It looks at first glance that the newly introduced Jinty Dock Tank was simply the early Minitrix model 2914 with a shorter chimney.  Certainly this model had been around since the 1966 Trix catalogue.  However a look at the spare parts lists reveals that as well as the body being different, a different motor had to be used in the UK Dock Tank version of the model.  If you have ever taken one of these apart, you'll realise that there isn't a great deal left after that.  However, the wheels, con rods, gears and such like are common components.  The early catalogues show the UK Dock Tank with black wheels - but my two versions and later catalogues show red painted wheels - like the original.

The Dock Tank was locomotive power provided with the introduction of a complete Hornby train set consisting of the loco, a closed goods van, an open wagon, a guards van an oval of track and a Hornby power controller.