I wonder how they cope in countries with a far greater temperature range, such as Hungary? Perhaps the steel used for the rails has a different composition - could it have a lower coefficient of expansion?
I wonder how they cope in countries with a far greater temperature range, such as Hungary? Perhaps the steel used for the rails has a different composition - could it have a lower coefficient of expansion?
The variation in the coefficient over the range of common steel alloys is quite small, so I would think that this difference will not be significant, amounting to about 40 mm in 1km of free unballasted rail over a temperature range of, say, 40K, and rather less in an actual installation (if my thumbnail arithmetic is correct).
Network Rail are reassuring the public that railways are safe, but I expect they are concerned.
The reports on these two derailments will be interesting (if technical) reading.
Might not end up being technical, perhaps more about assurance, EWATs etc
Indeed, but there must surely be a fair amount of technical and/or scientific detail.
True, but I was just wondering what the main focus of the report will be.
Yes, I see. As you say, there will no doubt be a good deal of reassurance.
Railways have a very good safety record these days, but this is sometimes overlooked by the popular press.
One wonders if it suddenly buckled with the stress of the train passing over. We can see that some ballast sacks were stacked nearby, perhaps the ballasting hadn't been tamped properly.
The anecdotal reports of rough riding remind me of the 1967 Hither Green disaster. Although the Hastings units, due to their design, did tend to ride roughly (as did the 1930s Southern Railway express EMUs including the "Brighton Belle"), the cause of the accident was a broken rail due to poor maintenance and the punishing effect on the track of multiple units with axle-hung motors. It's clear that the "irregularity" did not of itself cause the derailment as other trains, and indeed the front carriages of this train, passed over it safely.
So either rails buckled suddenly as the train passed over, due to excessive stress caused by heat or embankment subsidence; or (less likely) there was a failure on the train itself. The dreadful Enschede high-speed derailment in Germany, we mustn't forget, was caused by a broken wheel.
The statement was, 'Initial findings from the Rail Accident Investigation Branch (RAIB) found an "irregularity" '. That is an observation; not a conclusion. It will be one of many before this is over, and whether the media like it or not, we have to wait for the conclusions to be drawn by the people qualified to do it.
Indeed so. One point about the RAIB investigations is that they do not only give the immediate cause of an accident but go into the background factors which may have led to it. For instance, if an accident was caused by a broken rail, they'll want to know why that happened - poor quality manufacture, improper installation, lack of or inappropriate maintenance ... And then they'll further back still and look at structural, management and human issues that may have been involved. All very interesting!
I feel it was premature, and the future report may now be hemmed in by the interim report too.
I am very interested why you say this. Would you mind expanding on this?
Because the initial and obvious cause may not be the root cause of an event.
I hope the RAIB does not jump to conclusions, based on their interim report.
RAIB does not move quickly, so 'jumping' to conclusions is not RAIB's style!
RAIB has not stated why the train derailed and the web entry also says 'Some of the information discussed in this web entry may be refined as RAIB’s investigation progresses'. So there is room for any manoeuvres required.
The W&L’s (Welshpool and Llanfair) steam gala is this weekend. We have a family connection with the railway and we are hoping to go up to Welshpool on Saturday.
A lovely line - the wider gauge (2 feet 6 inches) makes it very different from the Welsh slate railways - and it runs through some delightful, if unspectacular, countryside.
IIRC, they now have at least one replica of an original coach, which were handsome bogie vehicles, scrapped when the GWR withdrew passenger services. They do, of course, still have the original two locomotives.
The original Company only ever had three coaches, but the present-day railway has an eclectic collection - on my visit in 1977, we rode in a wooden-bodied and wooden-seated ex-Zillertalbahn coach. A few years later, we rode in a very similar coach on the Zillertalbahn proper...
Having visited Hungary on a few occasions and travelled by train, my wife was delighted to ride in a MAV coach. We had hoped to travel on the Kecskemet line into the puzsta when we were in Hungary, but the timetable was so weird that we went by bus. Unsurprisingly the line closed soon after. We did manage a ride on the short Szilvasvarad forest railway (still running) and the Children's Railway.
Incidentally Budapest has a fascinating public transport system including tram, Metro (including Line 1, the oldest in mainland Europe), bus, trolleybus, river boat, rack railway, suburban railway and chairlift. There is also a funicular but this is technically separate and very much aimed at tourists. Vintage trams and buses make regular "nostalgia" journeys (at increased fares!).
I've never been to Hungary, but I see from videos etc. that the Budapest transport system is indeed varied and fascinating. The yellow and cream (or is it ivory?) livery is most attractive, and reminiscent of certain other cities...
Having visited Hungary, and lived in Lisbon for several years, I can safely agree that yellow and white separated by a brown band (or something similar) is the proper livery for trams, at least traditional single-deckers (I'm hedging by bets there before things get thrown at my by Glaswegians, Liverpudlians, Londoners and others). Modern multi-section ones seem to do better in plain yellow.
There's also Stuttgart, where the former yellow/white livery seems to have been replaced by plain yellow - which IMHO looks fine, as you say.
One livery I detest is the lime green and blue of the Croydon Tramlink cars, which replaced the original London red-and-white on the trams when the system first opened.
One thing I liked about Tramlink is that, when it opened, they numbered the cars consecutively from the last LT ones rather than starting afresh with 001.
Comments
The variation in the coefficient over the range of common steel alloys is quite small, so I would think that this difference will not be significant, amounting to about 40 mm in 1km of free unballasted rail over a temperature range of, say, 40K, and rather less in an actual installation (if my thumbnail arithmetic is correct).
True, but I was just wondering what the main focus of the report will be.
Yes, I see. As you say, there will no doubt be a good deal of reassurance.
Railways have a very good safety record these days, but this is sometimes overlooked by the popular press.
So either rails buckled suddenly as the train passed over, due to excessive stress caused by heat or embankment subsidence; or (less likely) there was a failure on the train itself. The dreadful Enschede high-speed derailment in Germany, we mustn't forget, was caused by a broken wheel.
I feel it was premature, and the future report may now be hemmed in by the interim report too.
I am very interested why you say this. Would you mind expanding on this?
Because the initial and obvious cause may not be the root cause of an event.
I hope the RAIB does not jump to conclusions, based on their interim report.
RAIB does not move quickly, so 'jumping' to conclusions is not RAIB's style!
RAIB has not stated why the train derailed and the web entry also says 'Some of the information discussed in this web entry may be refined as RAIB’s investigation progresses'. So there is room for any manoeuvres required.
A lovely line - the wider gauge (2 feet 6 inches) makes it very different from the Welsh slate railways - and it runs through some delightful, if unspectacular, countryside.
IIRC, they now have at least one replica of an original coach, which were handsome bogie vehicles, scrapped when the GWR withdrew passenger services. They do, of course, still have the original two locomotives.
https://www.alamy.com/stock-photo-coach-number-6466-on-the-welshpool-and-llanfair-light-railway-172129735.html
IIRC, the last movements of rolling stock from BR station onto WLLR metals, before the town section was lifted, were horse-drawn!
https://youtu.be/ahPjCldSGvE
The original Company only ever had three coaches, but the present-day railway has an eclectic collection - on my visit in 1977, we rode in a wooden-bodied and wooden-seated ex-Zillertalbahn coach. A few years later, we rode in a very similar coach on the Zillertalbahn proper...
Incidentally Budapest has a fascinating public transport system including tram, Metro (including Line 1, the oldest in mainland Europe), bus, trolleybus, river boat, rack railway, suburban railway and chairlift. There is also a funicular but this is technically separate and very much aimed at tourists. Vintage trams and buses make regular "nostalgia" journeys (at increased fares!).
One livery I detest is the lime green and blue of the Croydon Tramlink cars, which replaced the original London red-and-white on the trams when the system first opened.