🚀 go-pugleaf

greg byshenk wrote:
> 
> John R Cambron <*cambronj@chesapeake.net*> wrote:
> > greg byshenk wrote:
> > > John R Cambron <*cambronj@chesapeake.net*> wrote:
> 
> > > > I under stand that more doors = less crowding and faster loading and
> > > > unloading that will = shorter dwell times. Their is one problem, the
> > > > base WMATA car design like the bart car has a flaw that will not
> > > > easily make it possible to add more door without making the cars
> > > > heavier. The flaw is the car body it an interracial part of the
> > > > structure the car. Punching more holes in the car sides for door
> > > > would require beefing up the under fram to compensate loss of body
> > > > structural integrity. You got to remember that these car were built
> > > > like cabin of an passenger jet airplane, and out of aluminium to
> > > > boot. Frankly I think the more traditional way of building of
> > > > passenger railroad car would have been a better choice. Stainless
> > > > steel car body on a an undercarriage bearing all of the loading and
> > > > buffering.
> 
> > > I'm not sure whether this is a big issue -- how common is it to change
> > > the door configuration of existing equipment?  It seems to me that
> > > doing so would be rather a large undertaking -- regardless of whether
> > > the equipment is body and undercarriage or unibody construction --
> > > and that such configuration changes would normally be made at the time
> > > that new equipment is ordered.
> 
> > The issue is not to retrofit existing car with more door, it's
> > building new cars with more door using the the same car body
> > structural design.
> 
> I'm hardly an export in this area, but I suspect that a significant
> redesign would be involved no matter what body design was originally
> used.  It is not just a matter of chopping a new hole in the side of
> the car, I don't think.

True.

> > > Also, I suspect that adding more doors would _always_ make the car
> > > heavier, no matter what type of construction is used, because the
> > > doors and their associated hardware will be heavier than the simple
> > > walls they replace.
> 
> > That is quite likely to be true, but stainless steel is pound for
> > pound stronger then aluminium in this kind of application.
> 
> I have no idea whether or not this is true (I suspect that it will
> depend on how you define "this type of application").  More
> importantly, I don't see how it is relevant; after all a unibody _or_
> body-on-undercarriage design can each be made of aluminum _or_ steel.

Definition of "this type of application" using aluminium as part
structural design of a rail car body. Another application fuel sell in
a race car, cabin of a passenger jet airplane, non structural part
of an automobile . . .

As far as I know bart and WMATA metrorail are the only rail transit
system in North America that use aluminium for there car bodies.

As far as I know there has never been any railroad cars built
for any kind of service in North America be it be a common carrier,
rapid transit (metro or subway) system, lite rail/street car
system that used aluminium in the under carriage structure.

-- 
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NT Geek, MCP
Transit Geek
http://www.chesapeake.net/~cambronj/wmata/	
Model Railroader HO N                                   John R Cambron
http://www.chesapeake.net/~cambronj/sunbelt/        North Beach MD USA
Railroad Geek                                  cambronj@chesapeake.net
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