Fisher Price converted most of the (major) engines that had a "Thomas" or "Clam Shell" DU to use the Flat type that year. They did the same thing with Diesel and were going to update 'Arry and Bert, which ended up being released unofficially after 2013. Technically, the C battery engines can also use AA or even AAA (which are also 1.5V), but the battery has to be raised up somehow and AAAs are too short.
BTW: when this version came out, Ucwepn used it for his headlamp mod tutorial.
BTW: when this version came out, Ucwepn used it for his headlamp mod tutorial.
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