toggle quoted messageShow quoted text
first I must make a disclaimer, as SM owner I have never had anything to do with the pasaralle on a 54. However I understand it swivels on a vertical shaft in a tube. The problem arose after an offshore passage. There is a very high level possibility that friction created by salt crystals formed between the shaft and the tube as the water evaporates is the culprit. Simple rinsing with fresh water regularly will prevent this. If it is constructed of mild steel (surely not???) then obviously, given salts impressive ability to cause corrosion, if left it will soon change from a salt crystal problem to corrosion and application of high quality corrosion resistant lubricant following the rinsing is essential but be careful this does not entrap future salt crystals.
The swivels at the top of the main, mizzen and headsails suffer from the salt crystal problem causing friction, and in advanced cases seizing, particularly after extended offshore passages. In their case, being manufactured of less corrosion susceptible material simple flushing with fresh water provides a cure.
On 01 May 2020 at 07:57 Arno Luijten <arno.luijten@...> wrote:
You are confronted with the poor design of an otherwise very nice piece of hardware on your boat. To set off frightening you first. The repair of my passarelle was about 14k $.
The good news for you is that your rotary actuator is not yet completely seized up as mine was. That means you can probably still take it apart. But to get to that thing is quite the job. First you need to get all the hydraulic hoses off and sensors off. Before you do that make sure the passarelle sticks out 90 degrees. Now you can remove the top part. It's heavy, really heavy. About 100+ kg or so. once that part is off you need to get off the base part. Again not so easy as removing the bolts still leave the chaulking to stick. Once the base is loose you can bring this to a hydraulics shop and the can start rebuilding it.
A new rotary actuator is around 6k$ including transport.
My passarelle was fully overhauled, all seals were replaced all cylinders overhauled, a brand new actuator and the whole thing was repainted.
I made a small change to prevent the ingress of (sea)water into the rotary actuator by putting a cover over it and putting a think layer of lanolin grease under the cover. The problem is that the way the actuator has been designed is that part that rotates sits inside a large cylinder. There is a narrow seam between the moving parts on the top side of the actuator. Opacmare made a poor design choice here to allow seawater to reach this seam and slowy but surely get into the mechanism. Once that happens it starts rusting (it is all mild steel) and at some point it is stuck to the point you will never be able to disassemble it.
If you need more details let me know.