Subject: BAMA: DHF Rudder Loss
Date: Sat, 08 May 1999 07:43:15 -0800
From: Joe Siudzinski <siudzinski@telis.org>
To: "BAMA," <bama@tango.rahul.net>
Since it's more interesting to read about mishaps than non-problems, here's another article I had written back in 1992 for the Telstar Association newsletter about my rudder loss out by the Farallones. I end it by describing my new rudder - guess what: it disintegrated in the following year's wild and wooly Singlehanded Farallones Race, but that's another story...
RudderLess DoubleHanded Farallones Race
by Joe Siudzinski
"Boy, isn't this great!" I exclaimed to my crew soon after rounding the island in the 1992 Bay Area Multihull Association's DoubleHanded Farallones Race - the conditions were perfect: 20-knot southerly (unusual) winds resulting in a beam reach over slightly bumpy seas. The Farallones are a group of somewhat bleak islands 30 miles off San Francisco's Golden Gate and we were competing against over a hundred monohulls and a dozen multihulls in the late-April race. A couple of weeks previously I had also done this same course as part of the SingleHanded Sailing Society's annual event.
"Barf!", was the response from the leeward rail.
My crew, Mark Crane, is an athlete - he thinks nothing of a 50-mile bike ride in the morning before work and he recently became an avid scuba diver. It's just that, well, even Scop patches behind the ear don't seem to help, so he just grins and bears it, attributing it all to his family's history in farming and not seafaring. He is a novice to sailing - this was essentially his first sail - I figured some open-ocean exposure would put some reality into his "sailing away into the sunset" daydreams.
Anyway, there we were, bouncing along at a leisurely 8-10 knots on my comfortable (as in non-racing machine) well-equipped (loaded down) trailerable Telstar 8M (eight-meter) trimaran Second Tri - I was hand steering at the time (usually I just let my Autohelm aim the boat), when all of a sudden the tiller felt strange and then a second later I found myself clutching and then dragging aboard the entire tiller, rudder housing, and rudder. The rudder housing had essentially split in two and we now had the pieces strewn all over the cockpit!
"Not to worry", says I after trimming the jib and easing the main so the boat would continue by herself in the general direction of the coast - "let's just keep going with the sails alone...".
"Barf", said my crew.
On this tri I had often demonstrated how one sails and then turns the boat around without touching the tiller (I'd usually just lock it amidships). In my younger catamaran-racing days, for variety, we used to have rudderless races -- so I wasn't especially concerned over the loss of the darn thing (I was more concerned that monohulls were now starting to pass me!)
After stowing the rudder and remains of the housing down below, I tackled the business of properly pointing the boat in earnest. The first problem became immediately apparent: with the jib well trimmed and the main completely eased, the boat was still heading up way too much! I was dumbfounded, because in the past I had little trouble getting the boat to go wherever I wanted it to go, and yet now it didn't want to bear off and aim for the Golden Gate Bridge (the bridge really is tiny from that distance). I discuss the technical explanation for this at the end of this article.
"Not to worry" said I for the second time, "we'll just rig the steering oar!"
"Barf" was the response.
In addition to the collection of canoe and kayak paddles, I had added an 8-foot oar and a long 2" diameter closet pole for just this type of an eventuality - it's easy to store long skinny things in the outer hulls of a trimaran. I added these not because I was worried about the rudder housing integrity, but because of the potential of hitting something and having the rudder blade simply tear out the aft end of the housing. I bungie'd the pole to the oar and then bungie'd this into the crook of the bracing for my permanently aft-mounted mast support (for trailering). What I had was a steering sweep!
"Yay!" said I.
"Barf" said my crew.
It became immediately apparent by the amount of bending induced that the loads on the oar extension were significant. In retrospect, I should have immediately reinforced this by bungieing another pole alongside this one.
Anyway, we now had some measure of steering and were able to bring the boat more or less down onto the proper course, but only with the jib drawing, and the main completely eased.
The boat still had too much weather helm!
Since I wanted to get our speed back up (we were down to 4 knots) by having the main provide at least some drive, I put a reef into the main - it didn't change the helm much. I then tried dragging warps (two 60' spare sheets) off the port hull (remember, we're on the unusual starboard tack heading back towards the coast of California). This helped slightly (much less than I would have thought), but now being able to sheet the mainsail it only added back the speed that was lost through dragging the warps, so I eventually gave that up and brought the warps back on board (besides, it wasn't an elegant solution - it reminded me too much of boats that add weight underneath to keep them from tipping).
Still seeking to reduce the weather helm, I dook down the dodger - unfortunately it helped (unfortunately, because it started rain later that day). The thing that I had forgotten to try, and which should have been the first thing I should have done and which every dinghy sailor knows, was to partially raise the centerboard!!
The boat was now merrily wallowing along at about five knots, heading for the Golden Gate, and with my crew now steering (he promptly forgot about his other pastime), life became settled again - the steering was still being handled very delicately as that pole was sure bending - off-course bounces took a long time to correct.
There were still plenty of tricks left up our sleeves - I detail them at the end of this article. Now, before you start gee-whizzing about all this, don't forget that I had a steerable outboard motor which I could have lowered at any time I wanted to drop out of the race - and I had enough gas on board to motor back in all the way.
As we traced a drunken path through the seas, it became apparent that a method for bringing the boat sharply back on course was needed: there was no problem when the boat bore off too much - a rapid in-sheeting of the main would counteract this, but when it headed up was a problem - it seemed to take forever for the boat to bear off again. In order to counteract this, I took the spinnaker sheet and, from its turning block forward on the port hull, brought it back to the end of the boom (rigging it just like a preventer). This worked marvelously: as soon as the boat headed up (to starboard), I'd jerk the spinnaker sheet which pulled the boom forward, backwinding the main and immediately kicking the stern to windward. Rube Goldberg would have been proud of me! Despite a few round-ups (inadvertent tacks) and round-downs (inadvertent jibes) due to my lack of attention, things were going well and we were heading for the Bridge instead of Ocean Beach (a place South of the Golden Gate that was infamous in the last century for the number of ships which missed the Gate and came to grief there). By now we were definitely in last place, but, in talking with the Race Committee, I allowed as I was going to finish that darn race. They had been prepared for the usual all-night vigil, and now were so elated at being able to possibly quit early (just kidding), that we had quite a rooting section there on shore!
Things became somewhat uneventful - some anxious moments with a freighter (dropping off a pilot?) at the Lightbucket, but peaceful enough to make tea and relax - my crew was really getting into this steering business and became quite chipper..., uh, let's just say, less un-chipper. As we were approaching the Golden Gate Bridge (it seemed to be much narrower than I ever remembered it) there was this BIG SHIP (freighter? tanker?) coming out STRAIGHT AT US! At this instant the steering pole broke and we were resigned to watching the intact oar drift away. Luckily, we had the boat headed away from the ship, but as a precaution, I lowered the outboard and then, lo and behold, the boat became somewhat steerable without ever running the motor! The darn motor lower housing has enough surface area to provide a heck of a good rudder!!
Well, we happily aimed for the finish line - had one more inadvertent (but very smoothly executed) round-down/jibe followed by a tack to get back on course (the Race Committee was watching us through binoculars - ouch!) and we finally crossed the finish line as the fastest last-place boat in this race's 13-year history!
After crossing the finish line we started the drenched motor (I have nothing but praise for that old 9.8 Mercury), lowered the sails, docked the boat in SF Marina, and joined the Race Committee for a welcome pizza (my crew's appetite had renewed remarkably) - all this while dripping, as it was raining by now and my antique foul-weather gear wasn't quite up to the task.
My adventures didn't stop there - my crew went home that evening and next day I had to take the boat down the Bay about ten miles to Brisbane Marina - I simply planned on motoring home.
I started off in a dead calm and needed to make slight motor direction corrections roughly once a minute - to reach the motor, one has to contort one's body while draped over the aft railing.
Everything was fine until I crossed under the Bay Bridge (heading South) - the wind picked up to a strong Southerly and, with the incoming tide, the chop was miserable for my 26-foot boat. To add to the discomfort, the motor was getting airborne, so I had to continuously hand steer with the motor to both keep the boat on course and to keep the motor from over-revving as the transom lifted. That poor motor was getting drenched!.
Around Hunter's Point the wind had veered slightly to the East and I figured I was uncomfortably close to a lee shore - just as I turned away from shore, the motor quit - no warning, no nothing!
My main anchor is very accessible, and I had it going down in under ten seconds...down, down,... Hunter's Point is a Naval Shipyard, and the water depth is 100'! I had my entire 300' of anchor rode out by the time the 22# Bruce grabbed hold and everything settled down - whatever settled down means with an incoming tide bucking a 20-knot breeze.
After a much-needed tea break, I figured out why the motor would start and run fine until the gear was engaged - at which point it would die - a darn dockline had come loose and was wrapped around the propeller (I can't see the prop from the cockpit)!
Once I was happy with the motor, raising the anchor by hand proved impossible: the pressure of a now 25-knot breeze against my boat's windage was enough! I'm reasonably strong, but it didn't work, and no amount of running back to the motor, then running forward would allow me to get enough slack to even begin pulling in that 5/8" nylon rode.
What I then did was grab a couple of large snatch blocks and was able to reeve the line through them and back to one of my Harken 2-speed #16 primary winches - I brought in the first 200' of line one slow agonizing foot at a time!
The problems didn't stop there, because as soon as the anchor started breaking loose, the boat would start backing up to that close shore awfully fast - needless to say, I got a helluva lot of exercise alternating between running forward to lift the anchor, run back to add throttle and straighten out the boat, then run forward again and raise the anchor by a few feet - it didn't help that my going forward depressed the bow and lifted the transom which caused the motor to try running away! By the time I was done, I was drenched in sweat, but happily could now continue the bouncy motoring home. The thing I learned most was how to operate nimbly on deck with a safety harness and jacklines.
So there I was, hanging over the transom and continuously steering with the motor and altering the throttle for about an hour when about a mile from my marina all of a sudden the motor took an RPM nosedive and just before dying completely it sputtered back to life on one cylinder and ran this way, barely able to buck the now-changed tidal current. A good half-hour of this sputtering experience finally brought me into the marina, where, just as I started to pull into my slip, the motor gave up the ghost! - luckily I had enough way on to make an almost perfect docking maneuver, so the Sunday marina crowd was spared some excitement. Dissecting the rudder housing at home showed the failure to have been caused by what I believe to have been a poor layup - but what the heck, I was planning on replacing that rudder housing anyway, so this just speeded up my plans.
Regarding the motor, I didn't realize how quickly two-strokes eat up sparkplugs: after a couple of years of intermittent usage there simply weren't any electrodes left on those plugs! A good freshwater bath, a new impeller, two new platinum-tipped plugs, a lower housing oil change and a fresh oil and lube job, and it's as good as new.
Oh, yes. This year's race saw all sorts of records shattered: the first-to-finish was a Formula 40 TomCat which averaged over 18 knots for the 60-mile course. The other speedster was Peter Hogg who used this race as a tune-up for his new mainsail -- after the race he simply loaded up a few more stores and set off and broke the singlehanded sailing record from San Francisco to Japan! The great local sailing rag Latitude 38 gave an incredibly accurate writeup of my misfortune - heck, after all is said and done, the only thing I felt bad about was taking the dodger down, especially after obstinately resisting the razzing of the multihull crowd which considers it a no-no to go racing with it up. Technical Analysis
Why did my boat, which is very well balanced (normally has just a slight hint of weather helm) all of a sudden become almost unmanageable afterthe loss of the rudder? If you're interested, here's why -
If we're up above the boat looking down at it, we have to realize that there are a bunch of sideways forces tugging at the boat and trying to make it turn: above the water, the jib, which is trying to push off the bow of the boat, counteracted by the mainsail and dodger which are trying to push off the aft end. The rest of the hull's windage is probably fairly evenly distributed, with perhaps a slight bias to the high bow tending to blow off. Below the waterline, the lateral resistance to this side load is offered by the centerboard, hull shape, and rudder.
Looking at things very simplistically, we can call the centroid of the surface areas of the sails the Center of Effort (CE) and the centroid of the underwater surface areas the Center of Lateral Resistance (CLR). Still looking at things simply, if this CLR below the water is relatively in line with the CE above the water, we have a balanced helm - which means we can let go the tiller and the boat keeps going straight. In actuality, there are many other factors which contribute to helm variation, but I won't worry about them here (if you're interested, see the September 1992 issue of Wooden Boat).
The answer to the issue of rudder loss causing helm problems is relatively straightforward: on the Telstar, the rudder surface area is quite large, perhaps 1/3 the area of the centerboard. With the rudder missing completely, the center of lateral resistance takes a drastic jump forward: the main contributor now being the centerboard. Since the center of effort is unchanged, and with the center of lateral resistance having now moved forward, the CE is now aft of the CLR and thus the boat wants to round up, pivoting about the centerboard.
There are a number of things one can do in attempting to regain balance of the boat; i.e., to either bring the center of effort forward or bring the center of lateral resistance aft:
- Ease the mainsail
- Sheet in the jib
- Partially raise the centerboard: since it's not a daggerboard, it swings aft going into the trunk, thus moving the CLR aft
- Put up a smaller jib (which will move its CE forward)
- Reduce the size of the main (double-reef), but don't take it down completely because you still need it to 'steer' the boat
- Stick something like a flat board down into the water as far aft as possible
- Lower the outboard motor
- Drag more warps or even a small bucket off the leeward hull
PostScript
I've spent the rest of this summer sailing with a makeshift rudder using an old broken NACRA centerboard bonded to a 2x6 - this has worked so well that I have been very slow in completing my new custom rudder housing which allows the large rudder blade to slide down forward under the pintle/gudgeon and produce not only a balanced boat but a balanced (light-to-the-touch) rudder as well. The new housing is so strongly built (Kevlar + carbon fibre sheathing over the plywood) that I'm in the process of mounting the rudder pintles with lightweight hardware which I expect to shear because I want my transom to stay with the boat when I whap that deadhead with the new rudder one of these days!