THE GEOGRAPHY OF TRANSPORT SYSTEMS


Intermodal Terminal Equipment

A variety of equipment can be used to perform intermodal operations at a terminal. The choice of equipment is related to a number of factors in terms of capital investment, density and productivity.

  • The fork lift (not shown) can be considered the most basic piece of intermodal equipment but has limitations to be able to handle only loaded 20 foot containers or empty containers of other dimensions.
  • The straddle carrier is a flexible piece of equipment that can be used for all intermodal operations such as loading/loading railcars and trucks as well as stacking containers up to three in height depending if the straddle carrier is a 3-high or 4-high. So, depending on the straddle carrier type, the stacking density may vary between 500 and 700 TEU per hectare.
  • The reach stacker is also a flexible piece of equipment performing intermodal operations between rail and trucking as well as stacking. Since reach stackers are limited to stacks of three containers they can support a stacking density of 500 TEU per hectare.
  • The rubber-tired gantry (RTG) is a fixed intermodal piece of equipment that is used for loading and unloading railcars from trucks in high density terminals as it can span over up to 4 rail tracks. It is also used stacking operations where it can manage densities of up to 1,000 TEU per hectare with stacks of up to 4 full containers or 5 empty containers in height. It can service 8 to 9 trucks per hour, which involves 30 to 40 container movements since containers need to be reshuffled within their stacks. The RTG has higher acquisition costs, but lower operational costs.
  • The rail-mounted gantry (RMG) is a fixed piece of intermodal equipment that is widespan and can be used for intermodal operations over 6 to 10 rail tracks. While they tend to be mostly used at port terminals for operations over large container stacks, new intermodal rail terminals are increasingly relying on RMGs to perform intermodal operations over a series of train tracks, often with some below crane space for track-side stacking. A RMG used solely for stacking, it can accommodate densities above 1,000 TEU per hectare (4 full or 5 empty containers).
  • A portainer is a gantry crane strictly used to load and unload containerships and comes in different size base upon the ship class they can accomodate. While a Panamax portainer can accommodate ships up to 13 containers in width, Post-Panamax portainer reaches up to 18 containers alongside. The latest class of portainers is dubbed "Super Post Panamax) and can handle the latest generation of containerships of 12,500 TEU by being able to span up to 22 containers. Containers have to be brought to the portainer by holsters using chassis or by straddle carriers.