From: ce11son@yahoo.ca   
      
   On Mon, 19 May 2014 11:43:55 -0500, Larry Sheldon   
    wrote:   
      
   >On 5/19/2014 10:11 AM, Charles Ellson wrote:   
   >> On Sun, 18 May 2014 22:20:53 -0700, Glen Labah    
   >> wrote:   
   >>   
   >>> In article ,   
   >>> Larry Sheldon  wrote:   
   >>>   
   >>>> I have been studying all the pictures you nice people have pointed to   
   >>>> and I for the life of me see were the articulation "hinges" are nor how   
   >>>> they "work".  From the pictures, it looks like any articulation will   
   >>>> have one or more drivers fouling the boiler chassis.   
   >>>   
   >>>   
   >>> It really isn't very obvious, but on the larger Garratt locomotives the   
   >>> frame split is almost always above the 3rd driving axle.  Then, the   
   >>> upper body may or may not have some overhang one way or the other.   
   >>>   
   >>> It is probably best to see a model of one run, as that gives you sort of   
   >>> an above the model look as it goes around curves.  This is the best I   
   >>> could find so far, of a British 2-6-0+0-6-2:   
   >>>   
   >>> http://www.youtube.com/watch?v=mYlM-9j1AQI   
   >>>   
   >> "Hinge" and "frame split" could be slightly misleading, they don't   
   >> bend in the style of e.g. some double-section electric and diesel   
   >> locomotives but instead involve overlapping sections. There are three   
   >> main sections - two engines with the cab/boiler suspended between and   
   >> overhanging both of them.   
   >> The second and third rows of this drawing show the pivot points on a   
   >> SAR 400 class :-   
   >> http://www.johnnyspages.com/rail_dittys_files/garratt_diagram.gif   
   >>   
   >   
   >OK.  I think I had the pivot thing figured out (vice "hinge") bout it   
   >didn't (and still doesn't!) look like that driver can swing far enough,   
   >but I guess it does.  I assume that the bogey (pilot?  ??) next to the   
   >driver under the boiler (when provided) swing with the drivers?  Seems   
   >like it must else why have it?   
   >   
   The whole lot behaves much the same as two tank locomotives coupled   
   back-to-back, save for the cab/boiler doing the coupling via the   
   pivots.   
      
   >Thanks a lot.   
   >   
   >I can't believe I had never heard of them before.  I've long said it was   
   >a bad day that I don't learn something--this has been a real treat.   
   >   
   I also tripped over this page :-   
   http://www.cabbagepatchrailway.co.uk/articulated.html   
   so now I know what the difference is between a Garrett and a Mallett.   
      
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