause pantograph uplift forces to increase with speed. The continentals accepted this but BR - who had the best vehicle dynamics experts in Europe - working with Brecknell Willis came up with a pantograph design that didn't behave in the same way. You may have noticed the aerofoils on the design. The whole ECML electrification system was modelled from the ballast up to the overhead system using the class 91 and overhead line characteristics to optimize system performance. We know that it worked at up to 155mph and with appropriate maintenance would have been OK for regular 140mph running, which is what it was designed for. The whole lot had to be deigned to a price. BR was excellent at doing that. I remember in 1992 when I was working on the Taiwan High Speed Rail system a GEC-Alsthom engineer complaining about how cheap the 91's were and warning the team that they couldn't use UK prices to benchmark procurement. It is certainly true that the headspan design suffers from a 'one down, all down' problem but it was probably the only way to get the project delivered within budget.
  6. Very strange. Most - probably all - of the Safety Plans that I have reviewed in recent years use the standard ALARP triangle. The peak region contains risks that are identified as intolerable and must be eliminated/mitigated. The base of the triangle contains those risks that are deemed acceptable without further review (and there are a lot of these) while the majority of risks fall into the tolerable region. Those risks in the tolerable region are subject to continuing reviews to ensure that the risk is As Low As Reasonably Practicable. (Some Safety Plans also allow for unacceptable risks. These are risks that are usually time bound and where elimination measures are not reasonable practicable. They are permitted if management accepts them. Happens sometimes during system migration). Risk is probability times consequence. An example of an acceptable risk: there is a possibility that a jumbo jet could crash onto a station building causing multiple casualties. This is an example of a high consequence but extremely low frequency event where the costs of mitigation (eg rebuilding the station underground) are grossly disproportionate to the benefit. Management would not be criticised for not having this under review. There will be many other risks that are deemed to be acceptable. Risks associated with signalling equipment assessed to be SIL4 are likely to be considered to be acceptable even though SIL4 does not guarantee absolute safety, for the very simple reason that absolute safety does not exist.
  7. I think that the 350 figure was the total deaths attributed to falling from a train in the time that BR had been in existence. So less than 10 a year. As far as I know it excluded deaths and injuries at stations caused by people being hit by opening doors or injuring whilst alighting before the train had stopped. However, there were indications that the problem was getting worse. Fitting CDL on main line stock was a no brainer - it clearly fell within the realms of reasonable practicality.
  8. Equipment always conforms to the standards in force at the time of design. Occasionally standards may change during the design process, in which case it is usual to allow the standards existing at the time of contract signature to prevail. Conformance with standards is checked by the relevant assessment body (NOBO, DEBO). The relevant body depends whether the applicable standards are TSI's and associated EN norms, or National Notified Technical Rules (where TSI's are not applicable). Sometimes where a new standard results in significant additional work to demonstrate compliance there may be a period of grace to allow compliance. An example is EN50128 where the 2011 revision caused significant problems for the signalling system manufacturers. Compliance to the 2001 version was allowed for many years after. Occasionally a new regulation may be introduced which applies retrospectively. Central Door Locking on slam door stock is a good example. This only happens when it is assessed that continuing use of the existing equipment presents a significant safety risk that can be mitigated by measures which are assessed as reasonably practicable (ie the cost of implementation is not disproportionate to the benefit). Otherwise there is no requirement for equipment to be upgraded as new standards are introduced. If there were, you would for example have to resignal the entire system to use ETCS* HSTs do not comply with current crashworthiness standards, but as demonstrated by most incidents have reasonably good protection. The driver of the HST which hit the tree was reported as being unharmed. The 60 year old design stood up well. *Assuming that the UK hasn't yet repealed this part of the EU legislation that requires all new works and resignalling to be done using this system.
  9. I remember reading about drivers' recollections of A4's in reports of the 'Great Gathering' at York. More than one claimed that they had achieved 130mph+. Nothing verified of course. In the great scheme of things it is not particularly important whether Mallard's record could be broken. Somebody could design and build a steam loco that could achieve faster speeds, but what's the point? The British, German and American locos were of their age and that age has passed. Nobody is going to be designing new build steam for commercial use.
  10. You need to remember that this is for events that affect individuals. For multiple fatality events a different figure applies. (Sorry, no idea what it is currently). Countries that don't use ALARP use different criteria for single and multiple fatality events.
  11. Just to add to Northmoor's excellent comment on Platform Edge Doors. I was involved with the changes required to the signalling system on Bangkok Skytrain that were necessary when PEDs were installed. The installation works require changes to the high integrity (SIL4) software. These changes have to be independently assessed. It doesn't come cheap. The added checks also take processing time. We lost up to 2 seconds at each station stop while the additional processing takes place. Over the whole route this adds up. On a metro it can become critical. On BTS the main driver for the installation was the additional revenue from the electronic advertising. On Hong Kong MTR the main driver for the installation of full height Passenger Screen Doors was the energy saving made by not having the station air conditioning systems try to cool the tunnels. It is probably impossible to make a business case to retrofit PED/PSD on safety grounds alone, but as part of new build will be much easier to justify.
  12. My early career was with British Rail Research. In the more junior grades promotion was linked with technical knowledge: up to a certain level (equivalent to BR management grades 3 or 4) the higher the grade, the better you knew your subject. When I became a section leader I was in charge of people who knew a lot more about their specialist subjects than I could ever hope to know. I remember being asked by my manager about how I was coping with managing the team. I pointed out that it was the first time I had ever been in the position of having less knowledge than the people I managed. It was clear to me from then on that the best way to manage was to know who you could rely on and then rely on them. Know too those who might have their own agenda and work with those as best you can. Try to pick up the basics of each subject within the team and know what you can answer and what needs support. I am sure that the best managers that I worked for operated that way. You don't need to be a technical expert in rail to manage rail, but you do need to have sufficient engineering/operations knowledge to be able to interact to get the best from your team. I think that the rail industry, like every other, follows diversity principles which often seem to ensure that the correct boxes are ticked rather than appoint on merit alone.
  13. Not sure about the big railway as my recent experience is with metros and Taiwan HSR. These have diverse redundant comms routes with the option for local control if, for example, the route is completely severed in the middle.
  14. I was in the cab of an HST leaving Reading towards the west when our green signal momentarily went to red before returning to the green. The drivers blamed the 37 in the triangle causing loss of detection on a set of points. They weren't at all fazed by it. However, for me, seeing a loco on an apparent conflicting route cause the events was an exercise in sphincter control. As Simon says, lots of things can cause a signal to revert to red. Getting a transient wrong side failure would be a different animal.
  15. TI21 track circuits are supposedly traction immune, hence the name. They are still being installed today. The study talks about track circuits on AC electrified lines, which might mean they are simple DC type. Having written and/or approved signalling system safety cases, including for systems using TI21 track circuits, I find it very difficult to believe that wrong side failures would be more common than right side failures. I would also point out that the study predicts wrong side failures every 10-20 years. Given the length of time that DC and TI21 track circuits have been in use, you might have expected there to have been a few wrong side failures by now. It reminds me of the early days of safety cases, when we had an argument that the winter sun shining through a fence would cause shadows on the conductor rail resulting in partial melting of the ice on the conductor rail which would induce cyclic arcing of the collector shoes which would be at a frequency that would cause the AC track circuits to malfunction. I have a feeling that if the solar storm were large enough to cause this sort of issue, we might all have been fried anyway.
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