Objectives  To achieve lightweight design of double-arm propeller shaft brackets.

  Methods  By comparing and analyzing the requirements of the current domestic rules and the main classification societies in the world for the dimension of propeller shaft brackets, this paper interprets the differences between the rules, and searches for ways to reduce the weight of the double-arm shaft brackets from such differences. According to the differences between the rules, DNV-GL rules with significant differences from the CCS rules in the relevant aspects are selected. Based on the same propeller parameters, double-arm propeller shaft brackets are designed according to the minimum sizes requirements specified in the two rules. Subsequently, the strength and vibration performance of the double-arm propeller shaft brackets are verified by the relevant regulations of the national military standard.

  Results  The results show that the strength and vibration performance of the propeller shaft brackets designed according to the two rules meet the requirements. The total weight of the propeller shaft brackets designed according to the minimum sizes requirements of DNV-GL rules is reduced by about 16.8%.

  Conclusions  If the double-arm propeller shaft brackets are designed with the DNV-GL rules, the weight thereof can be reduced to some extent. This paper provides an idea for the lightweight design of the double-arm propeller shaft brackets in practical engineering.