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) could
take the same number of people, maybe more, than a single decker in less
length.

I'm guessing there are 2 reasons the main one being that double deckers have
always been a bit of a British oddity. Yes, there have been other places
in the world that used them but these days in particular the market is in
countries where single deck trams are the norm so we get single deckers.
The other reason seems to be loading times.

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

On Dec 20, 9:57*am, "Graham Harrison"
wrote:

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) could
take the same number of people, maybe more, than a single decker in less
length.

I'm guessing there are 2 reasons the main one being that double deckers have
always been a bit of a British oddity.

Partly because normal height clearances on roads (where trams run)
tend to be higher in the UK than other European countries, and most
trams are off-the-shelf European designs.

Berlin does double-decker buses (albeit lower ones than usual for the
UK, if I recall), but they are not common elsewhere in Europe for the
same reason.

OTOH, because the height clearance issue is the opposite way around
for rail, the UK doesn't do double-deckers on rail (the 4-DD excepted)
but they are very common in mainland Europe. Were the UK the main
supplier of trains to Europe, I expect the situation would be similar
to trams.

Neil

On 20/12/2011 09:02, Neil Williams wrote:
On Dec 20, 9:57 am, "Graham Harrison"
wrote:

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) could
take the same number of people, maybe more, than a single decker in less
length.

I'm guessing there are 2 reasons the main one being that double deckers have
always been a bit of a British oddity.

Partly because normal height clearances on roads (where trams run)
tend to be higher in the UK than other European countries, and most
trams are off-the-shelf European designs.

Berlin does double-decker buses (albeit lower ones than usual for the
UK, if I recall), but they are not common elsewhere in Europe for the
same reason.

Rome has, or at least had last time I was there, double decker buses.

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

On Tue, 20 Dec 2011 01:02:03 -0800 (PST)
Neil Williams wrote:
OTOH, because the height clearance issue is the opposite way around
for rail, the UK doesn't do double-deckers on rail (the 4-DD excepted)
but they are very common in mainland Europe. Were the UK the main

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.

B2003

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.
Many operators worked around this by building turning loops in which
no shunting was required but the entire tram went around on a cicle of
track to face the other direction. The provison of these prepared the
way for the next development which was that of the uni-directional
tram, having a cab at only one end and doors on only one side. They
were less flexible in service as they needed loops but from the
maintenance perspective there was less hardware to be maintained. The
absence of doors on the off side also meant that more seats could be
provided. From there they went to articulated trams which again was a
step backwards in terms of flexibility (compared to trailers) but had
advanatges in terms of passenger flow and better utilisation of space
etc. Also the concept was scalable so longer and longer trams could be
made just by adding intermediate segments.

On 20 Dez., 10:46, 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.
Many operators worked around this by building turning loops in which
no shunting was required but the entire tram went around on a cicle of
track to face the other direction. The provison of these prepared the
way for the next development which was that of the uni-directional
tram, having a cab at only one end and doors on only one side. They
were less flexible in service as they needed loops but from the
maintenance perspective there was less hardware to be maintained. The
absence of doors on the off side also meant that more seats could be
provided. From there they went to articulated trams which again was a
step backwards in terms of flexibility (compared to trailers) but had
advanatges in terms of passenger flow and better utilisation of space
etc. Also the concept was scalable so longer and longer trams could be
made just by adding intermediate segments.

Anf here lies the advantage of modern trams. They have more capacity
than buses and so if the traffic is there to justify it, they are
moder efficient operationally. 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. But high-capacity
trams which could take double the number of passengers as buses if not
more meant that the closure of many German systems was simply not a
feasible option. Of course many of the lesser and lighter lines did
close, and the tram system we see in Germany today are in many cases
just the skeletons of what once was.

On Dec 20, 10:54*am, amogles wrote:

and the tram system we see in Germany today are in many cases
just the skeletons of what once was.

And some cities closed them entirely, and operated the same routes and
infrastructure with buses. That lead to idiocy like these on the
Hamburg equivalent of Oxford Road (city - uni - where a lot of
students live), which should, as with Manchester, be a tram route.

http://commons.wikimedia.org/wiki/File:XXL-Bus.JPG

Neil

I've sometimes wondered why modern tramcar makers don't make double deckers.
Suggestions:
(1) Do you need two bods to 'police' both decks when one will do for an artic.

(2) With tightly knotted streets and high peak demand such as you would get in
say for example Dundee when the mill shifts ended, the smaller footprint would
be desirable. These conditions have largely gone.

(3) If you want a tunnel for your trams to burrow through the city centre or
just do dive-unders you're adding to the civil engineering costs.

--
Peter 'Prof' Fox
Multitude of things for beer, cycling and curiosities at www.vulpeculox.net
2 Tees Close, Witham, Essex, England +44 (01376) 517206

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?

On Dec 20, 11:27*am, PeterFox wrote:

(1) *Do you need two bods to 'police' both decks when one will do for an artic.

What bods would those be? Metrolink is DOO. If you mean conductors,
possibly or possibly not. Routemasters only ever had one, while I
think Blackpool tended to use two.

Neil