Flange Squiel

[Pompeyfan]

What is it? what causes it? and why is it so bad P3 fratton and entering portsmouth harbour?

also ive noticed that 158s don't squiel compared to the rest of the local traction

[BR7MT]

Put simply, it is because the wheel flange is not perfectly aligned with the rail.

More complex explanation:

A railway wheel is profiled in order that it naturally curves through a bend, when you constrain that movement with a bogie frame it negates that perfect curving performance. The flange therefore comes into contact with the rail (which should not happen under normal circumstances except at switches and crossings) and you get the squeel as steel rubs on steel.

It can be compensated for by the use of flange lubrication, but it will not cure it. Future rolling stock designs may include wheelsets that can be steered into a curve thus completely eliminating flange squeel and massively reducing flange wear and the need to re-profile the wheels so often.

Regards,

Dan

[timenec]

Class 66s have steering trucks which help to alleviate the problem but with very tight curves it can still be deafening.Go and watch the freights go by at Willesden High Level but take your earplugs.

[ianmacmillan]

It's not realy flange squeal.

On a curve the outside rail is longer than the inside rail.
This means that the outside wheel has to turn more revolutions than the inside which, with a fixed axle, is impossible so one wheel has to slip.

Railways compensate for this by making the wheel cone shaped so that the inside edge of the wheel tread has a larger diameter than the outside.
There needs to be a limit to the coning angle to prevent the flange climbing up the rail so you get the wheel slip squeal on tight curves.

There is also the problem that on a 4 wheel vehicle, the wheelset is not at right angles to the rail. Slack in the axleguides compensates for this.

Self steering suspension detects curvature and applies force to the axle to keep it at right angles.

[timenec]

"Squeal" also occurs when a steel wheel on the steel rail is right on the point of slipping,so close even the loco's radar cannot detect it but the good old human ear can!

[electric]

If it is wheelslip that causes flange squeal (i'm not saying it isn't for one moment) then why would they sprey the outside rail of Barnt green to reduce/remove flange squeal.

I was told (and so believe for now at least) that the squeal was the wheel hitting the outside rail after bouncing off due to the rails/wheels not been a perfect match, this may be where the wheel slip theroy comes in.

I'd have thought though that if the problem was adhesion when the last thing you'd want to do is to make adhesion worse by adding water to a dry rail.

Feel free to correct meas I was not training in track for NWR, but S&T

[dkightley]

The trams on the NET suffer from excessive squealing on a couple of the tight corners ......but only when its dry. When its precipitating, the wheels are quieter....and NET employees have been spotted with water spayers in dry weather at the "squealy spots"


Doug

[RobertM]

There are also 'mechanical lubricators' at the L&HR we have two of them, about 1/4 of a mile out of each terminus on opposite sides of the track that slowly discharge lubricant, that the wheels pick up and carry along with them around the offending curves.

The lubricant also builds up after time when were using our smaller engines, but when one of our fairburn tanks or 5643 comes along it scoops the build up off 'due to larger wheels', and somtimes you can feel/hear the diffrence a few curves later.

Robert

[tripman]

Hi. The worst "Squeal" I've heard is on Brightons' Volkes electric railway, just at the midway passing point on a dry day, you will see passengers with fingers in their ears.
CU Eric

[salopiangrowler]

Squeal you want to come to shrewsbury and watch the coal train going round "The Loop" or see a 158 going into Platform 3 off the wolverhampton line.

[andylloyd]

There seems to be 'over lubrication' in two areas of the ECML. The first being at Morpeth and the second at Alnmouth. The wheels spin madly.

Cheers

Andy

[enotayokel]

The Pending Pacer on the Gunnislake line

[WaltTFB]

The SVR has suffered with over enthusiastic flange lubricators at Highly, which made starting away towards Hampton Loade interesting from time to time.

[shaun123]

Pacer on the Earlestown Curve. Enough Said

[jonfun]

Pacer on the Earlestown Curve. Enough Said

Miles Platting Junction. Packed like sardines. Now ears barely work.