A fiber laser arrangement having a high beaming power includes a plurality of continuously operating coherent individual fiber lasers. A retractable barrier is provided between the lift platform and the support frame to provide a physical and visual cue to impede or discourage persons from intruding into dangerous areas of the loading device during raised operation. A subset of IPSGs is selected to maximize total profit resulting from provisioning a subset of VPN customers on the selected IPSGs. The opening interconnects the gas lock and the receiving region of the housing, and accommodates passage of the optical element between the gas lock and the receiving region. The inertial sensor mass has a greater density than the elastomeric material.