Choosing the right truck mounted crane for your needs is a complex exercise. However there are a couple of key factors to look for when making your choice.
Crane lifting weights and Distances
The basic job of a crane is to lift, and the second question is how far away the item to lift is.
All cranes are rated by their “Tonne/Meter” rating, or the tonnes to be lifted, times the number of meters of reach required.
Eg, Lifting 800kg at 15meters (from the centre of the crane, not the edge of the truck) of reach, requires 0.800 x 15 = 12 tonne/meters.
Most cranes can be specified with different number of hydraulic extensions, ie, how far its jib extends. So ordering a crane that at least reaches the length of the tray is a good place to start.
Truck size for Mounted Cranes
The second question is how big is the truck you need to fit the crane to, and what is you payload requirement. To add to the complexity of this question, do you want the crane behind the cab, or on the back of the tray. Placing it behind the cab keeps it out of the way, and gives you more load flexibility, however in Australia, front axle load limit is a critical factor, meaning heavy cranes may not be legal even on an empty truck if mounted behind the cab. A crane expert can answer these specific question for you, but a light weight and compact crane is a good place to start.
Radio Controlled or Manual Controls for your Crane?
While a manual controlled crane is cheaper to purchase, unless you have a two man crew in your truck, they also require a lot more walking around, and take longer to load and unload. Radio controlled cranes allow the operator to monitor and control the load from beside the load. Manual cranes require you to align the load, walk back to the controls, lower the load, and perhaps do this two or three times for every lift. Many building sites require a person alongside the load to monitor its lowering requiring either radio control, or second man in the truck.
Truck Mounted Crane Safety Systems
Every crane with more than 1 tonne on the load chart, requires a rated capacity limiter system. In effect this prevents the crane from being over loaded, and running the risk of the truck being pulled over by the crane. On all modern cranes this is a digital system, which recognises the amount of force on the crane, and electronically de-rates the crane to keep it within safe working parameters. For example, a crane may be able to reach 15 meters, and may be able to lift 3 tonnes safely at 5 meters, the crane will prevent that load being extended beyond its safe limit of (say) 5.5meters. In most cases, this is set by the crane dealer when fitting the crane to your new truck. These settings are different for every single truck /crane combination, and are required by law to be set at a safe level when the crane is delivered. It is both illegal, and extremely dangerous to disable these systems. These safety systems also look at the position of the stabiliser legs and determine the safe program according to the position of the leg. To ensure these setting are safe, they are generally set based on the truck being empty. Having a load makes the truck more stable (because it is heavier), but most crane control systems cannot identify this increased stability. The patented HMF EVS (electronic vehicle stability) system is unique, in that it sets the cranes performance parameters according to the stability of a truck dynamically, for every situation. This means the crane automatically increases its reach and lift capacity to the maximum safe level of the truck with its load at any given situation. More load, means more stability, means more reach. This is particularly important on medium and large cranes.
Crane Slewing Angle
The final piece of the puzzle to consider is the slewing angle. That is the amount of rotation the crane can make. A typical slew range is around 400-420 degrees, meaning the crane can rotate slightly more than a full circle. Some large cranes are equipment with a system called “infinite slew”, meaning the crane is not limited by the amount of rotation, it can go around in a full circle without limit, because it has very sophisticated rotary couplings, and slew motors instead of a rack, which allows the crane to rotate without limit.
Here’s a quick guide Ranked by Power to Weigh (Tonne/Meter divided by Tare Weight in tonnes) of some of Australia’s most popular truck mounted cranes:
NB Fassi F195A is 2520mm wide, which is over width for Australian Roads
Other Things to look for.
How many sensors are on this crane. With cranes becoming ever more sophisticated, safety systems and electronic sensors have increased in use enormously. Some crane manufacturers have simply added sensors to an old design, while others have re-designed their cranes for the new technology. Keeping the number of sensors to a minimum increases the on-road reliability.
How well protected are the hydraulic lines and sensors. Are they external or Internal? The less exposed the hydraulics are, the less likely they are to snag on a load, or kerb side object, reducing the risk of damage.
You’re about to spend a lot of money on a crane. Is it painted, or powder coated?