Welcome to another #RailwaysExplained thread... this one is another port over from the Site We Don't Mention. More to come!
HOW IT WORKS - TEST TRAINS (with some indulgent personal experience)
Back in 2019 a colleague posted this video. This innocent post started me on an odyssey which ultimately ended with me blagging my way into the cab of said train. Want to know more? Read on
#railways #OLE #OCS #OverheadLine
This entry was edited (1 year ago)
Garry Keenor
in reply to Garry Keenor • • •The train comprised diesel loco 67012, electric loco 90035 (pan raised), carriage M11074, DVT 82215, and diesel loco 67028 on a Swindon Transfer - Didcot return test train, with a non-standard class 90 pantograph. I dubbed this train the FrankenTrain™, a name which stuck.
This left many wondering what the hell this train was for. I'll try to explain that, while touching on some of the wider requirements for testing new OLE for entry into service.
Garry Keenor
in reply to Garry Keenor • • •The OLE test train was put together by a private sector testing company, initially for later stages of Great Western Electrification Programme. The train was to undertake mechanical & electrical testing of OLE between Bristol & Cardiff in advance of entry into service.
Mechanical testing was performed using the pan on top of the cl 90. It was unusual in 2 ways: it carried force & acceleration sensors so that it could measure contact force, and it was the only class 90 ever to carry an HS-X pan
Garry Keenor
in reply to Garry Keenor • • •The train was also intended to function as an electrical load bank, by using the class 90 to drive the train and draw power from the OLE. Staff in the lineside substations could then measure the electrical behaviour of the system as the train passes through.
When they weren't testing electrical behaviour, the train could be diesel hauled, which allowed the test team to decouple the energisation programme from the mechanical test programme.
But why the rest of the train, I hear you ask?
Garry Keenor
in reply to Garry Keenor • • •Well the class 67s could provide power away from the wires and *crucially* under wire that is complete but not yet energised. This allowed the test team to check mechanical performance with a raised pan before energisation. It gives the team more programme flexibility than a pure electric train - it provides "go-anywhere" capability.
The DVT allowed the driver in the 67 to control the cl 90 if needs be.
Garry Keenor
in reply to Garry Keenor • • •Obviously the test team need somewhere to sit, and monitor the tests; but the use of a mark 3 carriage was a personal request by me to wind up the HST nostalgists*.
So in summary it was a go-anywhere OLE test train. The project has previously used class 800s on hire from Hitachi (see img), but the FrankenTrain™ was thought to be more cost-effective, was under complete control of the test team, and meant the passenger operator wasn't a set short for regular services. Win-win
*not really
Garry Keenor
in reply to Garry Keenor • • •But why are OLE tests needed at all? After all, the Series 1 system had been proven in previous commissioning stages at 125mph.
The GW route, like all modern railways in the UK and EU, was electrified as a TSI-compliant* railway. That meant that all systems, incl. the OLE, had to meet performance requirements set out in European standards & written into UK law.
* now replaced by the NTSNs, which are currently identical to the TSIs. That's a whole other story
Garry Keenor
in reply to Garry Keenor • • •BEFORE I GO ANY FURTHER, lets deal with the Br*xit question head on.
Firstly, the TSIs and the European Standards they reference are *not* written or owned by the EU. They are written by CENELEC, a non-governmental European body of which the UK is a member. UK engineers helped write them.
Secondly, the purpose of the TSIs is not primarily to allow French trains to run in Austria. They are mainly to promote the single market in goods and services. This is a good thing.
Garry Keenor
in reply to Garry Keenor • • •If your pantograph is TSI-compliant, you can theoretically sell it anywhere that has TSI-compliant OLE. In practice it is more complex than that, but the aim is laudable.
The HS-X pantograph is already signed off as an interoperable constituent under the standards. This means we know it will work well with TSI-compliant OLE.
Garry Keenor
in reply to Garry Keenor • • •"Ah but if we ditched the TSIs we could build railways more cheaply". Well, maybe, maybe not. Standards provide a set of systems that we know will work well out of the box. Proven products can often be cheaper than experimentation.
Did you know that railways are being built in US and Canada that are compliant with the same standard? They aren't in the EU but they would rather follow a proven standard than write their own.
Garry Keenor
in reply to Garry Keenor • • •Digression over, back to the FrankenTrain™. Why did the OLE west of Bristol require testing? Because people in the UK interpreted the TSIs as saying that every new section of OLE requires physical testing prior to entry into service, even if it has been designed and built to the same standards as previous tested sections.
This is a hot topic that continues to be debated. People are understandably questioning this requirement when testing is so expensive.
Garry Keenor
in reply to Garry Keenor • • •Garry Keenor
in reply to Garry Keenor • • •simonbp
in reply to Garry Keenor • • •Apicultor 🐝
in reply to Garry Keenor • • •>If your pantograph is TSI-compliant, you can theoretically sell it anywhere that has TSI-compliant OLE. In practice it is more complex than that, but the aim is laudable.
Is this a reference to carbon vs copper contact strips on the panto?
Garry Keenor
in reply to Apicultor 🐝 • • •Moritz Krähe
in reply to Garry Keenor • • •Garry Keenor
in reply to Moritz Krähe • • •