DERS-3 / H16-44

Question: New Haven's Fairbanks-Morse units 560-569 appear to be the only units ever built incorporating the WABCO eight notch electric throttle-reverser, effectively an electric version of the common two-slot pneumatic throttle. (Not WEMCO... WABCO! See my posts in the Fairbanks Morse forum here, under control systems, for details.)

I am wondering if anyone here has specific knowledge as to why these units could not operate in multiple with anything else on the NH. I think they had No. 6 brakes, and photos appear to show a standard single jumper cable socket for MU .. I have no details but that could be it. They had no selector lever, which means they could not lead manual transition units. They did have the same solenoid sequence as the other electric throttle units, and PG governors. Anyone who can provide further information on these units or their control equipment, please do! Thank you!

WILL DAVIS

Hi
Maybe you should post the same question, on the New Haven Railroad Technical & historical webpage. https://www.nhrhta.org this is just a suggestion. Pat.

Pp. 465-468 of J. W. Swanberg's New Haven Power: 1838-1968 of 1988 states -- without going into precise detail that 590-599, Class DERS-3, could only MU with others in the same class.. A later order -- 1600-1614, Class DERS-6 -- could MU with EMDs and some ALCOs.
Initially, the OP engine would go longer before a rebuild was needed, but design complications made the overhaul expensive.
Crews had issues about the high running boards requiring stepping down into the engine compartment. Additional crew complaints focused on the 1600s having smaller cabs and higher end platforms than the EMDs those ALCOs they could MU with. There were also different ratings for safe minimum continuous speed.
The NHRTA archives may have details on the 590-599 contrtol systrem.