Bruce Hansen writes: This Floating Crane model appeared in the 1958 and later 8 1/2 set manuals. The A49 motor in this model moves the crane boom in/out from the model base and raises/lowers a block & tackle load.
The completed model stands over 30 inches tall and is over 30 inches long with the boom fully extended.
The model uses a gear box external to the motor. A strip is used to shift the gears. The P13 gear between the two CJ 36 tooth gears is driven by the A49 motor. The axles driving the block & tackle drum and boom are attached to the P13’s above each CJ. When the gear shift lever is moved, the strip linkage arrangement pivots on the P13 axle shafts and moves a CJ idler gear in contact with the A49 driven P13 gear.
When the lever pushed forward, the CJ closest to the base engages with the A49 driven P13 gear. The P13 gear just above the CJ is driven which turns the axle that retracts/extends the boom. When the lever is released, the spring pulls the linkage assembly back to the block & tackle position. A pawl engages with the boom CJ gear to stop the axle from spinning and extending the boom under its own weight.
The boom retracts/extends in about 5 seconds, raising/lowering the block & tackle takes about 30 seconds.