Episode 27 Broken Rudder

About a week before slipping the boat to replace the wobby prop, I decided to take some mates out on Moreton Bay with a view to getting a crew together for some races.

About half way between Green Island and Peel Island my mate on the helm told me that he had lost the steering. As you can imagine, this was quite a serious occurrence, and further inspection revealed that the rudder had broken about half way between the upper and lower pintles (the two hinges that connect the rudder to the transom). I called the Volunteer Marine Coast Guard on Marine Assist to inform them that we were having difficulties and then had a look. Fortunately, although the rudder had split, it had not completely parted at the break. There was enough material remaining on the rudder to allow us to lash the two halves together, rather like splinting a broken limb (I have never splinted a broken limb, but I have done some First Aid training). Although the top and bottom parts of the rudder wobbled in alarmingly independent directions, the whole had enough integrity to allow us to point the boat in the right direction. We limped back to Huybers (the marker post north of King Island), and then turned left for Manly Harbour, creeping along at about 3 knots and trying to nurse the boat over the stern-wakes of several stink-boats as they sped by. The prolonged use of the wobbly prop probably exacerbated the damage to the cutlass bearing as mentioned in my previous blog. I kept the Coast Guard informed of our progress, until we had tied up without assistance, and thanked them for keeping watch.

There is no good time to lose your steering, but losing it on a calm, sunny day, with the Coast Guard on watch a couple of weeks before a scheduled slipping is probably the best of a bad situation.

When we had got the boat slipped and the old rudder removed, we found that the timber core had rotted to a black mush. The rotted timber came out as a steady rain of black flakes from the cracks in the casing, which are just visible below the lashings in the photo below. Again, finding this before attempting some racing is better than finding it in the act.

Lashing on broken rudder

After the event, I asked the previous owner, who told me that the owner before him had replaced the original rudder with the bigger one that was now sitting on the back of the boat. The previous previous owner used to sail the boat hard (and had competed in the Brisbane to Gladstone races), and needed the bigger rudder to hold the boat on course. Fortunately for me, he had not thrown away the old, original rudder, which was now sitting under my back deck. 

The bigger rudder was made with a timber core and a GRP outer coat (which had kept it together as we limped back to Manly). Water had got into the core through the holes drilled for the fixing bolts, and the rot had hollowed it out until my mate put a little pressure on it in Moreton Bay. When you see the effect, you realize the importance of properly sealing holes in timber core construction. A good way to do this is to over-drill the hole, fill it with epoxy resin and then drill a hole through the resin at the correct size, thus ensuring that the timber core remains encased in GRP or resin.

Bottom part of broken rudder

Top part of broken rudder (upside down)

However, the finished surface on the original rudder was in poor condition.Because the anti-fouling had been out of the water for many years, it had cracked and degraded into a kind of soot. The gel coat had likewise been gouged and abused. I decided to sand it down, and went to work, perhaps unwisely, with a grinding disc. This proved to be very efficient at removing the old anti-fouling, gel coat and everything else right down to the GRP roving that covered the timber core and I ended up with a naked rudder, with the timber core clearly visible. Although this confirmed the competency of the timber core, it covered everything in my garage with a thick layer of dust to the express dissatisfaction of my wife. Having got the outer layers off, I then paid a yard-hand put them back on again, which he did very nicely. One unforeseen consequence was that the re-coated rudder was thinner than the original, leaving a small gap in the rudder brackets. This was fixed with some white FixTech filler.

Finally, I found that the Cavalier 28 came with two different types of rudders, depending on where they were made. The earlier models were made in New Zealand and had a Spitfire-wing profile. The later models were made in Australia and had the rectangular profile on my boat. The larger, replacement rudder was a one-off. I am quite happy with the original rudder that has now been reinstated. 

I am not sure I will get to the same kind of exertions that led the previous previous owner to fit the larger rudder. In any case, the larger rudder seems to be all about fighting the boat, rather than working with it. I don't have the race experience to make an authoritative judgment, but it seems to me that the energy spent in forcing the boat to do go against its inclinations could be better directed in making it go faster. his is about balancing the boat, as is whole science of itself.

Original rudder, before grinding

Original rudder, after grinding

Original rudder reinstated