Forklift Masts - different types and what they're suitable for.
Forklift operators have at all times to examine and distinguish the different types or classifications of forklift masts. For starters, these masts are what is commonly known as an “upright” and are to be the vertical assembly installed at the front of the forklift. This mast is responsible not just for the raising, lowering and tilting of the loads, but it also renders the other parts of the forklift to run their functions, e.g. the carriage, forks, etc.
Operators must also know that the masts’ carriage has an actuated hydraulic piston installed in the middle area of the mast. This piston is in sync with the pulling of the mast lever positioned in the forklift’s cowl as the piston raises the load of the fork. This entire complex mast system is run and lifted by the use of a hydraulic displacement and consequently lowered using the sheer force of gravity.
Another attribute that forklift operators must also know is the concept of free lift. This term refers to the distance that will be carried by the mast prior to the inner channel extending limit set for the forklift, which is the imperative for double-stacking in most trailers. In sync with this attribute is the forklift mast’s “side shift” feature, which allows the machine to do a horizontal movement of the forks to make sure that it can accurately pick and place loads in the least amount of time possible.
What also supplements the mast’s ability to do a simple direct lift or perform a multiple channel staging action are the different features of the mast depending on the type. These features can either enhance the forklift’s performance or extend the application range of the lift truck. That said, here are the different mast types available in the industry today:
General Overview of Mast Types and When To Ideally Use Them
1. Single-stage Mast
The main distinguishing feature of a single-stage mast is that it only ever has one channel to do the lifting, but it has a zero free lift. There are two side-mounted lift cylinders in this type, which provides for inner rails and indirect chain lifts to the fork assembly. This mast type is known for raising its carriage to a rate of about two inches for every inch of the cylinder rod extension.
Ideal Use: An ideal application of this type is for outdoor applications or conditions where there’s no environment barrier and an overhead clearance will never be an issue.
2. Duplex Upright
This mast is typically described to be a full-free lift, FFL, Hi-Lo or an FV Mast. It’s a two-stage assembly but with a full free lift capacity. This type also resembles the standard upright, and works in the same way, except for the fact that its primary and center-mounted cylinder provides for a full free lift.
When this mast’s primary cylinder raises the carriage to a 2-to-1 ratio, it’s raised to the top of the inner rails. This happens right before the hydraulic fluid is taken to reroute the mast to the side-mounted secondary cylinders for a strong direct rail lift.
Ideal Use: Because of this mast type’s great visibility, operators can find it ideal to employ this mast type for moving loads in trailers. The robust type of this mast can even withstand harsh outside conditions.
3. 3-Stage (Triplex, Triple, TSU, FSV Mast)
A three-stage mast or what’s known as a triplex is the industry’s most reliable, versatile forklift mast, making it arguably the most popular type in the industry. It’s an added distinguishing factor that this mast type has outer rails with a free lift ability. This mast’s two inner sections may also be able to lift loads that are higher than the two-stage type.
Ideal Use: Because of the mast’s robustness and versatility, operators find this type to be reliable equipment for warehouse applications. Warehouse work requires machines that don’t easily break down and can reach higher places, which in turn fits what a 3-stage mast can do.
4. Quad Upright (QFV Mast)
The quad upright or mast is made of four sets of rails and an added set of chains that assist it to allow for four stages of lift as well as a full free lift. There’s not a lot of difference between this mast type and a triple-stage upright except for the fact that the quad is equipped with a second set of chains and pulleys. This set is operated with the help of a secondary lift cylinder that empowers this type to lift to as high as four stages.
Ideal Use: Because a quad upright has the highest reach, it’s ideal to use this in warehouses or large-scale supermarkets that have very high stacking in their storage.
It’s essential to remind forklift operators that it’s not just how high a forklift mast can reach that matters when picking the right mast. Lowered height is just as important since the lifting capacity of a forklift can decrease when its load is raised. The down height plays a crucial role when the chosen application is to transport a load through a door or there are overhead restrictions.
Another important aspect to take note of in choosing a mast type is the load capacity. Going beyond the base capacity of a forklift may de-rate and delimit the productivity of the forklift, and could even risk damage to the machine.