Crash Safety of Lightweight Gantry in Aluminium

The first collision safe lightweight aluminium gantry has been designed and tested for credible vehicle crash conditions on motorways. The gantry design is based on standard Lattix structural components typically used for supports of fixed and variable message signs. The size of gantry supporting structures and transom is decided by the weight of variable message signs installed normally on the gantry. In the crash tests the lightweight gantry remained standing even after one leg from the nearside supporting frame had been destroyed. However, for the gantry to stay standing with both of the legs removed would require the weight of the variable message signs to be reduced to about half – those of current designs. The final conclusions from the simulations and tests of the lightweight gantry were that the lightweight gantry could only be deployed effectively if the overall weight of the variable message signs were reduced. It is expected that the performance of a lightweight gantry system based on the principles of the prototype currently tested would provide a viable economic solution assuming the modifications identified during the project are implemented. This development work is being investigated by the authors company in conjunction with suppliers of variable message signs. The objective is to produce a lightweight gantry system consisting of a series of standard gantry sections and fully functional lightweight signs.