755/4 seem OKish, it is the /3's that are throwing up the issues, so if the rumour/story is valid, maybe 4(5) car Stads on the Cambridge/Peterboros, rather than 3 ?
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Abellio Greater Anglia Class 755s (Regional Trains)
- Thread starter swt class 450
- Start date
755/4 seem OKish, it is the /3's that are throwing up the issues, so if the rumour/story is valid, maybe 4(5) car Stads on the Cambridge/Peterboros, rather than 3 ?
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Railperf
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If i remember correctly weight per unit is 168 tons for a 4 car and 132 tons for a 3 car. Either way, even the 3 cars only need around 4 to 5 mins to reach 100mph in diesel mode. So you would expect that these would have been tested under full load for much longer than that. And probably a cycle of full load followed by idling or to replicate real life driving. The 3_car units only have 1 engine per engine compartment so in theory should be more volume of space for heat to dissipate..
Power output
3 car - 2,600 kW Electric
3 car - 960 kW Diesel
4 car - 2,600 kW Electric
4 car - 1,920 kW Diesel
eastdyke
Established Member
Is it possible that Stadler are still a degree or two (literally) on the cautious side with the Engine Management System settings?
Given that the trains are Swiss, gradients really shouldn't be a problem...
Railperf
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Hold on here...there are no serious sustained gradients of any note on this route. There is nothing that compares to the Highland main line here. The gradients should be bread and butter to these. The 3 car units have the same power to weight ratio as an 8 car HST
Indeedy
BUT there has to be something between Bury and Chippenham, that is making the 755's poorly ? yes they throw a wobbly elsewhere, but this seems a popular area !
Railperf
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Three miles uphill from Bury towards Kennet no steeper than 1 in 128, followed by two miles downhill and a further mile uphill 1 in 154..then downhill all the way to Chippenham Jn. In fact the steepest uphill climbs are from Cambridge towards a summit at Dullingham 1 in 100 on the west side - but limited to 60mph - so again not too taxing. Steeper gradients exist on the East Suffolk line 1 in 75 and 1 in 80 but only a mile or so in length each and again low line speeds.Indeedy
Could something nearby the route in that area be causing some major electrical interference that is causing the trains control system to have a wobbly??
eastdyke
Established Member
Is it just the Ipswich towards Cambridge affected? Waiting for the single line? Any electromag stuff from RAFs (USAF) Mildenhall/Lakenheath?Indeedy
Peter Mugridge
Veteran Member
Interesting thought - that's not far from Mildenhall is it...?
I don't think the air bases will be having anything to do with the train problems.
The closest bit of track that a train from Cambridge to Bury St Edmunds would get to Mildenhall is near Kennett station, which is ~ 6 miles from RAF Mildenhall. Shippea Hill on Ely-Norwich line is ~ 5.5 miles from RAF Mildenhall, and closer to RAF Lakenheath.
If a train is going to be affected from 5 or 6 miles away, I would expect cars to be affected when they are a mile away.
Carlgoss
Member
Tannoy 'The Cambridge train is delayed.. this is due to electronic warfare operations'
eastdyke
Established Member
Midnight Sun
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There are USAF E-3's (Awacs) based at Lakenheath. I have seen them fly south over the line after take-off. As a high power lookdown Pulse Doppler radar is fiited. And as they are still at a low height (5000ft), could the radar signal be having a effect at this low height.
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hooverboy
On Moderation
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they've certainly got jamming systems on board that could screw up the electrics!
Icky Qualms
Member
There is a HV Sig supply cabin in Higham Yard
Apart from that nothing of significance that could possibly cause any electrical interference
It was reported that people living below Rampisham Transmitting Station on Toller Down (A356, Crewkerne to Grimstone) http://tx.mb21.co.uk/gallery/gallerypage.php?txid=1662&pageid=2500 used to have problems with using remote key fobs and had Russian coming through their toasters so it's not un-heard of for high power RF to cause issues though I would doubt that this is the problem here.
dk1
Veteran Member
Not true. Been loads of 3-cars on the Norwich-Cambridge/Stansted. Each route makes do with whatever is available.
dk1
Veteran Member
Beggars can't be choosers & all that. More seats than required at most times anyway.
WroxhamTroll
Member
Not exactly beggars more like paying customers, but most would prefer a service than none at all. The weeks of no service made me almost wish for a dogbox to show up!
Oh yes, not complaining at all. I'll take a 3 car FLIRT over a 153 (as I experienced in November) when the booked unit is not available any day!
I haven't seen people standing since the 170s left (Cambridge to Ely in the evening excepted). As you say, plenty of seats.
dk1
Veteran Member
Paying customers obviously (on the whole) but a train is a train regardless. I can't be doing with the pampering to exact class & carriages. As long as it arrives at roughly the time stated when the chips are down as they have been lately then that will do.
WroxhamTroll
Member
I think most folks just want what they pay for a seat in the class of booking within +/- 5 mins of schedule. Its the same with airlines and other transport services.
In December I drove to london each week which I thought would be terrible but turns out it was reliable, comfortable and cheaper! Not really the planet saving message.
Anyway back to the 755's are they all in service now? And how is the refueling working as this seemed to be a bit of a weakness.
Railperf
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Getting back to the 755/3 breakdowns, the section between Bury and Chippenham seems to be the most popular point of failure, so either the gradients are an issue - or it is a software glitch, or maybe the cooling system on the 3-cars is less up to the job than the 4-cars. Either way there are some very well paid Stadler and Deutz engineers out there whose job it is to sort the issues out!
Thankfully failures on my travels have been rare.
What does seem to be an issue is the fact there does not seem to be any early warning of an overheat situation. Once the alarms start going off, i understand the trains starts going through its engine shutdown procedure, and cannot be restarted until that has happened. The whole shutdown rebooting i am told takes around 15 minutes. Operationally that seems crazy. Surely there should be some early warning of rising temperatures so that drivers - a la class 800's - can ease off the power or take some measures to allow the train to cool down, rather than experiencing the sort of shutdown PC users experience when their PC decides to update and restart without any warning!
Thankfully failures on my travels have been rare.
What does seem to be an issue is the fact there does not seem to be any early warning of an overheat situation. Once the alarms start going off, i understand the trains starts going through its engine shutdown procedure, and cannot be restarted until that has happened. The whole shutdown rebooting i am told takes around 15 minutes. Operationally that seems crazy. Surely there should be some early warning of rising temperatures so that drivers - a la class 800's - can ease off the power or take some measures to allow the train to cool down, rather than experiencing the sort of shutdown PC users experience when their PC decides to update and restart without any warning!
Nighthawke
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No there are not nor at Mildenhall. The occasional one may visit or do an approach but none are based. Also the chance of one being in the area when a train passes is extremely low.
As for the theory of the bases having an effect on this stretch, well the Norwich-Cambridge line runs much closer to Lakenheath in particular and there have been no breakdowns there to my knowledge.
Maybe we should stick to facts rather than sci-fi speculation.
20-year Brandon resident and 40 years aviation knowledge.
eastdyke
Established Member
The fact is they keep on breaking down. Another near Kennett just now 