The View Up Here

Random scribblings about kites, photography, machining, and anything else

Pacific Catamaran (P-Cat) Rudders

Posted by Tom Benedict on 18/04/2012

Most of the time I try to write articles that might be of interest to at least one other person on the planet. I don’t always succeed, but that’s the goal.

This time I’m writing a question that I hope at least one other person on the planet can answer. In short, I’m stumped.

It has to do with the rudders on the Pacific Catamaran 19. They’re… well, they’re weird.

On the face of it, they’re not that different from any other catamaran I’ve seen: The rudder blade slots into a cast aluminum housing, and is held in place with a pivot bolt:

P-Cat Rudder Assembly

In the case of the P-Cat, the housing has a stainless steel sheet metal weldment bolted on top, similar to the rudder on a dinghy. And as with the dinghy rudder, a wooden tiller arm slots into the stainless weldment and is screwed in place. (I’ve omitted the teak tiller arm in these photos.)

Here’s where it gets odd: With most catamarans, there’s some means to lock the rudders either up or down. This doesn’t have anything even close. When I got the boat, the rudders had a wooden dowel stuck through the hole below the housing, with a length of shock cord wrapped around the dowel and then up and over the upper gudgeon pin:

P-Cat Rudder Down

The shock cord was dead, but I could see that with some new shock cord and a fair bit of tension, this would serve to hold the blade down in the water. Likewise, it serves to hold it up:

P-Cat-Rudder Up

But I’m not certain this is how the P-Cat rudders were originally designed. At best it encourages the rudder blade to be in the up or down position. But it’s a far cry from the Hobie cam lock system or the spring detent system on a Prindle. Those offer positive locks with a known position for the blade. This bungee system is more of a suggestion than an actual lock.

I think one of the previous owners of this boat realized this and did something to address it. On each of the rudder housings there’s a 1/8″ diameter hole drilled through the housing a few inches above the pivot pin. It goes straight through the housing, through the blade, and on through the housing on the opposite side. Stick a 1/8″ stainless  steel pin through it, and the blade is locked in the down position. Hey! A positive lock!

But what happens if the blade drags bottom, or you whack the tip of it on a rock or reef? The pin is small enough it should shear, but there’s no guarantee of that. It’s just as likely to rip the tip off the rudder blade or tear the rudder gudgeons out of the transom of the hull. With the Hobie and Prindle designs, at least, the rudder blade will kick up before it breaks.

So here’s where I’m asking for help: If you’ve ever seen a P-Cat rudder system and can tell me where I’m going wrong, please let me know. I’m not trying to do a factory-fresh restoration job on this boat. But I’d sure like it to work.

Thanks,

– Tom

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10 Responses to “Pacific Catamaran (P-Cat) Rudders”

  1. Curt Jordan said

    Hey,i’ll have to look at mine and see,but i believe it used a small cottor pin??

    • Tom Benedict said

      Hey, please do look. If you don’t mind taking a picture, I’d love to see what it’s supposed to look like. I get the feeling my boat was already somewhat modified before I ever got it.

  2. Kevin Hornby said

    I built the boats for years. The shock cord should be just as big as you can use. It is a loop from the top gudgeon thu the hole where the dowel is. The cotter pin was used to hold the rudders permanently up after beaching or trailing. The system works well when set up right. The shock cord will hold the rudder unless you hit something. Any body looking for P-cat parts?

    • Tom Benedict said

      Hey, this is great information! Thanks, Kevin!

      I think, judging from your description, I have our rudders set up pretty much the way you describe. But I’ll double-check when I get home. As for people looking for P-Cat parts, a great place to check is on The Beach Cats: http://www.thebeachcats.com/

      I know there are a couple of P-Cat sailors there and a couple of others who have been looking at getting one. Parts availability has been the deciding factor on at least a couple of people who eventually decided to go with another boat, instead.

      Hey, if you have ANY additional info on the P-Cat, I’d love to hear it / read it / see it. Mine is an early hull number and came without a spinnaker. But I’d like to see what the original spinnaker setup looked like. Right now I’m in no position to add one to my boat, but I’m always trying to collect data on these guys. Something else I’m curious about: There are four eyelets, two at the bows and two at the sterns. Are these for tying up? Or was there some other rigging that was supposed to attach to them? (I’m guessing it’s for tying up.

      Man, I’ve got a ton of questions…

      Thanks!

  3. David Sheldon said

    Tom,Kevin Hornsby is corret. The bunjee cord simply goes through the hole inte rudder looped over the gugeon.I had three of the boats over the years and this seemingly primitive system worked well. I never bothered with a pin. The shock cord held them in a raised position. The Hobie system was a major selling point over other boats at the time. The eyelets were for tying up.

    • Tom Benedict said

      Thanks, David!

      Yeah, once I tried it in the water I was convinced. It really does work quite well, and you don’t run the risk of a pin failing to shear and ripping things to shreds. Nope, the rudders worked out really well like that.

  4. Brett said

    Hi Tom, I just purchased a 1976 pcat and would love to compare notes. Hull 662. So far I am cleaning out mouse damage in the hulls, then on to other tasks. Could you please send the spec’s for your mast raise assist? Thanks, Brett in Wisconsin

    • Tom Benedict said

      If you’d like I can send you the CAD file for the spreader. There are likely better ways to make the thing, but it’ll give you a place to start.

      The whole idea was to create a pair of pivot points in line with the pivot point for the mast step. So basically anything that accomplishes that task would work fine.

  5. Tom House said

    I just tensioned the rudders by tightening the pivot bolt. I left it tight enough so friction kept the rudders either up or down when sailing. I left the bolts lose enough so if it hit something, they would pivot up enough to go over the obstacle. Then I’d have to hang over the stern to push the rudder back down.

    For trailering, I’d simply remove the rudders off the sterns.

    Still going strong after 20 years and the boat started off build hull number 54 in the 70’s and I got it in the 90s.

    I even rigged it so I could put a 35 ho outboard on the back when I used it for scuba diving in Mexico and sailing when there was enough wind.

  6. Richard Carriker said

    I raced PCats back in the late 60’s to the 70’s . The bungee cord held the rudder in place . If the bungee cord was tight and in good condition , we never had a problem with the rudder tilting back.

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