Different types of bad ride + other discussion of ride quality

[py_megapixel]

When rail enthusiasts talk about "bad ride quality" it does seem to me that this is very broad. In my experience the

• Wallowy - When you're sat down the ride feels smooth, but standing passengers are easily thrown off their feet because the train moves slowly from side to side. Examples include Desiros and Pendolinos, as well as the electric Civities
  
  
• Bumpy - On the worst examples it feels like every little imperfection in the track is being conveyed to your body - almost as if there isn't enough suspension. Examples include IETs, diesel Civities and (possibly the ultimate example) Pacers.
  
  
• Rattly - It doesn't feel bumpy or wallowy, but your seat, or the bodyside panels, are vibrating, often making a noise. Examples include Voyagers (which also have an awful buzzing at a certain point in their acceleration; I think that must be down to a resonant frequency), most buses especially when stationary, and some examples of Network Turbos.

Does this make sense or not? Am I insane to be categorising things this precisely?

Also by the way if you were to ask me what provided the best ride in the UK, that would probably have to go to a class 158/159... nothing more modern manages to beat it in my opinion. Unless you count Siemens Velaro (Eurostar and DB ICE).

 

[6862]

I agree that the Class 158 is generally a very comfortable ride. Of course it also depends on where you are sat in the carriage - over the bogies often feels more bumpy even on a type generally regarded as comfortable (such as Mk3 coaches). I also agree with your classifications, although perhaps the side to side motion you mention is more of a property of the track a unit/carriage is running over?

 

[LSWR Cavalier]

'Hunting' is one word used in this connection
What does it mean exactly?
..
One imagines heavier vehicles might ride better
What about the difference between passenger vehicles with motors and coaches without?

 

[Halish Railway]

I certainly agree with most of your points - I would also add the electric Civities to the ‘bumpy’ list, although some of them and indeed their Diesel equivalents do ride quite well (195124 from experience is quite good).

I would also add Mk3 coaches to the wallowy list, though the ex-EMT are really stiff and bumpy.

Also, anyone who wants to know how wallowy the Desiros can be should experience the Batley jolt (Fast on the Manchester-bound platform).

'Hunting' is one word used in this connection
What does it mean exactly?

Hunting oscillation is where the vehicle rocks from one side to another - It’s a consequence of the train wheel’s concave shape.

Edit - here’s a GIF demonstrating this

Hunting oscillation - Wikipedia

en.m.wikipedia.org

 

[fgwrich]

I certainly agree with most of your points - I would also add the electric Civities to the ‘bumpy’ list, although some of them and indeed their Diesel equivalents do ride quite well (195124 from experience is quite good).

I would also add Mk3 coaches to the wallowy list, though the ex-EMT are really stiff and bumpy.

Also, anyone who wants to know how wallowy the Desiros can be should experience the Batley jolt (Fast on the Manchester-bound platform).


Hunting oscillation is where the vehicle rocks from one side to another - It’s a consequence of the train wheel’s concave shape.

Edit - here’s a GIF demonstrating this

Hunting oscillation - Wikipedia

en.m.wikipedia.org

Hunting / Oscillation is something I've found the Hitachi 80X Series do at linespeed in certain coaches (those with the skateboard lightweight bogies). The rest of the unit is fairy harsh and will take most bumps going.

 

[Mikey C]

My last journey on a 442 (back in Gatwick Express days) felt quite wallowy

 

[route101]

If you sit on the right hand side of HST, quite noticible when something goes past at speed.

 

[NoMorePacers]

On my local line even the trains that are generally considered smooth or wallowy (158s, 170s, 185s) become rather bumpy, although that's probably more down to the poor track quality than anything.

 

[hooverboy]

'Hunting' is one word used in this connection
What does it mean exactly?
..
One imagines heavier vehicles might ride better
What about the difference between passenger vehicles with motors and coaches without?

"hunting" in an engine sense means you are firing the spark plug before you get to the correct point to ignite before top dead centre, so the mixture combusts and causes a bit of back pressure rather than full downforce on the cylinder head where it needs to be, hence having a very lumpy and uneven ride in said car.

not sure about suspension terms, but the CAF units do seem to be very firm(either set up firm to begin with or not adequate damping), so you do feel the bumps and track deficiencies/pointwork a lot more.Shame really, other than that i think they are actually very good rural/regional units, they accelerate like rockets!
I would say that if the price is right they are quite an adequate sprinter replacement, basic,no frills ,gets you from a to b but they are very much the ford escort of trains rather than a ferrari...does the job but that's about it.

Stadler seem to have nailed this,the only downside on the 755's being stipulations for fuel tank reduction,and so reduced range..i really like the 755's other than that.superb units.
with car analogies again, this is transport via audi instead of ferrari or skoda....quite pleasurable and a step up in luxury from the ford escort!

The other bit in the equation is also the fire safety rules about seats these days. up until 10 years ago there used to be quite a nice amount of padding ,which could easily forgive a hard riding class of traction.Now you have the bare minimum which means every bit of hard track is being transmitted straight to your body rather than a portion of it being absorbed by spongy bits on your buttocks

 

[Domh245]

"hunting" in an engine sense means you are firing the spark plug before you get to the correct point to ignite before top dead centre, so the mixture combusts and causes a bit of back pressure rather than full downforce on the cylinder head where it needs to be, hence having a very lumpy and uneven ride in said car.

not sure about suspension terms,

What you describe is knocking (igniting too early) - the only time I've ever heard hunting used in relation to an engine is where the idle speed is fluctuating around.

In suspension terms, this has been linked to in post 4, in real terms the hunting oscillation in the bogies tends to translate into a side to side wobble of the vehicle

 

[coppercapped]

'Hunting' is the railway equivalent of 'flutter' in aerodynamics - that is some of the energy of the vehicle's motion converts into vibration of the structure. If the structure is not sufficiently damped the amplitude of the vibration increases until the structure permanently distorts or fails. In the case of railway suspensions the lateral motion of the coned wheel was not sufficiently controlled by the suspension and the vibration amplitude was limited by the flanges hitting the rails.

What then tended to happen was that each wheelset in a bogie vibrated out of phase with the other one and the bogie rotated rapidly back and forth about its central pivot resulting that a very jerky lateral ride accompanied by loud banging at around 1 cycle per second.

This motion was continuous unless disturbed by rail joints, switch and crossing work or line curvature where the wheels were biased to the outside rail.

'Hunting' was very noticeable from the mid-1950s onwards with the general increase in train speeds. Bogies which were good for 70 or 75mph were found to be wanting at speeds above 80. The BR1 bogie was especially noticeable as its components wore quickly, 30,000 miles was its limit, and BR tended to use its newest coaches on its principle trains.

The whole theory was worked out by Wickens and others at BR Research in the early 1960s and since then this phenomenon has been designed out. At the time axles were located by axleboxes sliding vertically in hornguides - as there needed to be clearance between the two parts the lateral motion of one relative to the other was controlled by friction between the two parts which varied with the clearances and these changed with wear due to increasing mileage. Axles are now positively located by rods or arms or rubber bushes - or a combination of these components with known stiffnesses. In some cases stiffness can vary with the exciting frequency.

Vehicle riding is the subject of many learned papers and books. It is affected by a range of factors, stiffness of the track bed and rail fastenings, track alignment, tyre profile, stiffness of the primary and secondary suspensions in all planes, bogie rotational stiffnesses and inertias in yaw, pitch and roll, natural and forced resonant frequencies of the coach body and their interaction with bogie frequencies and so on and so forth.

If anybody is interested in more detail about the development of railway vehicle dynamics I can recommend 'A history of engineering research on British Railways' by A. O. Gilchrist, published by the Institute of Railway Studies and Transport History in 2006. (National Railway Museum, York or University of York, Heslington, York YO10 5DD). The ISSN is 1368-0706. Alternatively the document can be found on the WWW at <http://docplayer.net/15598662-A-history-of-engineering-research-on-british-railways.html>.

Of course none of this explains why these days the ride of the present generation of vehicles is so variable...

PS: I have heard that one of the reasons for the Class 80X's poor showing is that the lateral suspension has to be quite stiff to prevent the ends of the long 26 metre coaches going out of gauge at speed...

PPS: Confucius, he say, "All engineering design is a compromise".

 

[northernbelle]

I think it's fair to say that all recent stock tends to ride a bit more firmly than most BR era stuff - it's generally the penalty for reducing the weight of bogies and bodyshells.

Different stock tends to ride better or worse depending on the speed. I find Mark 3s are superb at mid range speeds but generally quite lively at the top end. Conversely, Voyagers seem to 'fidget' at the lower speeds but are superb at high speed.

 

[bassmike]

"hunting" in an engine sense means you are firing the spark plug before you get to the correct point to ignite before top dead centre, so the mixture combusts and causes a bit of back pressure rather than full downforce on the cylinder head where it needs to be, hence having a very lumpy and uneven ride in said car.

not sure about suspension terms, but the CAF units do seem to be very firm(either set up firm to begin with or not adequate damping), so you do feel the bumps and track deficiencies/pointwork a lot more.Shame really, other than that i think they are actually very good rural/regional units, they accelerate like rockets!
I would say that if the price is right they are quite an adequate sprinter replacement, basic,no frills ,gets you from a to b but they are very much the ford escort of trains rather than a ferrari...does the job but that's about it.

Stadler seem to have nailed this,the only downside on the 755's being stipulations for fuel tank reduction,and so reduced range..i really like the 755's other than that.superb units.
with car analogies again, this is transport via audi instead of ferrari or skoda....quite pleasurable and a step up in luxury from the ford escort!

The other bit in the equation is also the fire safety rules about seats these days. up until 10 years ago there used to be quite a nice amount of padding ,which could easily forgive a hard riding class of traction.Now you have the bare minimum which means every bit of hard track is being transmitted straight to your body rather than a portion of it being absorbed by spongy bits on your buttocks

I think the word you are looking for is "Pre-Ignition"

 

[cactustwirly]

The ride on the 345s is terrible full stop.
Very crashy and bumpy, with hardly any damping, so impacts such as points are very harsh.

 

[bassmike]

Apparently one of the best rides was in the old L N W R Oerlikon stock.

 

[Halish Railway]

I’ve always found the Desiro Cities to be quite rough - Especially on the ECML from Finsbury Park to Stevenage.

 

[Merle Haggard]

'Hunting' is one word used in this connection
What does it mean exactly?
..

I deduce you've never been on a coach with the original BR bogies at 70 mph or more, then; if you had, you would certainly know.
Sometimes triggered by a curve, or braking, and on jointed track. A hammering sound with a frequency of about 2 cycles per second from beneath (the bogies rotating between the limits of play of the flanges against the rails) is heard, and there is a side-to-side (lateral) oscillation of the body about 3 inches at a similar frequency. If extreme, you may feel yourself side to side sliding on the moquette.
Different hunting; but, for example, travelling on a train on the slow lines of the WCML and being overtaken by an express in the days of B4 bogies was interesting (and might put you off Inter City travel!). Although the bodies would ride smoothly, quite often the B4 bogie frame was see-sawing (frequency app 1/2 - 1 cycle per second) onto the bump stops, the coil springs on the axleboxes (and presumably also something further up was happily (?) absorbing the movement. By 'see-sawing' I mean rotating about a transverse axis through the pivot pin.
And, similarly, running alongside a Freightliner at 75 mph could be interesting, watching the flats rolling from side to side and the boxes tilting to the limit of movement of the twistlocks.
But they ever bounced off the rails (well, ok, there was that Met. Camm. unit on the north Wales coast around 1971 (I think)...

 

[hexagon789]

When rail enthusiasts talk about "bad ride quality" it does seem to me that this is very broad. In my experience the

• Wallowy - When you're sat down the ride feels smooth, but standing passengers are easily thrown off their feet because the train moves slowly from side to side. Examples include Desiros and Pendolinos, as well as the electric Civities
  
  
• Bumpy - On the worst examples it feels like every little imperfection in the track is being conveyed to your body - almost as if there isn't enough suspension. Examples include IETs, diesel Civities and (possibly the ultimate example) Pacers.
  
  
• Rattly - It doesn't feel bumpy or wallowy, but your seat, or the bodyside panels, are vibrating, often making a noise. Examples include Voyagers (which also have an awful buzzing at a certain point in their acceleration; I think that must be down to a resonant frequency), most buses especially when stationary, and some examples of Network Turbos.

Does this make sense or not? Am I insane to be categorising things this precisely?

Also by the way if you were to ask me what provided the best ride in the UK, that would probably have to go to a class 158/159... nothing more modern manages to beat it in my opinion. Unless you count Siemens Velaro (Eurostar and DB ICE).

BR had a number rating for ride quality:

1 - excellent
2 - very good
3 - good
4 - acceptable
5 - poor
6 - dangerous

I used to remember the figures Mk3s and Mk4s had but my mind's gone a blank.

I deduce you've never been on a coach with the original BR bogies at 70 mph or more, then; if you had, you would certainly know.
Sometimes triggered by a curve, or braking, and on jointed track. A hammering sound with a frequency of about 2 cycles per second from beneath (the bogies rotating between the limits of play of the flanges against the rails) is heard, and there is a side-to-side (lateral) oscillation of the body about 3 inches at a similar frequency. If extreme, you may feel yourself side to side sliding on the moquette.
Different hunting; but, for example, travelling on a train on the slow lines of the WCML and being overtaken by an express in the days of B4 bogies was interesting (and might put you off Inter City travel!). Although the bodies would ride smoothly, quite often the B4 bogie frame was see-sawing (frequency app 1/2 - 1 cycle per second) onto the bump stops, the coil springs on the axleboxes (and presumably also something further up was happily (?) absorbing the movement. By 'see-sawing' I mean rotating about a transverse axis through the pivot pin.
And, similarly, running alongside a Freightliner at 75 mph could be interesting, watching the flats rolling from side to side and the boxes tilting to the limit of movement of the twistlocks.
But they ever bounced off the rails (well, ok, there was that Met. Camm. unit on the north Wales coast around 1971 (I think)...

The Mark 1 bogies are an interesting one, designed for 100mph but they ended up only being passed for that with special maintenance - the last such vehicles being Mk1 BGs used on the Western pre-HST in sets of Mk2 coaches. Properly maintained the ride was reasonable but once the tyre profile wore it began to induce hunting at speed hence the 90 restrictions and why they were superseded by the expensive Commonwealths which did not suffer the same issue.

B4s are an interesting one as well, I've seen a few reports that they started to adopt a 'sway' at around 100mph.

 

[E27007]

I know how exactly how dangerous a 6 for ride quality can be, the ride would change from safe to violent and unsafe in a split second, I thought I was off the road, the side to side was a fast left-right-left-right snatch, the potential was there to induce a hernia or back injury. The fault was an incorrect P profile for the wheel diameter, When the stock was new, the tyres were turned to a published profile and the ride was perfect, after several several turnings in the wheel lathe, about halfway between new and scrap diameter, the wheel being smaller in diameter, the P profile was supposed to be changed to another specification, you've guessed correctly, the wheel lathe men were never informed, they turned to the as new profile.
I took one of these units on a 50 mile transit to a wheel lathe depot, it had been diagnosed as wrong profile, and limited to 45 mph, nothing in the fault book about restriction, and no message from Control, some very interesting (frightening) momemts for me on that trip

 

[colchesterken]

Had my first ride on a 745 last week ( sadly the train did not flirt with me ) Does anyone agree with me the sideways movement was more violent than on a Mk3 the suspension seems to be harder

 

[coppercapped]

SNIPPED

The Mark 1 bogies are an interesting one, designed for 100mph but they ended up only being passed for that with special maintenance - the last such vehicles being Mk1 BGs used on the Western pre-HST in sets of Mk2 coaches. Properly maintained the ride was reasonable but once the tyre profile wore it began to induce hunting at speed hence the 90 restrictions and why they were superseded by the expensive Commonwealths which did not suffer the same issue.

B4s are an interesting one as well, I've seen a few reports that they started to adopt a 'sway' at around 100mph.

Hmm! Are you sure about the 100mph requirement for the BR1 design? None of the reference books I have, going back many decades, make any reference to this point. Personally I find it very unlikely as work started on the design of BR's own bogie in the days of the Railway Executive - in other words before 1953 when there was no 100mph capable traction (with the possible exception of the LMS and LNER Pacifics) and no 100mph capable route. "British Railways Engineering 1948-80" by Johnson and Long, published by Mechanical Engineering Publications in 1981, has this to say (p292):

The four mainline companies chose their new standard bogies from amongst the designs of their constituent railways. Similarly the Railway Executive studied the designs of the group railways before deciding on the bogie to be adopted as a basis for a new British standard, in order to take advantage of the best features of all the existing designs. Test runs took place over the Great Central main line between Marylebone and Nottingham with the latest designs of the companies' coaches, first with wheels having tyres to the designed profile and second with worn tyres. Each coach was tested under 75 per cent load and care was taken to ensure that conditions were similar for each run. Track conditions and the riding qualities of the bogies were recorded for analysis and comparison. Double-bolster bogies of the type used on the LNER and GWR were found to provide the best ride, particularly with tyres in the worn condition. Of the two, the GWR bogie did marginally better and was adopted as the new standard, with some modifications to the secondary suspension.
The bogies were submitted to exhaustive tests before being adopted as the new standard. They also acquitted themselves very well in a competition, held under the auspices of the Office of Research and Experiment of the UIC, in which they were matched against the best European designs in riding trials in France and Germany. It was found, however, that after about 40,000 miles in normal service, there was a rapid deterioration in the wearing parts of the bogie and the quality of the ride. It was essential, therefore, to find a replacement bogie as quickly as possible.

The replacement was the Commonwealth bogie, the purchase of a trial set of which was authorised in 1955 and they entered service a year later. I remember that these were a revelation - much smoother and quieter because there was not so much loose ironmongery hanging around underneath. The primary suspension was still in hornguides, but with much tighter tolerances as the cast frame didn't distort; the compensating beam between the axleboxes constrained the axles to remain parallel. The secondary suspension used hydraulic dampers just like some of the newer cars at the time. What an advance! Johnson and Long again:

By the end of 1958 these bogies had run over 150,000 miles with a complete absence of deterioration. The Commission therefore decided that the Commonwealth bogie should be adopted as standard, pending the development of an improved British type.

The improved British type was the Swindon-designed B4.

 

[edwin_m]

'Hunting' is the railway equivalent of 'flutter' in aerodynamics - that is some of the energy of the vehicle's motion converts into vibration of the structure. If the structure is not sufficiently damped the amplitude of the vibration increases until the structure permanently distorts or fails. In the case of railway suspensions the lateral motion of the coned wheel was not sufficiently controlled by the suspension and the vibration amplitude was limited by the flanges hitting the rails.

What then tended to happen was that each wheelset in a bogie vibrated out of phase with the other one and the bogie rotated rapidly back and forth about its central pivot resulting that a very jerky lateral ride accompanied by loud banging at around 1 cycle per second.

This motion was continuous unless disturbed by rail joints, switch and crossing work or line curvature where the wheels were biased to the outside rail.

'Hunting' was very noticeable from the mid-1950s onwards with the general increase in train speeds. Bogies which were good for 70 or 75mph were found to be wanting at speeds above 80. The BR1 bogie was especially noticeable as its components wore quickly, 30,000 miles was its limit, and BR tended to use its newest coaches on its principle trains.

The whole theory was worked out by Wickens and others at BR Research in the early 1960s and since then this phenomenon has been designed out. At the time axles were located by axleboxes sliding vertically in hornguides - as there needed to be clearance between the two parts the lateral motion of one relative to the other was controlled by friction between the two parts which varied with the clearances and these changed with wear due to increasing mileage. Axles are now positively located by rods or arms or rubber bushes - or a combination of these components with known stiffnesses. In some cases stiffness can vary with the exciting frequency.

Vehicle riding is the subject of many learned papers and books. It is affected by a range of factors, stiffness of the track bed and rail fastenings, track alignment, tyre profile, stiffness of the primary and secondary suspensions in all planes, bogie rotational stiffnesses and inertias in yaw, pitch and roll, natural and forced resonant frequencies of the coach body and their interaction with bogie frequencies and so on and so forth.

If anybody is interested in more detail about the development of railway vehicle dynamics I can recommend 'A history of engineering research on British Railways' by A. O. Gilchrist, published by the Institute of Railway Studies and Transport History in 2006. (National Railway Museum, York or University of York, Heslington, York YO10 5DD). The ISSN is 1368-0706. Alternatively the document can be found on the WWW at <http://docplayer.net/15598662-A-history-of-engineering-research-on-british-railways.html>.

Of course none of this explains why these days the ride of the present generation of vehicles is so variable...

PS: I have heard that one of the reasons for the Class 80X's poor showing is that the lateral suspension has to be quite stiff to prevent the ends of the long 26 metre coaches going out of gauge at speed...

PPS: Confucius, he say, "All engineering design is a compromise".

The rotational dampers fitted to most bogie designs (often visible as a longitudinal shock absorber connecting a bracket on the bogie to one reaching downwards from the body) are an anti-hunting measure. They make it more difficult for the bogie to rotate, therefore reducing its tendency to oscillate. They do also make it less likely that the bogie will align itself perfectly on a curve, leading to some flange noise and wear.

 

[hexagon789]

Hmm! Are you sure about the 100mph requirement for the BR1 design? None of the reference books I have, going back many decades, make any reference to this point. Personally I find it very unlikely as work started on the design of BR's own bogie in the days of the Railway Executive - in other words before 1953 when there was no 100mph capable traction (with the possible exception of the LMS and LNER Pacifics) and no 100mph capable route. "British Railways Engineering 1948-80" by Johnson and Long, published by Mechanical Engineering Publications in 1981, has this to say (p292):

They were 100mph passed bogies originally the 90 without special maintenance cane in later. Deltics ran at 100mph with mixed Commonwealth and Mk1-bogied stock in the early 1960s when the line limits were raised to 100.

 

[gallafent]

I think the word you are looking for is "Pre-Ignition"

(aka pinking, aka detonation, …

 

[E27007]

"They were 100mph passed bogies originally the 90 without special maintenance cane in later. Deltics ran at 100mph with mixed Commonwealth and Mk1-bogied stock in the early 1960s when the line limits were raised to 100."

I recall Gresley Buffet cars in BR blue/grey livery,erected in the early 1930s and therefore veterans of 40 years, in ECML formations during the early 1970s, being hauled by 100 mph Deltics, The Gresley ex LNER Buffet Cars had the Gresley-Spencer-Moulton bogie and were said to be the best riding car on the railway, Declared surplus to ECML requirements, the Western Region were very happy to accept an allocation

 

[Flying Snail]

Anyone who wishes to know what hunting bogies feels like needs only to take a trip on the DLR, those things swing quite violently and always have done. I assume the reason for this and the reason it has not been rectified is because the suspension/wheel design is a compromise to allow the units take the very tight curves on the system.

 

[hexagon789]

Anyone who wishes to know what hunting bogies feels like needs only to take a trip on the DLR, those things swing quite violently and always have done. I assume the reason for this and the reason it has not been rectified is because the suspension/wheel design is a compromise to allow the units take the very tight curves on the system.

Possibly a bit like trams, the profile is designed more for tight curves than fast running as you surmise.

Certainly most trams tend to get a bit of a tail wag going when they get to their 70-80km/h ceiling.

 

[seagull]

The 'official' designations for reporting purposes are as shown in the photo.

 

[hexagon789]

The 'official' designations for reporting purposes are as shown in the photo.View attachment 83818

47s had a reputation for rolling like a ship in a force 12 at 95mph

Many of the modern units suffer from 'lurching' on rougher track and over points and crossings.

I've experienced something like High Frequency Vibration on 170s, the resonant frequency of the engine at a certain rpm seems to make the fixtures vibrate on some units but I wouldn't say the ride was affected.

 

[Peter Mugridge]

The 'official' designations for reporting purposes are as shown in the photo.View attachment 83818

When did "docking" get changed to "pitching"?