Adjustable gantry cranes can be adjusted in three ways: height, span and tread. Most adjustable cranes allow height adjustments. Some cranes allow height and span adjustment, while a select group allow adjustments in all three areas.
- Height adjustment – this consists of adjustable leg support frames. Usually spring lock steel pins are removed, the leg frame height raised or lowered and then the steel pins reinserted at the new height. This is especially useful when there are overhead obstructions that must be cleared during transit
- Span adjustment – this is the ability to change the clear span distance on the beam. There may be times when the traffic access in a facility is narrow, but overhead clearances are wide open. In this case, you would move the leg frames closer together on the I-beam, making the clear span narrower in order to move through the facility.
- Tread adjustment – at times both traffic access and overhead space is narrow. In this case, you need to make the tread width narrower. Tread width is the space between wheels on one leg frame. This width determines how much space is needed to move the gantry crane lengthwise through a facility while maintaining the full span length.
