• Our booking engine at tickets.railforums.co.uk (powered by TrainSplit) helps support the running of the forum with every ticket purchase! Find out more and ask any questions/give us feedback in this thread!

Class 442s - Now at the end of the road and to be withdrawn permanently

Status
Not open for further replies.
Sponsor Post - registered members do not see these adverts; click here to register, or click here to log in
R

RailUK Forums

S

swt_passenger

Veteran Member
Joined
7 Apr 2010
Messages
31,376
Monty said:
I wonder how much longer this will continue before SWR and NR are forced to get their head out of the sand admit their is a problem and fix it?
Click to expand...
Is it currently thought this change of aspect (COA) problem can be caused by any of the 442s, or could it be a few particularly “noisy” traction systems? Presumably someone is recording which specific units are involved?
 
T

theironroad

Established Member
Joined
21 Nov 2014
Messages
3,697
Location
London
TEW said:
There are signalling interference test trips in the system for the next few nights. ECS Bournemouth to Clapham and then several round trips between Claphan and Surbiton.
Click to expand...

Seem that the units involved in the 2. cOAs today berth tonight at fratton, so unless there's some last minute changes, then it'll be different units involved in tonight's testing.

Has anyone on here or elsewhere determined if it is the same leading unit having issues at earlsfield or is it all 442s?
 
Monty

Monty

Established Member
Joined
12 Jun 2012
Messages
2,352
swt_passenger said:
Is it currently thought this change of aspect (COA) problem can be caused by any of the 442s, or could it be a few particularly “noisy” traction systems? Presumably someone is recording which specific units are involved?
Click to expand...

Some of the travelling fitters I've had accompany me on a number of journeys theorised it may be a dodgy converter (takes the traction current and makes it suitable for 'hotel power') but its been a number of different units now so my money is on a fault with the signal itself (it's always the same one) which for some reason is more sensitive to the 442s.
 
T

TEW

Established Member
Joined
16 May 2008
Messages
5,847
Someone was asking about the PIS earlier. It is working on the Portsmouth runs and it is Celia making the announcements.
 
H

hwl

Established Member
Joined
5 Feb 2012
Messages
7,383
Monty said:
Some of the travelling fitters I've had accompany me on a number of journeys theorised it may be a dodgy converter (takes the traction current and makes it suitable for 'hotel power') but its been a number of different units now so my money is on a fault with the signal itself (it's always the same one) which for some reason is more sensitive to the 442s.
Click to expand...

The Southern / NR never got to the bottom of similar issues during their previous use (removed earlier than planned was their solution), probably all of the fleet caused issues and it was always in certain locations (just lots of them).

The auxiliary (hotel) converters are a known issue, originally they weren't down to be replaced as part of the re-tractioning but now are (hence the delay while they procured some) as the existing ones cause major EMC issues.

Rolling stock manufactures in general are discovering that low quality auxiliary converters are a reliability problem on much newer stock (they had regarded it as money saving area!)

The problem location at Earlsfield bears striking similarities to some of the Southern problem locations*:
- very close to major power feed
- complex trackwork near by (depot head shunt) why can change current return paths when the points in the depot are moved or set in a certain way which could effect allow the difference between return in each rail to exceed the permitted difference for the older impedance bonds.

* e.g. just after going past Lovers and Three Bridges heading north, London Bridge during very first stage of rebuild

The comparative lack of pick ups and the separation of return current from pick up locations also doesn't help with the impedance bond issues when there are 3rd rail gaps...

The impedance bonds at the rear of the "problem" section are ~375m away from the signal with clear line of sight. the track circuit section to the rear contains the depot exit trailing points. The 3rd rail swaps from left to right side ~110m into the "problem section" virtually the same distance as between the pick up shoes....
 
Last edited:
T

Thumper1127

Member
Joined
19 Jan 2019
Messages
167
Looks like 9P52 has had a COA at Earlsfield. That's a hat trick today, who gets to keep the match ball?!
 
RichSwitch

RichSwitch

Member
Joined
9 Mar 2017
Messages
71
Location
Portsmouth
I have an HNC in Electrical Engineering from 25 years ago, so some of the discussion on COA makes sense. I wondered if it makes a difference whether the train is drawing current (ie being driven) versus coasting over the troublesome section in question This is why I got out of engineering as soon as I could and moved into Human-System Interfaces

I believe the refurbishment is not bad for 30 year old trains, though whether this extends to crew areas such as cab interfaces etc I’m not sure.

At the moment, a lot of late running/arrivals. I’d expect some (re)familiarisation delay but it does seem a lot so far. I’m all for waiting and seeing, but whether passengers see it that way? On the COA problems, my hunch says they’re historical and thus unlikely ever to be resolved.
 
T

TEW

Established Member
Joined
16 May 2008
Messages
5,847
Does anyone know how many units are available for service now? I've had 7 so far (406, 408, 410, 413, 414, 417 and 420).
 
DelW

DelW

Established Member
Joined
15 Jan 2015
Messages
3,861
hwl said:
The auxiliary (hotel) converters are a known issue, originally they weren't down to be replaced as part of the re-tractioning but now are (hence the delay while they procured some) as the existing ones cause major EMC issues.

Rolling stock manufactures in general are discovering that low quality auxiliary converters are a reliability problem on much newer stock (they had regarded it as money saving area!)
Click to expand...

Presumably this is equipment that has been fitted since the original tenure of the 442s on the south-western up to 2006 (ish)? I know that inverter technology has developed a lot in recent decades, but what would they have been built with, earlier and simpler inverters, DC motor / AC generator sets, or was everything just DC-powered on board?

I'm hoping I can get to ride on one before they're re-tractioned, the sound of EE motors again would make a change from the warbling of the Desiros.
 
H

hwl

Established Member
Joined
5 Feb 2012
Messages
7,383
DelW said:
Presumably this is equipment that has been fitted since the original tenure of the 442s on the south-western up to 2006 (ish)? I know that inverter technology has developed a lot in recent decades, but what would they have been built with, earlier and simpler inverters, DC motor / AC generator sets, or was everything just DC-powered on board?

I'm hoping I can get to ride on one before they're re-tractioned, the sound of EE motors again would make a change from the warbling of the Desiros.
Click to expand...
Original as built as I understand it.
 
DelW

DelW

Established Member
Joined
15 Jan 2015
Messages
3,861
hwl said:
Original as built as I understand it.
Click to expand...
Ah, OK, thanks. I don't remember this having been an issue in their earlier days, so has the signalling become more susceptible to interference? Or did similar issues occur in the 1990s but there were no internet forums to tell us about it :s
 
H

hwl

Established Member
Joined
5 Feb 2012
Messages
7,383
DelW said:
Ah, OK, thanks. I don't remember this having been an issue in their earlier days, so has the signalling become more susceptible to interference? Or did similar issues occur in the 1990s but there were no internet forums to tell us about it :s
Click to expand...
Data recording is far better now.
12.5 years since they last ran on SW turf.
Internet has changed... (Some of the GatEx / SN era issues have been covered on the forum I'm sure)
Electrical power use in general is far higher e.g. 10car on the slows and desiros on the fasts and more 12car 450s than there used to be post 707 introduction - the power environment has changed.

I've got the 4REP/ '67 Bournemouth electrification problems report somewhere...
 
Last edited:
DelW

DelW

Established Member
Joined
15 Jan 2015
Messages
3,861
hwl said:
Data recording is far better now.
12.5 years since they last ran on SW turf.
Internet has changed... (Some of the GatEx / SN era issues have been covered on the forum I'm sure)
Electrical power use in general is far higher e.g. 10car on the slows and desiros on the fasts and more 12car 450s than there used to be post 707 introduction - the power environment has changed.

I've got the 4REP/ '67 Bournemouth electrification problems report somewhere...
Click to expand...
Understood, thanks for the explanations. I was an intermittent user of the Direct in the 1990s, but always the stoppers, so my memories are of the slammers rather than the 442s.
 
Monty

Monty

Established Member
Joined
12 Jun 2012
Messages
2,352
RichSwitch said:
I have an HNC in Electrical Engineering from 25 years ago, so some of the discussion on COA makes sense. I wondered if it makes a difference whether the train is drawing current (ie being driven) versus coasting over the troublesome section in question This is why I got out of engineering as soon as I could and moved into Human-System Interfaces
Click to expand...

It's happened when both the driver has taken power and while coasting.
 
spark001uk

spark001uk

Established Member
Joined
20 Aug 2010
Messages
2,325
i see 9P52 dropped 3 mins between wimbledon and clapham today, is that long enough to be a COA? Maybe someone else can confirm.
 
P

pompeyfan

Established Member
Joined
24 Jan 2012
Messages
4,188
Depends on what was in front of it. Not unusual to lose 3 minutes following a 2Lxx through there.

spark001uk said:
i see 9P52 dropped 3 mins between wimbledon and clapham today, is that long enough to be a COA? Maybe someone else can confirm.
Click to expand...
 
D

Dibbo4025

Member
Joined
21 Mar 2018
Messages
607
spark001uk said:
i see 9P52 dropped 3 mins between wimbledon and clapham today, is that long enough to be a COA? Maybe someone else can confirm.
Click to expand...
Running 3l from Woking so had 1A52 routed ahead at Surbiton, which has a stop at Clapham as well, causing the delay to 9P52
 
T

Thumper1127

Member
Joined
19 Jan 2019
Messages
167
9P16 sat just south of Godalming for quite a while this morning. Expect about 12 late at Guildford. Not sure if the issue is the train or infrastructure.
 
spark001uk

spark001uk

Established Member
Joined
20 Aug 2010
Messages
2,325
Ah OK cheers. Just came down on 9P19, arrived at the harbour 14L so not too bad.
I have to say that is still a dam smooth ride. Same as it was 3yrs ago, same as it was 30yrs ago.!
They made a good job of these refurbs, nicely lit, bright, and comfortable seats. The USB in standard is very slow, but other than that not bad at all.

Catch them while they've still got that new furniture smell.!!

What's the goal now then, once all ready will the 9 pairs be able to fulfil the whole half hourly fast service to Pompey via Guildford?
 
Last edited:
Status
Not open for further replies.

Top