Friends
Back in the day was it possible to MU F7's and F3's? Is there a list of what could or could not be MU-ed?
John
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John,
I am assuming you are talking about the prototype. When they were first introduced, many diesels by different manufacturers could not be MUed. Baldwin and others used a different control system than EMD for instance. By the mid 50's most of these problems had been eliminated. An easy way to check on what could be MU'ed to another unit is to look at the ends of particular units. If they had receptacles, they were set up for MUing. If there were little doors high on the nose of an F unit, near the headlight, it could be mu'ed elephant style - nose to tail. Many switchers were never set up for MU'ing as their primary use was as inividual units. So, if you are modeling the mid '50's or later, you are pretty safe MU'ing most units together.
Jim Taverna
I was told by an NYC buff that they could not MU EMDs and Alcos (obviously not baldwins) until after the first major rebuild when they were about 15 years old. At that point they standardized on the MU connections and control - at least between Alco and EMD.
EMD F3s and F7s could probably always MU and could MU with GP7s and GP9s most likely.
And various Alcos could MU with each other.
Again they have to have the MU connections on the end. F-units did not get MU connections until rebuilds it seems.
Originally Posted by prrjim:
Again they have to have the MU connections on the end. F-units did not get MU connections until rebuilds it seems.
Not quite. MU connections were also needed BETWEEN units! The "F" units and "E" units came right out of the EMC/EMD McCook plant with MU connections. Both 21/27 pin MU receptacles and air MU hoses for the train-lined sand control (forward & reverse sanding prior to electric control of the sanders).
Otherwise, railroads would not have able to operate A-B-B-A or A-B-B-B, or even A-A consists.
