Stick slip is out of the question.

The lubrication gap in the telescopic boom of mobile cranes is exposed to many pollutants, moisture and mechanical strain caused by ice and snow. Its lubricating film must remain in place in spite of all these factors. Stick slip is out of the question.

More and more spectators are gradually gathering near the building site. The assembly of a 65-ton rotor on a wind turbine draws attention, especially because the operation is clearly visible from a nearby main road. Operations of this scale involve spectacular special transports using huge mobile cranes; extremely heavy wind turbine components such as the rotor hub, rotor blades or complete rotor systems are assembled at vertiginous heights. They always fascinate onlookers. The same applies to large construction machinery, heavy concrete components for bridges, marine transmissions or boats being loaded onto vast special transporters.

65 tons is not a lot, considering that the maximal lifting capacity of large mobile cranes is firmly beyond 1,000 tons. Vehicles are becoming increasingly larger as demand for higher load-carrying capacities and longer tower constructions rises. In addition to the frequently extreme weight of the cargo, working with mobile cranes is complicated by the high level of precision required – giant objects must be maneuvered to a millimeter. Even the assembly and disassembly of the mobile crane itself can turn into a spectacular show if a long lattice boom luffing jib needs to be attached in addition to the telescope in a confined space, e.g. between blocks of houses.

Without mobile cranes, our work would be impossible: we need them to assemble powerhouses that weigh many tons, blades or entire rotors of wind turbines at a hub height of more than 90 meters. The right lubricant is essential for many aspects of these operations.

When we install entire wind turbine rotors, our cranes often have to lift between 60 and 120 tons.

Large mobile cranes are normally equipped with up to seven telescopic segments that can be extended by up to 100 meters. These segments consist of different grades of steel, welded and primed. Inside the tubular segments, hard sliding components made from a polyamide-based special plastic and fine-grained steel construction must absorb extreme surface pressure. The lubrication spot (or gap) is exposed to many pollutants from abrasion (sander dust from maintenance works), building site operations, moisture and mechanical strain caused by ice and snow. Its lubricating film must remain in place in spite of all these factors: under no circumstance must stick slip occur when the telescopic segments are extended or retracted. This could cause dangerous swinging or rocking motions in the crane system when loaded.

Correct application of the right lubricant can truly make or break an operation. BECHEM lubricant solutions are based on highly viscous, extremely adhesive base oils. These special lubricants contain a high dose of PTFE (polytetrafluoroethylene), giving it the desired friction coefficient for the highly stressed telescopic segments. With its classic product Berulub PAL 1 and the new addition Berulub TCG 1, BECHEM offers high-performance products with a long lifespan that ensure many safe telescopic operations without the need for re-lubrication. Berulub TCG 1 can even be applied in extreme sub-zero temperatures.

But there’s more to it than special grease. Special anti-friction coatings have great future potential.

The abrasion of the metal primer, an inevitable result of the movement of the telescopic boom, has a negative impact on the durability of the lubricant and the friction values of the tribological system. To counteract this effect, BECHEM has developed additional special products for modern telescopic cranes, which are currently about to be tested: anti-friction coatings. They are industrial coatings enriched with solid lubricants and additives at a specific pigment volume concentration. Besides improving their functionality, these substances give complex tribological systems such as telescopic constructions dry-running properties in case of insufficient lubrication. They also effectively protect the steel surface from corrosion without affecting the friction values of the lubricant, thus lowering the risk of downtimes significantly.

Write us if you want to learn more about our lubricants for cranes.

Product insights.

Detlev Heyn
Sales Manager Special Lubricants