Pantograph Instrumentation Systems

[Merle Haggard]

Moderator note: posts #1 - #13 originally in this thread.

So, at the moment 360s can only operate with one pan down (8 or 12) and max 75 mph North of Bedford.
I'm puzzled; will further overhead line work be necessary to get to the requirements of the new timetable (110 and all pans)?
Or is it because testing is needed to make sure that the OLE can cope with pans every 4 cars, which raises the question; why this has to be done empirically, rather than rely on design calculations and computer modelling?

Edit; couldn't spell 'Bedford' ...

 

[Roast Veg]

So, at the moment 360s can only operate with one pan down (8 or 12) and max 75 mph North of Bedford.
I'm puzzled; will further overhead line work be necessary to get to the requirements of the new timetable (110 and all pans)?
Or is it because testing is needed to make sure that the OLE can cope with pans every 4 cars, which raises the question; why this has to be done empirically, rather than rely on design calculations and computer modelling?

Edit; couldn't spell 'Bedford' ...

If a test train is damaged by incorrect modelling, it's cheaper to substitute it for another test consist than pay out for a broken passenger unit. It's also belt and braces.

 

[Merle Haggard]

If a test train is damaged by incorrect modelling, it's cheaper to substitute it for another test consist than pay out for a broken passenger unit. It's also belt and braces.

Thanks, fair enough. Unfortunately as well, 'the media' will pounce on any real or alleged shortcoming of railways even if innovation is involved.

 

[Philip Phlopp]

So, at the moment 360s can only operate with one pan down (8 or 12) and max 75 mph North of Bedford.
I'm puzzled; will further overhead line work be necessary to get to the requirements of the new timetable (110 and all pans)?
Or is it because testing is needed to make sure that the OLE can cope with pans every 4 cars, which raises the question; why this has to be done empirically, rather than rely on design calculations and computer modelling?

Edit; couldn't spell 'Bedford' ...

It's an updated OLE system so there's some additional testing to make sure the computer simulations and calculations are correct.

The design specification (3 x pantographs at 110mph, 2 x pantographs at 125mph, plus upgrade potential) for the MML once upon a time, a long long time ago, would have required the Series 1 OLE system, as found on the GWML, but as everybody now knows, it's "too heavy and complicated".

There has been an upgrade to the Series 2 OLE system (that which is found in the North West area and across the newly electrified routes in Scotland) to make it compatible with two of the three requirements (3 x pantographs at 110mph, 2 x pantographs at 125mph) and it has morphed into MS125, reflecting its place with the 'new' UK Master Series of electrification pick and mix systems.

The testing work using the DATS trainset is primarily to make sure the new MS125 system is doing as was predicted during the design and modelling stage, if it was normal new OLE installation, it would get no more attention than a quick sweep with the NMT or MENTOR, to confirm contact wire geometry/alignment, then a run with a couple of power hungry stock types to check the power supplies are working OK.

 

[Merle Haggard]

It's an updated OLE system so there's some additional testing to make sure the computer simulations and calculations are correct.

The design specification (3 x pantographs at 110mph, 2 x pantographs at 125mph, plus upgrade potential) for the MML once upon a time, a long long time ago, would have required the Series 1 OLE system, as found on the GWML, but as everybody now knows, it's "too heavy and complicated".

There has been an upgrade to the Series 2 OLE system (that which is found in the North West area and across the newly electrified routes in Scotland) to make it compatible with two of the three requirements (3 x pantographs at 110mph, 2 x pantographs at 125mph) and it has morphed into MS125, reflecting its place with the 'new' UK Master Series of electrification pick and mix systems.

The testing work using the DATS trainset is primarily to make sure the new MS125 system is doing as was predicted during the design and modelling stage, if it was normal new OLE installation, it would get no more attention than a quick sweep with the NMT or MENTOR, to confirm contact wire geometry/alignment, then a run with a couple of power hungry stock types to check the power supplies are working OK.

Thanks for that, too; I hadn't realised that the MML extension electrification was to a new spec. I should have - thankfully, the wires across Northamptonshire's landscape are supported by much less-visually-intrusive supports than the GWML's.

 

[Nym]

It's an updated OLE system so there's some additional testing to make sure the computer simulations and calculations are correct.

The design specification (3 x pantographs at 110mph, 2 x pantographs at 125mph, plus upgrade potential) for the MML once upon a time, a long long time ago, would have required the Series 1 OLE system, as found on the GWML, but as everybody now knows, it's "too heavy and complicated".

There has been an upgrade to the Series 2 OLE system (that which is found in the North West area and across the newly electrified routes in Scotland) to make it compatible with two of the three requirements (3 x pantographs at 110mph, 2 x pantographs at 125mph) and it has morphed into MS125, reflecting its place with the 'new' UK Master Series of electrification pick and mix systems.

The testing work using the DATS trainset is primarily to make sure the new MS125 system is doing as was predicted during the design and modelling stage, if it was normal new OLE installation, it would get no more attention than a quick sweep with the NMT or MENTOR, to confirm contact wire geometry/alignment, then a run with a couple of power hungry stock types to check the power supplies are working OK.

MENTOR doesn't measure geometry, it measures the contact wire contact forces and position of the uplifted wire, at the speed at which it is being operated.
Only non-contact systems can measure geometry, but if it's a new OLE installation, it should be measured as part of the installation / commissioning of the OLE.

The IET and Desiro contact forces will behave rather differently to that of MENTOR. Particularly the IET pantographs which use the BW HSX design rather then the HSA or HSP designs that MENTOR uses. (And I believe the Desiro uses one of).

Instantaneous changes in contact force perform much better over 110mph on the HSX, and it is less venerable to multi pantograph operation problems.

 

[Philip Phlopp]

MENTOR doesn't measure geometry, it measures the contact wire contact forces and position of the uplifted wire, at the speed at which it is being operated.
Only non-contact systems can measure geometry, but if it's a new OLE installation, it should be measured as part of the installation / commissioning of the OLE.

The IET and Desiro contact forces will behave rather differently to that of MENTOR. Particularly the IET pantographs which use the BW HSX design rather then the HSA or HSP designs that MENTOR uses. (And I believe the Desiro uses one of).

Instantaneous changes in contact force perform much better over 110mph on the HSX, and it is less venerable to multi pantograph operation problems.

The position of the uplifted wire is an intrinsic part of the geometry of the entire OLE system though...

And I should have said geometry data is now more frequently being recorded now by the use of instrumented pantographs on passenger vehicles running at line speed (and to service patterns) rather than MENTOR running in a Q path.

 

[Philip Phlopp]

Which stocks are fitted with contact force OHL geometry measurement other than test trains?

I can understand non-contact camera systems being fitted to passenger units as it's just a single box on the roof, but a contact force system needs quite a bit more equipment.

There should be 1 x Class 390 with a full contact force measurement pantograph instrumentation system designed by DB ESG now in service, with the same (new) instrumentation as fitted to MENTOR. I thought there was another couple of units in service/coming into service with the same setup, but looking at the contract documentation, I think there was just two additional sets of instrumentation ordered to go onto MENTOR.

 

[Energy]

There should be 1 x Class 390 with a full contact force measurement pantograph instrumentation system designed by DB ESG now in service, with the same (new) instrumentation as fitted to MENTOR. I thought there was another couple of units in service/coming into service with the same setup, but looking at the contract documentation, I think there was just two additional sets of instrumentation ordered to go onto MENTOR.

Why are they using a 390 for this?

 

[59CosG95]

Why are they using a 390 for this?

390s are one of, if not THE most power-hungry EMUs on the conventional network. They were used on both the Manchester - Liverpool and Euxton Jn - Manchester electrification schemes to check the power supply was adequate for a worst-case scenario IIRC.

 

[swt_passenger]

Why are they using a 390 for this?

On the WCML? To remove the need to run special test trains that are difficult to path in amongst the normal 125 mph timetable. Also allows testing at line speed.

 

[Philip Phlopp]

Why are they using a 390 for this?

In addition to the reasons provided above - speeds, pathing, power demand, the Class 390 pantograph behaves rather differently to other pantographs, in that it moves opposite to the tilt of the carriage, to ensure the pantograph head remains correctly alligned with the contact wire, which introduces another potential dewirement risk which can't be picked up by any of the other contact or contactless catenary monitoring systems.

 

[Domh245]

There's no plan for a 390 to be used for testing the MML wiring however that I'm aware of?

 

[Roast Veg]

Nor was one used on the GWML.

 

[Nym]

390s are one of, if not THE most power-hungry EMUs on the conventional network. They were used on both the Manchester - Liverpool and Euxton Jn - Manchester electrification schemes to check the power supply was adequate for a worst-case scenario IIRC.

Except that these OHL Geometry systems do not measure power draw or provide any kind of false load. The closest that they come is measuring the OHL voltage.

There's no plan for a 390 to be used for testing the MML wiring however that I'm aware of?

Nope, that's what the DATS 91s are being used for. I don't think they've been fitted with HSX pantographs though, so the 810s will still need homogenising.

Nor was one used on the GWML.

The 802s where extensively used on the GWML for geometry measurement.