Peter Frimberley wrote in
:

As well as being eyesores, urban monorails also drop oil on people
below, which will not go down well. The one in Sydney has strategic
oil-catchers under the track at places where either people congregate

SNIP


I'm not sure there'll be any oil left in the planet, by the time MonoMetro
is finally installed in London ;-)

Tom Anderson wrote:
On Fri, 17 Nov 2006, Peter Frimberley wrote:

I have never seen a "top suspended" monorail like the one in that
video though. Doesn't such a design make it massively more complex,
in that the trains have to be so much stronger to hang from
something rather than just sit there on a concrete beam?

Er, no. Rather than supporting N tonnes on a rail beneath them, they
have to support N tonnes on a rail above them. The difference will be
that a bottom-rail system is in compression, while a top-rail system
is in tension, which are completely differnt types of load. However,
i believe that common engineering materials, like steel and carbon
fibre, perform better in tension than compression, although
IANAengineer. If that's true, it would mean top-rail systems could be
lighter.

That would be true if the trains merely had to be strong enough to hold
themselves up, but they have to be strong enough to bounce off each other
and bounce off the ground.

It's certainly going to make the track bed harder to get through,
because the pylons will have to be so much higher, and it'll be more
difficult to integrate track and buildings. For instance the Sydney
monorail goes through the middle of the odd building (some of which
were there before they built it) and is just sitting on top of the
building walls (no doubt strengthened), top-hung must be way more
challenging to poke through existing structures or tight spaces.

Will it? You need exactly the same sized hole through buildings, just
with the rail at the top rather than the bottom.

I'm not convinced. With a dual rail train, you can poke the wheels through
the floor beneath the seats, making the rail pretty much flush with the
floor. If the wheels are at the top, they must sit on top of the (single)
rail, which must be above the roof of the train, giving a much higher cross
section. I find it hard to visualise a "monorail" with the wheels beneath,
because the so-called single rail must have at least two gauge corners,
making its description as a monorail meaningless.... surely a monorail train
is just a train with the flanges on the outside?... but I would imagine the
cross section would be nearer to a conventional train.

John Rowland wrote:

I'm not convinced. With a dual rail train, you can poke the wheels through
the floor beneath the seats, making the rail pretty much flush with the
floor. If the wheels are at the top, they must sit on top of the (single)
rail, which must be above the roof of the train, giving a much higher cross
section. I find it hard to visualise a "monorail" with the wheels beneath,
because the so-called single rail must have at least two gauge corners,
making its description as a monorail meaningless.... surely a monorail train
is just a train with the flanges on the outside?... but I would imagine the
cross section would be nearer to a conventional train.

In Den Haag, there is a relatively new full-size 4 track tram tunnel
that passes right through a couple of buildings, which look old enough
that they were probably already there beforehand.

Neil

In article ,
Tom Anderson wrote:
On Fri, 17 Nov 2006, Tristán White wrote:

Not really - I guess a deal was struck: we plug your exhibition, if we
can use your facts and figures to make a page up. I for one am delighted
they did as I may not have heard of this exhibition otherwise.

Ahem.

http://groups.google.co.uk/group/uk....ee89e31?hl=en&

Perhaps i should start including bar and events listings in my posts to
attract attention!

You could call it something like, "Time Out" ! ;-)

Nick