The first week of October we had the opportunity to study the construction of a German Propeller. The German Propeller has three blades which are made of hollow steel with the shank of these made of aluminum. The hub is made of forged steel, with a very high tensile strength.

The operation of the blades to increase and decrease the pitch is by the use of gears. Roller bearings are used in all movable parts of the propeller to keep the parts moving freely and from wearing out.

On the rear of the hub there is a large master gear which rides on roller bearings, and turns three smaller gears, one for each blade. Attached to the smaller gears is a shaft which goes through and turns a worm gear. The worm gear turns a gear which the blade is attached to. This controls the pitch of the blades. The small gear shaft rides on three rows of roller bearings. The blades ride on the two sets of roller bearings of three sets each.

This German Propeller is a well constructed propeller and is easily maintained. The blades are interchangeable and all blades can be changed without removing the propeller from the engine. The ships opinion is that the blade can be changed in five minutes.

*Propeller was most likely brought "home" from a 'Trucking Mission'.