There is more to designing a commuter railway line and its capacity than a specific train design. Why not use the Indian Profile, its 6 seats across with arm rests?I don't know the answer to your question but I wish the Indian profile were more common.
Let me tell you something, catering for bikes is optional, catering for wheel chairs is a legal requirement and community expectation.I know about those requirements, but my point is that there is a strong case for catering for bicycles, especially on heavy suburban rail with its wide station spacings:
*Wheelchairs must be accomodated and bicycles take up less space than wheelchairs
*Bicycle accomdation on trains means that people can bike to and from stations instead of walking, a great advantage on a line with widely spaced stations.
Nothing to do with size of train meaning there is space for bikes, its loading capacity. of the trains and even Sydney's high density loading would have no room on many services for bikes or if you tried you'd pi$$ alot of people off doing so and add to the dwell time. Fortunately Sydney has yet to have enough problems yet that will require the govt to ban them at certain times.What is "loading capacity"? And what problems?
Longer trains would be nice, but on existing tunnel lines its difficult to implement once built and rarely is as a result. Surface and viaduct is much more viable for extension.Is it true that no underground platforms have ever been lengthened?
The south and western lines are the two in the inner southern suburbs. And express trains sharing tracks with all stations trains is also not the sort of thing Dr. Bradfield would have proposed.
Quad track on south Line
Hex track on western then Quad
Quad on north (partial)
Rest are mostly double track
DD are being deployed in a very narrow part of the world and Luxembourg is basically a regional station stop for a line from Germany so I wouldn't count it (yes I've been there, I parked at the station). And again dear Mytone, the bulk of what you quoted is regional or outer suburban lines which no one has ever argued against. The rest of the RP forum is talking about inner suburban commuter, mostly underground. One day I hope you actually travel and learn the difference.What is this "narrow part of the world"? Indeed, most heavy rail networks with a large enough loading gauge for double decker trains are indeed regional and outer suburban.
Double decker trains are also being increasingly deployed in North America, again on the busiest systems that can covert.
Any rail operator sticking to single decker trains either doesn't have enough passenger traffic to justify double deckers, a too small loading gauge, or both.
DD stock is far more specific in design than SD and modern SD design was more closely unified than DD. Sydney is already a DD stock island in the DD world. Each batch is designed for only Sydney and basically would need to be rebuilt from ground up to be used in EU due to different loading gauge, length, min curve radius width, platform height etc etc. There will always be something. Sydney is already unqie being only 20m in car length.The Syndey double decker trains are the only ones built by EDI rail, the rest are from different suppliers. Single decker trains built for New South Wales also came from local suppliers such as Tulloch, and they were also unique to New South Wales.
Differences in maximum length and maximum width and differences in platform height and in minimum curve radius also affect single decker trains. If European double deckers would be too long for Sydney suburban, than so would single deckers of the same length.
Even Melbourne single deckers, fitted with standard gauge bogies, would not be able to run in Sydney.