This paper presents a design optimisation of a mechanism used to lift and turn heavy objects, in this case, a specific gear that weights 3000 kg. The objective pursued during the development of the project was to reduce the weight of the mechanism, and thus, make it more cost-efficient, as well as to improve the clamping system to secure that the heavy objects are safely handled. The method followed was to first identify the critical parts in cooperation with the client. Then, the corresponding analysis has been developed for each of those parts, by minimising the mass of two of them, and by selecting and dimensioning the guideways for the clamping motion in the other case. The key results obtained from these analyses were that the weight of one of the parts was reduced by 50 %, the clamping system was improved and that the stress analysis shows that the maximum stress is far below acceptable levels. Hence, it is concluded that it was possible to optimise the mechanism and reduce the weight, improving the handling of heavy objects.