Rapido is proud to announce the Montreal Locomotive Works S-13 and RS-23 locomotives! These two models are virtually identical from the frame up. In fact, they both used the same MLW-style switcher body and underframe of the previous S-11 and S-12 designs. Under the hood both used an ALCO 251c prime mover which generated 1,000hp. The major difference between the two versions was the S-13 rode on switching style AAR trucks while the RS-23 utilized road trucks.

British Columbia (formerly PGE) received the first MLW S-13s with an order of three, delivered in January 1959. Canadian National was the largest owner of S-13s, rostering 49 units with the first also arriving in 1959. Of these, 26 were assigned hump service in sets of three units. These were a variety of paint schemes for both BCR and CN before being retired or sold to short lines.

Canadian Pacific was the largest owner of the RS-23 locomotives with a total of 34 built betwee