CSXrules4eva:
then maybe you should add to that photo in your signature:
HEY MTV - PIMP MY RIDE !
[:-,]
If im not mistaken, the wheel is there version of our “Johnson Bar”. The bar that controls the timing of the valves, and is the reverse lever.
This is an electric loco. It looks like this:
The comment about the Euopean locos is right. The TGV i know for sure uses the wheel for speed control, and NOT for steering, or sleeping.
It seems that I recall a steering-wheel-like device that sat in front of the engineer on CP Hudson 2839 that was used in Southern Railway excursion service some years back, that was actually the reverse lever.
Can anyone confirm or deny?
Old Timer
uz, you used the wrong URL for the picture; try
http://rulez.pl/~sputnik/kolej/elektrowozy/pulpitep03.jpg
Not unusual to find a large wheel for “throttle” control on European electric designs; I remember seeing one on a rack railcar in the late '70s, and I suspect even a cursory search will turn up all kinds of examples.
IIRC there was a discussion in the Encyclopedia of World Railway Locomotives about precisely why the electric gear benefited from a large-diameter wheel. Winging it from memory – you have multiple tap-changing speed control (similar, I think, to what was on GG1s) but the tap switching is done mechanically. You’ve got a fair number of switched positions, with a fair amount of angular separation for isolation and positive location, but you also need a fair amount of input power to get each ‘notch’ engaged. So a wheel makes sense to get the desired angle (note that with screw advance you can easily use more than a full revolution of the input shaft for tap changing). You will put the wheel where it can be easily and conveniently grasped and turned.
Now, if I were a locomotive manufacturer and wanted to buy a large wheel with convenient hand grips fairly cheap, where do you suppose I would look? Unsurprisingly, to the vehicle manufacturers…
I have to admit that I would also use a horn ring (or rim-blow) on this wheel if I had electrical actuation of the locomotive horn (cf. GEs with that *** computer crossing alert “feature”)
Interesting aside on these designs: I would have thought that it would be easy to tell ‘at a glance’ what notch of the controller was selected by seeing where the wheel was turned to (think of a very large radio mixdown-board pot). In practice it doesn’t work out that way, even for the designs that have a ‘pointer’ attached to the wheel hub. You still want a separate indicator or gauge that tells you what ‘notch’ you’re in (and this indicator, if correctly designed, would also show you the