I have seen the term "Bozo Consists" when describing a consist that had
SD45s in it mixed with older SD7 & SD9s, this was due to the IDAC slow
crawl feature the SD45s and later EMDs were built with. The IDAC system
active, coal trains, ore/taconite trains could be loaded uniformly with
pretty much equal tonnage of cargo in each hopper. I think I saw the term
"Bozo Consists" used in a story on the Erie Lackawanna RR back when TRAINS
magazine had their "Locomotive of the month" thing that they were doing,
they would dedicate about three or four articles in the magazine to the
L.O.T.M. and look at how the locomotive was developed, numbers built,
variants thereof, etc.
Andrew Koetz
Re: compatibility of
engines<http://groups.yahoo.com/group/CBQ/message/45568;_ylc=X3oDMTJwb2VvZG8xBF9TAzk3MzU5NzE1BGdycElkAzE3MTI3BGdycHNwSWQDMTcwNTA2MzY5NwRtc2dJZAM0NTU2OARzZWMDZG1zZwRzbGsDdm1zZwRzdGltZQMxMzkyMTE2MjI4>
Mon Feb 10, 2014 10:30 am (PST) . Posted by:"Philip Weibler"
pawnbaw@sbcglobal.net<pawnbaw@sbcglobal.net?subject=Re%3A%20compatibility%20of%20engines>
Hello Bill and All -
In the early days - during WWII and in the immediate post-war years - there
were control problems when trying
to run locomotives from different builders in multiple unit sets. Baldwins
lived in a world of there own (someone
check me on this) with pneumatic controls. ALCo locomotives loaded
differently than EMDs and made starting
a heavy train a real challenge for the engineer.
Eventually the railroads got different types to play together nicely. The
27 wire m.u. connecting cable between units
became standard, electrical loading characteristics were adjusted, and
automatic transition became the norm.
Almost. Into the 1960s there were FT, F2, and F3 locomotives with manual
transition - the locomotive engineer had
to use a lever on the control stand to 'shift' the electrical power
circuits as train speed increased. This is why you see
photos of older units leading brand new ones. They'd be stuck in 'low
gear' if they were trailing.
Gear ratios were a problem 'way back when' - switch engines being towed in
a train were limited to 35mph or so.
Newer switchers with road trucks could run fine with the big boys. At the
other extreme, putting an old F2
behind an E9 and running 100mph would tear up the gearing and the traction
motors on the freight unit.
Horsepower ratings do not have to be matched. If the locomotive engineer
opens the throttle to 'Run 4' the big unit
will deliver half its power and the trailing GP7 will deliver half of its
power. Wide open, both units will deliver their
maximum power. This won't 'burn up' the GP7 - it will do what it was
designed to do and put out 1500 horsepower.
Nowadays the big freight units have all of their power output computer
controlled. PAW
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