This is a great way of carrying extra baggage when travelling off-road.
The geometry means that the trailing bike follows in the tracks of the front bike and it permits 90 degree cornering. Difficult bendy and undulating terrain can be tackled without problems. Whe riding, you can always be sure that if the front bike fits through a gap, the trailing bike will as well.
With other layouts I've tried, the trailing bikes swing wildly from side to side like the trailers of articulated HGVs.
No, I didn't pinch the idea from Jack Taylor. I arrived at it independently.
trailing bike follows in the path of tow-bike
child has less effect on tow-bike steering and ballance than high hitch designs
stable 90 degree cornering and short total length
front wheel of tow bike will try to lift when climbing in low gears
makes children think that simply rotating their legs is the same as pedalling