On Dec 20, 2:49*pm, wrote:
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.

But that would just shift the problem from the upper deck floor
aticulation to the lower deck floor articulation. The problem is
accommodating vertical curves on both floor levels simultaneously.
Without having a telescoping floor section vertical curves can not be
handled, and I would have worries about the safety implications for
passengers crossing the join as it stretches and contracts.

There's also the issue of where to put all the kit that sits on the
roof of a modern low floor tram (that in the days of high floor trams
might have been under the floor).

Robin