Public transport

Calliban · 2023-06-12 10:29:26

We do not appear to have a dedicated thread to public transport. I am starting this thread to provide a central location for rail, tram, bus topics.

Calliban · 2023-06-12 10:44:44

Topic No.1: Half bus, half tram vehicle. Tramlines and overhead electrification are a proven success in cities around the world. However, their relatively high installation cost makes them suitable only in areas with high population density, which excludes most of the US. Buses and coaches are common in the US and require little additional infrastructure investment, as they make use of the existing road. Unfortunately, bus wheels on asphalt, have 10x the rolling resistance of steel wheels on steel rails.
https://www.engineeringtoolbox.com/roll … _1303.html

My proposal is for a hybrid solution. This would involve a single steel slotted rail installed down the middle of a road lane, sunk into the road surface like a conventional tram rail. The bus running down the lane would be equipped with rubber tyres like a conventional bus. However, it would also have steel drive wheels running down the centre of the chassis. When the bus enters a lane equipped with a steel rail, hydraulics will push the steel wheels down into the slotted rail. The steel wheels will be pushed down until they support about 80% of the weight of the bus. The rubber wheeled tyres remain in contact with the road, providing stability. With steel wheels on steel rails having 1/10th of the rolling reistance of rubber tyres, the rolling resistance of the bus (and fuel consumption) can be reduced by something like 2/3rds. The bus can leave a railed section of the road, by releasing the hydraulic actuation, upon which the steel wheels are retracted on a spring.

The reduced energy consumption of a half tram, half bus, makes it easier to consider alternative methods of propulsion. The gyrobus is powered by a flywheel, which is recharged when the bus stops.
https://en.m.wikipedia.org/wiki/Gyrobus

Unfortunately, the high weight of alloy steel flywheels tended to limit range and resulted in relatively high electricity consumption. If most of the weight of the bus is supported on the steel rail, these problems can be greatly reduced. According to wiki:

'Fully charged, a gyrobus could typically travel as far as 6 km (3.7 mi) on a level route at speeds of up to 50 to 60 km/h (31 to 37 mph), depending on the total weight of passengers, as top speeds varied as passenger levels varied from stop to stop.'

By reducing effective friction by 2/3rds, we extend range between stops by a factor of 3. This makes the gyrobus a far more practical proposition for extending into places where stops may be several miles apart.

Last edited by Calliban (2023-06-12 10:59:28)

Calliban · 2023-06-12 11:50:31

Comparative energy consumption - trams and buses.
https://bathtrams.uk/the-most-energy-ef … transport/

The tram only makes a lot of sense if there are comparatively large distances between stops. This is because most or all braking energy is wasted.

Although they have relatively poor energy density (4-10KJ/kg), hydraulic accumulators are much cheaper than flywheels and hydrauluc systems are easy to engineer.
https://www.sciencedirect.com/science/a … 4218306443

Hydraulic hybrid vehicles have by far the best performance in braking energy recovery, recovering up to 80% of kinetic energy, and using it to accelerate the vehicle. A tram carrying 48 passengers, has a gross weight of 15 tonnes. To travel 5km, with 5 stops at 1km intervals, the tram will consume 2.8kWh. However, 80% of the energy consumption is used to accelerate the vehicle. If we can recover tram braking energy with 80% efficiency in a hydraulic accumulator, then energy consumption is reduced by 2/3. That reduces energy consumption to 0.93kWh per 5km, or 0.187kWh/km. If we assume a train powered by hydraulic accumulators that are reacharged when the tram stops, how heavy would the accumulator have to be to power the tram for 5km? Answer = 837kg, assuming an accumulator mass energy density of 4KJ/kg. That is 5.2% of the gross weight of the tram. Definitely achievable.

From the link, we can see that an electric bus is almost as energy efficient per passenger km as the tram. So hydraulic accumulators could power buses as well. However, the substantially greater rolling resistance of buses means that range between stops will be much shorter. Our tram might get a range of 10km before it needs to recharge its hydraulic cylinder. The bus would need to recharge after just 2km under the same assumptions. So realistically, every bus stop would need to be equipped for electric recharging.

Last edited by Calliban (2023-06-12 11:54:59)

tahanson43206 · 2023-06-12 11:57:07

For Calliban re new topic ...

Best wishes for success with this interesting new topic.

It has plenty of upside potential.

Your opening post (#1) can set the parameters you might have in mind for contributions to the topic.

It's not clear to me that your vision for this topic allows for the inevitable change to individualized "public" transportation as AI supported systems become more available. Eventually, if I am interpreting trends correctly, the ancient concept of a group of people climbing onto a multi-person conveyance will disappear.

The success of the Uber model seems (to me at least) to show very clearly where we (humans) are headed, and the offerings of electric scooters in large cities seem to show a related development.

I would be surprised if there are any wheeled buses left in operation anywhere on Earth in 50 years, except as tourist attractions. The only remaining steam trains are supported by tourist excursions. Quite likely a ride on a "bus" will seem like a lark to our descendants.

I asked Google to check India, and it appears to confirm steam locomotives are now limited to special situations:

Steam locomotives were introduced into India by the British and phased out by the early 1990s. However, Indian Railways apparently still has more than 250 of them, many of which are over 100 years old. A handful of steam engines pull toy trains on India’s mountain railways and other heritage trains such as the Steam Express1

(th)

Calliban · 2023-06-12 12:44:56

Steam engines became obsolete because of their low efficiency and low specific power (i.e heavy) compared to alternatives. Non-condensing steam engines had efficiency 1-10%, which increased to 10-20% when a condenser was added. Unfortunately, a condenser adds weight to an already heavy machine. The problem of weight is compounded if the engine is used to pull a suburban passenger train which must make frequent stops. All of the kinetic energy that the heavy train is carring is wasted when it stops. A diesel engine doing the same job will be 40% efficient and will be much lighter. Steam engines went out because of their poor systematic energy efficiency. Transatlantic passenger ships were replaced by jets for much the same reason. Steam held out for a while in places that had lots of domestic coal, but had to import oil. Post-WW2 Britain most notably. Also India.

Whilst it is difficult to predict the future, the low frontal area and low mass per passenger of collective transport, means that it will always beat cars (or uber taxis) on an energy efficiency basis, provided that you can fill most of the seats. American cities are so spread out over such stupidly huge areas, that private transport is really the only chouce for a lot of people living there. But the rest of the world didn't embrace suburban sprawl to the same extent. So you may find that 50 years from now, the American solution is different to what the rest of the world is using. We should also consider that the way people travel is dependant on other circumstances. If I get to a strange city and want to get to my hotel, I call a taxi, as much because they can take me exactly where I need to go. But if I am travelling to work on a daily commute in a place I know well, it would never be cost optimum to get a taxi. Taxis are only applucable for short journeys.

Last edited by Calliban (2023-06-12 12:54:02)

Terraformer · 2023-06-12 13:15:14

My proposal is for a hybrid solution. This would involve a single steel slotted rail installed down the middle of a road lane, sunk into the road surface like a conventional tram rail.

Baked.
https://en.wikipedia.org/wiki/Caillet_monorail
https://en.wikipedia.org/wiki/Ewing_System
https://en.wikipedia.org/wiki/Addis%27s … il_Tramway

Should be a lot easier to install, since you're not having to keep two rails aligned with each other, and far less road needs to be dug up. Should be a lot cheaper off road on dedicated tracks as well..?

I still really like the elevated systems. Construction costs are ~$100 million/km for current suspension railways, but so few have been built there's not exactly an industry to support them. Roller coasters, where there is such an industry, seem to top out at $20 million/km, so I expect there's quite a bit of room to reduce costs there. Easy to automate, on a dedicated right of way so you don't have to worry about other traffic, has quite a low land take and can run in existing corridors above canals and roads.

A suspension railway over the M62, if it achieved the speeds of the fastest suspension coasters (88 kmph), would be able to travel between Liverpool and Manchester city centres in under 40 minutes... comparable to the fastest services, which are theoretical at the moment because they keep getting cancelled. But with less energy use, and with automatic operation since there shouldn't be anything unexpected on the track.

tahanson43206 · 2023-06-12 13:21:45

For Calliban re topic ....

If you will permit a stretch of the concept of "public" .... Last night I caught an interview on CSPAN that seems applicable to to the US situation, to which you refer.

Paved Paradise: How Parking Explains the World Hardcover – May 9, 2023
by Henry Grabar (Author)
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“Consistently entertaining and often downright funny.”—The New Yorker
“Wry and revelatory.” —The New York Times

The author assembled great quantities of information about the impact of parking policy on American communities.

In particular, the requirement that new construction must have parking for all residents plus guests, or shoppers in the case of malls, has led to the diminution of central cities. The author gave numerous examples which I can support from personal experience, of cities being hollowed out to provide parking space.

The American compulsion for independence has resulted in a landscape with plenty of blemishes.

The Europeans appear to have successfully resisted the encroachment of the automobile.

I saw a picture recently of a huge underwater parking garage in the Netherlands, for thousands of bicycles.

That is an image that is unimaginable in America.

I think your vision of public transportation on Mars makes a lot of sense, because the planet will always be short of energy compared to Earth.

(th)

Calliban · 2023-06-12 13:46:17

Elevated systems have the advantage of being easily grade seperated because they go over everything. On Mars and the moon, there will be no roads unless we build them. Driving over unprepared dirt will be very punishing to vehicles, because fine dust will contaminate bearings and mechanical interfaces causing heavy wear. We could build gravel roads. But cable cars that don't have to interact with the surface at all sound like a better option. On Mars, these could run on direct electricity (without storage) from solar panels. Basically, direct drive DC motors.

We have discussed direct drive ropeways for hauling freight on this board as well. These are really very simple technologies. Everything except the cable can be carbon steel. The cable needs to be stainless steel to avoid brittle failure issues on Mars. The Martian atmosphere, thin as it is, has enough pressure to prevent oil based greases from evaporating. Not sure what we could use on the moon.

On Earth, we could combine the Ewing system with conventional diesel buses and reduce fuel consumption by 2/3. Heavy trucks could use this system as well to cut fuel usage dramatically. This would seem to be one of those technologies that never got adopted on a large scale because not enough people knew about it.

Last edited by Calliban (2023-06-12 13:53:53)

Terraformer · 2023-06-12 15:34:51

The worst part of the Beeching Axe wasn't closing the lines, it was lifting the tracks and scrapping the right of way. That went beyond saving money, it was deliberate destruction to ensure the cuts couldn't be reversed later.

There's someone out in I think Ireland who builds garden monorails to move things around -- How To Make Your Own Garden Monorail

For connecting rural communities together (and to towns that have railway stations), the single rail system might be a good fit. Not dealing with scarce land, not aiming for particularly high speeds. A very light railway system for passengers could reverse a lot of the branch line cuts, especially if the original alignment is still available for use. For metro areas we can use the more expensive elevated systems. And of course the current network would still exist, with a lot of slow trains taken off it since it's not being used as a makeshift metro or to provide stopping services to villages anymore, allowing faster trains between towns and cities.

Calliban · 2023-06-12 15:48:31

tahanson43206 wrote:

The author assembled great quantities of information about the impact of parking policy on American communities.
In particular, the requirement that new construction must have parking for all residents plus guests, or shoppers in the case of malls, has led to the diminution of central cities. The author gave numerous examples which I can support from personal experience, of cities being hollowed out to provide parking space.
The American compulsion for independence has resulted in a landscape with plenty of blemishes.
The Europeans appear to have successfully resisted the encroachment of the automobile.
I saw a picture recently of a huge underwater parking garage in the Netherlands, for thousands of bicycles.
That is an image that is unimaginable in America.
I think your vision of public transportation on Mars makes a lot of sense, because the planet will always be short of energy compared to Earth.
(th)

I think the US needs a 100 year project to rebuild its urban spaces. This man has the right idea.
https://carfree.com/

Although Europe certainly has its grotty bits, we never had enough space to fully embrace urban sprawl in the way that Americans did. Europe never had the sort of energy security that US oil resources allowed. The Americans had it all and they let it happen. Unfortunately, the mass motoring revolution turned out to be a road to nowhere. It turned cities into horrible places. It gave people unprecedented mobility, but it ruined all the places that they might want to go. I can certainly see where the anti-car lobby are coming from. Cars are pretty awful things. I find it hard to object to policies designed to reduce the number of them.

Terraformer · 2023-06-13 05:38:29

Another option to support ground level monorails is a support beam above the track -- https://en.wikipedia.org/wiki/Boynton_Bicycle_Railroad Requires installing posts of course.

I don't know how fast it could reach, but a cyclist on the Hotchkiss Bicycle Railroad managed 24mph, so if they didn't derail at that speed... I certainly expect it to be able to match buses. Might be more stable at higher speeds than the Ewing system?

With rubber tyres on the top beam, an appropriately designed system might be able to vary the friction and use it to handle far steeper gradients than typical railways can handle, both using it to brake and using it to haul the carriages up a slope.

Noteworthy that travel times in Britain are longer than they should be even assuming 60-80mph travel. Travelling at 80mph as the crow flies gets you Birmingham to London in 75 minutes. Best trains today will get you there in 90. It's even worse for the 75 mile journey from Manchester to Birmingham. If we had a direct route and travelled at highway speeds we could cut half an hour off the currently 90 minute journey...

Last edited by Terraformer (2023-06-13 06:32:59)

kbd512 · 2023-06-13 12:19:13

tahanson43206,

The following statement...

The Europeans appear to have successfully resisted the encroachment of the automobile.

Is at odds with these statements...

National Car Ownership Statistics at a Glance
A total of 278,063,737 personal and commercial vehicles were registered to drivers in the U.S. in 2021. The number of registered vehicles in the United States increased by 3.66% between 2017 and 2021, indicating an upward trend in car ownership.

In 2021, the number of the EU-registered passenger cars reached 253 million, corresponding to an increase of 8.6 % as compared with 2016. The highest number of registered passenger cars was observed in Germany with almost 49 million cars. Thereafter followed Italy (40 million cars) and France (39 million cars).

You could've disabused yourself of the belief that "Europe has successfully resisted the encroachment of the car" using two quick Google searches:
"number of cars in the us"
"number of cars in europe"

I'd wager there's a very similar number of registered / active-use vehicles in the US and the EU (both personal and commercial motor vehicles), since transport and energy are so closely tied to GDP, thus the US and EU GDP figures are quite similar, and the goods or services that change hands don't arrive by remarkably different methods.

In 2021, US consumed an average of 20.23 million barrels of oil per day, while EU consumed an average of 18.3 million barrels per day. This is in spite of the fact that the US covers about twice as much land area, so driving distances are greater. Over a year, American consumption is much greater, but again, twice as much driving equals twice as much oil consumption.

In 2021, approximately 18.3 million barrels of oil daily were consumed in Europe and the Commonwealth of Independent States. Oil consumption has declined since 2004, dipping below 20 million barrels daily for the first time in 2008.

The only thing that's recently changed, if you'll take careful note, is the lack of supply from Russia. Otherwise, similar numbers of people consume similar amounts of energy, if perhaps in somewhat different ways.

EU has a much more developed public transport support than the US, which only saves 2MBPD, tops, over what the US consumes while driving twice as far, on average. What's the lesson here? Public transport isn't saving much oil, and only at the expense of living standards. It's easy to figure out why they consume less- most of their population is aging out of existence. The elderly aren't driving to work every day.

The EU is not a great model for how we should do things here in America. They import everything instead of making it themselves and they still consume almost as much oil as a country covering twice as much land area. Either way, they still burn almost as much oil for the same or similar economic output. It doesn't matter where or in what application the oil is burned, the emissions don't magically disappear either way.

We can switch our cars to use hot water or hot rock or whatever (pumping and piping 10X the volume of solar and/or nuclear heated fluids), but the entire transportation sector in the US consumed 13.3MBPD. The light duty vehicles powered by oil consume only 42% of that total, so 5.6MBPD is a realistic max reduction if all vehicles in America used something other than petroleum products as their power source. Replacement of light duty vehicles alone is a multi-decadal project, yet still doable if we stop trying to complicate that task with electronics and batteries. If you "go electric", then you'll only end up increasing mining and electricity generation consumption of oil / gas / coal, because none of these vehicles are powered by photovoltaic panels or wind turbines. Again, those emissions still count towards the grand total, they still pollute, and the level and type of environmental destruction will rapidly overtake anything petroleum ever did or could do, because 100X more toxic waste is involved in Lithium / Cobalt / rare Earth metals production.

By all means, let's keep screwing around with electronics and batteries. Hammer your head into that brick wall of energy density / materials scarcity physics as much as you like, but you'll only be brain damaged in the end. 100 years from now, we'll still be using whatever coal / oil / gas is still left, but it won't be to create new electronics and batteries because we'll be too busy trying to keep people alive at that point, assuming no new world wars over energy. If you're like me and you think we need to quit being silly with our beliefs about the applicability of energy density and materials availability and recycling and limits to economic growth, then you start looking for more practical solutions that last much longer, don't require functionally non-recyclable electronics or electro-chemical batteries to function, and are vastly easier to recycle when that time inevitably rolls around. Refraining from completely ruining Earth's natural environment through mining activities before realizing that energy density and materials scarcity apply to the real physical world, is merely a bonus.

We've chased after energy efficiency for the past 5 decades, at least since the 1970s. Emissions keep going up every year by a considerable amount. We need to recognize when absolute efficiency alone isn't getting the job done, but also when one form of efficiency, namely using more and more electrical power, has created massive inefficiencies everywhere else. Playing pointless shell games doesn't solve any problems.

Computer efficiency doesn't equal energy efficiency, except when / where computers are involved. Computers can control energy flows, but otherwise do not produce or conserve enough power to matter much at the scale required. For example, EFI / Electronic Fuel Injection doesn't save much fuel over a properly tuned carbureter connected to a properly sized engine (one that is kept under heavy load most of the time), it merely ensures that the engine's tune / fuel consumption is optimal more of the time. This is easily demonstrated by absolute performance tests, wherein carbureters continue to beat out the best EFI systems our engineers have implemented thus far. EI / Electronic Ignition is another matter entirely, and clearly demonstrates superiority when the spark is consistently precisely timed. This should surprise no one, because carbs do precisely meter fuel, just as fuel injectors do, but the effect of proper ignition timing will either cause an engine to run quite well or die entirely, to say nothing of ultimate longevity in operation. Long story short, absolute precision helps when igniting fuel-air mixtures in piston engines, whereas minor variances in fuel delivery tend to balance each other out and mechanical devices can accurately deliver fuel with accurate signal input (mechanical measurement of volume and pressure). Aircraft engines, which are run at constant high load and perform well from a thermodynamic standpoint even when forced to use ancient fuel and spark delivery technology, likewise see little benefit from EFI, but substantial benefit from EI. Most pilots fine-tune the mixture control by hand to burn as lean as they can without running the engine too hot or losing power from insufficient fuel flow. What we could validly assert is that fully electronic engine controls permit more optimal torque / power delivery over a broader engine rpm range.

At a global scale, we're only consuming more and more energy of all types, year-over-year. As long as we continue to pursue planned obsolescence in its various forms (and electronics are the most energy-intensive and non-recyclable forms of energy usage or storage available), that trend will continue (because no other result is possible), rapidly becoming unsustainable inside of a single generation of this new-ish technology (we won't create the very first generation of replacement electrical / electronic transport and energy storage devices at present production rates). What I've accepted, whether or not anyone else has, is that whatever we're going to use to replace hydrocarbon fuels, is going to have to be very easy to obtain, very easy to recycle (optimally infinitely recyclable), and the raw materials are going to have to be available in very large quantities, at least 10X to 100X what we presently use (hydrocarbon fuels), on account of the sheer volume of materials required to truly replace hydrocarbon fuels at any meaningful scale. Small increases in efficiency won't get the job done.

kbd512 · 2023-06-13 13:09:38

At a global scale, passenger cars account for 8% of total CO2 emissions. Taking all of them away solves very little. Here in the US, CO2 emission from generating electricity already accounts for 31% of our total CO2 emissions. Assuming we could build enough BEVs to matter, which is not possible, then whatever benefit we think we're achieving by transitioning to electric cars is entirely psychological in nature. Our emissions from cars will instead be transferred into the category of all the new / non-existent electrical and electronic stuff we have to build to start using them at scale. It's a fool's errand, plain and simple. There is no solution that allows us to achieve personal transport electrification without also increasing CO2 emissions from electric power generation and storage, which already exceeds transportation CO2 emissions. That's the brutally honest and simple truth of this matter.

Here in the US public transport using buses or light rail means driving a very heavy vehicle around in circles, that's empty most of the time, and somehow theoretically achieving greater efficiency. Trains are definite "maybe it helps", but only in large cities and only when they're full most of the time. In Chicago, unless it's rush hour, the trains are mostly empty- like I was the only one sitting in an entire car for half of my ride from the O'Hare airport to the downtown area during a weekday only an hour or so before everyone was headed home. Europe doesn't show much benefit, and certainly not the massive benefit we'd need to achieve to do anything more than find another way to spend money (energy, ultimately) that doesn't exist.

SpaceNut · 2023-06-13 20:29:26

Commonly noticed for cities and vehicles is that downtown population density and street widths as well as parking are major issues for why cities die. Of course, the high density also has a higher risk to the individual traveling afoot.
One thing to note is that if the health of a person requires 2.5 hours of exercise a day and you make use of a manual means to create that transportation by your own power means a limitation of one-way distance to just half of that value at max speed of under 30 mph. The average bicycle is just 10 miles using human power while it does go up with pedal assist and even higher with throttle battery speeds.

Calliban · 2023-06-14 07:34:39

Kbd512, I am talking about cities, not nations as a whole. Two very different things. If you look at global data, Singapore and Hong Kong stand out as having very low car ownership per capita despite being prosperous nations.
https://en.wikipedia.org/wiki/List_of_c … per_capita

That is because they are city-states. If you live, work and travel within them, you really don't have much need for a car. The same is true for London and most other big European cities with mass transit systems. In cities like Brussels, Venice, Amsterdam, Bruges, Ghent, you can pretty much travel anywhere you need to go by tram or on foot. I know, because I lived in Belgium for over a year without any car at all. I got around just fine. That doesn't mean that you never need to use road vehicles at all. Taiwan has about 1/3 of the car ownership of the US, despite being one of the world's wealthiest nations. The reason is that most of the population live in quite dense urban settlements on the western coast. These have good transit links. In most of Europe, car ownership is relatively high. But that reflects choices rather than necessity. Unless you live out in the sticks, you really don't need a car in England in the same way you do in any part of the US. And if you own one, you probably drive it a lot less.

My point is that the US doesn't have to do things in the way it does. There is no need to spread suburbs over areas the size of small countries. This was a design choice that makes it impossible to live without the car, whenever you need anything. I would argue that quality of life in European cities is vastly better than it is in sole-less US suburbs. That is my opinion of course. But the fact is that most Europeans could still enjoy a good quality of life, getting to where they need to go, without cars. At least part of the solution for resource depletion and CO2 emissions could be to build more compact cities with mass transit systems. This is a long term project, but resource depletion is a long term problem.

Last edited by Calliban (2023-06-14 07:52:14)

Terraformer · 2023-06-14 08:21:45

Coventry is developed a "very light rail" system: Coventry Very Light Rail.

Unfortunately details about expected costs are thin on the ground (EDIT: first reference puts it at £10 million per kilometre, 2/3rds of what other countries can build cable car systems for). Whether it will be cheap enough to allow us to start reversing Marple's destruction of rural lines, I do not know. Would help if councils would safeguard future transit corridors in their development plans. Don't let any building in the city centre close it off entirely so that a future rail system has to knock down houses to get through. Preserve enough space through/between new neighbourhoods that at least a single line tram can be put there in the future. In the meantime it can be used for allotments or car parking, so long as it's understood that rail will go there should it become viable.

Last edited by Terraformer (2023-06-14 08:24:58)

Calliban · 2023-06-14 10:28:34

Terraformer wrote:

Another option to support ground level monorails is a support beam above the track -- https://en.wikipedia.org/wiki/Boynton_Bicycle_Railroad Requires installing posts of course.
I don't know how fast it could reach, but a cyclist on the Hotchkiss Bicycle Railroad managed 24mph, so if they didn't derail at that speed... I certainly expect it to be able to match buses. Might be more stable at higher speeds than the Ewing system?
With rubber tyres on the top beam, an appropriately designed system might be able to vary the friction and use it to handle far steeper gradients than typical railways can handle, both using it to brake and using it to haul the carriages up a slope.
Noteworthy that travel times in Britain are longer than they should be even assuming 60-80mph travel. Travelling at 80mph as the crow flies gets you Birmingham to London in 75 minutes. Best trains today will get you there in 90. It's even worse for the 75 mile journey from Manchester to Birmingham. If we had a direct route and travelled at highway speeds we could cut half an hour off the currently 90 minute journey...

If the balancing rail is high enough above the track, it can provide a DC power supply to the tram. A DC monopole power supply could ground through the rail embedded in the road.

In Bordeaux, trams are equipped with third rail ground level power supplies, with individual sections being switched on by an electromagnet on the train. This eliminates electrocution hazard and reduces energy losses. Power is returned through the running rails. With the Ewing system, we could support and power the train using a single embedded rail. The rail would be divided into short positive ahd negative sections. A rectifer would maintain a constant phase DC power supply to the tram. Magnetic switches would activate only the rail sections directly under the tram. This largely eliminates voltage drop along the rail, allowing low voktage DC to be used with minimal power losses.

Last edited by Calliban (2023-06-14 10:29:59)

Terraformer · 2023-06-15 05:49:09

Re. Ewing system speeds:

It reported an average working speed of 8 miles per hour but a trial run over 1½ miles(2.4km) with one car and four artilliary horses gave a speed of nearly 20 miles per hour.

https://wiki.fibis.org/w/Patiala_State_ … _Trainways

So for that particular system, it can compete with a bus on speed. Perhaps two wheels will increase the stability significantly enough to reach 30-40mph and still handle turns? Possibly with flanged precast concrete guides for the rubber tyres to run on, that can be canted on turns to help it across. Not a system that would work with street running, but this country is crisscrossed with rural lines that were lifted so that the Transport Secretary's motorway building company would get more contracts; rebuilding them, and establishing new lines, has a lot of value in itself. Especially if we can parallel the rural stretches of the main railway network and remove a large number of slow stopping services from it so that interceity trains can go at highway speeds (70-80mph).

Calliban · 2023-06-15 06:36:21

Ideally, we want a system that is flexible and will be compatible with existing roads and doesn't have to be grade separated. Dedicated bus lines can then be built incrementally to improve the performance of the system. It would work even better if the buses would also be able to detach from the rail and run on normal roads using their rubber tires. This wouldn't need a separate propulsion system, but would require a duel mode transmission.

We don't strictly need to electrify such a system, as by reducing rolling resistance by 90%, we reduce fuel consumption per mile by at least 80%. The bus can use a diesel engine, small GT burning hydrogen, stored heat engine, electric battery, flywheel or even hydraulic accumulator for power. There are a lot of options.

kbd512 · 2023-06-15 10:52:04

Calliban,

One aspect of vehicles we seldom discuss is that most of the power generated / consumed is used to move the weight of the vehicle, rather than the occupant(s) inside the vehicle. The trolley buses may require less power to overcome rolling resistance, but a large fraction of the power consumed is required to move the rest of the mass of the vehicle. A heavy bus or train does great on passenger density if it's actually filled with passengers, but most of the time it's not anywhere close to capacity.

Out of curiosity, how fast could a human-powered bicycle move if it was operated on rails?

We'd need to have a dedicated "bike lane monorail" for this scheme, but given how much lighter each individual vehicle could be, not to mention the monorail installation, is there enough of an advantage to doing transport this way, that humans could move about in a practical matter at, perhaps 20mph without undue effort, and then complete the rest of their journey on foot?

This is obviously more applicable to a city than suburban sprawl, but if the human is providing the power, then we don't need to figure out what's providing the input energy or how to get it to the point of use, because it's a human plus whatever food they've eaten.

I ask this because my wife and I ride large / fairly heavy "fat tire" off-road bikes around our neighborhood, because it's much faster than walking and that's what we have (I had faster / more road-suitable bicycles in my younger years, but the off-road bikes are more comfortable for us, and of course we can ride them off-road). Crossing a major intersection on a bike in Houston is almost suicidal, though. By the time I hop into a car, adjust the seat / seat belt / mirrors, start up the car, let the engine warm up for a couple of minutes until it settles into low idle, start-stop drive through multiple stop signs and lights to the nearby stores, it actually takes me more time for me to get to the store or gas station than it does to just ride there on a bike. I don't like wasting time, which is why I started using the bike more often to go get all the little things we normally drive to the store for (a gallon of milk or loaf of bread, a pack of smokes, a gallon of gas for my lawn mower). Inside of 3 miles or so in suburbia, my personal experience here in Texas is that a bike beats a car most of the time, due to all the stuff you have to do to use the car (assuming you're not slamming on the throttle and brakes and obeying the traffic laws). The only downside is the summer heat, which is hard to deal with by the end of the day.

I was wondering how fast / low-effort this could be if my bicycle was riding on a monorail and merely had "rims" instead of tires. I might have to carry the bike a short distance near the store, but this isn't much of a problem, especially if I could get closer to the store than the parking lot allows for. Most of the space is giant parking lots.

Terraformer · 2023-06-15 11:03:19

kbd,

To quote myself further up:

I don't know how fast it could reach, but a cyclist on the Hotchkiss Bicycle Railroad managed 24mph, so if they didn't derail at that speed... I certainly expect it to be able to match buses. Might be more stable at higher speeds than the Ewing system?

If you have segregated rights of way and aren't going that fast, your vehicles can be far lighter than current buses and trains, which are designed to give their occupants the chance to survive a 70mph collision with a truck. Cable cars are 150-200kg per seat IIRC? And the energy cost of accelerating to low speeds isn't that great -- accelerating a tonne to 11 m/s (25 mph) costs 17 Whr, most of which you can get back with regenerative braking. Bear in mind enclosed carriages benefit from streamlining.

It shouldn't be too difficult, for someone with the space to work, to build a short stretch of a clip together Ewing system for a bicycle with stabilisers...

Terraformer · 2023-06-15 12:01:46

Calliban,

How about combining a ground monorail with an aeriel ropeway? No good on corners, but if you have a straight alignment the monorail can support the weight whilst the cable keeps it from tipping over and pulls it along.

Calliban · 2023-06-15 15:43:44

Terraformer wrote:

Calliban,
How about combining a ground monorail with an aeriel ropeway? No good on corners, but if you have a straight alignment the monorail can support the weight whilst the cable keeps it from tipping over and pulls it along.

Cable cars have been proven to work. San Francisco still has a working system. In that city, the cable runs within ducts under the road. An arm from the car descends into a slot within the road surface and is attached to the cable under the road. There is no reason an overhead system could not be made to work as well. To avoid the problem of corners, each tram route could follow a loop. If people didn't mind variable speed, we could drive the cable hoist using a directly coupled mechanical wind turbine. But that woukd mean some days when the network ran slowly or not at all.

Last edited by Calliban (2023-06-15 15:45:42)

Terraformer · 2023-06-15 16:14:14

Another advantage of using an upper support rail over stabilising wheels: it makes changing the cant faily easy, including on streets. With two tracks, one has to be raised higher than the other on curves to keep the normal force in the right direction (which you can't do on streets that share traffic with other vehicles). With an upper guide rail, the train can be guided to lean into the curve; you could possibly take this to extremes if the supports are strong enough, and have them lean at 45 degree angles to take tight corners (for trains) at 70mph... or to have a tram be able to make a tight turn in a street without having to slow to a crawl.

I still think Ewing systems have their place, particularly as movable logging railways (I am keen to reduce clearcutting, but to do things differently they need a way to get the logs out), but I'm leaning towards the Boynton system for passenger travel. Seems better suited to tackling curves. And it could be designed to be backwards compatible with suspension railways...

Terraformer · 2023-06-15 16:28:54

A wealth of information on the Boynton Bicycle Railway: http://www.arrts-arrchives.com/LIBRR.html

My new favourite conspiracy theory is that the fire that put the first line out of operation was set by established players who were worried it would succeed.

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