gantries

A gantry is a term used for a framework consisting of one or more vertical supports and a horizontal bridge that spans between them. Gantries are used to support, guide, or move equipment over a space, and the term covers a range of applications in construction, industry, transportation, and science.

Gantry cranes: In crane engineering, a gantry crane has two or more legs that support a bridge carrying a hoist. The legs run on rails or other ground tracks, allowing the entire assembly to travel to lift and move heavy loads without relying on a fixed building structure. Gantry cranes are common in shipyards, rail yards, ports, and container terminals, and subtypes include full gantries and semi-gantries depending on leg configuration.

Road and rail gantries: On roadways and rail corridors, gantries span the transport lane to carry cameras, sensors, and tolling equipment. They support electronic toll collection, traffic management, and enforcement devices, and may be fixed or temporary in some projects.

Medical and scientific gantries: In medical imaging, a gantry forms the rotating frame of CT scanners, MRI machines, and PET scanners, housing the imaging components and rotating around the patient. In particle accelerators and beamlines, gantries are used to support and align detectors and beamline equipment, sometimes capable of rotating the apparatus around a fixed point.

Design and safety: Key considerations include load capacity, span, travel speed, stability, wind and seismic resilience, and maintenance access. Safety features typically include limit switches, anti-rollback mechanisms, and regular inspection protocols.