The need to make the most of the potential and easy movement of the video camera trolleys lead to what are known as ‘crab-dolly’. Apart from making it possible to steer the two rear wheels, the ‘crab-dolly’ also allows for moving all four of them at the same time. This means that the trolley can move immediately from straight to sideways like crab. The first ‘crab-dolly’ versions were called ‘Houston’ (1946) and ‘Selznick’ (1948). In 1950 the first hydraulically lifted dolly crane was produced. In the same year a very small dolly model was launched on the Italian market which could go through normal-sized doors or passaged, the forerunner of the modern-day Elemack ‘Octopus’. An example of how this type of dolly crane was used is the opening scene in Europa ’51 (1952) by Roberto Rossellini.