"Weekly maintenance and inspections are essential, as well," says Whiteis. "Proper torque on mounting bolts will vary from truck to truck, so consult your owner's manual. All bolts should be inspected for torque on a weekly basis."
Whiteis also recommends several other once a week checks on your service truck and crane:
- Visibly inspect all bolts and tighten as required
- Lubricate the rotation gear
- Inspect sheave bearings and replace if rough or loose
- Inspect body for any cracks around the crane box
"It may seem that quarterly inspections are less critical since they are not performed as regularly as more routine daily or weekly maintenance," says Whiteis. "Don't let the fact that this maintenance is performed less often give you a reason not to do it every three months like clockwork. This is just as important as checking your hydraulic hoses and fluid daily."
Such inspections and maintenance include:
- Inspect and grease lift cylinder bearings and the rotation bearing
- Check torque on the rotation bearing bolts
- Check and tighten bolts on rotation gear box
"At least once a year, you should drain, flush and refill your hydraulic fluid," Whiteis adds.
If a service crane is properly maintained and inspected, and the operator uses the outriggers and follows the load chart, the equipment will increase the efficiency and safety of your service technicians. However, Worman offers one final word of advice that should prevent most mishaps: "Be aware of your surroundings!"
Crane Safety Devices
Auto Crane offers the following overview of safety devices available on today's service truck cranes:
Anti-Two Block: This feature offers extra protection against potential danger if the traveling block comes in contact with the boom as the crane is being hoisted up or extended out. During operation, as the rope is retracted and the hook moves closer to the boom, the block trips the safety switch near the boom tip, shutting down the function capability of the crane. This automatic shutdown helps prevent line breakage or damage to the hoist, and is standard on most cranes today.
Hydraulic Overload Protection: Also standard in most service cranes is a sensor in the lift cylinder that monitors pressure during operation. If pressure exceeds prescribed limits, the sensor shuts off function to the crane. The sensor allows the crane to pick up only the amount of weight for which it is rated in all its positions, whether hoisting, extending or booming.
Counterbalance Valves: Counterbalance valves in a service crane's extension and lift cylinders prevent uncontrolled movement and lock the crane in where it's left, so it will not retract or extend without deliberate operation. This is particularly important in the event power is lost to the crane or a hydraulic hose ruptures, interrupting flow to the cylinders.
Redundant Pin Retention: Pins that hold cylinders in place should have dual retention, meaning if one pin fails, the bolt will not slip out since there is a second pin in place as a safety measure.
Function Interlock: Operators of most cranes in the service truck industry set the crane's speed prior to selecting an actual crane function.