Greater Anglia's Stadler Flirt - Class 745 & 755

[Zomboid]

No guarantee that they would interact with the crossings correctly either though...

[Pete 75C]

A normal service has been resumed through to Sheringham, so I'm assuming the plan to install treadles at the weekend went ahead?

Someone seems to have forgotten to cancel the replacement buses though, so folk at Sheringham this morning have more ways to get to Cromer than they could ever have hoped for...

[beast66606]

23 minutes ago, Pete 75C said:

A normal service has been resumed through to Sheringham, so I'm assuming the plan to install treadles at the weekend went ahead?

 

 

Yes, treadles installed.

[Bucoops]

26 minutes ago, Pete 75C said:

A normal service has been resumed through to Sheringham, so I'm assuming the plan to install treadles at the weekend went ahead?

Someone seems to have forgotten to cancel the replacement buses though, so folk at Sheringham this morning have more ways to get to Cromer than they could ever have hoped for...

 

I expect it is intentional - if the treadles don't fix the problem, an alternate is already in place. Rustling up buses at zero notice is never easy. If they don't have any further issue, they've wasted a bit of money on the buses, but haven't upset passengers by doing so.

[Pete 75C]

17 minutes ago, Bucoops said:

 

I expect it is intentional - if the treadles don't fix the problem, an alternate is already in place. Rustling up buses at zero notice is never easy. If they don't have any further issue, they've wasted a bit of money on the buses, but haven't upset passengers by doing so.

 

I've been told the replacement buses are booked until end of service Christmas Eve. As you say, probably a sensible overlap.

[DY444]

On 21/12/2019 at 22:39, jools1959 said:

 

Unless capacity is a issue, if it went all electric traction, just send it down the GE mainline and round London.  If they did wire up from Ipswich to Nuneaton, a high number of Intermodal stuff from Felixstowe goes north via LIncoln, so they’d have to wire that up as well.

 

Capacity is an issue on the GE/NLL/WCML route.  Not really anywhere to put a liner inside on the GEML except Colchester, the flat junction at Stratford, frequent passenger service on the NLL and paths at a premium on the southern section of the WCML.

[Classsix T]

Indeed, a major reason for installing Bacon Factory curve is to negate running as many via London 'liners. 

 

C6T. 

[russ p]

The treadles may have sorted the crossings but how does that stop them disappearing from track circuits? 

[The Stationmaster]

41 minutes ago, russ p said:

The treadles may have sorted the crossings but how does that stop them disappearing from track circuits? 

Depends which track circuits they were disappearing on.  It never seems to have emerged (in the public arena) as a major problem with these trains until the level crossing incident and that suggests it might only occur with a particular type of track circuit or in certain circumstances (hardly unusual with new trains).   One day we might find out?

[DY444]

3 minutes ago, The Stationmaster said:

Depends which track circuits they were disappearing on.  It never seems to have emerged (in the public arena) as a major problem with these trains until the level crossing incident and that suggests it might only occur with a particular type of track circuit or in certain circumstances (hardly unusual with new trains).   One day we might find out?

 

The RAIB are investigating the level crossing near miss so we should find out eventually

[iands]

2 hours ago, russ p said:

The treadles may have sorted the crossings but how does that stop them disappearing from track circuits? 

It's possible that the treadles have been "cut in" to the TC circuitry (additional relays/contacts) as well as the LX controls to aid the "detection" functionality - keeping the TC relay "down" until an "exit treadle" at the LX has been operated perhaps?

 

I'm sure someone like 'phil-b259' of this parish will offer some technical insight into how this could be achieved.

[russ p]

I believe they  have only put treadles on the three crossings at rackheath and not the rest of the line 

As Siggie said they lost another near Walpole 

[Zomboid]

Presumably a different problem with a different solution.

 

For example, leaf mulch should be largely done with for another 10 months now, so if that was part of the cause than the whole situation will be better now. Not that it necessarily is anything to do with leaf fall.

Edited December 23, 2019 by Zomboid

[tgk300]

This is my first post so forgive me if am making any major mistakes but I have a question that I have half the answer too already, It's just the second half I can't find anywhere. 

 

What is the weight of the 3 and 4 car Class 755 units? I read somewhere (maybe here) that they weigh something stupid like 144 tonnes, which to me seems strangly light. However, I then read that apparently they weigh more like 160 tonnes. 

 

I only ask as only the bogies on the driving cars are powered therefor giving only 4 powered axles for both the 3 and 4 cars units. Does anyone know how much of the 160 tonne is on the powered axles? I wonder this because I saw someone suggest that they maybe good for London Waterloo to Exeter Services seeing as they could be fitted with third rail gear and of course already have diesel engines. Although with them only having 4 powered axles, I don't know how well they would manage on Exeter and Honiton Banks. Sorry to drone on, its just a question I have had for a while and can't find a solid answer too. 

[Zomboid]

160 tons for a 4 car unit (if accurate) is 40 tons per vehicle. Which doesn't sound especially lightweight to me.

 

I don't think SWR have any plans to replace the 159s, so it'll be academic. The next franchise isn't for a few years, and if that franchisee wants new trains for the route they'll have a different catalogue to look in to what's out there now.

[tgk300]

Ah, when I said 144 tonnes, I mean't 114. 114 seems lightweight, 160 sounds about right to me. I did read somewhere that apparently the axle load for the driving bogies is 9 tonne, giving 36 tonnes total adhesive weight which isn't great really. 

 

Also, don't forget that a 3 car is more like a 3.5 and a 4 is more like a 4.5. 

[Angliacan]

More in keeping with the issues of introduction. The 3-car  755/3 seem to becoming the norm for Felixstowe Branch. Now had 755 336, 755 327  775 332 for rides.

755 336 Felixstowe

755 327 Trimley

755 332 Ipswich

With a link to my Flickr page. Only one not yet on Felixstowe 755 410 on the Gt Yarmouth.

 

Edited December 23, 2019 by Angliacan

[phil-b259]

9 hours ago, russ p said:

The treadles may have sorted the crossings but how does that stop them disappearing from track circuits? 

 

They won't - BUT in such situations temporary block working can be used (In other words get the driver of each train to confirm they are clear of the single line before setting the route for the next train in). If everyone is on the ball and only a single signaller is involved (the whole Sheringham line is controlled from a panel / workstation at Norwich after the Railtrack era resignalling)

 

However temporary block working is sod all use when it comes to Automatic level crossings.....

[caradoc]

Track circuits can be used purely for LC operation, for example on the Ardrossan Harbour branch in Scotland, where they do not control the signalling and the Signaller has no visibility of their status. If those were the only TCs affected by wrong side failures on the Sheringham branch, fitting treadles at the relevant LCs would solve that particular problem, as long as the units could be trusted to occupy correctly all other TCs ?

 

[phil-b259]

6 hours ago, iands said:

It's possible that the treadles have been "cut in" to the TC circuitry (additional relays/contacts) as well as the LX controls to aid the "detection" functionality - keeping the TC relay "down" until an "exit treadle" at the LX has been operated perhaps?

 

I'm sure someone like 'phil-b259' of this parish will offer some technical insight into how this could be achieved.

 

Much depends on exactly what has been installed in terms of both the track circuit configuration as well as the crossing control equipment. Without access to the signalling diagrams its impossible to say.

 

For example wiring extra relays or altering the circuitry which exists is something the local S&T department can do themselves in a relatively short timescale. If however everything is 'solid state' then you have to go and get the computer cards / chips reprogrammed by the likes of Alstom, Siemens, etc.

 

What I would point out is that if you had a 'strike in' and a 'strike out' track circuit setup then the near miss would never have happened - because once the train had activated the 'strike in' track then the 'track occupied' state should be locked in to the barrier controls till the 'strike out' track circuit was activated - thus preventing the barriers from raising like they did in the incident the RAIB are investigating.

 

[phil-b259]

3 minutes ago, caradoc said:

Track circuits can be used purely for LC operation, for example on the Ardrossan Harbour branch in Scotland, where they do not control the signalling and the Signaller has no visibility of their status. If those were the only TCs affected by wrong side failures on the Sheringham branch, fitting treadles at the relevant LCs would solve that particular problem, as long as the units could be trusted to occupy correctly all other TCs ?

 

 

Indeed so - which is why its pretty meaningless to guess what might have been done.

 

We need to know the exact nature of the signalling installed and full particulars of the crossing design to have any hope of working out what the NR S&T folk have done.

[ruggedpeak]

Just seen one of these new units in the platform at Norwich - don't know what sort as I was too busy looking at the bogies covered in a layer of light mud, with spray up the underframe behind the bogie. No pics but looks like someone's been taking them through muddy fields! Guess there some flooded muddy bits somewhere.

[Christopher125]

3 hours ago, caradoc said:

Track circuits can be used purely for LC operation, for example on the Ardrossan Harbour branch in Scotland, where they do not control the signalling and the Signaller has no visibility of their status. If those were the only TCs affected by wrong side failures on the Sheringham branch, fitting treadles at the relevant LCs would solve that particular problem, as long as the units could be trusted to occupy correctly all other TCs ?

 

 

AIUI that's the case - the Cromer branch was resignalled as a trial primarily using axle counters, but as described in The Rail Engineer (pg30) they also fitted level crossing predictors for the first time and these do use track circuits to detect oncoming trains and calculate the appropriate timings. 

 

...a level-crossing predictor was first introduced between Norwich and Cromer when the line was resignalled in 2000. The GETS Harmon HXP-3 uses audio frequency track circuits to detect an approaching train, and the rate of change of the inductance of the rails is used to determine its speed and hence calculate the trigger moment to provide and constant warning time for each train.

 

[great central]

8 hours ago, ruggedpeak said:

Just seen one of these new units in the platform at Norwich - don't know what sort as I was too busy looking at the bogies covered in a layer of light mud, with spray up the underframe behind the bogie. No pics but looks like someone's been taking them through muddy fields! Guess there some flooded muddy bits somewhere.

 

That's just general muck I think you'll find. If you look at a lot of the GA stock it's not very clean. Might have expected them to keep the new units looking better to show how much of an 'improvement' they are over the old stuff.

Some of the 156s are really filthy, but it is a dirty time of year and the newly 'Abellioised' EMR units are starting to look similar.

[russ p]

4 hours ago, great central said:

 

That's just general muck I think you'll find. If you look at a lot of the GA stock it's not very clean. Might have expected them to keep the new units looking better to show how much of an 'improvement' they are over the old stuff.

Some of the 156s are really filthy, but it is a dirty time of year and the newly 'Abellioised' EMR units are starting to look similar.

 Are they as bad as when central had those 156s in 158 livery they were always absolutely filthy