Gibson Manufacturing Corporation was a company that made tractors and railroad speeders.

[1][2] In 1933 Gibson recognized that there was a need for larger railroad speeders than those available on the market at the time.

[6] A, D, SD, and Super D tractors all used 6 HP Wisconsin AEH engines.

Seattle tractors were usually painted blue-gray with red sheetmetal.

"[citation needed] Several accessories were sold to go on these tractors, including two types of plow with Sandoval coulter disks, a disk harrow, dozers, and for the Model D a sickle mower.