Container Rail Mounted Gantry Crane. Product Name: Container Rail Mounted Gantry Crane. Lifting capacity: 400t, 100t, 130t, 100+100t. Span: 18~36m. Container dimensions: 20', 40’, 45’. Rail-type container gantry crane or RMG is mainly consists of the steel structure, lifting mechanism, micro-transfer mechanism, spreader anti-sway system