GBS replaces bearings of gearbox



Customer

A major carrier of tankers and container feeders. The customer has a fleet of more than 40 ships and transports these goods worldwide.


Challenge

GBS carried out an inspection on board of a container feeder on behalf of the customer, after the customer heard rattling noises coming from the gearbox while sailing.


This inspection with our videoscope showed that a number of bearings on the input shaft were damaged. One of these bearings had such damage that it was not safe to leave it in place. It soon became apparent that it was necessary to replace the bearings.


Solution

The customer commissioned GBS to remove the PTO shaft from the gearbox in order to replace the bearings. This turned out to be a lot more difficult than previously thought.


The shaft had to be hoist up through an emergency hatch, this was because there were too few lifting options on board to get the shaft out of the ship in any other way.


First of all, it had to be considered how the shaft could be “loosened”. There was limited space and the gears of the oil pump also had to be disassembled because they had to be measured and put on a technical drawing. As there were no more drawings of the gears available.


After it had been thoroughly investigated how the whole could be disassembled, the slings were attached and the chain hoists hung up. In total, 4 hoists were needed to remove the shaft properly and carefully. These hoists were then detached and hung elsewhere so that the shaft could be moved through the engine room towards the emergency hatch. The shaft would then be lifted from the ship using a crane via this hatch.

The shaft was now ready for transport to the GBS workshop. The shaft was brought to the workshop in Oud-Beijerland with the help of our own transport service. When the bearings were removed and the new bearings could be mounted, we ran into another problem. The fitting on the shaft was 0.02mm too small! To tackle this problem, we chromed the shaft and polished it to the correct size.


After this, the bearings were mounted and the shaft went back to the ship, here the shaft was reassembled and all other parts in the gearbox were inspected one more time to ensure that nothing was overlooked.


The gearbox was then closed and new oil was added, after which the gearbox was again ready to be used again.


Result

Thanks to the 24/7 shifts, the knowledge & expertise, all these problems were solved in less than a week and the ship was able to sail again quickly. Due to the rapid action of GBS, the financial damage caused by the downtime of the ship has been kept to a minimum.