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Electric bus - how to get artics viably electrified

General Transport Discussion not specific to one state

Re: Electric bus - how to get artics viably electrified

Postby Myrtone » Fri Jul 06, 2018 5:59 pm

tonyp wrote:In the latest October issue of their house magazine, DP Kontakt, DPP Prague (the city operator) clarifies further the details and definition of the Prague project. Unfortunately it's a PDF and in Czech, so I can't reproduce the useful diagrams, but they have better-defined the types of electric bus.

There are also equivalent types of electric rail vehicle.

tonyp wrote:At the first level there is the traditional trolleybus that runs 100% on overhead wire. Production of these has diminished in recent years and will eventually cease, if they haven't already.

Analogous to most electric rail vehicles, including most trams.

tonyp wrote:Next there is the partial trolleybus that has batteries and can run 10-30% of its service on batteries and only requires overhead wire for 70-90% of its run. This is now the standard type of trolleybus in recent years.

And this is my preferred option. They draw power from the overhead wires when under them and only run on battery power away from them. Dual straight-electric/battery electric drive also exists on some trams. I favour this for many kinds of road vehicle. I have even fantasised about making electric passenger cars like this, using special high reach trolley-poles.

tonyp wrote:Next there are two types of autonomous electric bus. The first (the type being tested in Prague) DPP now calls a dynamic electric bus because it can charge on the move (supplemented by static recharge at termini and at the depot). This can run 70-80% of its service on batteries and 10-30% on overhead wire. The alternative in-ground induction recharge method would also be considered a dynamic electric bus, but the system is so costly that it's unlikely to be a practical proposition.

The first type is also a "partial trolleybus".

tonyp wrote:Finally, there is the static electric bus that runs entirely on batteries with static (stationary) recharges at termini and/or at the depot. This is the only one of the four types that has a range limitation and the bigger the bus, the greater the range limitation.

This is much like nearly all electric passenger cars, and also to any combustion-engined vehicle as these are only ever refuelled when stationary, usually only at service stations or at depots. But battery electric cars are well suited to city driving, where the range of the battery is (more than) enough for short trips.
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Re: Electric bus - how to get artics viably electrified

Postby tonyp » Wed Oct 03, 2018 9:10 am

Here is an interesting paper on progress of in-motion charging technology which seems to be moving ahead in favour and may ultimately stack up as the technology to replace diesel:

http://www.scienpress.com/Upload/GEO/Vol%206_4_21.pdf
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Re: Electric bus - how to get artics viably electrified

Postby Myrtone » Fri Oct 26, 2018 10:41 am

Some sort of system of collecting electric current while moving (usually overhead power) is nearly always used on tram installations. It is standard on surviving first generation tramway network and is also part of most new tram and light rail installation, and is widely used on heavy rail, especially in an urban setting.
Overhead power is being installed on heavy rail networks even recently, think of the Adelaide electrification, and with trams making a comeback, it is installed on most newbuild systems. Yet there are hardly any new trolleybus wiring networks.
Also, hardly any first generation tramways (with overhead power) have been abandoned recently and none of the surviving ones have been de-electrified, yet a few trolleybus wiring networks have been dismantled.
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Re: Electric bus - how to get artics viably electrified

Postby Myrtone » Wed Nov 07, 2018 3:12 pm

Okay, I wonder, given responses in two other threads I started on trolleybuses, how well most others here understand trolleybuses, so I'll give a more detailed explanation here. First of all, the only fixed infrastructure they need is overhead wires, which should be pretty cheap to install, especially when compared to both rails and overhead wires for electric rail vehicles, and especially where the wires can be supported from buildings.
If the wires are above the centre lane of a three-lane carriageway, trolleybuses in any of the lanes can draw power from that pair of wires, so trolleybuses are more flexible than most others here seem to think, especially if they have auxiliary batteries.
Having said that, I have asked for a comparison of the difference between a trolleybus and a diesel bus with the difference between a diesel train and a straight electric train. But I still haven't got it.

By the way, there have been a few brand new trolleybus power networks this century, one is in Rome where trolleybuses returned in 2005, and they do use battery power on the most visually sensitive part of the route.
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Re: Electric bus - how to get artics viably electrified

Postby Linto63 » Wed Nov 07, 2018 6:13 pm

As explained on this thread, electric buses with batteries that are either self charging or can be replenished at termini, are just around the corner, so there is next to no chance of trolleybuses returning in this country.
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Re: Electric bus - how to get artics viably electrified

Postby Myrtone » Wed Nov 07, 2018 6:35 pm

An anticipation of improvements like that are not good enough, what matters here is the technology that has existed so far. Also, there are a few battery trams that can do the same but that hasn't stopped overhead power being deployed on new tram systems.
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Re: Electric bus - how to get artics viably electrified

Postby tonyp » Wed Nov 07, 2018 6:48 pm

Linto63 wrote:As explained on this thread, electric buses with batteries that are either self charging or can be replenished at termini, are just around the corner, so there is next to no chance of trolleybuses returning in this country.

Not in the traditional form, which is virtually no longer manufactured anyway, but the technology has been adapted into in-motion charging. Many of the new "trolleybuses" nowadays are actually dynamic electric (battery) buses with in-motion charging.
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Re: Electric bus - how to get artics viably electrified

Postby Myrtone » Wed Nov 07, 2018 7:44 pm

They still use external electricity by default, and wherever overhead wires are cheap enough to install per mile, this seems like a reasonable default.
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Re: Electric bus - how to get artics viably electrified

Postby Linto63 » Thu Nov 08, 2018 12:20 pm

Myrtone wrote:An anticipation of improvements like that are not good enough, what matters here is the technology that has existed so far.
Good enough or not, appears there is no appetite for the return of trolleybuses in Australia. Can't recall it even getting a mention in the various long term transport strategy papers that each state has produced.
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Re: Electric bus - how to get artics viably electrified

Postby tonyp » Thu Nov 08, 2018 1:49 pm

The Adelaide O Bahn was built with supports for poles to carry overhead wires for trolleybuses. In any case, as was said when this thread started, it's no longer relevant to talk about trolleybuses in the traditional sense as the technology has changed and morphed. Nowadays we're looking at battery buses and whether they're statically or dynamically charged. Trolley poles are necessary for dynamic charging. You can call them trolleybuses if you like but they're fundamentally battery buses that can charge on the move. They're not the same as buses that rely on running on wires with battery auxiliary.
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Re: Electric bus - how to get artics viably electrified

Postby Passenger 57 » Thu Nov 08, 2018 8:59 pm

Linto63 wrote:Good enough or not, appears there is no appetite for the return of trolleybuses in Australia. Can't recall it even getting a mention in the various long term transport strategy papers that each state has produced.

They're not sexy enough. The word "bus" is a turn-off. It looks like you may have missed those articles about and proposals for "trackless trams" though I'm not sure whether any of them have proposed overhead wiring. A more conventional term for these is guided buses.

As battery and charging technology improves the case for overhead wiring diminishes. Overhead does allow you to use vehicles with smaller batteries and simpler charging electronics (or alternatively extending the life of larger batteries) so may well become economical for certain segments of the networks. However, many of those highly trafficked segments would probably ultimately be more economic with rail so why go through a trolley bus stage?

From what I have seen in this country rarely do the planners crunch the numbers properly and propose a transport design justified by current and future demand. Rather the business cases are loaded with dubious external benefits or inflated demand numbers to achieve a viable cost-benefit ratio for someone's pet project or the project starved of capital.
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Re: Electric bus - how to get artics viably electrified

Postby Myrtone » Sat Nov 10, 2018 6:19 pm

Passenger 57 wrote:As battery and charging technology improves the case for overhead wiring diminishes. Overhead does allow you to use vehicles with smaller batteries and simpler charging electronics (or alternatively extending the life of larger batteries) so may well become economical for certain segments of the networks. However, many of those highly trafficked segments would probably ultimately be more economic with rail so why go through a trolley bus stage?

Overhead wiring will still be economical as long as trolleybus wiring is much cheaper to install per mile than both rails and overhead wires, and it is definitely easier to install, this can be done without resurfacing the road below.
Just remember that an equivalent of dynamic charging does not seem to be possible for internal combustion engined vehicles, which appears to be why they are always refuelled while stationary.
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