Case studies measuring the benefits of the HSS hump sequencing model

A model, entitled HSS, for selecting the sequence in which trains are to be humped in a rail hump yard, was applied to the Canadian National Railways' Taschereau Yard in Montreal. Based on the promising results of an eight-train pilot study, two separate case studies were performed. The first study compared FIFO and HSS in sequencing the 57 trains that arrived during a 24-h period. The other compared current operations and HSS in sequencing the 169 trains that arrived during a three-day period. Both showed improvements using HSS, with estimated time savings of about 3 and 0.6 h per car at Taschereau Yard, and corresponding estimated inventory savings of about $4000 and $700 per day, respectively. Keywords: humping, HSS, sequencing, railcars.