Caption: This photo is from around the height of excitement for the fans regarding CNs "Laser" service run thru power. It was prevalent on most of the daily trains #238 (Chicago-Montreal) and return #239. Not often would I catch the train with 3 Grand Trunks. Sometimes it was just two units, sometimes a DT&I mixed in, sometimes CN mixed in; you just never knew. The "Laser" was not an extra fast train, but just a catchy moniker for CN's TOFC (trailer on flat car) service using well cars in order the trains utilize the rather restrictive Port Huron-Sarnia tunnel under the St. Clair River. This operation started around 1982 and by 1992 CN had graduated to using containers, and with the later enlarging of the tunnel, double stacks. Containers proved much more efficient that moving truck trailers by rail. Power on this train, which is just hitting the CN Halton sub off of the Oakville, is GT 6419, 6405 and 6415.