[PRCo] Re: Articulateds

[Phillip Clark Campbell]

Mr.Dietrich;  That's an over-simplification isn't it; rarely do single vehicles exceed 50-foot lengths, but there are notable exceptions, WP 700s being one of them and they negotiated some severe turning radii didn't they.  Normal truck centers on artic rail vehicles like Boston and San Francisco are very similar to truck centers on single vehicles.  On these systems if the truck centers were longer they would not fit the 'existing system' would they.  Center overhang would be greater as would the end and they could touch on city curves.   Modern artic rail cars are not unlike chopping off one end of two standard trolleys at the king pin and joining them with a common truck  Thus turning radius is identical for both old trolleys and modern artic rail cars.

On buses the back end doesn't follow in the same path as the front axle does it; when there are 2 'back axles' on an artic the artic thus needs more room to turn.  This is just common logic isn't it.  There were / are some artic buses that had / have steerable rear axles so this axle would follow in the same / similar path as the center axle  (and considerably less turning ratio than on the front axle;)  this steerable rear axle artic takes the 'same identical space as a standard length bus to turn.'  But these steerable units were problematic since, once into a turn, the driver can't see what that rear axle is doing on the outside edge of the turn; other vehicles could move in here unseen by the bus driver and accidents could result as the back end swung out.  I have witnessed this myself.

On modern LR systems built from scratch  (Denver, San Diego, etc.)  the truck center distances on artic rail vehicles are considerably more than that used on the typical trolley of the 1940s.  This effectively limits the minimum turn radius which is 'greater' than the minimum turn radius for trolleys - considerably greater.

As with most everything in life, labor costs are the biggest chunk of expenses for delivering a product /  service aren't they; reducing labor costs is the key to artics, not the turning radius.



Phil






----- Original Message ----
> From: BobDietrich <bob.dietrich1 at verizon.net>
> To: pittsburgh-railways at dementia.org
> Sent: Tuesday, September 2, 2008 3:51:00 PM
> Subject: [PRCo] Re: Articulateds
> 
> Bendie busses and streetcars can get around tighter corners than can a
> longer rigid vehicle.  Also the other, cheaper to run, rules apply.
> 
> -----Original Message-----
> From: pittsburgh-railways-bounce at lists.dementia.org
> [mailto:pittsburgh-railways-bounce at lists.dementia.org] On Behalf Of Derrick
> J Brashear
> Sent: Tuesday, September 02, 2008 6:12 PM
> To: pittsburgh-railways at dementia.org
> Cc: Ken and Tracie; Milwaukee-electric at dementia.org
> Subject: [PRCo] Re: Articulateds
> 
> On Tue, 2 Sep 2008, Schneider Fred wrote:
> 
> > No brainer Ken.
> >
> > For most of my working life, platform employe wages have represented
> > more than half of the operating costs of delivering a customer to his
> > destination.   The more passengers each vehicle carries, the lower
> > the cost per passenger and the lower the cost per passenger mile.
> 
> it only works if you fill the vehicle at least as full as a shorter 
> vehicle, though.