ECML Electrification Class 91 Fleet March 2019 Service of 30 years

[keefer]

At the time of introduction I regularly talked to colleague in RCE Eastern who bemoaned the problems in respect of the limitations on felting the track due to the limited capability of the overhead to accommodate vehicle movement (even more than those I dealt with on the GEML). The maximum permissible kinematic vehicle movement on the ECML was apparently less than that for a T4 at 140 mph. The SIG bogies had less dynamic movement at 140mph than the T4; to do this they needed to be stiffer. The upshot was that when running at 125mph the ride was worse than a T4 and even worse than a BT10 in areas where track geometry was 'challenging'. I was told that by turning the bogies round 180 degrees and modifying the dampers etc they got the ride to something closer to the T4 but limited the stock to 125 mph.

 

GordonC, Bomag gave this answer previously regarding the SIG bogies

(I'm on my phone so couldn't just ref. the post #)

Edited January 17, 2019 by keefer

[Pandora]

From what I recall at the time, the dampers had been set very stiffly, and I was led to believe that it was because they had been ordered to be capable of 140 mph running. I am not certain that was the reason, but I know it took a considerable time to improve the ride. But of course perception is key here - the seats of the Mark IV's were considerably less padded than those of the HST's (even after their refurbs), and that was a source of adverse comment too. So add the two together and you don't quite know which was the primary reason for the perception of "rough riding" as opposed to the reality that the bogies were indeed harder-riding than those of the HST, but that tended to be more noticeable at lower speeds, especially across pointwork or jointed sections. At higher speeds, on CWR, you tended not to notice their ride, until you hit a wet spot or some other defect, and then, boy, did you feel it.

 

After the first few years, and the adjustments to the bogies and linkages (and maybe a mod, I am not sure), you tended not to notice it so much, but that could be because we had become more used to it.

 

I believe there was a difference to the way higher speed track was laid, in France and Switzerland anyway, compared to the UK, in terms of depth particularly and in weight of FB rail, but I am no expert on that, or on what difference that might have made to the use of SIG bogies.

The ECML, 30 years ago, was track maintenance by conventional ballast Tampers or by Stoneblowers which use small chippings of ballast?  The latter tends to leave behind an initial rough ride until the line has settled under traffic. Today when I travel ECML London to York I notice Bllast Tampers by Matissa at strategic stabling points, I believe the WCML tend to favour Stoneblowers for maintenance.

Edited January 18, 2019 by Pandora

[jjb1970]

These days the original mk. 4 ride quality would probably be par for the course given the appalling ride quality of some of the trains on the network. Even the new Eurostar trains are unimpressive.

[phil-b259]

The ECML, 30 years ago, was track maintenance by conventional ballast Tampers or by Stoneblowers which use small chippings of ballast?  The latter tends to leave behind an initial rough ride until the line has settled under traffic. Today when I travel ECML London to York I notice Bllast Tampers by Matissa at strategic stabling points, I believe the WCML tend to favour Stoneblowers for maintenance.

 

The two types of machine complement each other rather than a Stoneblower replacing a regular Tamper.

 

Part of what makes conventional ballast 'work' as a medium for supporting track is its irregular shape helping to lock each piece to its neighbour and the voids between which allow rainwater to speedily drain away

 

As such, care must be taken with the application of smaller chippings as not only do they inhibit the ability of the ballast to drain water by filling in the voids, they also tend to lack the locking function regular ballast* has, plus they get ground down to dust easier than the bigger ballast with said dust eventually forming a solid layer (if too much is created) through which water cannot flow, which in turn creates wet beds etc.

 

As such the WCML and ECML will regularly see conventional Tampers used to maintain track quality as well as the use of stoneblowers for tricky spots where regular Tamping alone will not solve the problem.

 

 

* one of the reason why the SECR and eastern division of the SR had such bad track was the use of shingle from dungarees as ballast. Lacking the locking ability of lumps of granite meant the track was insufficiently well supported and drained for larger, heavier and faster trains in the 1920s and 1930s

Edited January 18, 2019 by phil-b259

[phil-b259]

These days the original mk. 4 ride quality would probably be par for the course given the appalling ride quality of some of the trains on the network. Even the new Eurostar trains are unimpressive.

 

As has been noted, the SIG bogie design was fine on Swiss track which was maintained to a far higher standard than ours. Similarly most bogie designs emanating from Siemens are based around German track standards - which again have historically been far, far better than anything BR had.

 

The ability to come up with a well riding bogie on ropey track basically died with the end of BR in house rolling stock design as they were about the only nation in Western Europe that needed such expertise.

[rodent279]

Ken, I thought it was Doncaster? I was working for Eversholt at the time and responsible for trying to get a vibration monitoring system installed as a short term measure following the incident pending the rebuild programme. As I recall the cardon shaft demolished a waiting shelter on the platform (much to the chagrin of a passenger who had just left it) and embedded itself in a Mercedes in the car park. Perhaps there were two...........

A few years later when working for the Taiwan High Speed Rail Project, an Alstom representative noted that the locos had been built cheaply to meet the budget. Certainly when I was with Eversholt the price of the heavy maintenance exams was about the same as the initial build price. The cost of the subsequent refurbishment must have been huge.

 

The whole of the ECML electrification was done to a low price and BR did well to achieve that. People complain about problems with the OHLE, and span wire systems certainly have drawbacks, but I think it has subsequently been established that many of the problems arose from the zero maintenance policy adopted. Overall it was a project that was delivered on time and to a limited budget: what was the alternative given the lack of cash?

Were the cardan shaft problems also related to the trains running continually at a lower speed than they were designed for?

[david.hill64]

Were the cardan shaft problems also related to the trains running continually at a lower speed than they were designed for?

No, I don’t think so.

The reasons were complex. I did see an amazing dynamic simulation done by the ex BR Research dynamics engineers which showed some behaviour that the designer had not expected.

[Mike Storey]

 

 

* one of the reason why the SECR and eastern division of the SR had such bad track was the use of shingle from dungarees as ballast. Lacking the locking ability of lumps of granite meant the track was insufficiently well supported and drained for larger, heavier and faster trains in the 1920s and 1930s

 

The shingle from my dungarees has certainly supported a thing or two in the past.   But shingle from Dungeness was typical of the SER's and LCDR's cheapskate approach to just about everything. However, I guess if you used it now, it would have the added advantage of illuminating the track at night?

 

I guess it should be pointed out that, these days, there are multiple types of tamping machines, the most common (well it was when I was still in the game) are the Tamping & Lining versions, which not only packs the sleepers up to (or sometimes, down to) level, but also checks the rails are parallel and true, and adjusts them accordingly (within certain limits). There are also DTS (Dynamic Track Stabiliser) machines, which overcome the problems of having a TSR following tamping or stoneblowing, by following up a job and simulating the passage of trains over a week or so, in just a few minutes, so that full line speed can be restored.

 

It should also be noted that smaller stones are used for the sub-ballast layer (which supports the main, larger stone size layer) and which is designed to prevent incursion of groundwater and flora up into the ballast, and direct water coming down through the main layer into the cess. It is usually separated from the main layer by a permeable "ground sheet" these days, but the incursion of the smaller ballast up into the larger ballast has long been a much greater problem than the use of smaller chippings for patch repairs on the surface.

 

I only know these things from hundreds of hours spent (as OS) on engineering works, and then as a project manager, but must leave what this means in terms of effects on track and vehicle dynamics, to proper engineers......

[298]

No, I don’t think so.

The reasons were complex. I did see an amazing dynamic simulation done by the ex BR Research dynamics engineers which showed some behaviour that the designer had not expected.

I'm other words, it suffered a catastrophic failure...

[jjb1970]

The ability to come up with a well riding bogie on ropey track basically died with the end of BR in house rolling stock design as they were about the only nation in Western Europe that needed such expertise.

 

In the case of the newer Eurostar sets (e320?) they also ride noticeably worse than the original sets in France and Belgium as well, or at least the ones I've been on did. They have a rather fidgety ride with the same high lateral accelerations as Siemens trains on British track, and the body seems to roll from side to side as well.

[Ken.W]

I'm other words, it suffered a catastrophic failure...

 

I thought that was what happened to the BMW, skewered, quite literally, to the ground, in through the roof and through the floor.

 

Happened to see my mate that was that the other day, it was a BMW and the carden shaft also smashed the points at the south end of the platform before clearing over the road bridge!

Edited January 19, 2019 by Ken.W