This crane is based on the model best known from Leaflet No. 28 in the pre WWII Super Model Series. It was published in two versions, the first employing a bearing constructed from Part No. 119 the Channel Segment, while the later revision was modified to use Part No. 167, the Geared Roller Bearing.
Both of these versions of the model were powered by two side plate electric motors, although several illustrations in published in the 1929 Standard Mechanisms manual suggest that a single motor version had been under development at the time.
In the Meccano Magazine for September 1968 another version was published this time incorporating single motor drive and revised slewing arrangements made necessary by the withdrawal from the system of the parts that had been used pre WWII.
The pontoon has been redesigned to support the Flanged Rings used for the roller races of the bearing and which are of substantially smaller diameter than the earlier bearings. The sprocket and chain slewing drive described in the article proved to be ineffectual. The Large Toothed Segments and their matching pinion are much better in this application.
It proved frustrating to operate as the screw driven luffing rams work far too slowly and some attention to the ratios here seems warranted.
