The International Simutrans Forum

Development => Extension Requests => Topic started by: meme on April 02, 2011, 08:32:55 AM

Title: Electric + diesel locomotives without electricity
Post by: meme on April 02, 2011, 08:32:55 AM
Hello, I don't know how is it in other countries, but in Czech republic, we often use trolleybuses with a diesel backup engine , which can ride some distance without electricity .. Is it used for example for using trolleybuses in  section where aren't trolleys (one or two stops...) .. In simutrans it might be possible only with articulated trolleybuses (one part on diesel , one part on electricity, but it is not possible because of electricity is  preferred ...

hope do you understand ,

meme
Title: Re: Prefering diesel instead of electricity
Post by: jamespetts on April 02, 2011, 10:51:53 AM
Ahh, you are interested in vehicles which run on electricity when an electricity supply is available, but otherwise use a diesel engine, such as the BR Class 73 (http://en.wikipedia.org/wiki/British_Rail_Class_73) locomotive? Presumably, you would want to define a different running cost and amount of power for vehicle when running on diesel and electric, respectively?
Title: Re: Prefering diesel instead of electricity
Post by: The Hood on April 02, 2011, 12:16:43 PM
That's what it sounds like - It'd be nice if it could be implemented as a number of real-life situations exist with this in Britain, although I doubt it would be easy to allow diesel loco hauling of EMUs away from electrification but not travel "under the wires" where not needed (e.g. class 57s hauling pendolinos to Holyhead or the old diesel hauling of EMUs to Weymouth before it got electrified all the way).  Class 73s would make more sense then, and the new IEPs (assuming they get built) would be do-able too.
Title: Re: Prefering diesel instead of electricity
Post by: jamespetts on April 02, 2011, 12:32:38 PM
Ahh, this is not quite straightforward: we discussed this before, I think. In operation, it is very rare indeed for an electro-diesel to switch between diesel and electric mode: only the Class 74 (http://en.wikipedia.org/wiki/British_Rail_Class_74) ever did this in practice, and it turned out to be so unreliable that it was quickly limited to occasional use.

Mostly, electro-diesels such as the Class 73 will run an entire diagram in either electric or diesel mode, and only switch between them at a depot. This kind of functionality can be achieved in Experimental using the upgrading feature: define a "diesel" and "electric" class 73, and allow free upgrading between each of them and each other. The backup functionality (of having the diesel engine available in case of breakdown of electrical equipment or failure of supplies) has no real use in Simutrans, where individual breakdowns are deliberately not simulated.

The sort of situation to which you refer (allowing a diesel to haul EMUs; the Class 33s and 4TCs are perhaps the best examples) requires a whole new layer of simulation of changing convoy formations in service. This would also allow for the simpler situation of a train being hauled by an electric locomotive between A and B, and a diesel locomotive between B and C (and the same in reverse), as well as multiple units dividing and combining, banking, etc.. This I think can be done with without pernickity shunting by using a degree of approximation and abstraction, and I should like to see this in Experimental one day, but I consider it a rather low priority.
Title: Re: Prefering diesel instead of electricity
Post by: isidoro on April 02, 2011, 11:38:24 PM
Quote from: jamespetts on April 02, 2011, 10:51:53 AM
[...]
Presumably, you would want to define a different running cost and amount of power for vehicle when running on diesel and electric, respectively?

This shouldn't be very difficult to implement in the program.  These vehicles would be diesel ones with two sets of specifications, the first ones used in a non-electrified tile, the second ones in electrified.  The original diesel vehicle may even be a superclass of this mixed vehicle...  Routing left untouched.
Title: Re: Prefering diesel instead of electricity
Post by: ӔO on April 03, 2011, 08:41:22 AM
as a work around in experimental, maybe an option for having an upgrade to both operating modes will do if it's such a rarity that vehicles have to transition from two electrified sections?

electric <-upgrade-> diesel, at no cost and only switchable in the depot.
I would assume that the player would want to send their dual-mode convoy to the depot anyways, if they are transferring vehicles between depots.
Title: Re: Prefering diesel instead of electricity
Post by: meme on April 04, 2011, 02:30:04 PM
Sorry for bad understandability,  I've mean a vehicle , which primary works on electricity, but in some situations ,  when is it needed they're able to ride on backup diesel engine ( for example  , problem with trolley on railway etc. )  ...
maybe better explained here: (copied from some server)

Some trolleybuses (and most modern ones) have some form of alternative power source - a small diesel engine or a bank of batteries. These enable them to operate 'off-wire' for a short distance, enabling them to get round larger problems (a closed street, or a power failure), or return to depot if they suffer main electrical failure.
Title: Re: Prefering diesel instead of electricity
Post by: jamespetts on April 04, 2011, 04:43:11 PM
Hmm - how would that fit in with Simutrans? I don't think that we can simulate methods to ameloirate the consquences of incidental equipment failures, can we, if we do not (by choice) simulate those failures themselves?
Title: Re: Prefering diesel instead of electricity
Post by: skreyola on April 06, 2011, 03:46:18 PM
Unless there is a significant cost difference between running diesel and running electric, I think the engine should just run (as to game mechanics) as though it were straight diesel.
Having an interchangeable upgrade between d<->e probably won't work with line schedules... it would introduce too much micromanagement.
The other option would be to recode way restrictions to allow diesel fallback, I think, and I wouldn't hold my breath for that.
Title: Electric + diesel locomotives without electricity
Post by: meme on March 10, 2012, 04:19:03 PM
I would appreciate if was possible to use electric locomotive & diesel locomotive / steam locomotive on tracks without electricity - the elect. loco. would be like wagon and its power wouldn't work...
Title: Re: Electric locomotives without electricity
Post by: Combuijs on March 10, 2012, 06:21:25 PM
As the loc is not working, what do you want to achieve then?

And what's next? Planes that just can travel over roads instead of flying?  ;)
Title: Re: Electric locomotives without electricity
Post by: Ters on March 10, 2012, 06:41:41 PM
Quote from: Combuijs on March 10, 2012, 06:21:25 PM
As the loc is not working, what do you want to achieve then?

And what's next? Planes that just can travel over roads instead of flying?  ;)
I'm not sure what meme wants, but I would like this feature just to transport it from A to B. Planes can always fly to whichever airport they want.
Title: Re: Electric locomotives without electricity
Post by: VS on March 10, 2012, 06:59:34 PM
But Simutrans planes can drive on a taxiway instead of flying, really! And this video (http://www.youtube.com/watch?v=ukJtqg0W5iM) from real life shows that such behaviour is actually highly realistic!

Back on topic, this particular request has been raised in Czech board several times...
Title: Re: Electric locomotives without electricity
Post by: ӔO on March 10, 2012, 07:09:21 PM
it's not unusual for some trains and buses to have dual mode operation.

there are also times when electric trains need to be transfered over to another depot, but there is a gap in electrification network.
Title: Re: Electric locomotives without electricity
Post by: meme on March 10, 2012, 07:39:33 PM
I haven't meant dual mode, but having 2 locomotives: Electric and diesel on not electrified railway.. This is exactly what I wanted: "there are also times when electric trains need to be transfered over to another depot, but there is a gap in electrification network."
Title: Re: Electric locomotives without electricity
Post by: Fabio on March 10, 2012, 08:54:30 PM
There could also be dual mode locos.
In dats it could be like this

engine_type[0]=electric
Power[0]=x
Running_cost[0]= xx
Gear[0]=xxx 
engine_type[1]=diesel
Power[0]=y
Running_cost[0]= yy
Gear[0]=yyy 

The loco would use electric (typically cheaper) values if there are overhead wires (and no smoke), whereas it would use diesel values on unelectrified tracks.
This kind of locos are not uncommon in RL and here it would replace the fact that trains can't change engine outside depot.
Title: Re: Electric locomotives without electricity
Post by: meme on March 10, 2012, 08:58:50 PM
This could be also implemented for trolleybuses ( In Czech Republic, for example, most of new trolleybuses has secondary diesel engine..)
Title: Re: Electric locomotives without electricity
Post by: ӔO on March 10, 2012, 09:38:10 PM
i think the problem with with running diesel together with electric lies in the fact that the computer only considers one type of restriction upon path finding, instead of checking if its possible with the convoy's alternative source of power.
Title: Re: Electric locomotives without electricity
Post by: meme on March 10, 2012, 09:39:46 PM
It could be done the same way which is confirmed that electricity / track is available/reachable , I think...
Title: Re: Electric locomotives without electricity
Post by: greenling on March 10, 2012, 09:44:42 PM
In the Switzerland,Germany,France,USA gives Locomotives they can be drive with diesel and electric.
Here it`s a link how be talk over dual mode locomotives.
http://dmm.travel/news/artikel/lesen/2011/05/hybrid-loks-aus-kasssel-fuer-amerikanische-zuege-36128/ (http://dmm.travel/news/artikel/lesen/2011/05/hybrid-loks-aus-kasssel-fuer-amerikanische-zuege-36128/)
Edit:
In Simutrans exp it posible to build in a transferbridge betwen electric overheadpowerlinenetworks.
Title: Re: Electric + diesel locomotives without electricity
Post by: meme on March 10, 2012, 09:56:36 PM
simutrans experimental for Mac doesn't exist, I can't try it :(
Title: Re: Electric + diesel locomotives without electricity
Post by: greenling on March 10, 2012, 10:29:17 PM
Meme
oh that it very sadly!
Please Listen.
The Transferbridge for Electric Railroad engines in Simutrans exp it a Development project that not be simpel it to develop.
To develop it I must look me first of all in the Simutrans exp vehicle data like the works.


Title: Re: Electric + diesel locomotives without electricity
Post by: rsdworker on March 12, 2012, 05:13:09 PM
yes in demark - the intercity to esberg has dual mode - when its travels from copehagen to koling then train changes from electric to diesel - which is very useful for example line has no overhead wires to supply power to trains
in UK we have those - i can't remember where but only one class can change from diesel to electric
in simtrans - we need dual power - electric and diesel - some cases - metro can run third rail but if train has overhead line feeder and third rail shoe so means train can use overhead or third rail - its used in most places where overhead wires exists for example Line 5 and line 51 - the line 5 is tram which does not carry third rail shoes only overhead wires so the metro cars from line 51 (sometimes line 50 does use it) have overhead wires and third rail shoes - so to order make work the metro changes power at ZUID before going in short tunnel in shared tracks with tram - formerly tram line went on shared line through tunnel but its now diverted around due new metro line buiding work
Title: Re: Electric + diesel locomotives without electricity
Post by: isidoro on March 12, 2012, 10:12:36 PM
Technically, it shouldn't be difficult to program.  In path finding, consider a convoy to be electric if it is only powered electrically.  During convoy running, calculate a variable power depending on whether the track is electrified or not...

Title: Re: Electric + diesel locomotives without electricity
Post by: Ters on March 13, 2012, 05:20:17 AM
Running cost should also change, but what is the running cost of a locomotive that's just being pulled along? And should the diesel locomotive be running on the electrified sections or should the train switch to electric only? I guess the answer to that depends on the situation and/or the player.