[PRCo] Re: High Speed Trains!

Mon Nov 1 01:31:55 EDT 2010

Dick

Well, I respectfully have to disagree with you when you say that PCC cars did not have any rate of acceleration such as 4 mphps.  The design acceleration rate for PCC cars maxed out at 4.75 mphps, and the controllers were designed to provide any rate desired between 1.5 and 4.75 mphps.  How do I know this?  Because it is so stated in the definitive PCC treatise, by a couple of chaps named Carlson and Schneider.

Statistics for the Toronto A6-7&8 classes (all-electric cars) show an initial rate of 4.3 mphps. This was obtained under service conditions, as opposed to a theoretical rate.

Semantics may be an issue here.  The rates quoted are initial rates, as Fred points out in his email.  They were not sustainable all the way to balancing speed.  But the PCC was pretty quick on the getaway from a stop--even if Dave could outrun them by speed shifting!

dwight
  ----- Original Message ----- 
  From: Dick Hasselman 
  To: Fred Schneider ; bvolkmer at bellsouth.net 
  Cc: BillVigrass at hillintl.com ; rejmhj at netzero.net ; dgoehring at dejazzd.com ; holomky at yahoo.com ; cawoodbury3 at verizon.net ; afishel at interurbans.com ; gcubed at alum.mit.edu ; www.derf.1 at juno.com ; ge13031 at yahoo.com ; abbuchan1 at comcast.net ; trwells at comcast.net ; jmcgahern at gmail.com ; chrisjagodzinski at gmail.com ; ernclaw at comcast.net ; bobbackpac at sbcglobal.net ; joeschmidt at peoplepc.com ; wckinney at snet.net ; jswatson at bellatlantic.net ; editor at trainsmag.com ; kkeefe at kalmbach.com ; phillips605 at gmail.com ; dwightlong at verizon.net ; philgcraig204 at yahoo.com 
  Sent: Sunday, 31 October, 2010 17:14
  Subject: Re: High Speed Trains!

  Fred,

  I think you're right, that PCC cars didn't have any rate of acceleration such as 4 mphps!

  I threw away [long ago] the handouts which Westinghouse handed out at the NY Worlds Fair of 1939-40, which exhibited a PCC cab, an under-car controller/resistor, and a Clark truck - - so I cannot testify, but I'm sure that is a fact of record somewhere.

  However, it was impressive for that era, and also smoother that one felt from a K-6 controller!

  Dick H
    ----- Original Message ----- 
    From: Fred Schneider 
    To: bvolkmer at bellsouth.net 
    Cc: BillVigrass at hillintl.com ; rejmhj at netzero.net ; dgoehring at dejazzd.com ; holomky at yahoo.com ; hassel8 at comcast.net ; cawoodbury3 at verizon.net ; afishel at interurbans.com ; gcubed at alum.mit.edu ; www.derf.1 at juno.com ; ge13031 at yahoo.com ; abbuchan1 at comcast.net ; trwells at comcast.net ; jmcgahern at gmail.com ; chrisjagodzinski at gmail.com ; ernclaw at comcast.net ; bobbackpac at sbcglobal.net ; joeschmidt at peoplepc.com ; wckinney at snet.net ; jswatson at bellatlantic.net ; editor at trainsmag.com ; kkeefe at kalmbach.com ; phillips605 at gmail.com ; dwightlong at verizon.net ; philgcraig204 at yahoo.com 
    Sent: Sunday, October 31, 2010 11:31 AM
    Subject: Re: High Speed Trains!

    Look at the acceleration chart in the PCC book.  PCC acceleration is only at maximum for the first few seconds.   Your 4.0 (I think it was 4.2) would imply 10 seconds to 42 miles per hour.   Never.   It was about four seconds to 15 miles per hour and then the acceleration curve tapered off.   The PCC could reach about 25 by the end of a block and 40 by the end of a mile.   They could pretty well out run an automobile of the period when the traffic light went green but they were not a high speed vehicle.  

    On Oct 30, 2010, at 9:41 PM, bvolkmer wrote:

            If memory serves, PCCs and trackless trolleys accelerated at 4.0 but modern LRVs are more like 3.5 in deference to standing passengers as Mr. Vigrass points out.

            Braking is 4.0 but I do believe a bus driver with a heavy foot and do better, causing some passengers to get impaled by the farebox.

            Probably the main reason passengers prefer rail cars over buses.

            Bill Volkmer

            --- On Sat, 10/30/10, rejmhj at netzero.net <rejmhj at netzero.net> wrote:

              From: rejmhj at netzero.net <rejmhj at netzero.net>
              Subject: RE: High Speed Trains!
              To: BillVigrass at hillintl.com
              Cc: dgoehring at dejazzd.com, holomky at yahoo.com, hassel8 at comcast.net, cawoodbury3 at verizon.net, afishel at interurbans.com, gcubed at alum.mit.edu, www.derf.1 at juno.com, ge13031 at yahoo.com, abbuchan1 at comcast.net, trwells at comcast.net, jmcgahern at gmail.com, chrisjagodzinski at gmail.com, ernclaw at comcast.net, bobbackpac at sbcglobal.net, joeschmidt at peoplepc.com, wckinney at snet.net, jswatson at bellatlantic.net, bvolkmer at bellsouth.net, editor at trainsmag.com, kkeefe at kalmbach.com, phillips605 at gmail.com, dwightlong at verizon.net, fwschneider at comcast.net, philgcraig204 at yahoo.com
              Date: Saturday, October 30, 2010, 5:34 PM

              All - It is of course nonsense to limit rates to 2 mphps for the passenger's sake.  Light rail cars that operate in mixed traffic should go up to at least 4 mphps, as we have on subway-surface.  Buses go even higher.

              But, if you are going to have conductors walking the aisles picking up tickets, which you don't have on rapid or light rail transit, then you need to think about this subject from a human perspective.

              As for the GM Aerotrain, my recollections from riding it to Pittsburgh was that they pushed up the speed on curves - higher than the comfort level, not for imbalance reasons, but due to the track conditions found back then.

              I remember Harry Dougherty saying they hated those trains because of all the trouble getting them uncoupled.  Everyone on the RR knows you don't grease couplers.  But those cars had OB true tight-lock couplers which utilize a spring-loaded sliding wedge (the same scheme as is found on the CTA) and you had better keep it greased.

              Russ J.

              ------------------------------------------------------------------

              From: "Vigrass, Bill" <BillVigrass at hillintl.com>
              To: "David Goehring" <dgoehring at dejazzd.com>, "Gregory Gagarin" <holomky at yahoo.com>, "Dick Hasselman" <hassel8 at comcast.net>, "Cliff Woodbury" <cawoodbury3 at verizon.net>, "Alan Fishel" <afishel at interurbans.com>, "Greg Gagarin" <gcubed at alum.mit.edu>, "Fred Kossack" <www.derf.1 at juno.com>, "Dennis Lamont" <ge13031 at yahoo.com>, "Alan B Buchan" <abbuchan1 at comcast.net>, "Tim Wells" <trwells at comcast.net>, "John Mcgahern" <jmcgahern at gmail.com>, "Christopher Jagodzinski" <chrisjagodzinski at gmail.com>, "Ernest Clausing" <ernclaw at comcast.net>, "Bob Madsen" <bobbackpac at sbcglobal.net>, "Joe Schmidt" <joeschmidt at peoplepc.com>, "WILLIAM KINNEY" <wckinney at snet.net>, "Robert Watson" <jswatson at bellatlantic.net>, "Bill Volkmer" <bvolkmer at bellsouth.net>, "Jim Wrinn" <editor at trainsmag.com>, "Kevin Keefe" <kkeefe at kalmbach.com>, "Don Phillips" <phillips605 at gmail.com>, "Dwight Long" <dwightlong at verizon.net>, "Fred Schneider" <fwschneider at comcast.net>
              Cc: <rejmhj at netzero.net>, "Phil Craig" <philgcraig204 at yahoo.com>
              Subject: RE: High Speed Trains!
              Date: Fri, 13 Aug 2010 12:41:26 -0400

              All, I concur with much of what is below except the 2 mphps limit to seated passengers.   Many, indeed most, modern rapid transit and lrv’s accelerate and decelerate at 3 mphps WITH STANDEES (with handholds) routinely all day all rush hour.   No problems, usually.   It is s.o.p.

              Bill Vigrass, Supt. PATCO ret. 

              From: David Goehring [mailto:dgoehring at dejazzd.com]
              Sent: Wednesday, August 11, 2010 9:58 PM
              To: Gregory Gagarin; Dick Hasselman; Cliff Woodbury; Alan Fishel; Greg Gagarin; Fred Kossack; Dennis Lamont; Alan B Buchan; Tim Wells; John Mcgahern; Christopher Jagodzinski; Ernest Clausing; Bob Madsen; Joe Schmidt; WILLIAM KINNEY; Robert Watson; Vigrass, Bill; Bill Volkmer; Jim Wrinn; Kevin Keefe; Don Phillips; Dwight Long; Fred Schneider
              Subject: Re: High Speed Trains!

              Greg, One reason I always valued your opinions regarding locomotive  and air brake operation is because you always made allot of sense and you knew your subject. 

              I see that your are still at it. Thanks for your insight and opinion.

              I assume you solved the water in the tub problem.

              Dave

                  ----- Original Message -----

                  From: Gregory Gagarin

                  To: Dick Hasselman ; Cliff Woodbury ; Alan Fishel ; Greg Gagarin ; Fred Kossack ; Dennis Lamont ; Alan B Buchan ; Tim Wells ; John Mcgahern ; Christopher Jagodzinski ; David Goehring ; Ernest Clausing ; Bob Madsen ; Joe Schmidt ; WILLIAM KINNEY ; Robert Watson ; J William Vigrass ; Bill Volkmer ; Jim Wrinn ; Kevin Keefe ; Don Phillips ; Dwight Long ; Fred Schneider

                  Sent: Wednesday, August 11, 2010 9:48 PM

                  Subject: Re: High Speed Trains!

                  Gentlemen:

                      Eighty Years ago, my old math teacher used to give me some interesting problems, many based on the old "time for filling and draining a bath tub" problem.

                  When it comes to "High Speed Trains" the main goal of a passenger is to know how long it will take to go from City A to City B.  It is wonderful to think of speeds of 150 mph or higher, but few seem to appreciate the effect of acceleration and braking at each end of the desired running speed for a given distance, including intermediate stops and the dwell time at the stops. In the 1950's, GM build a "unit train" with a fancy head end locomotive and cars which were modified bus chassis.  It shaved about 40 minutes on the Pittsburgh - Philadelphia run, mostly by eliminating the need to change motive power in Harrisburg and reducing station dwell times.  It's running speed was the same as the then normal train, with a K-4 West of Harrisburg and a GG-1 East.

                      If one plots mph vs. time for any given constant speed run, one should get a rectangle (speed attained vs time at that speed) with two triangles at each end.  These triangles are acceleration and deceleration ('braking').  The area under such a curve is the distance travelled, and the slope at each end of the plot are usually the limiting factor for short distances, since, on a short distance, as soon as you reach a given speed you have to brake to stop at the next station. 

                      For seated passengers (no standees), the acceleration and braking should not exceed 2 mph/second for safety and comfort.  It is at least more than twice (about 5 mph/sec) on a plane when landing, and passengers are belted to their seats.

                      Another limiting factor of 'high-speed' are curves and other existing restrictions.  This is why the Acela can almost reach its design speed only on a few stretches between Washington and Boston. 

                      Thus, I question if any of our Government planners, financiers, politicians, etc. ever look at "the real world".  Has anyone taken into consideration the land cost to build HSR's with limited curves and speed restrictions?  The Russian Moscow - St. Petersburg line is virtually a straight line, except for one area South of St. Petersburg where there is a large S-curve, so that, the then (1880's) existing steam locomotives could negotiate the hill over that area.  The main problem with the current German High Speed train in Russia is the condition of the track, yet they still have shaved a lot of time for that run, with usually one stop in between the two terminal cities.

                              Thus, it should be pointed out to our "Government Planners", that High Speed Rail is probably an essential mode of transportation between major cities, but all aspects of railroading must be taken into consideration, - not just how fast can we get there!

                  Greg Gagarin

                  gcubed at alum.mit.edu

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