On 20/12/2011 10:50, D7666 wrote:
On Dec 20, 10:36 am, Graeme wrote:

I've never been convinced that premetro style tram tunnels are that good
an idea. Surely you want your high quality urban transport to be
prominently visible and easily accesible.

Ever used one.?


Pre-metro in tunnel? Yes in Brussels.

--
Graeme Wall
This account not read, substitute trains for rail.
Railway Miscellany at http://www.greywall.demon.co.uk/rail

A double deck tram has by nature about
the capacity of a double deck bus, so given the choice the operator
opts for the bus which is more flexible and cheaper.

You're limiting your thinking. In effect I'm asking why you can't take a
modern multi section single deck tram and build a double deck version.

"Basil Jet" wrote in message
...
On 2011\12\20 08:57, Graham Harrison wrote:
I can't find a tram related newsgroup.

I've sometimes wondered why modern tramcar makers don't make double
deckers. Yes, modern artics swallow lots of people quickly but they also
take up a lot of space. A double deck artic (with connections at both
levels)

How would the upper floor connection cope with vertical curves?

That's an engineering detail (he said having no idea what the answer is!).

On 20/12/2011 13:02, Graham Harrison wrote:

"Basil Jet" wrote in message
...
On 2011\12\20 08:57, Graham Harrison wrote:
I can't find a tram related newsgroup.

I've sometimes wondered why modern tramcar makers don't make double
deckers. Yes, modern artics swallow lots of people quickly but they also
take up a lot of space. A double deck artic (with connections at both
levels)

How would the upper floor connection cope with vertical curves?

That's an engineering detail (he said having no idea what the answer is!).

Not insoluble but possibly expensive.

--
Graeme Wall
This account not read, substitute trains for rail.
Railway Miscellany at http://www.greywall.demon.co.uk/rail

On Dec 20, 2:04*pm, Graeme Wall wrote:

Not insoluble but possibly expensive.

It presumably depends on the size of the curves. SBB IC2000 stock has
upper level gangways only.

Neil

Graham Harrison schrieb:


I've sometimes wondered why modern tramcar makers don't make double deckers.

The dwell time is too high for competitive timing. In those days, when
people couldn't afford automobiles, this was less of a concern, and it
still might not be in the 3rd or developing world, but for success of a
tram system in the modern world, every second (per stop) counts.


Hans-Joachim



--

Frieda Uffelmann * 15. August 1915 â€* 9. Dezember 2011

http://zierke.com/private/tante_frie...abgestellt.jpg

d schrieb:


Though even the euro double deckers (or at least the ones I've been on in
france) are really at the limit of practicality. The top deck is rather
low height and the curved sides impinge quite noticably. Its only really in
the USA that you get proper double deckers.


Try Finland.


Hans-Joachim




--

Frieda Uffelmann * 15. August 1915 â€* 9. Dezember 2011

http://zierke.com/private/tante_frie...abgestellt.jpg

On Tue, 20 Dec 2011 13:04:23 +0000
Graeme Wall wrote:
On 20/12/2011 13:02, Graham Harrison wrote:

"Basil Jet" wrote in message
...
On 2011\12\20 08:57, Graham Harrison wrote:
I can't find a tram related newsgroup.

I've sometimes wondered why modern tramcar makers don't make double
deckers. Yes, modern artics swallow lots of people quickly but they also
take up a lot of space. A double deck artic (with connections at both
levels)

How would the upper floor connection cope with vertical curves?

That's an engineering detail (he said having no idea what the answer is!).

Not insoluble but possibly expensive.

Have the universal joint at floor level with the upper deck instead of at
floor level with the lower deck. Fairly simple.

B2003

On 20/12/2011 09:46, amogles wrote:
On 20 Dez., 09:57, "Graham Harrison"
wrote:

And, I am aware of the new double deck trams in Hong Kong.

Alexandria also has some double-deck trams. I beleive they are of
Chinese make.


In the past, double deck trams were more common. Paris and Berlin both
had them and no doubt several other cities besides.

I am not sure about the details, but I believe that one factor that
was different in the UK was legislation concerning trailers. I am not
sure whether they were banend outright, or it was something else.
Anyway, although some British trams did have trailers, they were
extremely rare. Where the Germans for example used trailers to grow
capacity, British operators built upwards.

Of course one disadvantage of trailers was that they needed to be
shunted at the at end of trip, and so loop tracks had to be provided.

They use gravity shunting at Ramsey (Rhumsaa) on the Manx Electric
Railway, incidentally, when they run a trailer.

On 20/12/2011 11:46, Graeme Wall wrote:
On 20/12/2011 10:50, D7666 wrote:
On Dec 20, 10:36 am, Graeme wrote:

I've never been convinced that premetro style tram tunnels are that good
an idea. Surely you want your high quality urban transport to be
prominently visible and easily accesible.

Ever used one.?


Pre-metro in tunnel? Yes in Brussels.


They have one in Newark, New Jersey, as well. It's called the Newark
City Subway.