Double decker transport - UK compared with Europe

[whole diary]

[Noggin]

If the use of rail continues to grow, then someone will have to decide what to do with busy terminal stations, such as those in London.

Perhaps someone has ... with Thameslink, Elizabeth Line, Crossrail 2 so far, and HS1^▸ (High Speed line 1 - St Pancras to Channel Tunnel) relieving some pressure inbound from Kent.  Could there be more in the series? 

As has been repeated frequently (including in this thread), not only are double-deck trains difficult in terms of loading gauge, but they significantly increase dwell times, are difficult to make accessible, you lose significant area with the stairs and the upstairs/downstairs split makes the train less secure compared with modern full-width gangway designs where effectively the whole train is an open cylinder with few hidden corners where anything untoward can go on etc.

Far better to spend money on increasing the length of trains and service frequency (which has the further benefit that a more frequent service is more attractive to users).

As Graeme says, Thameslink and Crossrail (1 and 2) have the dual benefits that they reduce the number of services turning around at the London Terminii (hence the rebuild of London Bridge to have more through platforms and fewer terminating platforms), and also that they relieve pressure on the tube network (Central line for Crossrail, Victoria line for Crossrail 2). There's also the proposed Bakerloo line extension which should provide an alternative to heavy rail in SE London.

As for Crossrail 3, it's unlikely to be built for another 10 years at least, and who knows how London's geography will have changed by then. There's a whole thread on Skyscraper City (http://www.skyscrapercity.com/showthread.php?s=ff6f228432d711905417057aee9ddd38&t=1381717), but NW to SE would fill a gap in the map, and if you wanted to be radical, you could even take over the Metropolitan line re-electrify it at 25kV together with Chiltern and send it through the City to connect up with the Fenchurch Street lines. 

[Bmblbzzz]

Should this thread really be in The Wider Picture... or The Higher Picture? 

[Tim]

why we only have single decked carriages?

Other's have answered this question in general terms.  There does remain however the question of why HS1^▸ (High Speed line 1 - St Pancras to Channel Tunnel) doesn't have double decker trains.  The first generation Eurostars were build to GB^▸ (Great Britain) loading gauge so that is your answer, but the new e320 trains are only single decker.

My understanding that there is room for double deckers here (and with few stops that arguments about increased dwell times does not apply).  The only reason I can think of is what might seem like a perverse desire to keep the trains long so as to comply with Chunnel safety regs. 

[ChrisB]

or the extra cost in building deeper/bigger tunnels? And what about the London terminal? isn't that into/out of a tunnel too?

[Tim]

As I understand it the whole route into St Pancreas is built to the GB^▸ (Great Britain)+ gauge used in France where there are TGV^▸ (Train a Grande Vitesse) duplex trains. 

[stuving]

A load of new Paris RER trains have been ordered (by STIF). The design is based on Alstom's X'trapolate series though for some reason (probably devious and political) Bomardier are helping them.

These are double-decker trains, not unusual on the RER, but this time also open throughout (car-width gangways) and with a very high standing capacity. They quote 1860 passengers in a 130 m length - compare that with Crossrail's 1950 (min) in 205 m (max).

Alstom's announcement has a cut-away picture in it, which shows large vestibules with only tip-up seats, and that area is marked "5 minutes". Then there's downstairs, with 30 seats in 3+0, but several of these are tip-ups, marked "20 minutes". Then upstairs is 18 seats in 2+0, again with some of them tip-ups, and marked "50 minutes".

Now that pictures has ambiguities: upstairs could be 2+2 with the nearside cut away, and downstairs might have single seats along the nearside. But then some seats shown down might flip up - or even all of them! Cramming so many people into the length is not going to be easy.

I can't explain, in terms of vehicle lengths and numbers, how trains are made in 112 m and 130 m lengths. Despite being Alstom the bogies are not shared. The inner vehicle length does look short, though, presumably to optimise the vestibule and double-deck lengths in relation to the number of doors). 

You might well call them sheep trucks (they are better then cattle at climbing the stairs). To compare with here, the furthest terminals are Malesherbes at 60 km on RER D, and will be similar for Mantes-la-Jolie on RER E once extended. Those are straight-line from the city centre, on which basis Reading is also 60 km. Thameslink of course goes a lot further.

[This seems as good a place as any ... for now, anyway.]

[grahame]

Having travelled on the final journey in passenger service of the 4DD, I have read about its story before and after with interest.

A new website on the subject - coming right up to date with the efforts to preserve / conserve / pass on to heritage the remaining two carriages has been lauched .. https://www.bulleid4dd.org.uk

Conceived by OVS Bulleid for the newly nationalised Southern Railway’s commuter route from London Charing Cross to Dartford, the two 4DD electric multiple units were the only double-deck trains to run on the main line railway network in Britain.

The 4DD Double Deck units were a unique experiment in UK^▸ (United Kingdom) train design, an experiment which carried on in service for over 20 years. The trains were withdrawn in 1971, and only two coaches from one of the units remain both in poor condition and in need of some care and attention.

This website is dedicated to the history of the 4DD Class Electric Multiple Units. It supports the Facebook interest Group

If you have an interest in the 4DD units, or any photographs or memories of the unit either in service or in later life that we could use please let us know via the contact page.