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Different types of bad ride + other discussion of ride quality

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E27007

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In our discussions about bad ride, note how many current motor cars have poor ride quality compared to older cars such as Citroen (DS), Renault (16) and Peugeot (504) even BMC cars (1100/1300/1800 Maxi) with clever interconnected hydraulic suspension , car suspension has been repurposed over the decades from "comfort and compliant" to " harsh and stiff" to support or encourage aggressive driving. Driving as a Sport over a means of Travel. Perhaps the railway engineers designing trains have the same mentality are their counterparts in the car industry.
 

AM9

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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. .../QUOTE]
I've noticed that although not all trains do badly. The notorious Mill Hill bumps on the MML fasts would be quite rough when in a 319. When the Electrostars arrived, although smoother, they really did lurch at some of the bumps, - even the brand new 387s behaved that way. The 700s though seem to ride them a lot better, even though they take them at 100mph linespeed.
 

edwin_m

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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.
I believe DLR wheel profile is more like heavy rail than trams, which isn't optimum for tight curves. The hunting is probably indeed caused by having bogies that are easy to turn to take those curves, and therefore don't damp out that type of oscillation.
 

Wilts Wanderer

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Worth noting that its not only bogied vehicles that suffer from hunting. In fact, a 4-wheeled vehicle with poor ride is a very serious matter as the forces involved in the oscillation are greater, as it involves the entire vehicle weight. The oscillation frequency acts as a resonance with the suspension and can ultimately lead to derailment, in a similar way to vertical bouncing on cyclic top. Pacers with worn / incorrect tyre profile have been notorious for it at times - my experience with this was around the time FGW absorbed the Wessex Trains franchise and moved the DMU fleet from Canton to St Philips Marsh - for months the 143 fleet was absolutely horrific. Had some terrifying runs through Sapperton Tunnel including one occasion when luggage was flung out of the overhead rack and the driver had to reduce speed to below 50mph which seemed to be the trigger speed on straight track.

Incidentally vehicles passed for more than 75mph require extra yaw dampers between bogie and body, which are quite obvious when you
look for them. A good example being the Turbo fleets- 165/0 do not have them whereas 165/1 do, despite having otherwise identical bogies.
 

43096

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Incidentally vehicles passed for more than 75mph require extra yaw dampers between bogie and body, which are quite obvious when you
look for them. A good example being the Turbo fleets- 165/0 do not have them whereas 165/1 do, despite having otherwise identical bogies.
The Class 458 fleet had its yaw dampers removed when it was regeared for 75mph.

The big exception to this is the BT10 bogie, which doesn’t need and doesn’t have a yaw damper.
 

Bletchleyite

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The Class 458 fleet had its yaw dampers removed when it was regeared for 75mph.

Interesting. Why remove them? To save on maintenance, or does it reduce track wear somehow?

I did notice that Swiss EW IV coaches rated for 160km/h don't have them, but those rated for 200km/h do - their absence is quite obvious because the empty mountings are still there.

The big exception to this is the BT10 bogie, which doesn’t need and doesn’t have a yaw damper.

Arguably it does need them (or something else) - the Mk3 coach has a very characteristic side to side sway which shows inadequate damping.
 

43096

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Interesting. Why remove them? To save on maintenance, or does it reduce track wear somehow?
Maintenance reduction, I believe. If you don’t need them, why keep them?

Arguably it does need them (or something else) - the Mk3 coach has a very characteristic side to side sway which shows inadequate damping.
That is very arguable. 45 years in service says otherwise.
 

Wilts Wanderer

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Interesting. Why remove them? To save on maintenance, or does it reduce track wear somehow?

Probably a bit of both - yaw stiffness (which improves ride) also generally increases poor curving characteristics, as the bogie is less able to bend along the longitudinal axis. This is more pronounced when running below linespeed on higher speed track with a high cant angle, and can lead to several issues the worst being rolling contact fatigue in the rail (also known as gauge corner cracking.)
 

43096

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Pacers have been in service for a while as well, and they have always had an awful ride :)
BT10s are not an awful ride, though. Quite the opposite in fact. Your view is something of an exception to the norm - there are far more of the view that the BT10 remains unsurpassed in terms of ride quality.
 

Wilts Wanderer

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I’m nor an expert on ride dynamics by any means, but I do wonder how much of the Mark 3 coach’s generally excellent reputation for good riding is attributable to the bogie design, and how much is attributable to the suspension. It’s been widely reported in the last few years that particular Mark 3 fleets ride quality has deterioriated heavily and it’s been linked to a change in suppliers for suspension components / non-availability of the original design replacements. IIRC the VTEC sets were seen to be very poor, the XC and GWR sets not so bad.
 

Bletchleyite

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BT10s are not an awful ride, though. Quite the opposite in fact. Your view is something of an exception to the norm - there are far more of the view that the BT10 remains unsurpassed in terms of ride quality.

I wouldn't say the Mk3 had an awful ride (the Mk4 can have that "accolade"), but to suggest they are unsurpassed is unfair to trains with a genuinely excellent ride such as the Class 158 and the heavyweight Class 221.
 

Wilts Wanderer

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I wouldn't say the Mk3 had an awful ride (the Mk4 can have that "accolade"), but to suggest they are unsurpassed is unfair to trains with a genuinely excellent ride such as the Class 158 and the heavyweight Class 221.

I think you’d have to run a 158 at 125mph in order to fairly compare the riding quality to a Mark 3.
(Edit - I agree the Mark 4 ride was appalling at times! Although not nearly as hair-raising as when new, apparently. Irony really that their replacement is considerably worse.)
 

DustyBin

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I agree with the comments re the 158’s they ride very well. I find the Networkers (465 and 466, I don’t think I’ve travelled on a 365) provide an excellent ride, they absorb rough track really well but at the same time aren’t wallowy.

The Metropolitan Line A-Stock was very ‘lively’ over rough track, even at low speed though tunnel sections. I used to find it quite entertaining being thrown about but I suspect I was in the minority!
 

hexagon789

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385s seem to behave a bit like your 387 description
I believe DLR wheel profile is more like heavy rail than trams, which isn't optimum for tight curves. The hunting is probably indeed caused by having bogies that are easy to turn to take those curves, and therefore don't damp out that type of oscillation.

Ah, so the opposite essentially!

I wouldn't say the Mk3 had an awful ride (the Mk4 can have that "accolade"), but to suggest they are unsurpassed is unfair to trains with a genuinely excellent ride such as the Class 158 and the heavyweight Class 221.

Originally nothing surpassed it is would say, but nowadays with various modifications such as the changing of certain parts which are no longer manufacturered etc then it's not as good as it was.

It's worth noting that the French, very proud of their Corail coach ride quality and which is generally considered the benchmark in Europe, were quite impressed with the BT10 bogie ride and a comparison showed that at low speeds the BT10 rode slightly better, and high speed the Y42 of the Corail did and at 100mph there was little between them.

Weight often improves ride at speed and the Corails are 10 tonnes heavier than a Mk3. I think part of the reason the Mk3s sway a bit at speed is they are so light and the suspension is quite soft.



The big exception to this is the BT10 bogie, which doesn’t need and doesn’t have a yaw damper.

Don't the bogie traction rods perform much the same function on BT10s?
 

coppercapped

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The Class 458 fleet had its yaw dampers removed when it was regeared for 75mph.

The big exception to this is the BT10 bogie, which doesn’t need and doesn’t have a yaw damper.
The BT10 bogie does need and does have a yaw damper, except that it's not obvious. It used the same principle as that also used in some earlier bogies such as the B4 being a large disc of friction material, essentially brake lining, surrounding the centre location pin. It's protected from the elements and so offers consistent friction values.

I wouldn't say the Mk3 had an awful ride (the Mk4 can have that "accolade"), but to suggest they are unsurpassed is unfair to trains with a genuinely excellent ride such as the Class 158 and the heavyweight Class 221.
Of course the 158 has a better ride than the BT10/Mark 3 combination. It used BR's next iteration of bogie design after the BT10 and the Series 3 bogie now used in its thousands under the PEP derived vehicles, Networkers, Electrostars and Turbostars. It used all the experience from these coupled to a very stiff body formed of welded aluminium extrusions.

It's a pity the Series 4 wasn't more widely used but apparently the position regarding the ownership of the intellectual rights got very confused at the time of the various BREL/ABB takeovers and the dismemberment of BR's design offices.
 
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cactustwirly

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The BT10 bogie does need and does have a yaw damper, except that it's not obvious. It used the same principle as that also used in some earlier bogies such as the B4 being a large disc of friction material, essentially brake lining, surrounding the centre location pin. It's protected from the elements and so offers consistent friction values.


Of course the 158 has a better ride than the BT10/Mark 3 combination. It used BR's next iteration of bogie design after the BT10 and the Series 3 bogie now used in its thousands under the PEP derived vehicles, Networkers, Electrostars and Turbostars. It used all the experience from these coupled to a very stiff body formed of welded aluminium extrusions.

It's a pity the Series 4 wasn't more widely used but apparently the position regarding the ownership of the intellectual rights got very confused at the time of the various BREL/ABB takeovers and the dismemberment of BR's design offices.

I think the best riding bogie is definitely the one fitted to the 165s and 166s. Absorbs bumps very well and very little sideways motion.
Just a pity that it was ruined by bombardier as the 387s have some very violent sideways jolts, ruining the ride quality.
 

43096

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I think the best riding bogie is definitely the one fitted to the 165s and 166s. Absorbs bumps very well and very little sideways motion.
Just a pity that it was ruined by bombardier as the 387s have some very violent sideways jolts, ruining the ride quality.
Glad it's not just me who thought that about 387 ride quality. Very easy comparison to do on the same track out of Paddington.
 

AM9

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Glad it's not just me who thought that about 387 ride quality. Very easy comparison to do on the same track out of Paddington.
It's a shame that in its 18 year product life, Bombardier didn't get around to correcting a flawed bogie setup on the Electrostars, -I would have thought that the availability of the 110mph versions would have triggered that.
 

cactustwirly

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Glad it's not just me who thought that about 387 ride quality. Very easy comparison to do on the same track out of Paddington.

It's still better than the 345s however. 800s ride better in my opinion.
 

coppercapped

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I think the best riding bogie is definitely the one fitted to the 165s and 166s. Absorbs bumps very well and very little sideways motion.
Just a pity that it was ruined by bombardier as the 387s have some very violent sideways jolts, ruining the ride quality.
The basic bogie, as I wrote in post 18, is the same in both designs of vehicle, it is BR's Series 3.

There may be subtle differences in spring and damping rates because of the differing masses of the coach bodies and it is likely, but I don't know, that the secondary air bellows are supplied by different manufacturers and may also have slightly different characteristics.

The other differences are that the Class 165 and 166s have 23 metre long bodies which will increase the polar moment of inertia compared to the 20 metre long bodies of the 387s and make the ride slightly smoother. The 165s and 166s have a 90mph top speed while the 387s are permitted to reach 100/110mph and so may have slightly stiffer yaw dampers to cope with the higher speed which will have the effect of making the ride firmer in response to lateral inputs.

If the train operators were more persistent it might well be that Bombardier could have further tuned the suspension under the Electrostars, but as the TOC's major single source of money (aka 'the customer', otherwise known as the DfT), wasn't interested in passenger comfort (see 'ironing board seats' ad nauseam) I'm not surprised nothing was done.
 

E27007

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A companion to ride quality is the state of the track that the stock has to deal with. BR had a large fleet of Tampers and the target for each midweek night shift was 80 chains of tamping.
NR have a fleet which is less than half in size and the target per midweek night shift is 40 chains.
 

CBlue

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Agreed that 387's don't ride as well as Networkers. The ones used on Cambridge fasts certainly bump and lurch about more than the 365s' did - although they're still far better than the Mk3 derived units which felt like they were about to fly off the track every time something came the other way...700s are far better in that regard even if the seats are rubbish.

Never really thought much of the Mk3 coach myself. Ride always seemed to have quite an unnerving floatiness to it.
 

AM9

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A companion to ride quality is the state of the track that the stock has to deal with. BR had a large fleet of Tampers and the target for each midweek night shift was 80 chains of tamping.
NR have a fleet which is less than half in size and the target per midweek night shift is 40 chains.
That's true but many of the posts here are comparisons between different classes running over the same track. A good suspension system should give reasonable performance over all likely track 'imperfections'.
 

physics34

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377/387s suffer alot of sideways swing. Whether thats due to poorly maintained dampers or bad design im not sure but it definitely makes their ride quality worse in certain respects to the mk1 stock they replaced.

(Sorry didnt see above comments)


It's a shame that in its 18 year product life, Bombardier didn't get around to correcting a flawed bogie setup on the Electrostars, -I would have thought that the availability of the 110mph versions would have triggered that.

I think same as with previous comments about seating.... the people involved just dont care enough about passenger comfort.

I remember the comments other staff when the 377s were first tested about how bad the ride was (between brighton and seaford).
 
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AM9

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... I think same as with previous comments about seating.... the people involved just dont care enough about passenger comfort.

I remember the comments other staff when the 377s were first tested about how bad the ride was (between brighton and seaford).
I don't think the seating has anything to do with the trains ride. Stock that doesn't handle track irregularities well suffers more maintenance issues. The lateral lurches of the Electrostars affect standing passengers even more than those who are seated.
 

physics34

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I don't think the seating has anything to do with the trains ride. Stock that doesn't handle track irregularities well suffers more maintenance issues. The lateral lurches of the Electrostars affect standing passengers even more than those who are seated.

yeh i meant in terms of rail companies/executives not evaluating overall passenger comfort.

A ride on the Dorking to Horsham line can be quite eye opening (and armrest gripping!). 455s along this route definately didnt have the lurch effect, at least to the magnitude of the 377s.

..and i guess you are right, the more lurching and side to side sway the units suffer, the more maintainence they will require.
 
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