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Electrification - long term thinking
Question
This is a topic that has been discussed many, many time in the IET Railway Technical Network Executive Committee meetings, with lots of different views and opinions on what is needed and how it could work. Anyone got any thoughts on this?
13 Replies
Denis McMahon
292 Posts
This is a very broad topic, which may be the reason for lack of response so far.

Here in the south we tend to take electric railways for granted; they have been with us for a long time. Even so, things have not stood still. The introduction of newer trains with different driving characteristics has necessitated the installation of new substations along the routes.

Across the nation, over the years, we have seen the electrification of principal routes - the so-called west coast and east coast main lines. Ongoing is the Great Western electrification, behind schedule and over-budget. I'm sure it will be great when it is finished. What next? The electrification of the Trans-Pennine route is much discussed but when it will happen is anyone's guess.

On Tyneside, in the early 1960s, an electric system similar to the Southern Region third-rail system gave way to diesel. (Interestingly in this period also, trolley buses in the area were phased out.) In the early 1980s the lines were re-electrified to create the Tyneside Metro we know today. I don't think we'll see trolley buses again, but trams are making a come-back in modern form in several cities.

We have a mix of electrification systems - third rail and overhead line at 25 000 volts. The Eurostar trains cope admirably with both. There was a 2 500 volt overhead line system on the Manchester to Sheffield freight route, which gave way to diesel in the early 1980s. I understand that the locomotives were sent to the Netherlands; I don't know if they are still in service.

There are a few ideas anyway - would anyone like to enlarge on any of them?
mapj1
2633 Posts
Really if there is to be anything more than lip service to the environmental aspects, then there should be no longer be any  'if' in electrification, and overhead wires running an HV at 50Hz AC should be the preferred way of upgrading existing lines. Modern AC controls allow regeneration by inverter and transformers back into AC supplies, so the arguments that used to supported  using DC traction currents on the rails at a variety of voltages that date from the era of the mercury arc rectifier should now be retired. This reduces the number and complexity of feeder sub stations, and the risk to life, and potential for flooding problems  is far lower.
I'm not sure why it is so much more expensive in real terms to convert lines to electric than it was a few decades ago, I suspect creeping bureaucracy , the use of layers of subcontracting leading to a lack of economy of scale, rather than actual change to the technical issues of making holes in the ground and installing  gantries and insulators, though if others know better I'd be very interested. to know why.
Andy C
17 Posts
mapj1:
Really if there is to be anything more than lip service to the environmental aspects, then there should be no longer be any  'if' in electrification, and overhead wires running an HV at 50Hz AC should be the preferred way of upgrading existing lines. Modern AC controls allow regeneration by inverter and transformers back into AC supplies, so the arguments that used to supported  using DC traction currents on the rails at a variety of voltages that date from the era of the mercury arc rectifier should now be retired. This reduces the number and complexity of feeder sub stations, and the risk to life, and potential for flooding problems  is far lower.
I'm not sure why it is so much more expensive in real terms to convert lines to electric than it was a few decades ago, I suspect creeping bureaucracy , the use of layers of subcontracting leading to a lack of economy of scale, rather than actual change to the technical issues of making holes in the ground and installing  gantries and insulators, though if others know better I'd be very interested. to know why.


There's this little thing called 'loading gauge' that tends to get in the way! (Or perhaps kinematic envelope might be better). Unfortunately, most of the UK rail network was built to quite reduced dimensions when compared with the Berne loading gauge used across much of europe or even the massive LGs in the US. Tight clearances mean any prospective upgrading to overhead HV would be accompanied with major bills for replacing overbridges or lowering track to accommodate the necessary clearances for the wires and all the associated disruption. I know of many incidences on the WCML where birds sheltering on the tops of wires under bridges have got too close to the structure and struck up an arc between the bridge and wire usually resulting in the burning through of the wire and more disruption to the network. Admittedly, there would be benefits in doing away with the third rail system, not the least being less risk of electrocution!

Regarding trolleybuses, why not bring them back? They are more flexible than trams, especially where sharing routes, infrastructure and vehicles are cheaper and cyclists don't have to contend with tracks in the road. Simples!

Helios
103 Posts
I guess its how things fit with energy systems overall, and its complex because electrification has given some advantages in being able to fit motors underneath carriages , but obviously a system that is on or off could use less energy overall if we get to KJ calculations , and not all electricity is from renewables , depends what your view is I guess theres some figures in IET magazine on how much current railway uses in diesel terms .
But it is not just electrification of land transport. If we are to get to net zero emissions by 2050, then we have to address other GHG emission sectors and activities: aviation; shipping; heating; industrial processes; agriculture; etc. A massive ask for the paradigm step up of net zero emissions energy that electrification of our whole modern society will require.
Simon Barker
761 Posts

Regarding trolleybuses, why not bring them back? They are more flexible than trams, especially where sharing routes, infrastructure and vehicles are cheaper and cyclists don't have to contend with tracks in the road. Simples!

I suspect these days, it would be cheaper to buy battery powered buses, and install quick charging points at strategic points around the bus network where buses tend to stop regularly (e.g. railway stations).  The buses could get a full charge overnight in the depot.

Andy Millar
1725 Posts
Andy C:
mapj1:
Really if there is to be anything more than lip service to the environmental aspects, then there should be no longer be any  'if' in electrification, and overhead wires running an HV at 50Hz AC should be the preferred way of upgrading existing lines. Modern AC controls allow regeneration by inverter and transformers back into AC supplies, so the arguments that used to supported  using DC traction currents on the rails at a variety of voltages that date from the era of the mercury arc rectifier should now be retired. This reduces the number and complexity of feeder sub stations, and the risk to life, and potential for flooding problems  is far lower.
I'm not sure why it is so much more expensive in real terms to convert lines to electric than it was a few decades ago, I suspect creeping bureaucracy , the use of layers of subcontracting leading to a lack of economy of scale, rather than actual change to the technical issues of making holes in the ground and installing  gantries and insulators, though if others know better I'd be very interested. to know why.


There's this little thing called 'loading gauge' that tends to get in the way! (Or perhaps kinematic envelope might be better). Unfortunately, most of the UK rail network was built to quite reduced dimensions when compared with the Berne loading gauge used across much of europe or even the massive LGs in the US. Tight clearances mean any prospective upgrading to overhead HV would be accompanied with major bills for replacing overbridges or lowering track to accommodate the necessary clearances for the wires and all the associated disruption. I know of many incidences on the WCML where birds sheltering on the tops of wires under bridges have got too close to the structure and struck up an arc between the bridge and wire usually resulting in the burning through of the wire and more disruption to the network. Admittedly, there would be benefits in doing away with the third rail system, not the least being less risk of electrocution!

Regarding trolleybuses, why not bring them back? They are more flexible than trams, especially where sharing routes, infrastructure and vehicles are cheaper and cyclists don't have to contend with tracks in the road. Simples!

We've managed to electrify Paddington to Cardiff, even through the tunnel and Steventon bridge! Entertaining at times (I was on the fringes of the assessment body team) but it's amazing what you can do with a bit of engineering.

In any meetings with NR electrification teams I keep mentioning Paddington to Plymouth (or indeed Penzance), just for fun...

Cheers,

Andy

Why electrify with all overhead gantry and cables construction problems and costs, the summer droopy cables problems and pantographs tearing them down, ice on cables in winter, cables being stolen, cables being damaged in severe weather, trains stranded with power outages/problems, long line losses and inefficiencies, etc?

Why not just use hydrogen trains that only need refuelling points at strategic points along the routes?
Helios
103 Posts
I haven't seen any data on electric buses , and am waiting to see how they fare in winter , so don't know . I can imagine the single deck bus working ok on battery , but not a fully loaded double decker . As for trolley buses bit too old technology for me to have any real view, there is a trolley bus museum at sandtoft and really great tramway museum at crich in Derbyshire . People who I know who did remember trolley buses , describe the frequent stops to re attach the pantograph using a hook on a wooden pole. Contactless charging is being explained , but I am not to sure if its efficienct as things have to be aligned precisely . If the battery is at 80% charge after 5yrs that's a big problem , current battery tech is not yet perfected.  
Helios
103 Posts
Its been a really big race to develop truly green technologies, because we haven't thought through the effects , I think when we look back some engineering approaches will have been misleading , in efficiency terms. The need at the moment I think is in halting marine pollution , most cities are by sea or river and sea cities rely on fish caught locally .
From my perspective things are getting very dangerous on pollution , to at least keep foods clean  
As demonstrated last year across England and Wales, a power outage that brought trains, industry, hospitals, homes, etc, relying on grid distributed electricity, to a standstill, highlights that electrification of everything adds a huge vulnerability to society - we need energy resilience and diversity of an integrated energy system in the future as we have today.
https://www.bbc.co.uk/news/uk-49300025 
Thank you, 

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