A rail mounted gantry is a heavy, overhead crane typically used to load and unload heavy items on docks and in rail yards or factories. These cranes consist of heavy, A-frame constructions located a distance from each other and fitted with train-type wheels on their wide, lower sections. These wheels run on parallel railway tracks, allowing the structures to move up and down the rails. The two A-frames are connected at their top ends by a cross rail arrangement on which an overhead crane is mounted. The complete rail mounted gantry can thus move forwards or backward along the lower rails, while the crane transverses the gap between them on the upper tracks allowing the gantry to cover large loading areas.
Loading docks, rail yards, and heavy manufacturing facilities often require cranes that can lift extremely heavy, large loads and move them long distances to discharge points. When the lifting operations are located within buildings, these functions are typically carried out with conventional cross-travel overhead cranes. When the loading and offloading take place outside, another solution is required. In many instances, this solution takes the form of the rail mounted gantry, which allows for the lifting of high and heavy loads across a large loading area. These gantrys are also capable of moving suspended loads over considerable distances between loading and offloading points.
The heart of the rail mounted gantry system is a pair of railway type tracks situated parallel to each other. The separation distance between the tracks and their lengths are dictated by the requirements of the loading facility. Running on wheels on each of the tracks is a high, robust A-frame assembly, the top portions of which are joined together by a track assembly that supports a cross-travel overhead crane. The overhead crane is then free to travel between the uprights along the upper tracks. In other words, the entire assembly forms an inverted square "U" with its open ends running on the lower rails.
The rail mounted gantry allows excellent flexibility regarding its range of loading movement. The crane can lift and lower loads at any point along its range of travel between the uprights. Once lifted, the entire gantry can then move along the main, lower tracks to drop the load at a discharge point. Both the crane functions and the gantry track movement are controlled from an operator station located on the crane assembly. This flexibility makes the rail mounted gantry ideal for loading and offloading cargo containers and other large loads that require both heavy-lifting capacity as well as extended headroom and travel capacity.