Original MK4 ride quality

[Bridge189]

I know on the MK4s today tend to be very popular with practically everyone on here and people like their very smooth ride and internal space.

However speaking to a few colleagues who were around when the 225s first came online said that the reality back then was very different, allegedly the trains used to bounce, sway and rock around like a fairground ride with cups and glasses know to slide off tables or jump about in First and the customers began to loath them with many regulars vowing never to travel on them again. Also seeing people trying to walk down the isle was also apparently very entertaining for staff. Apparently BR were tearing their hair out not knowing what was causing it and in the end heavy mods to the bogies and vestibules stabled them out to the way they are now. Was this the case or is this widely over exaggerated?

Being a fairly newby to the industry I can't comment personally

 

[northwichcat]

They were changes to the mk4s as a result of safety concerns which led to them being grounded and modified in 1998: http://www.railforums.co.uk/showthread.php?t=32734

 

[sprinterguy]

They were changes to the mk4s as a result of safety concerns which led to them being grounded and modified in 1998: http://www.railforums.co.uk/showthread.php?t=32734

That's something different though, that was caused by a derailment at Sandy due to, as is explained in that thread, wheel cracks. Investigations into trouble with the ride qualities of the mark 4s had taken place much earlier in the trains' lives. This website details some of the research work that was undertaken to rectify the issues:
http://www.traintesting.com/ic225_6.htm

Trouble with bogies

The coaches underwent the statutory acceptance testing on the main line but unfortunately the performance of the SIG bogies was found wanting. The ride at 125 mile/h was unacceptable, the lateral behaviour and the curving ability as well as excessive vertical movement from track defects resulted in the body of the coaches contacting the bump stops on anything but straight CWR.

However the coaches were being delivered as planned and the service introduction was a fixed date so they were put into service with these inherent defects. I recollect that this lead to a number of caustic comments from passengers when we were seen walking through the train. We were often stopped and berated about the ride qualities, one passenger even comparing the MK4 coach ride to the Blue Pullman – which suffered from notoriously poor ride quality.

The ride of the Mk4 coaches with SIG bogies was considered to be unacceptable and extensive testing took place between Doncaster and London (Ferme Park) when various combinations of hydraulic dampers were exchanged and trialled - all the dampers were changed at one time or another - lateral, yaw and vertical

I remember we used to have the test car with the Mk4 coach at Derby where it was set up for the day's testing. It would then be hauled by class 47 to Donny where it would be coupled to a class 91 and a short train and run a return trip to Ferme Park. Often dampers would be changed before the train returned

Two major decisions came from these tests and the difficulty of achieving an acceptable ride quality. One involved rotating the bogie by 180 degrees to reduce the angle of the yaw dampers to mitigate the input from the bogies into the bodies and the second modification was to fit inter-vehicle dampers between vehicles. Drastic action which achieved a reasonable ride in the end.

 

[O L Leigh]

I first encountered these coaches back in the early 1990s and can't honestly say that I can recall any rough riding, certainly nothing violent enough to spill drinks and such. However, having said that, wheelflats did seem quite common.

O L Leigh

 

[Polarbear]

As I recall, they could have a "hard" ride when new. In the early days, a run with Mk4's could be quite lively but I suppose having been spoilt rotten by years of Mk3 travel, it would be very difficult to improve on.

 

[DXMachina]

but Polarbear, your profile image suggests you're naturally tolerant of bad riding stock

 

[Polarbear]

but Polarbear, your profile image suggests you're naturally tolerant of bad riding stock

Touche..!!

Never got on a Blue Pullman, but have read many reports of their riding like a sack of bricks.

 

[Bald Rick]

Absolutely correct. The suspension was tuned for 140mph running, but at 125mph it wasn't so good. Something to do with the natural frequency of the body shell and the way the inter coach gangways help smooth lateral movement. There was a tendency to lurch into curves and '50 pence' around them.

It took a while for the fleet guys to work it out, and the answer was retuning the suspension and installing a lateral damper below the gangways. This sorted it. And just as well, as the ride quality was specified in the construction contract.

Plenty of articles by Cap'n Deltic in Modern Railways around 1990/1 if you can lay your hands on them.

 

[Oswyntail]

I remember (as a regular user back then) some of the phenomena described - certainly the sliding cups - but also feeling that there was an improvement on the Mk3s. The improvement programme coincided with my not travelling as much, but definitely worked.

 

[LE Greys]

Absolutely correct. The suspension was tuned for 140mph running, but at 125mph it wasn't so good. Something to do with the natural frequency of the body shell and the way the inter coach gangways help smooth lateral movement. There was a tendency to lurch into curves and '50 pence' around them.

It took a while for the fleet guys to work it out, and the answer was retuning the suspension and installing a lateral damper below the gangways. This sorted it. And just as well, as the ride quality was specified in the construction contract.

Plenty of articles by Cap'n Deltic in Modern Railways around 1990/1 if you can lay your hands on them.

Interesting. I remember this as well, plus very creaky gangways. The mods improved it, but I remember it recurring right up to the 'Mallard' overhaul. Indeed, it still happens a little sometimes, maybe when a coach gets a bit worn.