Bruce Hansen's Type III Dockside Loader

Bruce writes: "Here's a Dockside Missile Loader built from a 1963/64 #10129 Master Power type III set. When Gilbert introduced type III parts in 1963, they were available in four sets. The Master Power was the largest of those sets.

What's unique about this set and model is the part# 903 Programmer. The #69 Powermatic motor was placed between the #903 programmer and the #95 hoist. The motor drove both accessories which were interconnected with a link bar. The link bar was driven side to side via a cam on the programmer. The resulting action was automated shifting of the #95 hoist between drum A and drum B.

The shifting cycle is about 5 seconds. So, as the model runs, the programmer holds the hoist in drum A for 5 seconds, then shifts to drum B for 5 seconds. The cycle repeats until the motor is stopped. This model is set up so drum A controls raising/lower a crane boom. Drum B is used to raise/lower a ball hook on the crane and drive the model down the track via the hoist's PTO shaft and ladder chain which runs down to a sprocket/ wheel.

The model actually ran better than I expected. The 3-4.8V Powermatic motor didn't have nearly the torque of an A49 type II motor. The timing of the action was perfect; when starting the model at one end of the track, the hoist starts to raise the boom. After a programmer shift, the crane starts to creep down the track and the ball hook raises. Another shift occurs and the cycle repeats itself. The three actions timed out right at the end of the track: the ball hook was all the way up, the crane boom was at its top position and the traveling crane was at the end of the track.

The action can be backed up by reversing the transformer's polarity switch and the cycle repeats in reverse. The programmer was available only in 1963 and 1964 making it a somewhat scarce part."