Production around the clock
At Palm, headquartered in Aalen, Baden-Württemberg, everything revolves around waste paper. Nine paper machines in five mills produce around 2.2 million tons of newsprint and corrugated base paper every year. Paper production runs around the clock. The demands placed on the eleven double-girder overhead cranes, which have been in use at the mill in Wörth am Rhein since the start of production in 2002, are correspondingly high. They store the finished paper rolls, which weigh several tons. "The cranes are in use day and night," says Sven Bohrer, electrical engineer at Palm. "If one were to break down, production would have to come to a standstill or at least be slowed down considerably until the damage was repaired. That would cost us time and money." Konecranes has therefore closely examined the gear oil in the hoists of eight of the eleven double-girder bridge cranes. This is because the oil is very revealing: The abrasive metals and wear materials it contains allow conclusions to be drawn about the condition of the entire gearbox. Nico Zamzow, Vice President Industrial Service EMEA Central at Konecranes on the method: "The oil analysis protects the crane. It allows any damage to be detected and rectified at an early stage. In addition, plant operators can use the detailed analysis report to optimize the repair and maintenance of the cranes and thus extend their service life enormously."

Oil analysis reveals the condition of the gearbox
For the oil analysis at Palm, the Konecranes experts take samples from the hoist gearboxes of the eight double-girder bridge cranes. "The samples are analyzed in our own laboratory. The employees in the laboratory compare the current condition of the oil with samples that we took in 2016," says Nico Zamzow. "This is how we ensure the validity and quality of the test results." The result for Palm: seven of the eight cranes are "healthy", with little to no foreign bodies or wear substances in the gear oil. However, the gear oil of automatic crane 5, which is used in the roller bearing, contains an increased proportion of ferrite. Nico Zamzow: "Iron particles in the oil indicate increased wear, for example when metal parts rub against each other."

Crane Reliability Study reveals solution
If the cause of the wear is not rectified, this can cause lasting damage to the gearbox. "If the gearbox seizes up while a pulley is hanging on the hook, it becomes very difficult to recover it and repair the crane," explains Nico Zamzow. To determine whether damage has already occurred, the Konecranes experts use the Crane Reliability Study (CRS). In this modular analysis, they check safety-relevant components such as the hoist gearbox, the steel structure, the drives and the crane's electrical equipment. The procedure is individually tailored to each crane using Konecranes' MainMan software. In addition, the maintenance experts interview crane operators and technicians on site. The results of the analysis are incorporated into a detailed report for the operator - with specific recommendations for action. At Palm, Konecranes also used an endoscope to examine the hoist gearbox. "Just like in medicine, we can use the endoscope to reach inaccessible areas without having to take the entire gearbox apart," says Nico Zamzow. "For the CRS, we use a special, oil-resistant model that was developed for industrial use and can be equipped with different lenses."
After the endoscopic examination, it was clear to the service experts that the hoist gearbox needed to be replaced. The cable drum, the cable drum bearing, the slip ring assembly, the drum clutch and the motor clutch also had to be replaced. "Because we detected the wear at an early stage, we can replace the old gearbox with a new one without affecting production," explains Nico Zamzow.

Safe transportation in the future too
Papierfabrik Palm will continue to rely on services such as repair and maintenance work from Konecranes in the future. Jürgen Friedmann, Head of Mechanics at Papierfabrik Palm, is delighted with what has been achieved: "The experts from Konecranes have been very flexible in adapting to our requirements for the availability and productivity of our cranes. Thanks to the oil analysis and endoscopic examination, our cranes are now running like clockwork for years to come."

Crane Reliability Study CRS
The Crane Reliability Study (CRS) is a manufacturer- and type-independent crane reliability analysis from Konecranes for crane and hoist components such as hoists, motors, ropes, gearboxes and crane runways. The CRS consists of various modules:
1. inspection and analysis of technical documentation using Konecranes' MainMan software
2. analysis of processes and procedures as well as interviews with operators and maintenance staff
3. detailed analysis of assemblies and components using state-of-the-art measurement technology
4. cost analysis and return on investment

The final test report provides an overview of future maintenance, servicing and modernization requirements in order to increase the safety, availability, productivity and service life of the crane systems.