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Regarding aeriel tramways and suspension railways, rollercoaster builders achieve far lower costs than transit builders. Galactica and Smiler (Alton Towers) come in at £25 million per km, for systems that travel at 50mph. About a third of what extent suspension railways get. And they do it upside down and with crazy gradients. Makes me more confident that the high price tag for current suspension railways is driven by inexperience, and would fall dramatically if we got serious about building them. Napkin math suggests the main energy consumption of them would actually be deceleration and acceleration, not air resistance, if the stops aren't that far apart. But they wouldn't be going 50pmh through a city. Probably more like 20mph when stops are a mile apart.
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If we are dealing with long vehicles moving at 20-30mph, then air resistance is going to small. You can estimate energy consumption by calculating rolling resistance and applying force x distance formula.
Interestingly, a passenger tram or train may not need an overhead electric power supply, especially if its route has low gradient. It can recharge a flywheel or hydraulic cylinder at it's designated stops. We could install electrified pads on the track where it stops. This should reduce installation costs. These mechanical systems also capture breaking energy very efficiently. When the train stops, an electrically powered centrifugal pump is activated, pumping hydraulic oil out of a saddle tank into the hydraulic cylinder. The train accelerates by opening a valve allowing pressurised hydraullic fluid to drive hydraulic motors along the wheel hubs. When the train brakes, the same motor becomes a pump.
Last edited by Calliban (2023-03-15 06:04:44)
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The late, great David McKay did a good job of assessing the art of the possible when it comes to improving sustainability of transportation.
http://www.withouthotair.com/c20/page_118.shtml
I will repeat some of his data on energy consumption here.
Private transport:
Average UK car (33mpg) = 80kWh/100-km.
Small velobile = 1.3kWh/100-km.
Bike = ~2kWh/100-km
Hydrogen 7 BMW concept car = 254kWh/100-km
G-wiz electric = 21kWh/100-km
Tesla Roadster = 15kWh/100-km
For the first three, energy consumption is either chemical energy, or inmtge case of hydrogen, the energy needed to make the chemical energy.
Public transportation:
An 8- carriage electric train, travelling at 100mph, all seats occupied = 1.6kWh/100 passenger-km
London underground train (all seats occupied) = 4.4kWh/100 passenger-km
Trolley bus (all seats occupied) = 7kWh/100 passenger-km
London bus = 32kWh/100 passenger-km (average occupancy)
Croydon tram link = 9kWh/100 passenger-km (average occupancy)
For Japan, average values 1999 (kWh/100-passenger km):
Car = 68
Bus = 19
Rail = 6
Air = 51
Sea = 57
Full infographic here.
http://www.withouthotair.com/c20/page_128.shtml
Rail appears to be an excellent option, because it achieves low energy consumption per passenger-km, whilst retaining high speed. It is also suitable for direct electrification, which eliminates end use consumption of fossil fuels. Direct electric is in many ways a better option, because the vehicle does not need to carry batteries and recieves power via a sliding contact with an overhead cable or conductor rail. The obvious problem with rail, whether it be tram, underground or mainline, is that it is only suitable for point to point transit. It cannot take you door to door. It is not so good if you need to travel with goods either, which you need to carry onto the train and stow. It is also only practical when passengers travelling point to point reach a critical mass.
Some 580 billion passenger-km were travelled in the UK in 2020, a 33% reduction from 2019.
https://www.gov.uk/government/statistic … itain-2021
Suppose we were able to deliver the 870 billion passenger- km of transport using mixed mode electric rail with average energy consumption 6kWh/100 passenger km? How much electricity would we need? Answer = 52TWh. That is is about 17% of UK annual electricity production. Clearly from an energy standpoint, an expansion in electric rail travel is achievable. If all of the same passenger km were delivered by a single occupancy Tesla Roadster, we would need roughly 3x as much electrical energy - 130TWh per year, or an increase of 43% in electricity production. This would be difficult, but possible from a producer viewpoint. Where it starts to look less achievable is when we examine embodied materials, not just in the cars but in the extra grid infrastructure that would be needed to charge them. Train lines centralise the electricity demand to a degree. We need step down transformers and cabling. Conductor rails can be made from steel. The cabling connecting them will be copper or aluminium. The step down transformers will presumably need copper coils, wrapped around iron cores. The cabling delivering power to the transformers will be aluminium alloy.
Most people in the UK live in or close to densely populated towns or cities. If liquid fuels become scarce, the topography of the country would allow us to get by with some mixture of rail (passenger and freight), buses, bikes and pedestrianisation. That conclusion would be true for most other European countries as well. The US population would have more difficulty I think. They have a lot more energy resources as they live on a lightly populated, resource rich continent. But conversely, they need more energy resources to live comfortably.
Last edited by Calliban (2023-03-15 07:48:23)
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We also had discussion on sky tram, cable car before on Mars I will see if I can find the posts. I think it might have been in one of those
rail system, Martian Gravity machines or space subway elevator transport topics.
I might give the thread a bump the next time I see news on trains or transport.
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How light could a suspension rail carriage be, per passenger? A cursory search tells me a 12 seater minibus weighs 3.5 tonnes, or 300kg a passenger. It's plausible that a carriage could be even lighter than this. Wood is a viable material for much of the structure -- the best WW2 plane was made mostly from it. A lightweight, renewable resource.
As they would be trains, carriages could be attached and removed according to expected demand, to avoid hauling around empty weight. This is a big part of why buses perform so poorly on an energy basis; most of their energy is used in accelerating due to the stop start nature of their trips, and if you run a double decker on a route that could be served by a minibus you're massively increasing the consumption here. Perhaps 500kg of mass per passenger, including the passenger, could be achieved on average? If the train accelerates to 15m/s (~30mph) every 1.5km (further distances than for buses, but not unusual for suburban transit), the energy per passenger-km will be 0.5*500*15^2/1.5 = 250*150 = 37.5kJ. Or a smidgen over 10Wh. Electric regen braking could recover maybe half this, hydraulics 70%. So the actual stop start cost might be 3-5Wh/passenger-km...
Perhaps for short trips at least a flywheel would be the best power option.
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Terraformer, I don't know enough about rail car construction or safety regulations to comment on realistic deadweights. I know that a typical UK passenger rail carriage weighs about 100 tonnes. If you divide that weight by the number of seats, you can work out weight per passenger. After some high profile accidents, safety regs were introduced concerning chassis performance in crashes. Carriage cladding is typically aluminium. Aluminium could replace steel for the chassis as well, but that would impose changes to inservice inspection, as aluminium is more vulnerable to fatigue cracking. There are stronger alloy steels that could be used to reduce weight at some extra cost. In the SE England, this would be very desirable, because the third rail network is generally overloaded. Regenerative braking for trains using flywheels or hydraulic accumulators is desirable even on electrified networks. Trains draw the highest loads during acceleration. If using third rail at 750V, the train can draw a maximum of 3MW from the track.
If we take your value of 500kg per passenger. Wiki estimates rolling resistance for tram wheels on rails to be 0.005.
https://en.m.wikipedia.org/wiki/Rolling_resistance
To move 500kg along a level track, therefore requires a minimum of 24.5N propulsive force. That equates to 24.5KJ/passenger-km, or just under 7Wh. In addition to the 10Wh you calculated for acceleration, that comes to about 17Wh per passenger km. Electrical distribution losses are about 10% using HV catenaries or 20% for a third rail. So real energy cost will be around 20Wh/passenger-km, or 2kWh per 100 passenger km. This matches quite well the energy consumption values calculated by Dr McKay.
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Edit: According to this forum, about 80 people per carriage, which would put weight at 1200kg per passenger.
https://www.railforums.co.uk/threads/ho … ge.145876/
Adjusting the figures above woukdbput energy consumption at 4.8kWh/100p-km, or 2.0kWh/100p-km if there are long distances between stops.
Flywheel powered buses have been built and used in the past.
Last edited by Calliban (2023-03-16 04:22:22)
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Calliban,
I'm talking about suspension railways here. It's unlikely that there will be a cow lying on the track, or a truck broken down on a level crossing. Not necessarily travelling at high speed. The carriages should be a lot more like cable car cabins, which mass about 100kg per passenger. 150kg per passenger in Japan.
I think passenger rail gets something like 80-100 a carriage, so a lot heavier. There's a great advantage to elevating it if so. Alongside the other advantage of making it easier to automate. I want cheap transport.
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Two similar but slightly different concepts:
https://en.m.wikipedia.org/wiki/Aerial_tramway
https://en.m.wikipedia.org/wiki/Suspension_railway
Both look promissing. The aerial tramway has two additional advantages over a conventional railway. It is much cheaper to build and because it is elevated, it is easier to install over existing towns. No need to tear up streets or dig tunnels. This is something that could work in a lot of places.
Terraformer, at 100kg per passenger, energy consumption should be less than 1kWh/100-pkm. That beats just about any other mode of transportation. We would need towers and lifts to get up and down. Lifts could be hydraulically powered with energy recovery.
Last edited by Calliban (2023-03-16 04:44:52)
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Tbf I think the $100+ million per kilometre cost of existing suspension railways is strongly driven by the fact there's only three of them. As I said before, roller coaster construction costs are far lower ad requir much the same engineering, if a bit more extreme. I don't see any reason why Galactica, which is suspended and goes upside down on massive gradients, would necessarily be far cheaper to build than a similar system that is only a level route and has an enclosed cabin and doesn't go upside down. A mature system, especially with prefabricated parts rather than custom, should get the costs down dramatically.
Pedestrian Observations post on Suspended Railways.
Big advantage in turning radius, since the carriages can swing outwards to maintain gravity in the right direction (towards the floor). Particularly important when you're constrained for space to turn. Intrurban systems are less constrained here of course, but still have the advantage they could be placed over motorways. Suspension railways >> aeriel tramways when it comes to capacity.
Whilst it's definitely possible to go high speed on them (there are rollercoasters that do), I don't think any have been built yet. Perhaps best to move commuting to the skies and free the existing railway lines for the fast trains.
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Even at current costs (~£80 million per km), connecting up England's second city, the Lancashire Conurbation (Liverpool-Manchester), with suspension rail would cost approximately £20 billion to get similar connectivity to the London Underground. That's the same amount that was spent on Crossrail; if it's considered worthwhile to spend that much on London, I'm sure it's worth it for the next largest city in the country.
Doing so would be by far the biggest suspension rail project to date. Hopefully the costs would come down significantly as it progressed, given the experience and dedicated production. With commuting taken off the railway lines they could be upgraded to deliver faster rail across the north.
Providing such networks in all our major conurbations, making them equal to London where transit is concerned, would cost us one HS2 Phase 1. I suspect the benefit would be far greater than HS2 will deliver if it gets done.
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Terraformer, presumably £20bn to connect Manchester to London? If it costs that much to connect Manchester to Liverpool, then we are being ripped off. The Crossrail project was absurdly expensive, but it did involve a lot of tunnelling in a place riddled with underground services.
Overhead tramways are only worth developing if they are relatively cheap for passenger transport compared to existing rail. If that turns out to be the case, then we have the option of installing them practically everywhere and gradually turning our rail network over to freight. If that can be done, then routine transportation in Britain could end up becoming fossil-free. I find the idea of transportation without using oil products almost too good to be true. But for all of human history until a century ago, this was reality everywhere. Britain's rail network was coal powered. Now, we have a realistic shot at building a prosperous economy that does not require combustion!
Last edited by Calliban (2023-03-16 15:08:13)
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Calliban,
I'm not talking about connecting Liverpool to Manchester, but connecting Liverpool, Warrington, Bolton, Ellesmere Port, Wigan etcetera etcetera together. The London Underground is 402km long; I think the Lancashire Metropolis could be similarly connected together for about 250km of track. At the price per km of existing suspension railways, that's about £20 billion.
But as I said, roller coaster construction costs, and aerial tramways, suggest to me that's far higher than what we *could* build them for. Given that the latter can be done for £20m a km bidirectional, and the former can get costs as low as £3m a km unidirectional... that should give us an idea of how much the actual engineering might cost. The issue current systems have is they're uncommon. I don't think there are any off the shelf parts available for this. What might costs come down to if we focused on mass production, the way steel rails are made? 1/2th, 1/3rd current cost?
Liverpool and Manchester having the first interurban suspension railway would certainly rhyme with their history. Who knows, maybe if their mayors got started now and worked with Peel Group (Ship Canal owners; they have right of way going right from the centre of one to the centre of the other) it could open on the 15th of September 2030, marking the bicentenary of the Liverpool and Manchester Railway.
As for London to Manchester, we should have asked Ferrari World who they contracted to build the Formula Rosso. 150mph elevated rail for 25 million a kilometre. Could do four tracks for a fraction the cost of HS2. Roller coaster engineers should move into the transit business.
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A total project cost of £20bn, would amount about £3000/capita across the Lancashire, Mersey and Greater Manchester areas. So the investment would not be excessive if it results in even a small increase in national GDP.
From my investigations into renewable energy, I have come to realise the wisdom of building things to last. We can make lofty claims about recycling, but the bottom line is that dismantling something and recycling it is unnecesarily energy intensive. It involves more labour than is neccesary. More transportation than neccesary. And steel must be be heated to melting point and cast into new components. Far better simply to make something that doesn't wear out. Like those 17th century Dutch windmills and Victorian railway bridges. It would make sense to apply some Victorian engineering to a project like an aerial tramway. Brick or stone towers that absorb forces compressively, cast iron pylon arms that resist wear, fatigue and corrosion, hydraulic lifts with components that don't wear out. Our fossil fuel supplies are gradually diminishing. When we build, we should be building to last forever, or at least as long as reasonably practicable. The cables, motors and bearings will require periodic replacement. There is no avoiding that because they are moving parts. But the towers and support pylons can be built in a way that allows extreme longevity.
This should become a cultural movement across the western world, I think. When your energy budget is gradually shrinking, it makes more sense to build for permanance and long-term reusability. It should apply to everything we use. Instead of putting food into tins and packets, we should be putting it in standardised glass jars that get reused over and over again. We should be building vehicles that last 100 years, with modular components that can be replaced when wear or corrosion makes them unusable. Our appliances should be built in the same way. They should be designed for long life and repairability. Our buildings should be compressive masonry structures designed to last for centuries and designed to be beautiful, as befits permanent structures. For anyone that cares about environmentalism, such a movement is far more practical and productive than the increasingly vacuous and perverse Green Movement. I propose the 'Permanence Movement'. For the purpose of forward discussion, an 'item' is the word I will use to describe any tool, appliance, machine, vehicle or structure, that has utility to human beings.
How do we make 'items' that last forever? By forever, I essentially mean a timeframe that is long compared to an average human lifetime. This could be anywhere between 100 and 1000 years, depending upon the nature of the item. We need to think about the sort of assaults that an item will face over its lifetime. By this I mean repeated stresses (bending, shearing and compressive); accidental damage due to drops, impacts, heating, etc. Abrasion for parts that come into contact. Weathering - hot and cold cycles, exposure to damp, the wind, acidic rain, etc. We need to make items that either resist all of these things for the duration of their lives, or have components that can easily be replaced and swapped out without too much energy and labour cost.
We see some examples of the Permanance Thinking already in society, although increasingly modern society has turnedaway from it. But in the nuclear sector, light water reactors are being designed to last 80 years, thanks to good water chemistry control, new oxidation and radiation resistant alloys and control of thermal stresses. This is happening because nuclear powerplant are expensive to build and decommission, but cheap to operate. It would make sense building a plant that operates for a century or more if we can.
Last edited by Calliban (2023-03-17 04:49:07)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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more bad designs in Turkish regions?
One person killed, seven injured, 184 stranded midair after cable car pylon collapses in Turkey
https://www.theguardian.com/world/2024/ … -in-turkey
buildings that collapse during quakes and transport that fails on a spree installing these cheaper things...however 'Earthquakes' on Mars are not expected to be as powerful as Earth
another Turkish event, the Pamukova train derailment a fatal railway accident which occurred at Pamukova district of Sakarya Province in northwestern Turkey when a higher speed train derailed, at which 41 passengers were killed and 80 injured.
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For transportation of freight over medium distances, ropeways could be one of the most promissing options on Mars.
https://solar.lowtechmagazine.com/2011/ … a-bargain/
In situations where we need to transport materials from mines 10's of km to a base, ropeways would be cheaper to establish than railways. In some situations it is practical to power ropeways entirely be gravity. Where driving power is neccesary, PV panels can be directly coupled to DC motors, driving the ropeway at about human walking speed.
These systems consist of cables running over pulleys mounted on poles. There are no complex parts involved and it should be possible to make everything insitu. The poles can be be made from cast iron. The cables can be made from manganese steel. The pulleys can also be made from manganese steel. The buckets from low alloy steel. All things we can make on Mars as soon as we establish a limited steel making capability. On advantage that Mars does have over Earth is that corrosion is unlikely to be a problem in the thin, oxygen depleted Martian atmosphere. On Earth, stainless steel would be needed for cables and other steel components must be drip galvanised. None of that would appear to be neccesary on Mars.
Last edited by Calliban (2024-04-15 03:01:50)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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