Re: [NSW] Cityrail Millennium Train

["Adam Dunning" <adamdunning@start.com.au>]

Errr I'm sorry, Citroen invented the monocoque body in the 30's.


"jjjim" <jjjim@bigpond.com> wrote in message
3A97533F.2684C396@bigpond.com">news:3A97533F.2684C396@bigpond.com...
> Its funny how you have to take collisons in to consideration in sydney ;)
>
> BTW subaru invented the monocoque Car in the 50's it was called the subaru
320 or
> something,  a
>
> Al wrote:
>
> > Geoff Lillico <glillic@msn.com.au> wrote in message
> > JApl6.1603$v5.5993@newsfeeds.bigpond.com">news:JApl6.1603$v5.5993@newsfeeds.bigpond.com...
> > > Yes there are standards in place.
> > >
> > > I would hazard a guess and say that not one correspondant to this
thread is
> > > a structural engineer and nor am I, but unless you have substantiated
> > > evidence to the contrary, I believe it is unwise to suggest that these
new
> > > trains do NOT comply to the standards set for the Bureau of Rail
Safety of
> > > D.O.T. or those of the Australian Standards Authority.
> > >
> >
> > You could be right there, but anyway it's not a structural engineer
you're
> > after, but a mechanical, which I'm starting my final year in on Monday,
so
> > here's my probably totally flawed thoughts about it.  Don't take it as
gospel,
> > but rather as a guide to what the designers are considering.
> >
> > I also work for a company which makes fire trucks, and has done work for
> > Goninan on train bodies, bogies etc.  Actually, half the people on the
floor
> > there worked for Goninans when they were making the Tangaras and NRs,
but
> > that's another story.
> >
> > One thing to consider is that the trains could be built as a monocoque
or
> > unitary construction, similar to a passenger car such as a Commodore or
> > Falcon.  They do not have a fixed chassis such as a truck, but rather
the load
> > is taken by the panels all over the vehicle.  This could explain why it
looks
> > flimsy, where it could actually have a very strong rigidity (essentially
one
> > big box section).  Advantages to this are light weight and high
strength,
> > which is one reason why most passenger cars are made this way now.  It
also
> > gives better energy absorption in a crash, which is why newer cars are
more
> > survivable than older ones in crashes.
> >
> > Also, the material used can affect the standards.  Judging by the colour
of
> > the metal in the photos, it's either aluminium or steel sheeting,
probably
> > aluminium, cause it can be made extremely strong but remains
lightweight, with
> > a steel framework as a cheap, but effective backbone.  People, by and
large,
> > aren't all that heavy (2000 people on an 8-car train ~ approx 180 - 200
tonnes
> > to give a comparison to freight trains), so most of the structural
strength is
> > required for the shock loadings that the trains experience, such as
going over
> > gaps in the track at points, wind blast from passing trains at high
speed, and
> > full throttle-full brake scenarios, such as an uphill into a station.
> >
> > Finally, the type of accident or load that you consider can make the
shape
> > substantially different to what you expect.  Passenger cars are designed
for
> > accidents coming into the car from the plane of the road (ie front and
sides).
> > What are the kinds of accidents a train can expect?  You could possibly
design
> > the cab as a crumple zone, on the assumption the driver can get out in
time
> > (re Glenbrook).  This also works both ways for front and rear end
collisions.
> > You don't have to worry about T-bones, but rolling is another
possibility,
> > where you don't want the structure to collapse onto people inside it,
which is
> > where a monocoque has another advantage.
> >
> > Hope that helps,
> >
> > Al
>