What causes overhead line problems?

[Agent_Squash]

Inductive charging exists, you may even be using a device capable of it at this moment.
Whether it can be scaled up to the power levels required by a train, especially in a dynamic (non-static) environment may well be another matter.

The efficiency losses are ridiculous with current inductive charging technology.

 

[Falcon1200]

There are many causes of overhead line (OLE) problems, some already mentioned here. Vandalism is certainly an issue, such as objects dangled from an overbridge as at yesterday's incident at Stevenage - BTW I hope that, despite the disruption they caused, the person involved survives, but coming into contact with the OLE is extremely dangerous; There was a similar case near Motherwell where a boy hung a cable from a bridge, the marks left by his trainers on the bridge parapet after 25kV had passed through him were visible for years afterward.

Objects thrown onto the OLE are an issue too, in fact one location near Wishaw was so prone to this that standard practice was to immediately advise the BT Police of any OLE problems in the area. And a less obvious cause is birds building nests in OLE structures in spring, unless spotted and removed in time these can eventually get large enough to trip out the OLE. An

d the weather is of course a major problem, for example strong winds blowing trees into contact with the OLE, or in extreme cases, objects such as trampolines and even garden sheds bringing the wires down!

 

[Glaswegian]

Inductive charging exists, you may even be using a device capable of it at this moment.
Whether it can be scaled up to the power levels required by a train, especially in a dynamic (non-static) environment may well be another matter.

Is that the same as magnetic levitation, or is magnetic levitation another possibility? (But only in very limited circumstances, I would think.)

 

[zwk500]

Is that the same as magnetic levitation, or is magnetic levitation another possibility? (But only in very limited circumstances, I would think.)

Maglev is slightly different as the train doesn't need traction power - the electromagnetism is provided from the track. The only on-board power is the 'hotel' load, which is apparently provided by linear motors with batteries. Therefore the amount of power the inductive charging needs to produce is a lot less than if it was actually powering motors to move the train.

 

[TheEdge]

Inductive charging exists, you may even be using a device capable of it at this moment.
Whether it can be scaled up to the power levels required by a train, especially in a dynamic (non-static) environment may well be another matter.

I don't think charging a phone and supplying 25kV traction power to a moving train are really in the same league.

 

[DarloRich]

Is our infrastructure so poor that a slight gust of wind can blow down miles of wiring

No - next question.

The causes of OHLE failure are wide, varied and often frustratingly caused by third party issues.

 

[JamesT]

I don't think charging a phone and supplying 25kV traction power to a moving train are really in the same league.

A bit of Googling finds https://www.stellantis.com/en/news/...-dynamic-induction-charging-becomes-a-reality

Inauguration of the “Arena del Futuro” (‘Arena of the Future’) circuit built by A35 in collaboration with Stellantis and other partners, to field test revolutionary electric charging with dynamic induction

The 1,050-meter-long circuit is located in a private area of the A35 autostrada, near the Chiari Ovest exit, and is powered with an electrical output of 1 MW

Using DWPT (Dynamic Wireless Power Transfer), electric vehicles can be charged “wirelessly”, by driving them in wired lanes with an innovative system of turns installed under the tarmac

It’s road rather than rail, but it doesn’t seem implausible that you could use a similar system for powering trains. The test system has an output of 1MW, a Class 700/1 at full load is 5MW so it’s in the right ballpark.

The efficiency losses are ridiculous with current inductive charging technology.

An efficiency figure isn’t mentioned, which does suggest it’s not particularly impressive in that regard. There are some quotes on other pages about it being ‘comparable’ to plug-in charging, but that seems to be based on losing the conversion stages for grid->charger->battery->motor when wireless goes directly receiver->motor.

I’m not suggesting we should be tearing down the wires tomorrow, just that alternatives to direct contact for powering vehicles do exist and aren’t science fiction.

 

[Cowley]

I think a general nudge back in the direction of discussing OHLE might be necessary here. If anyone wants to start a discussion on other forms of powering trains then we can start a thread in the speculative section.

Thanks

 

[BingMan]

I'm intrigued to know how you expect Network Rail to bend the basic properties of electromagnetic energy to somehow to get away from conductor to conductor contact in an electrical circuit. Short of plasma based OHL and pantographs I think its a pretty insurmountable issue.

On board batteries or fuel cells?

 

[STEVIEBOY1]

There do seem to be alot of Overhead Line issues this week, I think on GWR, East Coast and today in Southern Scotland. (I am glad I live in SR 3rd rail land.)