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Title: Problems with new Class 385 Trains in Scotland Post by: SandTEngineer on March 07, 2018, 16:15:05 This sounds a very reasoned argument from ASLEF
http://www.aslef.org.uk/article.php?group_id=6091 Quote Fish bowl vision problem scuppers plans for new trains - 12 February 2018 ASLEF, the train drivers’ union, has called on Humza Yousaf, Minister for Transport in the Scottish government, to ensure that ScotRail’s new trains are fit for purpose – and warned that unless modifications are made to ensure the trains are safe, drivers will refuse to work them. Kevin Lindsay, ASLEF’s organiser in Scotland, said: ‘There’s a problem with the new Class 385 units that Transport Scotland and ScotRail have purchased. The windscreen is curved and, at night, is making drivers see two signals. It’s like looking through a fish bowl all the time. ScotRail is trying to get Hitachi to come up with a solution but, so far, I’m afraid, they have failed. I’ve informed ScotRail that we won’t allow these trains to come into service like this.’ The new Class 385 electric multiple unit is being built by Hitachi for ScotRail. The train company has ordered 70 (46 three-car and 24 four-car sets) to run from Glasgow to Edinburgh via Falkirk. They were due to come into service next month (March). ‘The effect of the squashed window means that the window is giving the impression that drivers are looking through a fish bowl to view signals,’ said Kevin. ‘I have advised the company that if this problem is not resolved to our satisfaction then we will inform our members that the trains are not safe to drive in the dark.’ Drivers on a recent test run travelling between Glasgow Central and Paisley Gilmour Street immediately became aware of problems viewing of signals from the driver’s cab while sitting at Glasgow Central waiting to leave. They reported: ‘We could see a reflection of the signals on the right hand side – showing two signals. This was even more noticeable when approaching signals travelling between Glasgow Central and Paisley when, on some occasions, we could view two or three signals when we should have been viewing only one.’ Kevin added: ‘The safety of passengers – and train crew – is absolutely paramount in the rail industry. ASLEF welcomes investment in new rolling stock and new infrastructure, but it has to be fit for purpose. That’s why I’m calling on the minister to ensure these trains are safe when they come into service.’ Further info on the new trains here: https://www.railengineer.uk/2018/02/07/on-board-scotrails-new-class-385/ and here: http://www.bbc.co.uk/news/uk-scotland-43031527 Title: Re: Problems with new Class 385 Trains in Scotland Post by: JayMac on March 07, 2018, 16:33:48 1960?
Class 303? Edit: Ahh... reference in the OP to similar events in 1960 has been removed. Title: Re: Problems with new Class 385 Trains in Scotland Post by: SandTEngineer on March 07, 2018, 16:37:14 1960? Sorry BNM Imust have been editing my post as you were reading it ::) I removed my reference to 1960 as I thought younger members on here might not have a clue what I was on about and I remembered that was all about exploding transformers, not windscreens..... :PClass 303? Edit: Ahh... reference in the OP to similar events in 1960 has been removed. Title: Re: Problems with new Class 385 Trains in Scotland Post by: stuving on March 07, 2018, 16:53:04 I heard that last month, but it wasn't clear if it was serious. I also didn't realise the AT200s were that shape - that's a very sharp curve round to the side of those windows, isn't it? I can imagine that could be like - well, more of a jam jar, really.
Title: Re: Problems with new Class 385 Trains in Scotland Post by: JayMac on March 07, 2018, 16:57:59 Class 303s did have curved windscreens. As did the later Class 310 and 311. I wonder if these had reflection issues too. Reading elsewhere on the internet, it's suggested that the 303, 310, and 311s were retrofitted with toughened flat windscreens because the curved windscreens shattered too easily when struck, either deliberately by stone throwing vandals, or by ballast thrown up.
Title: Re: Problems with new Class 385 Trains in Scotland Post by: rower40 on March 07, 2018, 17:16:52 Class 303s did have curved windscreens. As did the later Class 310 and 311. I wonder if these had reflection issues too. Reading elsewhere on the internet, it's suggested that the 303, 310, and 311s were retrofitted with toughened flat windscreens because the curved windscreens shattered too easily when struck, either deliberately by stone throwing vandals, or by ballast thrown up. And very pricey to replace!Title: Re: Problems with new Class 385 Trains in Scotland Post by: rogerw on March 07, 2018, 18:24:45 I am sure that there was a similar issue with the Class 309 (Clacton) units
Title: Re: Problems with new Class 385 Trains in Scotland Post by: MrC on March 11, 2018, 15:19:18 Class 303s did have curved windscreens. As did the later Class 310 and 311. I wonder if these had reflection issues too. Reading elsewhere on the internet, it's suggested that the 303, 310, and 311s were retrofitted with toughened flat windscreens because the curved windscreens shattered too easily when struck, either deliberately by stone throwing vandals, or by ballast thrown up. And for a (slightly) more current unit - see the class 442. I can't remember any similar issues driving them but it could be down to the relationship between screen, driving desk and seat. Certainly no more issues with screens breaking than with classic Desiros but screen replacements were very expensive. Title: Re: Problems with new Class 385 Trains in Scotland Post by: eightf48544 on March 12, 2018, 12:06:54 I am sure that there was a similar issue with the Class 309 (Clacton) units Weren't they rebuilt with flat screens. Fantastic units 0-60 in the lenght of the platform! Plus when first in service superb steak baps from the Griddle. Title: Re: Problems with new Class 385 Trains in Scotland Post by: stuving on March 12, 2018, 19:32:24 If your job is designing trains, and you are asked for one with a gangway in the end, you'll probably want to make the windows used by the driver as big as possible in the space that's left. You may well be tempted to curve the window around onto the side, roughly matching the curvature of the body shell. Unfortunately, that has optical implications.
Bending glass will naturally lead to a nearly constant thickness, which results in the outer face having a bigger radius of curvature than the inner one. Those different curvatures mean it's a lens: but a cylindrical diverging one in this case. At first sight that's the wrong kind - it would make light paths diverge while, for two images to be seen, light paths have to converge after passing through separated areas of the window. There are two reasons why that might still happen. One is the that this lens is curved as a whole, through a right angle, leading to some parts being passed through at oblique angles. Simple "thin lens" theory doesn't cover that, and the appropriate "thick lens" analysis is out of scope for here. The other factor is that outside the curved area the glass is flat; light paths diverging from each other in the curve will converge with undeviated paths via the flat parts. A quick look at the sums suggests that the overall effect is big enough, but it's not easy to say how much of the field of view it affects - but then we are told that drivers have seen it happen. So the effect isn't anything strange, inexplicable, or even surprising. You would think Hitachi's design teams would be aware of it as a possibility, and if not would have spotted it in initial design checking and proving. And then there's the history - a quick look at the online pictures of old British EMUs and DMUs (plenty of those!) would show some with odd-looking windows that were obviously modified to remove such a curve. Which, even without knowing for sure why, is a big hint. So, no excuses on this one - careless design. Title: Re: Problems with new Class 385 Trains in Scotland Post by: stuving on March 15, 2018, 09:29:18 I heard that last month, but it wasn't clear if it was serious. I also didn't realise the AT200s were that shape - that's a very sharp curve round to the side of those windows, isn't it? I can imagine that could be like - well, more of a jam jar, really. Looking at another picture of a 385, I realised I'd misunderstood the shape of that front window. The very curved part I saw was actually the body shell, and the window glass itself is almost flat. It is, however, sharply angled both vertically (i.e. raked) and, even more so, horizontally. It's hard to judge that angle or the curvature from any one still photo. The shape of the window opening is also very confusing. There's a view over the driver's shoulder in that Rail Engineer article in which the opening looks perfectly rectangular, and not skewed at all. I think this is the eye/brain jumping to illusory conclusions based on assumed right angles and perspective. In reality the shape has no parallel sides or right angles, as well as not being a plane figure at all. (https://www.railengineer.uk/wp-content/uploads/2018/02/The-drivers-view-400x400.jpg) That all makes it hard to work out what might be going on, so even opening out my envelope to use the inside won't help. The skew angle and glass thickness must be important, and perhaps the glass isn't uniform thickness, most likely towards the edges. If it is an edge effect, the simplest fix would be to blank out that part. However, the view is already very restricted by the opening and that protruding gangway, so even a small loss of that looks problematical. None of which alters the conclusion - all concerned accept it's a real issue, and the fault is entirely Hitachi's. Title: Re: Problems with new Class 385 Trains in Scotland Post by: stuving on March 15, 2018, 09:35:54 None of which alters the conclusion - all concerned accept it's a real issue, and the fault is entirely Hitachi's. I also found this in another rail Engineer article (https://www.railengineer.uk/2017/11/01/building-scotrails-385s/): Quote The AT200 trains that ScotRail have procured are the Class 385 EMUs and have a feature unique to the Hitachi’s AT series trains. This is due to the requirement for the Class 385s to have the “ability to support at-seat catering which is available to all passengers”. This innocuous sounding phrase in Transport Scotland’s franchise specification requires a front-end corridor connection. This unique aspect of the Class 385 required a modified design that had to consider crash worthiness, driver ergonomics and possible driver sighting issues. To optimise the cab and interior design, Hitachi engaged the services of the University of Liverpool’s Virtual Engineering Centre (VEC). VEC was also used to get feedback from drivers and train crews as part of the design process to ensure their buy-in. So Hitachi may be having "ongoing discussions at a higher level than usual" with their suppliers/consultants/collaborators*, but as design authority the buck is still all their own. *Draw the pen through such of the words as are inappropriate. This page is printed from the "Coffee Shop" forum at http://gwr.passenger.chat which is provided by a customer of Great Western Railway. Views expressed are those of the individual posters concerned. Visit www.gwr.com for the official Great Western Railway website. Please contact the administrators of this site if you feel that content provided contravenes our posting rules ( see http://railcustomer.info/1761 ). The forum is hosted by Well House Consultants - http://www.wellho.net |