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| Steventon Bridge & electrification 10/03/2020 at 23:49 #123691 | |
Albert
1315 posts |
To all of you who like to play SwinDid - the name Steventon can be clearly seen on the panel just west of Didcot. The electrification of the GWR caused quite some disturbance there before (see https://www.railengineer.co.uk/2018/08/30/steventon-bridge-demolition-local-voice-rejects-proposed-10-months-of-disturbance/). As the bridge is too low, trains either had to pass it on diesel power or reduce their speed to 60mph, and replacing it seems too complicated politically. Very silently the speed has been raised to 110mph last September, or at least, I found it out today by reading this article: https://www.railengineer.co.uk/2020/03/06/steventon-bridge-overcoming-the-obstacle/ Surprisingly nothing has changed in the field, it is all a result of computer calculations to determine what speed is 'acceptable' (for keeping good contact, and not breaking the wire.) The article is rather technical and focuses more on the computer model and the experiments to validate it. Interesting for me (given computer modelling will soon be my job) but to us railway enthusiasts, it does leave some questions. Such as: will this speed limit be valid for all types of electric trains, or have only the class 800/802 and 387 received clearance to run at 110mph here? What about electric freights (if there are any in the region?) P.S. my job will not be directly related to railways. AJP in games Log in to reply |
| Steventon Bridge & electrification 11/03/2020 at 00:43 #123692 | |
Edgemaster
332 posts |
Albert in post 123691 said:will this speed limit be valid for all types of electric trains, or have only the class 800/802 and 387 received clearance to run at 110mph here? What about electric freights (if there are any in the region?Partial answer from the author's twitter account: Quote: Don't think there is any restriction on an HS-A pan... key thing is all the tests we did were multi-pan trains. 3 modern pans at 80m spacings (3x4 car class 387) is a much more onerous performance condition than a single HS-A Last edited: 11/03/2020 at 00:43 by Edgemaster Reason: None given Log in to reply |
| Steventon Bridge & electrification 11/03/2020 at 07:24 #123694 | |
Peter Bennet
5402 posts |
‘this is a train not a ship!’ Peter I identify as half man half biscuit - crumbs! Log in to reply |
| Steventon Bridge & electrification 11/03/2020 at 10:17 #123698 | |
lazzer
635 posts |
Albert in post 123691 said:Very silently the speed has been raised to 110mph last SeptemberYou make it sound like it should have been on the evening news or something. The only people who need to know about the linespeed being changed are railway staff, contractors etc. To that effect, notices were posted prominently at all GWR depots advising drivers of the speed increase, and that there was no longer any need to run on diesel mode through that section when driving an IET. The temporary "Diesel" and "Pan Up" signs between Causeway crossing and Wantage Road were recovered. (Also, the majority of the "disturbance" in the Steventon area during electrification work came from the NIMBYs living nearby, who objected to the masts, wires, and new prison-style fencing going up, thus blighting their view of er, a railway line ...) Log in to reply |
| Steventon Bridge & electrification 11/03/2020 at 11:20 #123699 | |
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Peter Bennet
5402 posts |
lazzer in post 123698 said:Albert in post 123691 said:My reading of the article was that the 60mph limit was for operational reasons, due to the gradient profile of the wiring. Testing proved that 110mph was within the tolerance so the limit was raised to 110mph.Very silently the speed has been raised to 110mph last SeptemberYou make it sound like it should have been on the evening news or something. Peter I identify as half man half biscuit - crumbs! Log in to reply |
| Steventon Bridge & electrification 11/03/2020 at 11:42 #123701 | |
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Humorist
102 posts |
Much was made in Scotland about the Hitachi class 385s, that their pantographs were designed to be sacrificial. That meant that, if the pan struck an obstacle in the OLE, the pan should be detached, rather than bringing down a mile or more of OLE. At least, that was the theory, and it sounded good. Did Hitachi make the class 800 series pans similarly sacrificial?
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