Class 222, what is up with their wheels?

[nottsnurse]

First thread alert!!

I'm a regular commuter Nottingham to Leicester and I've started to really notice how 'rough' the wheels often sound when I'm on a 222 compared to the HSTs that I also use. At the moment I'm sat on the 0630 to STP and it's sounds (and feels) like the unit has square wheels!

Is this a problem 222s are known for? Is it a specific issue that relates to their DMU design (drive forces through the wheels) that the Mk3 wheels don't suffer from or are they just rubbish wheels?

Please excuse any lack of correct terminology, although I've always been interested in the railways I'm far from being knowledgeable about these things.

 

[Qwerty133]

Is this a continuing problem or just something recent?
If it's just recent, the 222s run more stopping services than HSTs, so will be breaking more and when trains can't grip when breaking is when wheel flats occur. Being leaf fall season gripping to the rails is much more difficult.

 

[Ash Bridge]

Is this a continuing problem or just something recent?
If it's just recent, the 222s run more stopping services than HSTs, so will be breaking more and when trains can't grip when breaking is when wheel flats occur. Being leaf fall season gripping to the rails is much more difficult.

Perhaps another reason is the fact that the 222s axles are all powered, so when accelerating away from stops the wheels could also suffer adhesion problems, unlike HST trailer cars which of course are unpowered.

 

[jopsuk]

222s have relatively small wheels don't they? Generally, larger wheels make for a smoother rider. I'd also guess that with a smaller wheel even a small flat spot will create a more noticeable "thud"

 

[nottsnurse]

I've noticed the 'thudding' throughout the seasons since I've been regularly using them (since 2011), not on all units, just certain ones.

 

[Hairy Bear]

Hey its leaf fall season and they are very prone to sliding, thats why theres alot of hexagonal wheels on them. Even a hint of rain in another county and they slide in simpathy. Just something you have to get used to. Thats why they invested in a wheel lathe rather quickly.

 

[Minilad]

This sounds like wheel flats caused by wheel slide. More prevalent at this time of year

 

[455driver]

Perhaps another reason is the fact that the 222s axles are all powered, so when accelerating away from stops the wheels could also suffer adhesion problems, unlike HST trailer cars which of course are unpowered.

No they are not!

 

[Bigfoot]

No they are not!

Not aware of any mu with every axle powered. Loco yes...

 

[Mugby]

How are wheel flats detected? Is it someone's responsibility to report them?

I understand that they can actually correct themselves but meanwhile it could be a long time before a wheel is treated on the lathe.

 

[badassunicorn]

I know for some TOCs you can submit a "rough ride" report, but otherwise I would imagine it gets picked up either by the driver noticing it or on inspection at a maintenance point.

 

[The Planner]

They can be detected by WILD (wheel impact load detection) systems on the track where the data is fed back to the operators.

 

[class 9]

Also known as 'wheelchex', operators will only be informed if there is a serious problem which requires the trains to be examined ASAP.

 

[talltim]

Not sure the driver would notice a flat in the middle of the train. Doles the guard/train manager/whatever they call them have any responsibility for reporting them?

 

[Ash Bridge]

No they are not!

Not aware of any mu with every axle powered. Loco yes...

I stand corrected!
So should be two axles per vehicle then?

 

[edwin_m]

222s have the inner axle of each bogie powered if I recall correctly.

WILD, Wheelchex and a new one called Gotcha are systems on the track that measure the forces from passing trains and can detect problems such as wheelflats or uneven loading of wheels.

 

[61653 HTAFC]

They were built by Bombardier, so being Canadian they have square wheels...

 

[The Planner]

Also known as 'wheelchex', operators will only be informed if there is a serious problem which requires the trains to be examined ASAP.

Wheelchex is getting replaced by GOTCHA, all the operators get the data from that whether it alarms from level 1 to 4 or not.

 

[bunnahabhain]

Not sure the driver would notice a flat in the middle of the train. Doles the guard/train manager/whatever they call them have any responsibility for reporting them?

Yes, the guard will probably report them if they're bad.