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Author Topic: Electric buses: Why were trolleybuses ever scrapped?  (Read 13588 times)
Reading General
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« Reply #45 on: February 29, 2020, 10:10:14 pm »



One of the factors given against trams by the Local Enterprise Partnership was that they run on fixed routes. As RG says, this is actually an advantage once the utilities have been moved, and development grows along good transport links. So long as they go close enough to major residential areas to get people out of cars, and MetroBust doesn't go particularly close to some major areas it is said to serve, then why not?



  There is a thinking in the U.K that tram routes must be segregated and run along former rail lines than main roads into cities. Some sections of systems are based on former rail lines yes, but really the tram is go anywhere, within reason. This thinking appears to be based on accommodating mass moving public transport AND continued mass car use, i.e the tram will not be able to move along the main road quickly as there will be traffic congestion there. But, if we design our public transport routes properly in the first place we will manage to reduce the congestion, even on the busiest of corridors.
  As to why infrastructure free transport is preferred, short term cost aside, it is probably again factoring that the traffic will always be there, plus an attempt to replicate the convenience of motor car freedom with our public transport. 
  It's about time we began to tackle congestion, rather than avoid it, and our main roads becoming available for our most dominant form of urban transport in the future be that trams or trolleybuses.
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stuving
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« Reply #46 on: February 29, 2020, 10:24:12 pm »

Relaying of utilities is something that is likely to happen soon anyway with upgrades to electricity supplies, replacement of gas pipes to cope with hydrogen, and who knows what for TV, phones and internet.

There has been a massive programme of cast iron gas main upgrading anyway for safety reasons  with methane, but this has largely been done by relining the pipe with a plastic pipe. Moving pipes would be another game entirely. 

I do not think that further changes to mains will be necessary for a change to hydrogen even though H2 is a smaller molecule.   

There are two potential problems with hydrogen in current mains. The big high-pressure mains put in for natural gas can't be used as the steel would suffer embrittlement. So that's one one big programme of street digging if it goes ahead, though quite what the replacement pipes would be isn't clear (nor if there is a viable one).

Low pressure and house mains would have more hydrogen leakage through the solid walls than of methane, but still so small no-one would miss it. However, if it accumulates in closed spaces, the greater explosion hazard of hydrogen (lower ignition energy and wider explosive mixture range) does raise serious issues. Again, it's not clear if anything better is available, but the real issue may be that we need bigger pipes (lower volumetric energy capacity and higher total demand for domestic CHP). If trenchless methods can't do that size increase, even with developments, then all our streets get shredded. But it's by no means certain we'll go down that route. 
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martyjon
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« Reply #47 on: March 01, 2020, 08:54:00 am »

This cropped up elsewhere.  Open top electric trams......... Roll Eyes Tongue Grin
https://www.youtube.com/watch?v=u-vzquULeQ4


When Bristol had trams they were all open top, find a photo anywhere of a closed top tram running in Bristol.
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martyjon
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« Reply #48 on: March 01, 2020, 09:03:08 am »

A Question please,

Can Trams and Trolley buses run along the same routes?

I'd say NO but hope someone can clarify the issue.

I base the Can't share the same routes on this beauty.

Trams use a pantograph to collect power from overhead lines and return the current through the rails just the Overhead powered trains.

Trolley buses have normal tyred road wheels and don't have steel wheels or rails.  Huh Huh

Trolley buses have a contact pole that makes contact with a Twin overhead wire.

More to the point some 50% off road vehicle pollution comes from Tyre particles and brake dust and the particles from Tyres really are UNPLEASANT.

So the future should be TRAMS and not Trolley buses  Wink


Just replace the pantograph with 2 poles, simple.
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ellendune
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« Reply #49 on: March 01, 2020, 01:24:24 pm »

There are two potential problems with hydrogen in current mains. The big high-pressure mains put in for natural gas can't be used as the steel would suffer embrittlement. So that's one one big programme of street digging if it goes ahead, though quite what the replacement pipes would be isn't clear (nor if there is a viable one).

Low pressure and house mains would have more hydrogen leakage through the solid walls than of methane, but still so small no-one would miss it. However, if it accumulates in closed spaces, the greater explosion hazard of hydrogen (lower ignition energy and wider explosive mixture range) does raise serious issues. Again, it's not clear if anything better is available, but the real issue may be that we need bigger pipes (lower volumetric energy capacity and higher total demand for domestic CHP). If trenchless methods can't do that size increase, even with developments, then all our streets get shredded. But it's by no means certain we'll go down that route. 

I had not considered the transmission network, but that is a relatively small part of the network by length. 

You make some good points on the distribution mains though.  I would suggest there would first be an emphasis on energy conservation from a policy point of view as well as cost that might reduce the need for additional capacity.  I expect hydrogen to be more expensive than methane so I doubt whether the economics of CHP would stack up against grid power.   
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« Reply #50 on: March 01, 2020, 02:04:46 pm »

The older members here, myself included, will recall when hydrogen was piped to homes and businesses in large quantities. It took a decade to convert the UK (United Kingdom) to run on natural gas, and the "town gas" produced from coal was still being burned somewhere in 1976. That varied in composition, but was up to 60% hydrogen by volume. (It also contained other goodies like methane and carbon monoxide, the latter making sticking your head in the oven a popular suicide method.) 40 million appliances were converted to run on natural gas. The existing iron pipework didn't leak any more than it used to, but was prone to getting brittle and breaking in bad winters. It was all replaced by polyethylene by the mid-00's. That local network should work fine with hydrogen, although the bigger stuff will need to be changed or lined as ellendunne says. Modern appliances, especially condensing combi boilers, are a lot more sophisticated than their 1970s equivalent, and it may be problematic to change them from methane burning, but as a nation we have changed completely once in my lifetime, so I am sure it can be done again.

I read this article about how EDF proposes to produce hydrogen by electrolysis during quiet times at nuclear plants, something that would rid us of the CO2 produced by the current industrial process of knocking the carbon atoms off methane molecules. That could give us a theoretically limitless supply of hydrogen with none of the dreaded carbon, and just some highly radioactive waste to get rid of. Win some, lose some.
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« Reply #51 on: March 01, 2020, 05:25:10 pm »

When natural gas replaced town gas there was an increase in gas leaks and explosions.
This was not because the new fuel was inherently any more dangerous, but because natural gas was very dry unlike town gas which contained a lot of water vapor.
Many joints in iron or steel gas pipe were made with hemp or similar natural materials, mixed with jointing compound.
Any minute and utterly insignificant leakage kept the jointing material damp.

When dryer natural gas came into use, this initially minute leakage dried out the jointing material and the leak got worse. Sometimes with fatal results.
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A proper intercity train has a minimum of 8 coaches, gangwayed throughout, with first at one end, and a full sized buffet car between first and standard.
It has space for cycles, surfboards,luggage etc.
A 5 car DMU (Diesel Multiple Unit) is not a proper inter-city train. The 5+5 and 9 car DMUs are almost as bad.
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« Reply #52 on: March 01, 2020, 07:07:30 pm »

I read this article about how EDF proposes to produce hydrogen by electrolysis during quiet times at nuclear plants, something that would rid us of the CO2 produced by the current industrial process of knocking the carbon atoms off methane molecules. That could give us a theoretically limitless supply of hydrogen with none of the dreaded carbon, and just some highly radioactive waste to get rid of. Win some, lose some.

Yes it is feasible, it is whether the economics stack up.  Electricity is currently about 5 or 6 times more expensive per KWh than natural gas (to the consumer).  Assuming some loss of efficiency in converting that energy to hydrogen, then I would expect hydrogen to me significantly more expensive that natural gas. 
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TonyK
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« Reply #53 on: March 01, 2020, 08:15:58 pm »

Yes it is feasible, it is whether the economics stack up.  Electricity is currently about 5 or 6 times more expensive per KWh than natural gas (to the consumer).  Assuming some loss of efficiency in converting that energy to hydrogen, then I would expect hydrogen to me significantly more expensive that natural gas. 

This is where things will get tasty. My smart meter tells me that on my new tariff (started on the anniversary of the previous one) energy by gas costs me 2.56p per kWh. Electricity is 14.752 p/kWh, and the daily standing charge is higher too. I have an induction hob rather than gas, but heating and hot water come via the cheaper method. I should think running a bus by electricity will not be a free fuel option, but neither will hydrogen.

Which serves to remind me to send in a reading for the solar panel I forget all about.
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mjones
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« Reply #54 on: March 01, 2020, 09:03:52 pm »

This report from the Committee on Climate Change  has a lot of useful information about hydrogen in transport. But they do highlight the problems with the efficiency of production. 

https://www.theccc.org.uk/publication/hydrogen-in-a-low-carbon-economy/

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« Reply #55 on: March 01, 2020, 09:32:37 pm »

This is where things will get tasty. My smart meter tells me that on my new tariff (started on the anniversary of the previous one) energy by gas costs me 2.56p per kWh. Electricity is 14.752 p/kWh, and the daily standing charge is higher too.

Various sources suggest that a gas fired power station is around 60% efficient - so if I buy 2 x kWh of gas at a cost of 5.12p, I should be able to generate electricity I can sell for 14.752p?   Hardly green, but sounds like a nice little money earner.  Can it be scaled down for domestic use??
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TonyK
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« Reply #56 on: March 02, 2020, 12:37:50 am »


Various sources suggest that a gas fired power station is around 60% efficient - so if I buy 2 x kWh of gas at a cost of 5.12p, I should be able to generate electricity I can sell for 14.752p?   Hardly green, but sounds like a nice little money earner.  Can it be scaled down for domestic use??

In a nutshell, that's the business model behind the CCGT (Combined Cycle Gas Turbine) industry. Electricity generated by gas causes a loss of energy, but adds value by making it available where it is needed. A factor of six seems a big markup, but there is much that couldn't be driven directly by gas.

I don't think the power companies make more from electricity than gas per kWh delivered, as they buy both wholesale and sell it on. Jeremiah Colman reckoned that he made his fortune from the mustard that was left on the plate rather than from what was eaten. The modern parallel is the money made from people who don't change tariff or supplier and pay the standard rate, be it for gas or electric.
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ellendune
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« Reply #57 on: March 02, 2020, 08:27:41 am »


Various sources suggest that a gas fired power station is around 60% efficient - so if I buy 2 x kWh of gas at a cost of 5.12p, I should be able to generate electricity I can sell for 14.752p?   Hardly green, but sounds like a nice little money earner.  Can it be scaled down for domestic use??

In a nutshell, that's the business model behind the CCGT (Combined Cycle Gas Turbine) industry. Electricity generated by gas causes a loss of energy, but adds value by making it available where it is needed. A factor of six seems a big markup, but there is much that couldn't be driven directly by gas.

I don't think the power companies make more from electricity than gas per kWh delivered, as they buy both wholesale and sell it on. Jeremiah Colman reckoned that he made his fortune from the mustard that was left on the plate rather than from what was eaten. The modern parallel is the money made from people who don't change tariff or supplier and pay the standard rate, be it for gas or electric.

A manufacturer of hydrogen would also have to include costs of the gas transmission and distribution as well as paying off the capital costs of the manufacturing plant. 
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TonyK
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« Reply #58 on: March 02, 2020, 01:03:29 pm »

There are many possible solutions to the transport side of things, the trolleybus one of them. Her Majesty's adoring government has to take more of a lead than it does at present, though, because the current way of doing things is wasteful. Bristol, Leeds and others spent years of time and shed loads of money bidding for a share of a finite pot of cash against others, and knowing that someone wasn't going to get what they wanted, and ended up with ponced-up buses that have hardly been run in before the government announced that it wants to have all electric buses. Buses are further complicated by being privately owned, so not easily replaceable without big private investment as well as infrastructure paid for by public funds that is sufficiently attractive to the private sector to get the money back from access charges. MetroBust in Bristol has shown that that isn't easy with ordinary buses, as the operators can choose to use different routes.

Throwing £500 million or £1 billion in a pot and inviting every transport authority in the land to bid for a share is slow and wasteful. Better for the government to start the process properly by saying "We like what we see in Manchester / Nottingham / Mulhouse / Shanghai. We think trams would work for medium to large citieswith potential routes, while trolleybus may fit large towns better. We have a preferred specification to take advantage of economies of scale - who wants to be first?" Finance could be on the HS2 (The next High Speed line(s)) model (or Manchester Metrolink for that matter) - government brokers the loan at preferred rates, agrees how much the local authority has to pay back over how long, then the system gets built and any profit can be used to expand. Every system is future proofed - bus-only and trolleybus routes built so they can be converted to rail, all tram lines ready for tram-train etc - Simples. Probably not as simples as I make it out to be.
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broadgage
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« Reply #59 on: March 02, 2020, 01:30:25 pm »

This is where things will get tasty. My smart meter tells me that on my new tariff (started on the anniversary of the previous one) energy by gas costs me 2.56p per kWh. Electricity is 14.752 p/kWh, and the daily standing charge is higher too.

Various sources suggest that a gas fired power station is around 60% efficient - so if I buy 2 x kWh of gas at a cost of 5.12p, I should be able to generate electricity I can sell for 14.752p?   Hardly green, but sounds like a nice little money earner.  Can it be scaled down for domestic use??

Very few, if indeed any gas fired power stations achieve 60% efficiency, 50% is very good, and 40% more likely under real world conditions of part load operation and allowing for start up losses when not continually required.
Domestic sized generators that burn natural gas are available, but are significantly less efficient than large power stations.
It is most unlikely that the electricity supply industry would buy your power at full retail price.

The idea is only worthwhile if there is a significant demand for heat, that can be supplied almost for free from the engine cooling system.
Hospitals, hotels, and industrial laundries use a vast amount of hot water, and some DO generate electricity from natural gas, or from oil. The process is known as CHP or combined heat and power, and is only worthwhile if there is a large and paying demand for the heat.
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A proper intercity train has a minimum of 8 coaches, gangwayed throughout, with first at one end, and a full sized buffet car between first and standard.
It has space for cycles, surfboards,luggage etc.
A 5 car DMU (Diesel Multiple Unit) is not a proper inter-city train. The 5+5 and 9 car DMUs are almost as bad.
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