" GE " make Semi-Traction motors are suitable for applications which demand a high starting torque. Semi-Traction motors are basically Series DC Motors

Common uses of the series motor include crane hoists, where large heavy loads will be raised and lowered and bridge and trolley drives on large overhead cranes. 

The series motor provides the starting torque required for moving large loads. Traction motors used to drive trains are series motors that provide the required torque and horsepower to get massive amounts of weight moving.