Rubber-Tyred Gantry Crane (RTG)
A Rubber-Tyred Gantry Crane (RTG) is a mobile yard crane mounted on rubber tyres that stacks and retrieves containers in the container yard. Spanning several rows of containers plus a truck lane, it travels along a block of stacked boxes, lifting them on and off trucks and stacking them typically four to six high — the mainstay of yard operations at many container terminals.
Because it runs on tyres rather than fixed rails, an RTG can be moved between yard blocks, giving flexibility (its rail-mounted cousin, the RMG, is faster but fixed). RTGs deliver high stacking density, making efficient use of scarce yard space, and are increasingly electrified and semi-automated. Directed by the terminal operating system, RTG productivity and positioning are central to how many containers a yard can hold and how quickly it can serve trucks and the quay.
Yard space is one of a terminal's scarcest resources, and the RTG is how many terminals pack containers densely while still serving trucks quickly. Its stacking height and flexibility directly set yard capacity, which is why RTGs — and how well an operating system positions them — are central to terminal economics.
What is the difference between an RTG and an RMG?
An RTG runs on rubber tyres and can move between yard blocks; an RMG (rail-mounted gantry) runs on fixed rails, faster but not relocatable.
Why are RTGs widely used?
They stack containers high for dense yard use while remaining flexible enough to move between blocks and serve trucks.