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Powered Industrial Trucks (Forklift) eTool
 Types & Fundamentals

   Parts

     Mast and Carriage
     Forks
     Attachments
     Nameplate
     Danger, Warning &
        Caution Labels
     Controls
     Instruments
     Battery
     Overhead Guard
     Tires
     Safety Devices
Parts:
Mast and Carriage
Reach truck with mast extended.
Figure 1. Reach truck with mast extended.
The mast is the vertical assembly that does the work of raising, lowering, and tilting the load. The mast supports the carriage that allows its vertical movement with the hydraulic lift. The carriage is made of flat metal plates that move along the mast by chains or are directly attached to the hydraulic cylinder. The hydraulic lift cylinder supplies the power to lift the load.

Mast Types
There are a number of mast types:
SIMPLEX:

The features of a simplex mast are:
  • Single stage mast.
     
  • Limited Free Lift (4-6") Free lift is the distance the forks go up before the mast is extended.
     
  • Recommended Use: In loading and unloading trucks and in areas where overhead clearance is a problem.
DUPLEX:

The features of a duplex mast are:
  • Two stage mast.
     
  • Has greater Free Lift (50-60") than the simplex mast.
     
  • Can load and unload higher-tiered stacks than simplex.
Triplex mast in narrow aisle rider reach truck. Note that the forklift is removing stock from a rack. Foot and truck traffic in the opposite aisle way should be controlled to prevent injury from falling materials.
Figure 2. Triplex mast in narrow aisle rider reach truck. Note that the forklift is removing stock from a rack. Foot and truck traffic in the opposite aisle way should be controlled to prevent injury from falling materials.
TRIPLEX:

The features of a triplex mast are:
  • Three stage mast.
     
  • Has same Free Lift (50-60") as duplex mast but extends further.
     
  • Can load and unload higher-tiered stacks than simplex or duplex.
 
QUAD:

The features of a quad mast are:
  • Four stage mast.
     
  • Has same Free Lift (50-60") as duplex or triplex mast but extends further.
     
  • Can load and unload higher-tiered stocks than the duplex or triplex, but requires precautions at its highest lifting heights.
Note: The lifting capacity of the forklift decreases as its load is raised. For more information, see Load Handling and Narrow Aisles.


Visibility
Mast configuration can affect the operator's visibility. Newer mast designs, such as those that use two side cylinders, can provide substantially improved visibility compared with some older mast designs that have a single central cylinder. (Figures 3 and 4)

The operator should travel with the load trailing and/or use a spotter whenever necessary to achieve adequate visibility.
 
Mast with central cylinder obscuring visibility.
Figure 3. Mast with central cylinder
obscuring visibility.		 High visibility mast with hydraulic cylinders on the sides.
Figure 4. High visibility mast with
hydraulic cylinders on the sides.

Types & Fundamentals | Operating the Forklift | Understanding the Workplace | Training Assistance
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