From: lfsheldon@gmail.com

On 5/19/2014 5:09 PM, Charles Ellson wrote:
> 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.

Until I moved to Nebraska after living most of my life in California the
Southern Pacific Mallets which were odd in that they ran cab forward (we
called them "mallet inverteds") ostensibly to keep from killing the crew
in long tunnels.  (No word on what the crews in the helpers did).

Thanks again.

--
Idioten aangeboden. Gratis af te halen.
h/t Dagelijkse Standaard

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