• Kristin Thompson

Outside Chance: Maintaining Outdoor Cranes



Regardless of where your crane is located, regular overhead crane maintenance is important to ensure safe crane and hoist operation and extend the useful service life of your equipment. However, overhead cranes that either permanently or partially operate outdoors require a bit more TLC from time to time as they are directly exposed to Mother Nature.


Moisture

The constant influence on an outdoor crane is – of course – the weather. Rain and humidity can cause rust corrosion in the joints, wires, bearings, wire rope, drum, and in all moving parts, which can cause a loss in the overall strength of the crane over time. In the depths of winter, snow and ice can gather on crane runways and interfere with the motion of the bridge – even seizing the crane altogether.


Outdoor gantry cranes motor filled with ice.

Temperature

A sudden temperature decrease can put the tensile strength of all the materials used to construct an overhead crane to the test. Many materials can become brittle during a cold snap. When a material becomes brittle, it becomes much more fragile. Any additional stressors on these brittle materials, such as shockloading, overloading, or even a random impact can create cracks, nicks, or more complicated and costly issues down the road. Variable Frequency Drives (VFDs) used in certain crane and hoist motors do not perform well in temperatures below -10C. Conductor bar systems can react and even fail with exposure to frost, causing the crane to single phase or lose power all together. Frigid temperatures can wreak havoc between the moving parts of a motor and diminish the proper flow of oil. Even pendant buttons can crack, crumble, or fail if the temperature dips below a certain level.


On the flip side, sudden high temperatures can be just as damaging to multiple components of an outdoor overhead crane system. Oil seals can sweat leading to oil leaks inside gearboxes. Extended exposure to UV rays can cause insulation wires to harden and crack. Hot and dry weather can lead to dirt, dust, and sand accumulating along crane runways which can obstruct movement and safe operation.


Birds nest discovered inside a cranes gearbox.

Nature

Though an infrequent occurrence but no less critical, small animals and birds can also cause damage to your outdoor overhead crane system. Mice and squirrels can find their way into panels, chewing on wires and interfering with contactor movement, while panel boxes and crane runways can become appealing locations for birds to build their nests.











Kristian’s TLC Tips for Maintaining Your Outdoor Overhead Crane


  1. Ensure your outdoor crane is constructed from a high-strength steel to withstand any large fluctuations in temperature.

  2. Installing panel heaters inside all bridge panels, especially those operating from VFD control!

  3. Heat it up! Utilizing heated conductor bar will alleviate the build up of any condensation and eliminate the fear of frost along the power bar.

  4. Lubrication is key! Maintain crane and hoist oil type and levels based on temperature breakdown within the manufacturer's specifications for your equipment.

  5. Consider using SOOW rather than SOW cable to protect your crane’s wiring. SOOW has both an oil-resistant insulation and an oil-resistant outer jacket while SOW only consists of the latter.

  6. Install rail sweeps on the ends of your endtrucks. Rail sweeps are a type of brush that works to remove debris, dirt, sand, and snow with each pass of the bridge beam.

  7. Switch your pendant! Invest in a specialized DST pendant that can withstand temperatures as low as -60C without malfunctioning.

  8. Invest in defense control! Installing shields over your wire rope hoist protects the rope drum and wire rope from snow and moisture. You can also protect your bridge with a custom cover to eliminate many of the worries precipitation can cause.


Bridge crane with custom built cover installed at a water treatment facility.

Most importantly, the biggest weapon any overhead crane owner has in the battle against Mother Nature is maintenance. Call your Kristian crane service representative today to craft a customized inspection and preventative maintenance program for your outdoor crane systems! Regular checks and upkeep by a qualified team is essential to preventing all weather-related crane issues before they become critical.