This paper deals with a first implementation of the socalled motor calculus within Modelica. The motor calculus can be used to describe the dynamical behaviour of spatial multibody systems in an efficient way. This method represents an alternative approach to modelling of multibody systems. In the paper, some fundamentals of motor calculus are summarized. Furthermore, a simple implementation of motor algebra by special additional Modelica code within some components of the Modelica Multibody Standard Library is presented. This approach fully corresponds with the paradigm of object-oriented modelling. However, the present realisation is not equation-based in its full sense because of the missing possibility of operator overloading (at least in the available Modelica simulator environment). Instead of this, some functions are used carrying out the necessary calculations. Using this implementation, some examples are given to prove the applicability and correctness of the implemented approach.