Rob Vetter is technical director and managing partner with the Ives Training Group, in Blaine, WA, USA, a leader in North American mobile equipment training systems since 1981.

---

The popularisation of rough-terrain variable-reach forklifts (otherwise known as telehandlers or telescopic materials handlers) in recent years is remarkable but not unexpected, given the combination of power and versatility they offer the end-user.

Technically, a telehandler is considered an Industrial Truck Association (ITA) class 7 rough-terrain powered industrial truck (PIT), but any similarity between it and its vertical-mast cousins ends there. Let's take a look at some of the main differences.

It has a boom instead of a mast
Telehandlers are built with a horizontal boom rather than a vertical mast. The boom is capable of being elevated and extended/retracted (telescoped) by the operator. How much and how far depends on the model.

You can adjust the level
This is a unique feature of the telehandler, whereby the operator can adjust the lateral (side to side) angle of the chassis up to 10 degrees in either direction using hydraulic controls, to level the machine with the aid of a bubble-type level indicator in the cab (see picture). This is a very handy feature to use before elevating the boom.

There are multiple steering modes
Most telehandlers have several steering options: front steer, circle steer and crab steer. Choosing the 'front steer' option causes only the front wheels to react to movement of the steering wheel, while the 'circle steer' option causes the front and rear wheels to turn in opposite directions, giving the unit surprising manoeuvrability. Selecting 'crab steer' causes all four wheels to turn in the same direction, allowing the unit to move diagonally over the ground.

There are several carriage options
The carriage of a telehandler can not only be tilted forward and back, but many manufacturers offer options whereby it can also be made to pivot (left and right) around its vertical axis or rotate (radially) around its horizontal axis. These options make the unit more versatile and allow it to make full use of the many lifting/work attachments that are also available, such as materials buckets and jibs.

Its load capacity is variable
Determining the load capacity of a telehandler is a completely different exercise than it is on a vertical mast unit. Since its capacity is dependent on such things as boom angle and extension, the deployment of outriggers (if equipped) and which lifting attachment is used, the operator must consider these items in the calculation of the maximum capacity of the unit in a given configuration, using load charts and other capacity-related information provided by the manufacturer.

It has unique operating characteristics
With so many options and systems unique to telehandlers, it is extremely important for operators to receive equipment-specific training and evaluation. The best piece of advice I can offer that will move you in that direction is: READ THE MANUAL! The manufacturer's operating manual is a rich source of equipment-specific information and a must for any operator to become very familiar with.

Following are examples of the types of equipment-specific items I found in the manual of one of the many telehandlers I have encountered when training operators. Had I not checked, I may not have known that:
* The boom would not extend unless the outriggers were deployed.
* At boom angle greater than 40 degrees, the axle oscillation system locks up, the transmission shifts to neutral and the park brake is automatically applied.
* If the direction selector is activated less than three seconds after start-up, the unit will not move and will need to be restarted in order for it to get through its self-diagnostic systems check.
* The frame tilt will not work when the boom is elevated past horizontal.

These may seem like standard issues for those that are used to working with this equipment, but imagine the adjustment that an operator of a vertical mast-type unit would have to make.

Telehandlers are incredibly versatile and practical machines that are utterly unique in design and operation compared to conventional vertical mast forklifts. Operating these units requires thorough, make- and model-specific operator training and plenty of hands-on practice because in improperly trained hands, they can be as destructive as they are useful.