Unusual visitors make their presence known at Altoona, WI on a snowy March day in 1973. It had not been the norm to have GP35/ballast unit (slug) sets operating on the Twin Cities Division mainline, but a heavy flow of traffic on CNW that winter as well as possible spring flooding likely played as factors placing this power on this route. CNW 841 was a "normal" GP 35, while the other two, from a later order, were unique in having larger fuel tanks and roof top torpedo tube style air reservoirs. Only the Frisco (SLSF) had similar GP35s, and theirs also had dynamic brakes unlike CNW.
