"Pole trailer" means every trailer or semitrailer attached to the towing vehicle by means of a reach, pole, or by being boomed or otherwise secured to the towing vehicle, and ordinarily used for transporting long or irregular shaped loads such as poles, pipes, or structural members capable, generally, of sustaining themselves as beams between the supporting connections.
(ORC 4511.01(O))  (1969 Code Sec. 70.01)