60mph Pacers

[starrymarkb]

I've just read on another forum that some Northern 142s and 144s have now had a 60mph speed restriction slapped on then due to faults and condition.

Is there any truth in this?

 

[driver9000]

16 units are affected. There is a problem with some of the final drives which could cause a failure (see RAIB alert for Durham). Running at a lower speed lessens the chance of failure and should a failure occur the shaft should be retained within the loop around it. Once 18000 miles have passed without incident the restriction will be lifted.

 

[strange6]

16 units are affected. There is a problem with some of the final drives which could cause a failure (see RAIB alert for Durham). Running at a lower speed lessens the chance of failure and should a failure occur the shaft should be retained within the loop around it. Once 18000 miles have passed without incident the restriction will be lifted.

Puts my faith in Northern stock does that!

 

[northwichcat]

Let's hope they keep those units off the Stockport-Manchester section of track in the peak periods, especially the peak time extras between Macclesfield/Crewe and Manchester as a Pacer that can do 75mph can cause tailbacks.

 

[strange6]

Let's hope they keep those units off the Stockport-Manchester section of track in the peak periods, especially the peak time extras between Macclesfield/Crewe and Manchester as a Pacer that can do 75mph can cause tailbacks.

I thought you had to drive a pacer off a sheer cliff edge for it to do 75mph

 

[northwichcat]

I thought you had to drive a pacer off a sheer cliff edge for it to do 75mph

They can do 75mph if they are on a line with 75+mph running (e.g. the WCML) and more than a few minutes between stops.

Not that you want to be on a Pacer doing 75mph with the squealing, bouncing and drafty doors.

 

[seagull]

The RAIB alert that was referred to earlier:

"The RAIB is carrying out an investigation into an incident which occurred at Durham station on the East Coast Main Line on Sunday 10 April 2011.
At about 12:30 hrs, a final drive cardan shaft dropped onto the track from an empty passenger train travelling from Neville Hill depot (Leeds) to Heaton depot (Newcastle). During the incident, which occurred while the train was travelling at approximately 75mph (120 km/h), a member of the public sustained a minor injury from a piece of ballast thrown up onto the platform.

The train involved was formed of two 2-car Class 142 units. The shaft detached at the front end of the third vehicle and was not held up by its retention devices. It damaged the underside of the third and fourth vehicles, piercing the fuel tank on the fourth vehicle and releasing the contents onto the railway.

Since October 2010 there have been a number of incidents of cardan shafts failing on similar types of train. In one other case, the broken shaft was not retained and fell from the train."

 

[northwichcat]

They go on to say

The RAIB investigation will examine the sequence of events leading up to the incidents, the design, maintenance and overhaul of the cardan shaft and final drive, the design of the cardan shaft restraining straps and other factors which may have affected the incidents.

Affected parties within the rail industry have been informed of the investigation and are assisting the RAIB in establishing the cause of the incidents.

The RAIB’s investigation is independent of any investigations by the safety authority (the Office of Rail Regulation).

The RAIB will publish a report, including any recommendations to improve safety, at the conclusion of its investigation. This report will be available on the RAIB website.

 

[strange6]

They can do 75mph if they are on a line with 75+mph running (e.g. the WCML) and more than a few minutes between stops.

Not that you want to be on a Pacer doing 75mph with the squealing, bouncing and drafty doors.

Yeah, I know they have a theoretical top speed of 75mph but quite often you need to be going downhill for it to do that hahaha

 

[142094]

Not that you want to be on a Pacer doing 75mph with the squealing, bouncing and drafty doors.

That is one of the highlights of any trip on a Pacer!

 

[northwichcat]

That is one of the highlights of any trip on a Pacer!

It's worse at higher speeds though unless you're comparing running on good track at a low speed with running on bad track at a higher speed.

 

[Eng274]

The RAIB alert that was referred to earlier:

"The RAIB is carrying out an investigation into an incident which occurred at Durham station on the East Coast Main Line on Sunday 10 April 2011.
At about 12:30 hrs, a final drive cardan shaft dropped onto the track from an empty passenger train travelling from Neville Hill depot (Leeds) to Heaton depot (Newcastle). During the incident, which occurred while the train was travelling at approximately 75mph (120 km/h), a member of the public sustained a minor injury from a piece of ballast thrown up onto the platform.

The train involved was formed of two 2-car Class 142 units. The shaft detached at the front end of the third vehicle and was not held up by its retention devices. It damaged the underside of the third and fourth vehicles, piercing the fuel tank on the fourth vehicle and releasing the contents onto the railway.

Since October 2010 there have been a number of incidents of cardan shafts failing on similar types of train. In one other case, the broken shaft was not retained and fell from the train."

That is a serious problem, does it specify whether it came off altogether or just at the differential end? It is probably more of a disaster for just one end to come off, as if running with the loose end 'trailing' it is bad, but in the other direction it would be catastrophic as the shaft jamming itself into the trackbed could push the mechanicals up through the floor of the train, especially at speed!

Hopefully this can be resolved swiftly, it would put a huge spanner in the works if major rebuild work was needed to improve their durability.

EDIT: Do Pacers need cardan shafts, since the driven axles are fixed and hence the freedom of movement to extend for bogie pivoting is unnecessary?

 

[driver9000]

The units are being given additional inspections to the bearings which should catch a problem before it fails.

 

[Old Hill Bank]

be it 60 or 75mph on a pacer, it's sure to put Alton Towers down on visitors

 

[driver9000]

EDIT: Do Pacers need cardan shafts, since the driven axles are fixed and hence the freedom of movement to extend for bogie pivoting is unnecessary?

Yes they do otherwise they won't move. The cardan shafts connect the engine to the transmission and then to the final drives. Bogie stock have an additional short shaft between the master and slave drives.

 

[Eng274]

Yes they do otherwise they won't move. The cardan shafts connect the engine to the transmission and then to the final drives. Bogie stock have an additional short shaft between the master and slave drives.

I should have been clearer - I meant, between the transmission and the final drive, why would a completely solid prop shaft not be apt as opposed to an extendable cardan prop shaft like on bogied units?

 

[starrymarkb]

I should have been clearer - I meant, between the transmission and the final drive, why would a completely solid prop shaft not be apt as opposed to an extendable cardan prop shaft like on bogied units?

Suspension. The axle can move go up and down and tilt relative to the chassis and engine. It's not effective on the worst bumps will will smooth the ride somewhat

 

[Anvil1984]

Its 60 MPH when running ECS, linespeed when in service. The thinking behind it is that the carden shaft has time to cool down when its stopping but gets hotter when its on a long trip (ie Heaton to York) so thats the precaution

 

[driver9000]

Because it wouldn't move without the shaft, which are all called 'cardan shafts'. There has to be a degree of flexibility to account for the suspension moving. As far as I'm aware the shafts aren't extendible on either bogie or fixed axle stock, they are fixed length with a 'flex'capability built in to them at their joints with whatever they are attached to.
--- old post above --- --- new post below ---

Its 60 MPH when running ECS, linespeed when in service. The thinking behind it is that the carden shaft has time to cool down when its stopping but gets hotter when its on a long trip (ie Heaton to York) so thats the precaution

Initially it was ECS but it is now for all movements.

 

[Anvil1984]

Because it wouldn't move without the shaft, which are all called 'cardan shafts'. There has to be a degree of flexibility to account for the suspension moving. As far as I'm aware the shafts aren't extendible on either bogie or fixed axle stock, they are fixed length with a 'flex'capability built in to them at their joints with whatever they are attached to.
--- old post above --- --- new post below ---


Initially it was ECS but it is now for all movements.

Ah I apologise, havent been in work for a few days, just what I've heard from others

 

[northwichcat]

Its 60 MPH when running ECS, linespeed when in service. The thinking behind it is that the carden shaft has time to cool down when its stopping but gets hotter when its on a long trip (ie Heaton to York) so thats the precaution

But then what's the difference between a 142 running an overnight Liverpool-Manchester Airport service which doesn't stop between Liverpool and Manchester and running ECS between Warrington Bank Quay and Liverpool Lime Street? If anything in those instances it's would be the in service running that would have less time to cool.

 

[driver9000]

But then what's the difference between a 142 running an overnight Liverpool-Manchester Airport service which doesn't stop between Liverpool and Manchester and running ECS between Warrington Bank Quay and Liverpool Lime Street? If anything in those instances it's would be the in service running that would have less time to cool.

All movements with affected units is now 60mph.

 

[matchmaker]

Suspension. The axle can move go up and down and tilt relative to the chassis and engine. It's not effective on the worst bumps will will smooth the ride somewhat

Suspension? On a Pacer? Isn't that an oxymoron?

 

[strange6]

Suspension? On a Pacer? Isn't that an oxymoron?

No, the oxymoron was the person who designed them in the first place

 

[starrymarkb]

Suspension? On a Pacer? Isn't that an oxymoron?

They do indeed - Not very effective suspension but it's there. If they had no suspension they'd shake apart even on smooth track!

The FGW 142s give a surprisingly good ride on the main line. On Perfect track pacers are fine - on rough track you get
[youtube]ya1hG7F_EPg[/youtube]

Look how it smooths out (relativly) when it hits CWR!

 

[strange6]

They do indeed - Not very effective suspension but it's there. If they had no suspension they'd shake apart even on smooth track!

The FGW 142s give a surprisingly good ride on the main line. On Perfect track pacers are fine - on rough track you get
[youtube]ya1hG7F_EPg[/youtube]

Look how it smooths out (relativly) when it hits CWR!

That's pretty bad. Just as bad as the Atherton Line to Wigan

 

[Kingfisher200262]

All movements with affected units is now 60mph.

Probably a silly question, but how will a driver booking on, know whether it's an "affected unit" or not?

 

[Eng274]

No, the oxymoron was the person who designed them in the first place

There's an oxymoron in charge of the country, but that's for another thread :roll:

 

[BestWestern]

There was an incident very similar to this I'm sure, involving an SWT 159 quite some years back now. Seem to recall it was also a case of a cardan shaft dropping, which then wrenched the engine from the underside of the train. So presumably this could potentially happen to any DMU, dependant on maintenance and wear? Anybody else remember that?!

 

[ACE1888]

Had a 153/142 combo on the return from Exmouth this week, we chose the 153 unsurprisingly....