Reading General
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« Reply #195 on: November 17, 2021, 21:53:30 » |
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I saw one move through platform 3 at Oxford station last week towards the sidings. I couldn’t see it on the real time trains website.
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anthony215
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« Reply #196 on: November 18, 2021, 17:12:27 » |
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I was in Palmer Park, Reading about 1210 today and saw 3V11, 769 937 returning ecs to Reading from Gatwick on time. Looked very smart.
Try the Park's TuTu's Cafe, it's very good.
OTC
According to the gwr staff 769937 seems to be the most behaved of the 769s they've received so far
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stuving
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« Reply #197 on: December 15, 2021, 22:31:46 » |
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It also might hint that the 769 introduction is still a LONG way off.
... and maybe getting longer off! While GWR▸ 's herd were doing better than the rest, recently they haven't done at all well. With six runs to Gatwick a week planned, so far this week it's been four no-shows out of six. That may be due to last week, where there were three failures at Guildford (one after a failed attempt to fail at Redhill, followed by a successful failure on the way beck). Two runs went OK, the sixth was cancelled. These runs are still being called mileage accumulation, but with some scope for training. So far that's been training driver managers and trainers, but even if driver availability allowed their inclusion, ASLEF» still don't.
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RichT54
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« Reply #198 on: February 16, 2022, 22:35:14 » |
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There's been an interesting conversation on RailUK Forums today: Possibly. 769s like 319s before them have two AWS▸ receivers. The AWS magnets on DC▸ electrified lines have a much stronger magnetic field to overcome the electromagnetic interference from the 3rd rail so there is an AWS receiver for DC, and another for AC & diesel. The switch from one to the other should happen as part of the power changeover procedure, but if it doesn't then the train can be running with the wrong receiver active, which can result in lots of AWS irregularities. That's just an educated guess on my part though as to what happened on 939 today.
Meanwhile, 936 failed at Guildford this afternoon with a traction motor fault, could only get as far as Wanborough on the other motor, so headed back to Guildford, and is now sat in disgrace in the sidings awaiting rescue tomorrow. There are four traction motors, yes, but it's only possible to isolate pairs of motors so if one develops a fault that requires isolation, then two motors are lost. I probably could have been clearer in that it was one pair that had been isolated leaving one pair operational, i.e., 50% power. Performance on one pair of motors is pretty dire, especially on any sort of gradient like the 1 in 100 leaving Guildford on the down Ash.
Reading low level line has been attempted from a standing start on one pair of motors a while ago - I can't remember the exact gradient (something severe like 1 in 35?) but that one very nearly didn't make it. Edit: forgot the link https://www.railforums.co.uk/threads/gwr-class-319-769-information-discussion.174866/page-51#post-5538947
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« Last Edit: February 16, 2022, 22:47:21 by RichT54 »
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eightonedee
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« Reply #199 on: February 22, 2022, 18:55:05 » |
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Doesn't look like the failure rate is improving?
Saw first one at Guildford this evening, but all shut up and dark in the sidings beyond platform 8 and the temporary site offices. Another failure?
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stuving
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« Reply #200 on: February 22, 2022, 19:30:13 » |
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Doesn't look like the failure rate is improving?
Saw first one at Guildford this evening, but all shut up and dark in the sidings beyond platform 8 and the temporary site offices. Another failure?
Yes. Though it's got a traction motor fault, which might be attributed to the original 319. But the result is it lost the use of half its motors, and was unable to get up the hill to Wanborough. Hence it was sent to the naughty siding to wait for someone to do the sums to see if another 769 could pull it up 1/100. Plans to shift is on Friday were Euniced, but I though there was another go planned today. At least, there was an ECS▸ move from Oxford to the sidings, and another from there to Reading depot. Some timing reports of that are showing, but rather too few to be really convincing, so maybe (given that it's still there) that didn't happen.
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eightonedee
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« Reply #201 on: February 22, 2022, 22:40:40 » |
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I have just realised why they are no longer going to use them for bi-mode trains between Reading and Oxford - they will need all 19 to run up and down the North Downs line rescuing one another when they break down!
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RichT54
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« Reply #202 on: February 23, 2022, 17:57:45 » |
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stuving
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« Reply #203 on: February 28, 2022, 19:03:13 » |
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And less than a week later the same unit (769936) has been and gone and done pretty much the same thing again. This time it's at Redhill, and in another naughty siding - number 2 is a series of ...
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IndustryInsider
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« Reply #204 on: February 28, 2022, 19:24:15 » |
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Hopeless!
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To view my GWML▸ Electrification cab video 'before and after' video comparison, as well as other videos of the new layout at Reading and 'before and after' comparisons of the Cotswold Line Redoubling scheme, see: http://www.dailymotion.com/user/IndustryInsider/
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stuving
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« Reply #205 on: March 02, 2022, 00:01:33 » |
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I commented earlier that the traction system was part of the 319, not the conversions. In the latest case of failure that's even more relevant, as at Redhill it was running on third rail. I've heard that 319s had a poor reliability record in this area, and that does seem to be the case. In 2015, DfT» hit GTR with a section 55 improvement notice, for its number of cancellations. GTR's excuse generator came up with some explanations for the poor fleet reliability on Thameslink and Southern operations, citing "Inherited door system and traction motor failures on the class 319" and "...failures on a small number of train systems in the class 387/1 introduction". As further detail, they said: The two highest failure factors are doors and traction motors and this plan focuses on these two issues.
A door system intervention was undertaken by the previous franchisee between May 2014 and September 2014. This was intended to improve the performance of the door system across the fleet. However the work resulted in a much higher failure rate and the underlying door performance worsened.
Traction motors and motor alternator sets on Class 319 units require a very high level of maintenance attention to their commutators to remain reliable. The small number of maintenance roads in Bedford coupled with the very high fleet mileages and the time consuming and intrusive nature of the work, provided insufficient depot pitted road access for it to have been delivered effectively. Consequently the condition of the commutators on the Class 319 traction motors and motor alternators has deteriorated over recent years. This has led to electrical flashovers as a result of poor commutation resulting in significant delays and cancellations. I guess that's what you get if you choose to do up old trains. I wonder how much work Porterbrook did on those areas? The GWR▸ ones do have new 3-phase inverters to cope with the extra load of cabin air cooling, so presumably they at least don't still have the old motor alternators.
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Surrey 455
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« Reply #206 on: March 02, 2022, 20:20:56 » |
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A door system intervention was undertaken by the previous franchisee between May 2014 and September 2014. This was intended to improve the performance of the door system across the fleet. However the work resulted in a much higher failure rate and the underlying door performance worsened.
Traction motors and motor alternator sets on Class 319 units require a very high level of maintenance attention to their commutators to remain reliable. The small number of maintenance roads in Bedford coupled with the very high fleet mileages and the time consuming and intrusive nature of the work, provided insufficient depot pitted road access for it to have been delivered effectively. Consequently the condition of the commutators on the Class 319 traction motors and motor alternators has deteriorated over recent years. This has led to electrical flashovers as a result of poor commutation resulting in significant delays and cancellations.
The previous franchisee being First Group a.k.a. First Capital Connect. You'd think that someone at First Group would have remembered the previous problems with these trains before a different subsidiary took them on.
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GBM
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« Reply #207 on: March 03, 2022, 07:08:47 » |
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The previous franchisee being First Group a.k.a. First Capital Connect. You'd think that someone at First Group would have remembered the previous problems with these trains before a different subsidiary took them on.
Surely that depends on whether the DfT» instructed First to take/use them?
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Personal opinion only. Writings not representative of any union, collective, management or employer. (Think that absolves me...........)
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onthecushions
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« Reply #208 on: March 03, 2022, 11:29:49 » |
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The d.c. traction motor and pneumatically operated doors are not exactly key NASA space technologies. There is a little more excuse for software but that has had decades on the learning curve.
The 769 problems say more about present UK▸ rolling stock engineering expertise than they do about the relatively simple 319 stock. This should last indefinitely, like the 4SUBs which went to the torch in full working order with only wear and tear maintenance over their (several) lives.
OTC
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