On these days forklift operators typically depend upon any one of four different forklift mast types. Manufacturers do not always use uniform terminology to refer to these components. One company may describe its masts in terms of the lift mechanisms, while another may base its descriptions of masts on the number of mast sections.
1. Simplex Mast
Usually these forklifts can lift loads only limited distances. For instance, they may lift cargo onto the back of a truck.
This common type of standard forklift mast employs an arrangement of a stationary outer rail and a sliding inner rail with chains to lift a carriage and forks. The maximum extension of the inner rails will limit the height of load lifting.
2. Duplex Mast
This mast is the optimal choice when loads need to be double-stacked and the lift truck will not be placing such loads into high racking. Material handling application examples include freight cross-docking and manufacturing component delivery operations. (Also known as: Duplex Upright or Two-Stage Free-Lift Mast).
This type of mast has a hydraulic cylinder located in the center of the mast assembly that helps push loads upwards, enabling the load to rise while the mast itself remains stationary. Once the carriage reaches the top of the inner rails, two supporting side rails complete the lifting process.
3. Triplex Mast
These widely used masts have become the most popular recently. They enable loading and unloading at higher elevations than duplex masts.
A Triplex mast differs from the Duplex because it includes two sliding rails plus a single stationary rail: it is often found on a reach truck as it can extend a load further to reach greater distances. A large hydraulic ram in the center of the mast assembly performs most of the lifting of the forks and carriage. Secondary hydraulic cylinders lift the middle sections and a chain system, which pulls the inner section and the carriage when the mast is fully extended. (Other terms for this type of mast: Third Stage Mast, FSV Mast, Triple Mast, Triple Stage Upright).
4. Quad Mast
As the name suggests, this complex mast depends on four sets of rails and chains to move loads. Forklift operators typically require advanced training in order to use this type of mast, which reaches much higher elevations and may have restricted visibility.
A Quad mast can provide full free lift as it operates similarly to the Triplex. However, its powerful hydraulic secondary cylinder rails and chains permit extra extension. (Also known as: QFV Mast, or Four Stage Mast).