Class 800 electrical interference issues on the Northern ECML

[PeterC]

You don't work in my industry. In my industry, it really doesn't matter how wrong the specification is, it is always the manufacturer's / suppliers fault for not utilising their magic Crystal ball and predicting the last minute change in specification that the customer requires.

Sounds like the classic relationship between my various employers' in-house IT departments and the business. We never found third party suppliers in our sector ready to roll over and take the financial hit in that way.

 

[matacaster]

Assuming it relates to the traction motors etc, if there is room, would a cheap faraday cage around the offending components on the locomotive be of help?

 

[gingertom]

Assuming it relates to the traction motors etc, if there is room, would a cheap faraday cage around the offending components on the locomotive be of help?

there's rather a lot of components. 9 Car IEP has 5 powered vehicles = 10 powered bogies = 20 traction motors plus traction inverters. That's a lot of Faraday cages per set.

 

[edwin_m]

EMC requirements in general are mandated by EU Directive 2014/30/EU.

For the railway industry in particular European Norms 50121, 50126 and 50128 are particularly important. I would be very surprised if any procurement documentation did not require compliance with these standards for any new trains. I do know that testing on the former GWR demonstrated that the 800's did not comply with these requirements, but I have no idea what was done about making them compatible.

It sounds very much like it is a problem for the train maker to resolve. Yes, the signalling systems can be modified to make them work with the trains - we know that from the GWR testing - but that's not the whole story. There are many other things that can be affected by EMC, heart pacemakers, the railways neighbours such as hospitals, televisions and computers, taxi firms radio systems, and many more things. It is important that the train is made to comply and that whilst the signalling can be made to work the greater risks are also negated.

Assuming it relates to the traction motors etc, if there is room, would a cheap faraday cage around the offending components on the locomotive be of help?

The specific problem with signalling is probably not radiated interference, which is what EN50121 mainly addresses and what might be solved by Faraday cages (although the motors and traction equipment have metal cases anyway). The big issues in the 1990s were to do with conducted interference - the traction motors and electronics operate at various frequencies and, despite filtering, components of these can be drawn from the supply and back through the rails. The return current passes directly through track circuits which are obviously highly safety-critical and also sensitive because they operate with currents of the order of one amp and the traction current is in the hundreds of amps albeit mostly at 50Hz. There is also some risk of induction into conductors parallel to the track.

Most of the signalling on the ECML north of Colton Junction was installed just before electrification as early-vintage Solid State Interlocking along with some unusual hybrids of relays and SSI. I don't recall the track circuit types and I don't know whether it has been significantly upgraded since then, but if not then it pre-dated the advent of AC motors which really kicked off the issues with rolling stock safety cases. Some kit only slightly younger went in west of Didcot as well as around Paddington (although I think the latter was upgraded). Railtrack published some limits for current drawn at various frequencies which were intended to clarify the issue, and I would suspect the current (!) problem is whether the train is outside these limits or whether the limits don't actually cover the susceptibility of the signalling equipment in question.

 

[43096]

To be fair to them they really havent - You can design something and then build it but if its only when testing starts that issues are found then thats when they are found. And they started testing last year was it? And the issue has only been discovered now so not exactly 'years'

The first set arrived in the UK in March 2015 for the test programme. They've had 3 and a half years since then. That is way more than most new trains have for their test programmes.

The whole IEP project has been an expensive shambles - this is just the latest part of this fiasco. The whole reason for going to Hitachi was sold as "bringing Japanese standards" - on the evidence so far with IEP and the frankly embarrassing 385 window saga, they have not done so. Perhaps the purchase of AnsaldoBreda will increase their standards!!!!

 

[Clip]

The first set arrived in the UK in March 2015 for the test programme. They've had 3 and a half years since then. That is way more than most new trains have for their test programmes.

And the problem has only just arisen from what i can see so, in your wisdom, how could they have sorted out an issue in 3 years that has only just arisen?