Bionic Duckweed Rears its ugly head again

[DerekC]

I have been involved in the "Bionic Duckweed" saga from right back in about 2007 when Captain Deltic first coined the phrase in response to a DfT White Paper which didn't commit to electrification.

On the one hand, electrification makes total sense, must be the preferred decarbonisation solution for 80 - 90% of the network and we need commitment a rolling programme now.

On the other, the "Bionic Duckweed" label is a cheap throw away line intended to rubbish opposition to innovative solutions, whatever they might be. Fuel cells are established technology into the lower end of the power range needed for trains and hydrogen (as the Network Rail Traction Decarbonisation Strategy says) is a definite contender for longer rural routes where electrification isn't going to be economic. The key question is which out of battery or hydrogen technologies is going to be the right solution and that depends on how the two develop. Incidentally, algal production of hydrogen from waste using sunlight works in the lab, and would be a game changer for energy generally if it could be made to work economically in bulk.

== Doublepost prevention - post automatically merged: 13 Nov 2020 ==

We could use unobtainium instead, if you like?

Yes, yes. Luckily, @43096, you were scrapped at Drapers Yard in Hull almost exactly 53 years ago!

 

[edwin_m]

I have been involved in the "Bionic Duckweed" saga from right back in about 2007 when Captain Deltic first coined the phrase in response to a DfT White Paper which didn't commit to electrification.

On the one hand, electrification makes total sense, must be the preferred decarbonisation solution for 80 - 90% of the network and we need commitment a rolling programme now.

On the other, the "Bionic Duckweed" label is a cheap throw away line intended to rubbish opposition to innovative solutions, whatever they might be. Fuel cells are established technology into the lower end of the power range needed for trains and hydrogen (as the Network Rail Traction Decarbonisation Strategy says) is a definite contender for longer rural routes where electrification isn't going to be economic. The key question is which out of battery or hydrogen technologies is going to be the right solution and that depends on how the two develop. Incidentally, algal production of hydrogen from waste using sunlight works in the lab, and would be a game changer for energy generally if it could be made to work economically in bulk.

I don't think anyone's disputing that. But nor does anyone with technical knowledge consider that either battery or hydrogen is the best answer, or even an answer, for high speed rail or heavy freight. Furthermore electrification is likely to have the best whole-life costs of any solution except on lines with very low useage. It is telling that you haven't identified any other innovative solution that has a chance of solving this problem at lower cost.

 

[43096]

I have been involved in the "Bionic Duckweed" saga from right back in about 2007 when Captain Deltic first coined the phrase in response to a DfT White Paper which didn't commit to electrification.

On the one hand, electrification makes total sense, must be the preferred decarbonisation solution for 80 - 90% of the network and we need commitment a rolling programme now.

On the other, the "Bionic Duckweed" label is a cheap throw away line intended to rubbish opposition to innovative solutions, whatever they might be. Fuel cells are established technology into the lower end of the power range needed for trains and hydrogen (as the Network Rail Traction Decarbonisation Strategy says) is a definite contender for longer rural routes where electrification isn't going to be economic. The key question is which out of battery or hydrogen technologies is going to be the right solution and that depends on how the two develop. Incidentally, algal production of hydrogen from waste using sunlight works in the lab, and would be a game changer for energy generally if it could be made to work economically in bulk.

The problem is though, that the niche solutions (I'll be polite...) are being proposed as a substitute for that 80-90% of the network that has to be properly electrified. Quite why this country thinks those solutions are a substitute is utterly unfathomable; no other country is doing the same. The use of derogatory (to some) terminology for this sort of non-solution is entirely appropriate and justifiable in my view, as it draws attention to the stupidity.

Yes, yes. Luckily, @43096, you were scrapped at Drapers Yard in Hull almost exactly 53 years ago!

Lost on me. Some sort of tea-making device I assume.

 

[swt_passenger]

On the other, the "Bionic Duckweed" label is a cheap throw away line intended to rubbish opposition to innovative solutions, whatever they might be.

I thought his aim was to rubbish supporters of (untried) innovative solutions, such as gullible MPs...

 

[DerekC]

I thought his aim was to rubbish supporters of (untried) innovative solutions, such as gullible MPs...

Yes - got my words wrong there, but you knew what I meant!

== Doublepost prevention - post automatically merged: 13 Nov 2020 ==

The problem is though, that the niche solutions (I'll be polite...) are being proposed as a substitute for that 80-90% of the network that has to be properly electrified. Quite why this country thinks those solutions are a substitute is utterly unfathomable; no other country is doing the same. The use of derogatory (to some) terminology for this sort of non-solution is entirely appropriate and justifiable in my view, as it draws attention to the stupidity.

I don't think that kind of terminology ever works in the long term. You need to keep on patiently explaining the reality of the situation. It was that, not Captain Deltic, that got electrification back on the agenda in 2009 and it will again.

== Doublepost prevention - post automatically merged: 13 Nov 2020 ==

PS - if, @43096, you are not a kettle you are only half a traction solution!

 

[GRALISTAIR]

Also I know that it was only part of the identified problems on GWML, but using untried technology aka HOPS train did not work out too well. Electrification is so absolutely tried and tested and it works and the electricity can be GREENLY generated.

 

[Tio Terry]

Also I know that it was only part of the identified problems on GWML, but using untried technology aka HOPS train did not work out too well. Electrification is so absolutely tried and tested and it works and the electricity can be GREENLY generated.

One of the other problems peculiar to GWML was that back in BR days the Western Region decided to direct bury their lineside S&T cables. When it came to boring holes for masts they managed to cut through those cables causing many delays which cost a fortune. To try to avoid this they had to hand dig each mast site to determine the exact location of the cables before they dare use an auger, which took time and cost a lot of money. All of that would not have been necessary in most other locations around the railway which put cables in concrete troughs which can easily be seen in most cases.

From memory, didn't the DfT require a re-design to allow 140mph running after the initial design for 125mph had already made a significant start? More waste.

 

[GRALISTAIR]

It is of course GWML scheme that really spooked the DfT and HM Treasury which has lead in part to the search for a bionic duckweed solution.

 

[Romsey]

It shouldn't be an issue - it should be turned into an opportunity.

What the rail industry needs to embrace is the idea of compact, modular hydrogen generating stations located alongside the existing National Grid connectors for rail electrification, so should green hydrogen become a thing, it can be shown as a useful energy source for rail electrification - and you still have all the benefits of removing fuel storage and heavier traction equipment from trains.

In the real world, away from tragically stupid Tory MPs, green hydrogen will never be a thing - it's too inefficient, the losses during electrolysis, compression, storage and the fuel cell process too steep to ever come close to rivalling pulling 25kV AC from a wire above the train.

HOORAY - Thanks for stating what folks need to remember about hydrogen as a power source!
From memory about 30 to 35% of the generated power actually propels a hydrogen fuelled train. Install OHLE or 3rd rail with suitable trains and it's over 90%

 

[Tio Terry]

It is of course GWML scheme that really spooked the DfT and HM Treasury which has lead in part to the search for a bionic duckweed solution.

Yes, pity they had not decided on MML first, all those cable problems would not have existed!

Unfortunately the heavy overspend and the arrival of Grayling at the DfT resulted in curtailment of the electrification programme and more bi-modes.

 

[edwin_m]

One of the other problems peculiar to GWML was that back in BR days the Western Region decided to direct bury their lineside S&T cables. When it came to boring holes for masts they managed to cut through those cables causing many delays which cost a fortune. To try to avoid this they had to hand dig each mast site to determine the exact location of the cables before they dare use an auger, which took time and cost a lot of money. All of that would not have been necessary in most other locations around the railway which put cables in concrete troughs which can easily be seen in most cases.

Also the decision was made to start installing the OLE before re-signaling, which was necessary to provide immunity when OLE was powered up and would have taken most of those cables out of use. That can probably be laid at the door of over-hasty planning and agreement to an equally over-hasty delivery programme, in turn due in some part to a rapid policy reversal coming from the top, when electrification came into favour after a 25-year gap.

HOORAY - Thanks for stating what folks need to remember about hydrogen as a power source!
From memory about 30 to 35% of the generated power actually propels a hydrogen fuelled train. Install OHLE or 3rd rail with suitable trains and it's over 90%

Remembering of course that hydrogen isn't a power source at all*. It's a means of storing and possibly transporting energy, much less efficient than certain other means but which is useful in some situations.

*Skating lightly over the fact that, strictly speaking, nothing is a source of power - according to the law of conservation of energy.

 

[Irascible]

Also the decision was made to start installing the OLE before re-signaling, which was necessary to provide immunity when OLE was powered up and would have taken most of those cables out of use. That can probably be laid at the door of over-hasty planning and agreement to an equally over-hasty delivery programme, in turn due in some part to a rapid policy reversal coming from the top, when electrification came into favour after a 25-year gap

Remembering of course that hydrogen isn't a power source at all*. It's a means of storing and possibly transporting energy, much less efficient than certain other means but which is useful in some situations.

*Skating lightly over the fact that, strictly speaking, nothing is a source of power - according to the law of conservation of energy.

Indeed hydrogen is a fancy battery - the advantage comes in that it's charging rate is massively faster than a more solid one. If you have excess renewable electricity ( say, solar, or wind, or a combination ) & excess renewable source material ( water ) then efficiency of production is less of an issue, but all the other problems of using it are still around.

Is there any advantage of using a fraction of 25kV ( say, 6.25kV ) for less heavily used routes, these days?

 

[MarkyT]

One of the other problems peculiar to GWML was that back in BR days the Western Region decided to direct bury their lineside S&T cables. When it came to boring holes for masts they managed to cut through those cables causing many delays which cost a fortune. To try to avoid this they had to hand dig each mast site to determine the exact location of the cables before they dare use an auger, which took time and cost a lot of money. All of that would not have been necessary in most other locations around the railway which put cables in concrete troughs which can easily be seen in most cases.

Also the decision was made to start installing the OLE before re-signaling, which was necessary to provide immunity when OLE was powered up and would have taken most of those cables out of use. That can probably be laid at the door of over-hasty planning and agreement to an equally over-hasty delivery programme, in turn due in some part to a rapid policy reversal coming from the top, when electrification came into favour after a 25-year gap.

In BR(WR) 1960s/70s era signalling, cables between lineside cabinets, through which most vital signal circuits are routed, WERE generally placed in surface concrete troughs near the trackside. The deep-buried cables were typically large telecoms cables that called in at very few intermediate lineside cabinets, their primary purpose being to carry railway telephone circuits and management data services over longer distances between major equipment buildings and offices, including the control telemetry for the remote relay interlockings from the various PSBs. The failures during the electrification project were particulalry disruptive because such a major trunk cable being cut could isolate every remote interlocking beyond the damage, resulting in a widespread loss of control. The only hope for some residual control remaining would be where so-called override controls with limited functionality had also been provided, hopefully routed in a different parallel cable. Some remote interlockings were also equipped with local emergency panels where full functionality could become available once again as soon as suitable operating personal had been found and dispatched to those locations. Burying these trunk cables was not solely a WR thing at the time; it was common in other regions and generally in the telecoms and power industries, and similar events might have happened elsewhere if they'd made the naive assumption that stanchions could be piled in wholesale with little risk while the old S&T cabling remained fully functional. It turns out that was an extremely poor project decision.

 

[theageofthetra]

I work in the renewable energy sector, and there is a growing momentum behind hydrogen. I am sceptical that it will ever be useful or used for significant portions of transport.
Where I do believe it will come into play is for energy storage of excess renewable electricity. Batteries are very expensive, of limited capacity and in the case of lithium ion batteries degrade over time - possibly very quickly depending upon the duty cycle. If instead you use that excess renewable energy to make hydrogen, you can stuff that into the national gas grid, which offers a storage capacity that is unlimited in all practical senses. That hydrogen is then used to heat homes and offices etc in cold weather and run factories, which helps to decarbonise heat and industry.
There is a pilot programme taking place at the moment called HyDeploy which is verifying that up to 20% hydrogen can be injected into the grid without any impact upon end users. There's also a move to make all new gas appliances "hydrogen ready" which will allow them to utilise higher blends in the future.
At the moment, the main transmission network (which is where most of the storage capacity is) is not suitable for hydrogen and is the biggest challenge.

Having said all that, it would be possible to site a hydrogen production facility at a rail depot, and purchase cheap excess electricity to make hydrogen for fuelling trains. Technically it's not that difficult, it's the commercial and economic practicalities that are where it gets difficult.

Going a bit off topic but are mega capacity flywheels being considered for excess energy storage? I remember years ago reading about a French hospital that had one buried deep in the basement that was used to provide back up power.

 

[norbitonflyer]

Is there any advantage of using a fraction of 25kV ( say, 6.25kV ) for less heavily used routes, these days?

I can think of no reason why 6250V would be an advantage. High voltages are used to reduce losses in transmission which scale as the square of the current so a high voltage/ low current set up means less transmission loss, meaning you can put your substations further apart.
Moreover, dual voltage system adds complication as you need two sets of transformer windings. There were several transformer fires ineraly BR ac emus as a result of faulty changeover equipment.

 

[trebor79]

Going a bit off topic but are mega capacity flywheels being considered for excess energy storage? I remember years ago reading about a French hospital that had one buried deep in the basement that was used to provide back up power.

Flywheels are being deployed, but that's more about grid frequency response than energy storage per se.
With a grid run largely on steam turbines, as demand increases beyond prosuction, kinetic energy in the turbines and alternators is converted to electrical power, which allows down the rotational speed. This reduces grid frequency which means more power is brought online to maintain it at 50Hz. Vice versa also true.
With a grid moving more towards renewables, where there are no moving masses directly connected to the grid, and connections made using frequency inverters, this feedback mechanism no longer holds true.
The flywheels emulate the effect. If demand surges, the rotational kinetic energy will start to be extracted, slowing the flywheel and reducing grid frequency. This can be used as a signal to bring more power online from elsewhere, temporarily interrupt a big industrial user etc.

So flywheels will smooth very short term differences in supply and demand, in the same way that turboalternator sets do, or did. They also help to maintain the grid frequency and provide a control input for balancing mechanisms. It would by very difficult to balance a grid with purely synthetic frequency inputs.

 

[DerekC]

Flywheels are being deployed, but that's more about grid frequency response than energy storage per se.
With a grid run largely on steam turbines, as demand increases beyond prosuction, kinetic energy in the turbines and alternators is converted to electrical power, which allows down the rotational speed. This reduces grid frequency which means more power is brought online to maintain it at 50Hz. Vice versa also true.
With a grid moving more towards renewables, where there are no moving masses directly connected to the grid, and connections made using frequency inverters, this feedback mechanism no longer holds true.
The flywheels emulate the effect. If demand surges, the rotational kinetic energy will start to be extracted, slowing the flywheel and reducing grid frequency. This can be used as a signal to bring more power online from elsewhere, temporarily interrupt a big industrial user etc.

So flywheels will smooth very short term differences in supply and demand, in the same way that turboalternator sets do, or did. They also help to maintain the grid frequency and provide a control input for balancing mechanisms. It would by very difficult to balance a grid with purely synthetic frequency inputs.

Good explanation. You might see the name "synchronous condenser" or "synchronous capacitor" in this context. That's the name for the synchronous motor/generator which is connected to the grid and attached to the flywheel. They were used for many years for power factor correction but became obsolete when power electronics took over this function. They are now coming back into favour for exactly the function that @trebor79 describes. There is a good article about them here:

https://search.abb.com/library/Down...LanguageCode=en&DocumentPartId=&Action=Launch

The intermittency and variable nature of solar and wind power presents a growing challenge for power networks. Renewable energy is playing an increasingly important role in the energy mix, but such sources lack the capability to tolerate network faults or play a grid support role. As a result, the increasing penetration of these sources of power in the energy mix is reducing the resilience and stability of electricity networks ...........................A growing number of network operators and renewable energy developers, are now turning to synchronous condensers to provide additional short-circuit power to strengthen their grid. SCs also help maintain power quality and provide fault ride-through capability.

 

[hwl]

HOORAY - Thanks for stating what folks need to remember about hydrogen as a power source!
From memory about 30 to 35% of the generated power actually propels a hydrogen fuelled train. Install OHLE or 3rd rail with suitable trains and it's over 90%

In the range 23-28% rather than 30-35%.

 

[Bald Rick]

It is of course GWML scheme that really spooked the DfT and HM Treasury which has lead in part to the search for a bionic duckweed solution.

Partly.

Gospel Oak to Barking was the straw that broke the Camel’s back.

 

[hwl]

Good explanation. You might see the name "synchronous condenser" or "synchronous capacitor" in this context. That's the name for the synchronous motor/generator which is connected to the grid and attached to the flywheel. They were used for many years for power factor correction but became obsolete when power electronics took over this function. They are now coming back into favour for exactly the function that @trebor79 describes. There is a good article about them here:

https://search.abb.com/library/Down...LanguageCode=en&DocumentPartId=&Action=Launch

Plenty being installed at newer larger renewable installations currently at NatGrid's insistence. The class 700 power cut incident the other year refocused a few minds!

== Doublepost prevention - post automatically merged: 14 Nov 2020 ==

Partly.

Gospel Oak to Barking was the straw that broke the Camel’s back.

A classic case of the design contractor not doing enough on the ground survey work then internally outsourcing the bulk of the detailed design work overseas to people who have/had never to the London let alone Gospel Oak to Barking resulting in an unbuildable/unworkable design. Then there were the rule change issues and all the other issues faced by other schemes.

Adapting the classic surveyors /civils saying "You pay for the survey now or even more later"

 

[edwin_m]

Indeed hydrogen is a fancy battery - the advantage comes in that it's charging rate is massively faster than a more solid one. If you have excess renewable electricity ( say, solar, or wind, or a combination ) & excess renewable source material ( water ) then efficiency of production is less of an issue, but all the other problems of using it are still around.

Indeed so, hydrogen has its place in the future energy mix. But that place isn't about powering trains, except on a fairly small number of lightly-used routes where there's no point in installing overhead line.

Flywheels are being deployed, but that's more about grid frequency response than energy storage per se.
With a grid run largely on steam turbines, as demand increases beyond prosuction, kinetic energy in the turbines and alternators is converted to electrical power, which allows down the rotational speed. This reduces grid frequency which means more power is brought online to maintain it at 50Hz. Vice versa also true.
With a grid moving more towards renewables, where there are no moving masses directly connected to the grid, and connections made using frequency inverters, this feedback mechanism no longer holds true.
The flywheels emulate the effect. If demand surges, the rotational kinetic energy will start to be extracted, slowing the flywheel and reducing grid frequency. This can be used as a signal to bring more power online from elsewhere, temporarily interrupt a big industrial user etc.

So flywheels will smooth very short term differences in supply and demand, in the same way that turboalternator sets do, or did. They also help to maintain the grid frequency and provide a control input for balancing mechanisms. It would by very difficult to balance a grid with purely synthetic frequency inputs.

I wonder if the power electronics in renewable power sources could be configured to support the grid frequency by monitoring it and advancing their own phase and increasing their voltage ever so slightly when it's below 50Hz. If they all did that, programmed with the right control algorithms to avoid overshoot and oscillation, perhaps they could have the same sort of effect as a large rotating machine?

 

[DerekC]

I wonder if the power electronics in renewable power sources could be configured to support the grid frequency by monitoring it and advancing their own phase and increasing their voltage ever so slightly when it's below 50Hz. If they all did that, programmed with the right control algorithms to avoid overshoot and oscillation, perhaps they could have the same sort of effect as a large rotating machine?

Hmm - I guess that a wind turbine actually is a large rotating machine, so in theory it might be possible to use some of its rotational energy to keep the voltage and frequency up whilst the turbine slows down a bit. I found this paper about control strategies for wind turbines, which on a quick skim suggests that the control engineers have rather a lot to think about without trying to keep the grid frequency up! However I would be surprised if somebody isn't considering the idea if it could save lots of money spent on synchronous capacitors.

https://www.sciencedirect.com/science/article/pii/S2468227620303045

An overview of control techniques for wind turbine systems ... ........................"Renewable energy is being embraced globally as a viable alternative to conventional fossil fuels generators. This is in direct response to the challenge of depleting fossil fuel reserves and its impact on environmental pollution. Wind energy has continued to play a signifi- cant role and can be regarded as the most deployed renewable energy source, however the efficiency level and cost effectiveness of a wind turbine (WT) system with regards to wind application is very much dependent on its control. This research paper reviews the vari- ous control methods associated with wind energy control. More recently there has been an attempt to review these control techniques but the authors have focused more on the maximum power point tracking (MPPT) techniques and pitch angle control of WTs how- ever discussions around stall control of the WT is not presented in these research papers. This review paper presents a detailed review of the various operational control strategies of WTs, the stall control of WTs and the role of power electronics in wind system which have not been documented in previous reviews of WT control. This research aims to serve as a detailed reference for future studies on the control of wind turbine systems"

PS - I wondered if this was too far off topic, but then "Bionic Duckweed" covers pretty much anything ....

 

[norbitonflyer]

Hmm - I guess that a wind turbine actually is a large rotating machine, so in theory it might be possible to use some of its rotational energy to keep the voltage and frequency up whilst the turbine slows down a bit. I found this paper about control strategies for wind turbines, which on a quick skim suggests that the control engineers have rather a lot to think about without trying to keep the grid frequency up! However I would be surprised if somebody isn't considering the idea if it could save lots of money spent on synchronous capacitors.

https://www.sciencedirect.com/science/article/pii/S2468227620303045


PS - I wondered if this was too far off topic, but then "Bionic Duckweed" covers pretty much anything ....

As I understand it, the generator in a wind turbine is essentially a large regenerative brake. If you disconnected the generator, the blades would spin much faster. The generator holds the speed of the blades constant, so the energy extracted is always at the same frequency 50Hz.

That's why, however fast the wind is blowing, the blades always turn at the same speed, and however gusty it is, all the blades in a windfarm turn at the same speed.

The only time it stops, other than maintenance, is if the wind isn't strong enough to turn the blades even if the generator is disconnected, orifit is so strong the generator (brake) can't slow it down.

 

[DerekC]

As I understand it, the generator in a wind turbine is essentially a large regenerative brake. If you disconnected the generator, the blades would spin much faster. The generator holds the speed of the blades constant, so the energy extracted is always at the same frequency 50Hz.

That's why, however fast the wind is blowing, the blades always turn at the same speed, and however gusty it is, all the blades in a windfarm turn at the same speed.

The only time it stops, other than maintenance, is if the wind isn't strong enough to turn the blades even if the generator is disconnected, orifit is so strong the generator (brake) can't slow it down.

I think you should read the article. A modern wind turbine is connected to the grid via a DC link so that the turbine frequency is decoupled from the grid frequency (hence the problem we are discussing). And the controller varies blade pitch and rotor speed within the operational range of wind speed to maximise generated power. Above a certain wind speed the turbine operates at constant power (the maximum capability of the generator) until it reaches the safe mechanical limit, after which the brakes come on and the blades are feathered to ride out the storm.

 

[edwin_m]

As I understand it, the generator in a wind turbine is essentially a large regenerative brake. If you disconnected the generator, the blades would spin much faster. The generator holds the speed of the blades constant, so the energy extracted is always at the same frequency 50Hz.

That's why, however fast the wind is blowing, the blades always turn at the same speed, and however gusty it is, all the blades in a windfarm turn at the same speed.

The only time it stops, other than maintenance, is if the wind isn't strong enough to turn the blades even if the generator is disconnected, orifit is so strong the generator (brake) can't slow it down.

I think you should read the article. A modern wind turbine is connected to the grid via a DC link so that the turbine frequency is decoupled from the grid frequency (hence the problem we are discussing). And the controller varies blade pitch and rotor speed within the operational range of wind speed to maximise generated power. Above a certain wind speed the turbine operates at constant power (the maximum capability of the generator) until it reaches the safe mechanical limit, after which the brakes come on and the blades are feathered to ride out the storm.

In fact you're both right. The regenerative brake on a modern 25kV electric train runs in just about the same way - the AC motors generate a frequency that depends on the train speed, this is rectified to DC then inverted back to AC at the 50Hz frequency and correct phase to be fed into the overhead line.

 

[Tio Terry]

In BR(WR) 1960s/70s era signalling, cables between lineside cabinets, through which most vital signal circuits are routed, WERE generally placed in surface concrete troughs near the trackside. The deep-buried cables were typically large telecoms cables that called in at very few intermediate lineside cabinets, their primary purpose being to carry railway telephone circuits and management data services over longer distances between major equipment buildings and offices, including the control telemetry for the remote relay interlockings from the various PSBs. The failures during the electrification project were particulalry disruptive because such a major trunk cable being cut could isolate every remote interlocking beyond the damage, resulting in a widespread loss of control. The only hope for some residual control remaining would be where so-called override controls with limited functionality had also been provided, hopefully routed in a different parallel cable. Some remote interlockings were also equipped with local emergency panels where full functionality could become available once again as soon as suitable operating personal had been found and dispatched to those locations. Burying these trunk cables was not solely a WR thing at the time; it was common in other regions and generally in the telecoms and power industries, and similar events might have happened elsewhere if they'd made the naive assumption that stanchions could be piled in wholesale with little risk while the old S&T cabling remained fully functional. It turns out that was an extremely poor project decision.

Interesting.

I wonder why the Signal Engineers were so concerned about their circuits being single, not double, cut and the possibility of false feeding in the event of cable damage by augers if their cables were in troughing?

I know from personal experience that GEML(E&W), ECML and large parts of the WCML lineside cables of all types were in troughing, what other mainlines direct buried cables? I know a number of secondary lines mole plowed cables - I had a hand in quite a bit of that as well - but I was under the impression that direct burial on mainlines was a GW thing.

 

[GRALISTAIR]

Partly.

Gospel Oak to Barking was the straw that broke the Camel’s back.

Of course I forgot about the problems there. Hopefully lessons have been well and truly learned.

== Doublepost prevention - post automatically merged: 14 Nov 2020 ==

A classic case of the design contractor not doing enough on the ground survey work then internally outsourcing the bulk of the detailed design work overseas to people who have/had never to the London let alone Gospel Oak to Barking resulting in an unbuildable/unworkable design. Then there were the rule change issues and all the other issues faced by other schemes.

Adapting the classic surveyors /civils saying "You pay for the survey now or even more later"

 

[trebor79]

I wonder if the power electronics in renewable power sources could be configured to support the grid frequency by monitoring it and advancing their own phase and increasing their voltage ever so slightly when it's below 50Hz. If they all did that, programmed with the right control algorithms to avoid overshoot and oscillation, perhaps they could have the same sort of effect as a large rotating machine?

No that wouldn't work. Bad things happen if your equipment is out of phase. Best case scenario you end up with a rubbish power factor and generate a lot of waste heat somewhere. Worst case you cause something to catastrophically fail.
Fundamentally, if grid frequency is dropping you need to generate more power somewhere in the system.
Furthermore, if you had a fully renewable grid with no rotating masses then the frequency wouldn't drop in the first place because it would be entirely synthetically generated. In that case, demand/generation mismatch would manifest itself in other ways that are less acceptable to consumers and the grid operators. Principally I think you'd end up with a lot of voltage fluctuations, which suggests higher currents than desired when voltage is low, so more waste head through resistive losses and possibly exceeding the treated capacity of some equipment.

 

[Energy]

We could use unobtainium instead, if you like?

At this rate we will have our trains pulled by horses as their waste can decompose...

On a serious note, hydrogen and batteries are not right for most of the network. Hydrogen is a pain and inefficient to produce, batteries are good but have a limited range and get expensive when you have to put a lot of them in plus they are made from materials which aren't that green to get (although Tesla are working on ones from silicon). For most of the network 25kV OHLE is the best solution and the one with MPs want, they just don't want the high cost which would come down if we had a proper rolling program for electrification.

The diesel issue is completely different, it suddenly looked green while electric trains have been known to be green for a long time. Not only do they not produce emissions and don't use the not so green materials batteries use but you don't need to bother refueling/recharging them, EMUs are easier to maintain, last longer and are cheaper. Long term OHLE is cheaper for most of the network. Also hydrogen trains are rather slow right now...

 

[Domh245]

Also hydrogen trains are rather slow right now...

The iLint will do 140kph, which is entirely adequate for just about any UK rail application of hydrogen, so that doesn't really wash as an argument