Before revision:  For the case of three or more masses, we obtain conjectures for the globally optimal load that are strongly supported by extensive computational results . To obtain these, we use techniques from nonsmooth optimization, employing the recently developed open-source software package GRANSO (GRadient-based Algorithm for Non-Smooth Optimization) to maximize the load subject to appropriate nonsmooth stability constraints .
After revision:  For the case of three or more masses, we obtain conjectures for the globally optimal load that are strongly supported by extensive computational results , obtained using the recently developed open-source software package GRANSO (GRadient-based Algorithm for Non-Smooth Optimization) to maximize the load subject to appropriate nonsmooth stability constraints .