Types of Forklift Masts
Forklifts are an essential piece of equipment for most warehouses, making it possible to safely store and move products and materials in a timely manner. One of the most important parts of a forklift is its mast.
Also called the “upright,” the mast performs the task of lifting and lowering the load on the forks. There are many types of masts, each with its own height and stacking requirements. When buying or leasing a forklift, understanding the features and capabilities of the mast will ensure you get the right forklift for the job.
Different Types of Forklift Masts
Forklift masts come in four basic types.
Single Stage Upright.
This type of mast is sometimes referred to as a “standard upright” or “V-mast.” It consists of a two-stage assembly with two rails – one stationary and one that moves. Two side-mounted cylinders provide lift to the rails. An indirect chain provides lift to the carriage/fork assembly.
Single stage masts have one channel with a limited lifting height (a.k.a “maximum fork height”). They don’t provide full free lift, which is the ability to lift the load and forks without moving the mast channel. As a result, the mast must extend higher than other masts when stacking loads. Single stage masts work best with:
- Low lift heights
- Self-propelled, walk-behind equipment
- Outdoor applications where overhead clearance isn’t a problem
Also known as the “Duplex Upright,” the two-stage mast consists of a two-stage assembly. Unlike the single stage mast, its primary center-mounted cylinder can provide the full free lift. The cylinder raises the carriage to the top of the inner rails at a 2-to-1 ratio. At that point, hydraulic fluid gets rerouted to the secondary cylinders to provide the direct rail lift. Great for handling heavy loads at low lift heights, two stage masts are common in high-capacity forklifts of 15,000 pounds or more.
Two-stage masts are best used for:
- Stacking and double stacking
- Indoor applications where overhead clearance is limited
- Trailers and box cars where visibility can be poor
The three-stage is one the most versatile forklift and commonly used masts. Its higher lift capabilities make it well suited for a variety of general warehouse applications. Three stage mast forklifts with base capacity of 2,000 to 6,000 lbs. can lift up to almost 16 feet.
Also known as the “triple” or “triplex” mast, the three-stage uses two movable rails and one stationary to provide a three-stage lift with full free lift. The primary cylinder provides the full free lift of the carriage and forks. The secondary lift cylinders directly lift the intermediate rails. For the final lift, the chains pull the inner set of rails along with the carriage/fork assembly.
The three-stage mast is ideal for jobs where:
- The forklift needs to reach above-average heights
- Full free lift is required
- Duplex masts are not available
Also called the “Quad” mast, the four-stage uses four sets of rails and a second set of chains to provide the highest reach among forklifts. Quad masts work much the same way as three stage models. The main difference is the additional set of chains and pulleys that provide the fourth stage of lift. Quad masts also offer full free lift, but the lifting capacity decreases with heavier loads.
Ideal for high stacking in specialized warehousing, quad masts:
- Can load and unload higher-tiered stacks than double or triple stage masts
- Can lift to heights up to 20 feet
- Require extra caution due to their high lifting ability
Mast Functionality and Safety
When purchasing a forklift, keep the following in mind:
- Lift height. When selecting the mast, add at least six inches to the height of your tallest racking shelf. This margin of error will provide enough clearance for operators to safely handle loads at height.
- Height when lowered. Each type of mast comes to rest at a different height when fully lowered. Make sure the model you choose can fit any height restrictions for your doorways, loading docks and other entrances.
- Capacity. Some mast features – such as the side shift on a triple stage mast or an extended tilt – can reduce the lifting capacity of the forklift. For example, suppose your forklift has a base capacity of 5,000 lbs. Raising it up to 188” and tilting all the way forward could cut your base capacity in half.
- Load backrest. Most forklifts come with a 48-inch load backrest. If your warehouse has lights, sprinklers, or other items that could be damaged by lifting, consider asking the manufacturer to customize the backrest to your needs.
The most important aspect of operating any forklift is always operator safety. No matter what type of forklift or mast you use, every operator should be fully trained and certified before getting behind the wheel. For fast, affordable forklift operator training, visit us at forkliftcertification.com.