Our expertise with the thermal lance was needed in southern Italy. And once on the spot it turns out: thermal lance is not always the best solution.
The call reached us through a colleague company, an urgent request for immediate assistance on board the Living Stone.
Of Living Stone is a ship designed to lay cables in the seabed. The ship is owned by DO NOT SAY, an international group of companies, specialized in dredging works.
Of 85 tons deck crane on board (supplied by Huisman Equipment) can lift heavy objects and assist in construction- or demolition works of oil platforms, construction of ports and the like.
The bearings of the front boom are worn and need to be replaced. During the work it turned out that the 2 pins around which the front arm hinges were stuck and could not be disassembled. The request was to arrive immediately and remove the pins using the thermal lance. The ship was in a dry dock in Palermo, Sicily, Italy. Googling shows 2482km. So three hours later we leave with a fully loaded bus.
Thermal lances are not always the best solution
Because it turned out on site that it was impossible to deploy the thermal lance, we had to come up with something else. A huge hydraulic cylinder was very close to the back of the pins and this meant that there was an unacceptable risk of damage to this cylinder . We decided to organize a morning meeting where all parties involved were present.
During the meeting at which employees of DEME, ship's crew members, technicians from Huisman Equipment, and we are present, the options are discussed. To dismantle the cylinder there must be 2 thick plates of Fe 690 be burned out. Have these plates machined new and receive them on site 2 to soften, this time is not there.
Gently pressure was exerted on us to deploy the thermal lance anyway. An impossible task, where the probability of consequential damage to the cylinder was unacceptably high, we gave a guarantee that this would damage the very precious cylinder. We also suggest making a last attempt to remove the pins with hydraulic equipment. This had already been tried by Huisman's technicians, but by fabricating a special tensile structure we were able to pull the pins with a multiple of the previously applied force. The chance of success was considered small, but anything was better than being delayed for two weeks. Meanwhile, the order for the de 2 thick plates have already been put into operation.
Still achieved a successful result
About 10 hours later the entire crew is having their evening meal, the 1st pin has now been disassembled. The plan to go with a, tensile construction manufactured by us on board, exerting an enormous force on the stuck pin proved successful. With a thud that was audible throughout the ship, the pin came loose from the bronze bushing. Because we were working on a scaffolding at a height and wind gusts of 70 km / h came by, we had to stop work afterwards. The next day the preparations on the 2nd pin were carried out. This was disassembled in the same way. Because we had tackled the most difficult pin first, success was guaranteed in advance. The strong wind makes it irresponsible to continue the work, we work on scaffolding at a considerable height.
Inside 1,5 day the job is done
The next morning the wind has died down, instead we get downpours. About 13:00 the second pin has been disassembled. Our work is done.
We decided to take the evening ferry from Palermo to Genoa. This saves us driving 1400 km on the return journey. The rest of the day we assist the mechanics with the installation of new bearings and the 2 new pins. A very satisfied client, who expresses his thanks several times, we leave behind in the evening.
Do you have a problem with pins in pivot points or shafts stuck in their bearings?
If you've already tried everything and can't remember how to disassemble a part: Neem contact with us! We are happy to assist you.
