david.hill64

Indeed it is: vehicles I am currently assessing for operation in Taiwan are designed to this standard. I suspect that as well as the US, Japan also does not use any EN standard for domestic builds. The point is that the UK was not able to specify load cases that may be more relevant. In the bad old days after the problems with 158's, BR engineers knew what was required and could guide the builder to an acceptable solution. It is only recently that severe yaw damper bracket problems have re-emerged and these are vehicles that comply with the TSI and supporting EN. This to my simple mind suggests that the load cases in the standard are not severe enough for vehicles operating on UK infrastructure.

The short answer is because it would have been illegal to require them to be suitable for British conditions. All rolling stock for EU main line railways by law has to comply with the Technical Standards for Interoperabilty and supporting Euronorms. Railways are not permitted to require more restrictive requirements for their system. The TSI has a gauging derogation for UK (so does acknowledge some differences to continental practice) but the loads that have to be carried by the structure, including body-bogie connections are mandated in EN12663. Yes, Hitachi might have chosen to design something that could withstand greater loads but were under no immediate obligation to do so. I haven't seen the procurement specification but it is likely to have required compliance with applicable standards. If the real railway has a different environment Hitachi will argue that it is not its problem. Of course it may now be possible to migrate BS-EN standards to be more GB-centric but there will be issues with this too.

No, it was the BR Research prototype design for visually sensitive areas...............

BREL (or a later naming thereof) came up with a generic design of vehicle that used glued and huck-bolted sections. Taipei Brown line mrt has some examples.

It is normal when trains are coming off lease for the maintenance regime to be reduced so that work that isn't essential to keep the trains safe in the short term is not carried out. If you need to return them to service for what is an indeterminate amount of time then rather more than an A exam may be required.

Actually it isn't because Agility trains provide trains under a train service contract. If they cannot provide the required number of trains then they are penalised. Arguably it is the only thing DafT got right with the procurement.

Repair welding in the same sense as you could do it for a steel structure is likely impossible. You might be able to do something as a short term measure while a proper solution is devised. Welding aluminium is never easy and will not solve the issue which is that the stresses the component is being asked to bear are greater than it can support. Either you need to reduce the loads or beef up the part so that it can do what it needs to. If it goes the same route as the 158's then the bodies will need to be completely stripped, the affected areas cut out and a new section welded in. You might argue that at the same time they could knock 3m off the length of each car which would resolve some of the other issues. (Removes tongue from cheek). So yes the interior is likely to have to be stripped out unless in the last 30 years somebody has found a cheaper alternative.

My recollection is that the first class 158's also suffered from early failures of the yaw damper brackets due to fatigue cracking. Weld repair of cracks in aluminium is a fruitless exercise. Aluminium, unlike steel, doesn't have a fatigue limit: every cycle of stress causes fatigue damage. In steel, below a certain level of stress, the material can withstand an infinite number of stress cycles. In aluminium you have to make sure that the fatigue stresses are so low that cracking cannot develop. Welding (almost) always introduces small defects that act as stress raisers. If you weld repair an area that is already cracking you will achieve at best a temporary solution. IIRC the affected 158s had to be withdrawn, stripped down, the affected area cut out and a new, stronger, section welded in. A lot of computer modelling was done by BR Research to ensure the repair would be robust (my bridge partner at the time was the head of that section and used to regale me of the progress between hands of cards). So I think that Hitachi is in for a very expensive time to do a redesign and replacement exercise on all affected fleets. I would guess that some clever people are going to do some complex stress analysis and fracture mechanics analysis to determine how big the cracks can be before they represent a real risk of failure. We may well find that an enhanced monitoring regime will enable affected units to return to traffic safely until modifications can be carried out. I was confused by the references to fatigue cracking of the jacking points. There shouldn't be any stress in these except when in use. Looking at the photos it seems that the jacking point and yaw damper attachment are in the same piece. For the reasons given by Jim Snowdon early in this thread there will be a lot of high frequency low amplitude forces transmitted from the bogie through the yaw damper. I strongly suspect these will be the issue. I can understand that the general public can understand a jacking point but will not have the foggiest idea about yaw damper fixings. As to the question of whether the design should have been better, obviously it should have been. But I have a lot of sympathy with Hitachi. Under the current approval regime they must, by law, comply with the EU Technical Standards for Interoperability and subordinate euronorms called up by these standards. If the design complies with these standards (and it must), the assessment body is not allowed to question the design. If we go back to BR days enforcement of standards was subject to contract law and failure to comply could only result in worst case as a civil matter. Nowadays failure to comply is a criminal offence. If BR didn't like an aspect of the design then this would have been picked up in design scrutiny and a redesign mandated. Provided BR had a genuine reason the contractor would always comply. Whilst the current suite of euronorms provides a coherent and usually sufficient suite of standards I think we have lost that level of group knowledge that BR had and the industry is poorer for that. If the current suite of standards fails to account for Network Rail's crappy track quality then an issue is inevitable.

Back in the late 60's I was on the morning Gloucester to Birmingham stopper hauled by a Peak. We were signalled clear through the stop at Ashchurch and the driver had obviously forgotten the stop. Realising this the bobby dropped the pegs resulting in a full brake application. We sailed past the signals and reversed back. Different days!

Now supplied. Thank you. David

I have mislaid my instructions for the DJH 00 kit of a BR standard class 5. If anyone can pass a set to me I would be most grateful. All reasonable costs reimbursed. Thank you. David

The trains are sealed with a constant pressure inside the car which means that the bodyshells expand and contract as the pressure outside changes (as it does in a tunnel transit). The smaller windows are better able to withstand the flexing and are less likely to pop out.

There is a presumption in the EU standards that railways were developed in accordance with UIC norms. For UK this is not correct and the major difference is of course the structure gauge. The TSI's note this and there is an exemption from compliance with normal gauging requirements for UK and Ireland contained in the TSI's. But, some things have been missed: the obvious example is electrification clearances where the TSI assumes compliance with the standard European structure gauge and cannot easily be achieved for UK infrastructure. I cannot answer your question directly: you would need to find somebody on the drafting committee. I think the point is that the crashworthiness standard fails to consider adequately the possibility of large sideways deflections following a low speed shunt. For the reasons you describe, the consequences are potentially more severe in the UK.

36km/h is 10m/s and quite likely chosen as an arbitrary figure because it is a convenient number and of course all calculations are done in SI units. Whether there is justification in adopting 10m/s as opposed to 8.75 or 11.32m/s (for example) is open to conjecture. Somewhere in the minutes of the meetings of the drafting committee there will be a rationale. As pointed out by phil-b259, of more interest is the derailment behaviour of the IET as obviously becoming foul of an adjacent running line holds the possibility of a high speed collision occurring. I am presently involved with the safety assessment of a new Asian metro system and here the collision requirements go beyond those specified in the European TSI and supporting norms. In the EU such an approach is not possible for main line railways as compliance with TSI's and supporting norms as judged via the Common Safety Method is the only acceptable legal method of specification and review. It will be interesting to see if after 1st January UK deviates in the face of identified deficiencies in the standards. Requiring dynamic analysis of low speed collisions would seem a useful first step. I am not knocking EU standards per se: they form a comprehensive interrelated coherent set that mostly do the job required.

Yes, only power cars and it was nominally 6%g above 90mph and 12%g below. I say nominally as the braking on the power cars was 80% disc brake and 20% block brake. While the brake force of the disc brakes was essentially independent of speed, that of the block brakes was very non-linear. So at low speeds - say below 20mph - the actual braking rate of the power cars would be above 20%. However, in a full rake such niceties could be ignored. Trailer cars were only ever single stage braked at nominal 9%g. So for a standard length HST the overall brake rate worked out at about 9%g. Problems would occur with short sets. The Stationmaster has referred to special restrictions for the short formed 'Top of the pops' run. At speeds above 90mph a short set would have substandard brake performance - at low speeds below 90mph the brake rate would be higher than that of a full length set. Various brake modifications were carried out. The original Ferodo brake pad material had a wonderful friction characteristic: stable at all speeds and temperatures giving a very consistent brake performance. But, as well as emitting the horrible smell during heavy brake applications (necessary if the driver had been in search of his '140 club' tie) the pads contained asbestos and were horrible to the discs causing hot spotting that led to cracking and, on occasions, ejection of the discs at speed. As an interim solution BR research developed a stronger form of cast iron, called compacted graphite, to replace the original flake graphite discs. Compacted graphite was more resistant to cracking than the flake iron and had a better thermal conductivity than spheroidal graphite iron. (Flake and spheroidal graphite irons were the most commonly used forms of cast iron). The power car discs continued to have problems with an average life of about 12 months, so wheelset replacements were necessary between overhauls. This was costly. The pricing structure meant that the regions paid a fixed price for a replacement wheelset irrespective of what was wrong with the old one, so cost savings were made by doing disc replacements at depots. Although not an easy job, as the Lucas Girling discs were split (not continuous rings) it was possible. A solution came with a change in disc and pad supplier. The German company BSI developed a continuous ring disc that was able to expand on its mountings to allow for the thermal expansion in braking. Allied to an asbestos-free brake pad produced by Becorit the discs were able to absorb the brake energy from 125mph at a constant 9% g rate, abandoning the two stage brake and giving a brake rate for HST's independent of train length. At about the same time the trailer cars were fitted with a UIC pad holder to replace the technically superior but patented Girling design and the Becorit pads used. This also required a change to the brake distributors as the friction coefficient of the Becorit pads, while conforming to the BR (and UIC) standard, was lower than that of the Ferodo pads. I wasn't involved with later changes but Knorr Bremse also produced discs and I understand that the braking rate of the power cars was reduced again to extend brake life (presumably at the expense of brake rate).

It has been a long time since the last update! Like other suppliers we are experiencing very long lead times for the supply of components, so restocking is taking a long time. We are trying to mitigate this by ordering larger quantities than usual, but the downside to this is that they take longer to produce. The first batch of Coal Engines sold out but a second batch will be available in late December (Only one left unreserved) and a third batch on order. We are still waiting on bodies for the final design of Bowen Cooke tender. The LNWR D87 van has been a very long time in production. As soon as we have a set of assembly instructions we will be able to release them for sale. I will be back in UK full time from Christmas and expect to be able to progress some other new designs. David

Bill has been in hospital but is out now. He also had no access to his workshop for a long time. David

Actually it did. The team at Derby warned Thornaby that there was a problem on a specific cylinder of the 37 fitted with the Demon equipment. Thornaby fitters couldn't find anything wrong but at the next overhaul the cylinder head was found to be cracked. The whole main point of condition monitoring is to permit predictive maintenance as well as an aid to fault finding. As well as diesel engine monitoring, one of the LM 321 units was fitted with a door monitoring system that was able to identify 21 (IIRC) different fault conditions and predict when these would become critical using a neural network program. All this was over 30 years ago and it has taken this long for the industry to catch up with what BRR was doing.

Ken, I've not been on the forum for a while so would have said earlier: shouldn't the strengthening rib for the cab roof be in the inside? David

The video of Sweet Pea on the Middleton brings back happy memories. The loco was owned by the Leeds University Railway Society and used as the main motive power when students were running the goods traffic in the 1970's. Getting it to start on a cold winter day could be a nightmare. It required two people: one on the starting handle (yes, it really is a hand cranked start) and one on the decompressors. Plenty of easy start in the air intake and if that didn't work a paraffin soaked rag set alight instead. When the crankman had built up enough momentum there would be a huge shout and the decompressors released. With luck it would fire without backfiring and after a couple of minutes warming up it would be ready for the off. I was a lot happier when I graduated to electric start, warm cab and air brakes! (And even happier with a hot cab and steam brakes).

For the reasons that Simon has outlined I think it unlikely that Crossrail would be thinking about abandoning CBTC for the central section at this time. However, some observations: CBTC is (was?) only allowed in the central section under a derogation from the European Commission; the derogation requires that there is a migration path to ETCS, so it is possible that this has been factored in to the design of the ETCS sections. Reasons for allowing CBTC included headway requirements (now achieved with Thameslink ETCS) and PSD interfacing (achieved on Bangkok Skytrain, which isn't an ETCS system but uses ETCS hardware) so the technical reasons for using CBTC may no longer be valid (if they ever were). When I was evaluating proposals for the Istanbul Marmaray project, Siemens had an excellent technical solution to the requirement for CBTC to be fitted to the local trains and ETCS to the freight and other passenger trains. Siemens CBTC was able to fall back seamlessly into ETCS mode (with a hot standby) in case of CBTC failure. It is therefore possible (but speculation on my part) that migration of the CBTC to ETCS on the central section may not be too difficult. Doing it before revenue service will save much pain later. Removing one set of signalling equipment will assist system integration issues and later aid reliability/availability. However, it will give Bombardier a headache in changing onboard equipment.

At the risk of becoming too political, why not? Publicly listed private companies are owned by shareholders, such as pension funds and insurance companies, who invest in order to get a return. No business is going to survive if it doesn't make money. So the question is: can private companies offer anything that government owned ones cannot? I suspect that the answer in the case of a management contract micromanaged by DfT the answer may well be no. Whatever is put in place is likely to be a short term measure.

Don't forget that lead is poisonous, so I would not run the risk, however small, of contaminating the oven with lead and infusing it into the Sunday roast, or pizza or whatever floats your culinary boat.

True, but many more recent kits allow for a floating centre axle, which is a better solution. The only other point of course is to ensure that the axle bearings are at the same spacings as the coupling rods.

A bit late to comment now but you can use a gas ring or cooks blowtorch safely to disassemble a poorly built nickel silver or brass model. 'Normal' solder melts at about 186 degrees, far below the temperature when brass glows red (650 - 750 degrees). Obviously not suitable for whitemetal!!! Once apart the desoldering wick is useful for cleaning up. You do need to ensure that the chassis rolls freely without the rods on and that all wheels touch the ground at the same time and the axles are parallel to each other. Your jig will assist in that. I would also strongly recommend investing in a 3/16" and a 4.8mm parallel hand reamer. Run these through the bearings to ensure that the axles are a good fit (ie not too tight nor sloppy). Not cheap, but well l worth it. David