Bavaria 40 Ocean - dropping rudder - but what clearance?

[Yngmar]

I've just received my shiny new Jefa roller (bottom) bearing and the boat is coming out in a week. However, therein lies the problem. To install it, the rudder has to come out. But there are loads of other jobs too, including scraping, skin fittings, coppercoating and saildrive works. For all of these, it'd be quite convenient to have to boat at the regular level, which is with the bottom of the keel near ground level. But not for the rudder.

On Jefa's excellent FTP server I've found a construction drawing of my rudder and worked out that the boat needs to be pretty far up, specifically with the bottom of the keel almost a metre (0.92m) above the ground. That gives me the exact clearance under the rudder (1.34m) that I need to drop it straight down and clear the hull with the top of the rudder shaft.

But! The bottom bearing is a self-aligning one, meaning once the top is released, there is a certain degree it can go sideways, increasing the further down it is (but limited by the bearing frame). So finally my question, how much minimum clearance do I really need to get the thing out? Did you do this before, and how did you do it? I cannot dig a hole in the boatyard, it's tarmac.

The alternatives are less than ideal, either doing it in the slings in a hurry and at great cost, or asking the boatyard to lift the boat onto a higher cradle after all the other jobs are done. I'll talk to the boatyard about that, but knowing them anything involving lifting the boat will probably be another hefty charge and who knows if they have supports of that size (they shoud, but...).

[dawntreader]

I very much doubt you will have sufficient clearance unless the keel is higher than you propose. See this link from the forum:

http://www.bavariayacht.info/forum/index.php/topic,442.msg2456.html#msg2456

Also, I would check all fixings before she comes out of the water to ensure they will release. When I came to drop my rudder the steering quadrant holding bolts had fused with their housings and took a lot of effort to break out . If all appears free then it is possible to drop the rudder just before they put her on the cradle. For this you will need some help as the rudder is (top) heavy. If you have a hole through the square top of the rudder stock this is very useful for support the free weight of the rudder as it drops down, and is brilliant for replacement as it aligns to top of the stock 

[Yngmar]

I'm fairly sure about the clearance required, which I've worked out based on this rudder drawing I found: ftp://ftp.jefa.com/old_boat_spare_parts/Bavaria/Bavaria40_Ocean_P_2000-2003/Bavaria40_Ocean_type_P_2000-2003.pdf

However I've since spoken to the boatyard and we've come to an agreement about doing it when the boat is being lifted and it's actually a good way (in theory). The plan is basically to lift the boat out of the water, put it in the cradle, but leave the travelift and slings in place (for which I'll have to pay by the hour ). Then take off the quadrant and top fastening (the rest I can take off while still in the water) and lift the boat off the rudder. Remove rudder, put boat back down in cradle. Reverse procedure when lifting back in (and pay for another hour of holding).

I've just tested all the fixings (good suggestion - luckily they're all turning) and taken off the inner hatch to the transom to make this all as fast and easy as possible. My only worry is that the old bearing is seized around the rudder shaft and turning in its housing, instead of the shaft turning in the bearing, in which case it might need convincing to come out and rack up the cost. So wish me luck 

[MarkTheBike]

Good luck, Yngmar! I do remember reading somewhere that having one of those one-ton builders' bags slung from the winches will avoid an accidental rudder drop. Once free, the whole lot can be lowered to the ground by letting the ropes slip on the winches.

[dawntreader]

Yes, good luck. Once you have the rudder shaft out the bearing will still be in its housing. I struggled to remove it until I had properly cleaned the edges to the access hole - it then pulled out fairly easily.

[Yngmar]

Dropped my rudder today (or rather, left it sitting on a block and used the travelift to lift the boat off the rudder). Needed the full clearance, because the bottom bearing ball does not rotate in the housing at all. Rudder post is 1.34m up into the hull, so that's the clearance needed below the rudder to get it out.

The housing looks good from the outside, the bottom bearing ball is however thoroughly stuck in there and won't turn (looks to be mostly fouling, but may be also corrosion from the housing or simply swelling, not sure yet). Will try again after it had a chance to dry out, in case it was swelling. Otherwise cut/chisel it out (new Jefa roller bearing ball already here).

Reason for dropping the rudder is that said bearing ball has wear around the inner hole that left the rudder wobbly (not hugely so, but the surveyor recommended fixing it at some point and since the boat is coming out anyways...).

Dropping the rudder was easy. Checked all nuts and bolts were moving a few days before. Before maneuvering into the travelift, took off the rudder position sensor and loosened the top hose clip on the gaiter. Once the boat was held in slings, removed quadrant and the rest of the hose clips, then the "squeeze" screw on the top nut and finally the top nut. Top nut did not want to move while holding the weight of the rudder, but did move by hand once we put a wedge underneath that held the weight of the rudder. The top nut can be turned with a C-Spanner (pin spanner?) 55mm wide with 9mm pins, but we didn't have one (nor did we need it - stainless guy offered to make one if required though).

The rudder is bloody heavy and heaviest at the top. Between two strapping lads we barely managed to let it down gently and put it on some wood blocks. No significant amount of water based on knocking and moisture readings, but might drill a drain hole just to be sure.