Caption: Fort McMurray-Edmonton train 556 has just changed crews in Lac La Biche Alberta and is resuming it's southbound trip. A keen eye will note the antenna affixed to the sun visor of 5263, this is part of the satellite phone system used on this line to contact the RTC and other parties. Another interesting point to observe is the single sulphur tank car amidst the string of coke cars. This is to accommodate the rotary couplers located on one end of the coke cars. Basically all the cars with the rotary coupler on the north end of the car need to be grouped together in order for the rotary coupler system to function properly, and the same goes for the cars with it on the south end. The tank car is acting as an adapter between the two as it is sometimes impossible to connect the train line hoses on sulphur cars when they are not uniformly oriented.