141/142 Squeak/sequel

[CardiffKid]

Question for someone in the know, what is it that makes 141/142s squeak so much? I’ve not noticed it on other trains.

Is there any sort of measuring/recording of the sound level made? How close to the legal/recommended levels of noise do they get to?

 

[northwichcat]

Question for someone in the know, what is it that makes 141/142s squeak so much? I’ve not noticed it on other trains.

Because they are cheap builds which aren't properly bogied.

Unless you mean the 3 preserved 141s on heritage lines the 141s are rotting in sidings in Iran after being exported when West Yorkshire saw some electrification around the turn of the millennium and withdrawn when Iran purchased some brand new Korean DMUs.

142s, 143s and 144s are still in service in here.

Is there any sort of measuring/recording of the sound level made? How close to the legal/recommended levels of noise do they get to?

It varies between lines and people all like the claim it's terrible on a sharp bend close to them. Also whether the windows are open or not makes a difference to passengers on board. Despite claims about how the approach to Lincoln Central is it is no way near one of the worst lines for Pacer squealing.

 

[Moonshot]

Question for someone in the know, what is it that makes 141/142s squeak so much? I’ve not noticed it on other trains.

Is there any sort of measuring/recording of the sound level made? How close to the legal/recommended levels of noise do they get to?

First and foremost, they dont have bogied wheelsets like other trains do.

As to noise levels, this is a very good question, and in fact I would have felt very sorry for residents living in houses close by when I was on one of these at 4.30am on a very humid night traversing a very sharp bend on a rarely used diversionary route.

 

[BestWestern]

"141/142 Squeak/sequel"

...I would imagine many of Northern Rail's passengers would very much hope that there won't be a sequel!

 

[northwichcat]

...I would imagine many of Northern Rail's passengers would very much hope that there won't be a sequel!

There might be a sequel in the form of a low cost replacement for Pacers: http://www.railforums.co.uk/showpost.php?p=1862847&postcount=87

 

[Strathclyder]

To cut the story short, they were a cheap solution to a rolling stock shortage in the 1980s.
That said, for all the abuse they get on here & elsewhere, I think they've done what they were built for rather well these past 30 years or so. I'd much rather have a Pacer than no train at all, to be honest.

 

[Moonshot]

To cut the story short, they were a cheap solution to a rolling stock shortage in the 1980s.
That said, for all the abuse they get on here & elsewhere, I think they've done what they were built for rather well these past 30 years or so. I'd much rather have a Pacer than no train at all, to be honest.

Yes they have done - but the ravages of time will inevitably take their toil.

 

[edwin_m]

As stated, it's likely to be to do with the four-wheel configuration in place of the bogies on other passenger trains.

Each bogie swivels under the train and has two axles relatively close together, so the wheels are nearly parallel with the rails even on curves. However with the longer wheelbase of the Pacer, the wheels will be at an angle to the rails on tighter curves and this means the rail is likely to rub against part of the wheel flange. As the flange is further from the centre of the wheel, it is moving at a different speed from the tread and the rail and this causes the squeak.

A former colleague of mine spent a few happy weeks as a graduate trainee circa 1988 riding round on Pacers with some sound recording equipment. I don't know if they supplied him with ear protectors too.

 

[Wavertreelad]

As stated, it's likely to be to do with the four-wheel configuration in place of the bogies on other passenger trains.

Each bogie swivels under the train and has two axles relatively close together, so the wheels are nearly parallel with the rails even on curves. However with the longer wheelbase of the Pacer, the wheels will be at an angle to the rails on tighter curves and this means the rail is likely to rub against part of the wheel flange. As the flange is further from the centre of the wheel, it is moving at a different speed from the tread and the rail and this causes the squeak.

A former colleague of mine spent a few happy weeks as a graduate trainee circa 1988 riding round on Pacers with some sound recording equipment. I don't know if they supplied him with ear protectors too.

I'm surprised nobody mentions about the rattles as well....

 

[krus_aragon]

As stated, it's likely to be to do with the four-wheel configuration in place of the bogies on other passenger trains.

If I can offer my own explanation/analogy...

Most rail vehicles have their axles and wheels mounted on bogies, which means they can "steer" around curves. The Pacers, as a cheap branch line solution, had their axles mounted directly to the bodies, and can't steer. This is fine on straight track and gentle curves (ignoring suspension issues), but on moderate to tight curves each vehicle is effectively skidding around the corner.

 

[43367]

But why do they screech more than other units when they are braking to a stop, ( seems worse between 15mph-0mph), and its seems to be the 144's that are worse than the 142's.
Also its more noticable on a morning when they come in empty stock from the depot, could this be due to the brake brocks being cold???

 

[455driver]

Just a guess-

Pacers have 2 brake blocks per wheel, Sprinters only have one per wheel, is it possible that the 2 blocks set up some sort of harmonics in the wheels.

 

[Wolf]

Probably to do with the fact that the 14xs are lighter weight than other units.

Or possibly even to do with the amount of brake pressure exerted depending on the loadings because of the fact that they have weigh load valves in their BCUs as opposed to Variable load valves like the 15xs since they have no secondary suspension.