Sail trim and weather helm on an E38

[rwthomas1]

Hello All,
I went racing with a club member on his C&C 35 and watched carefully how that boat was trimmed, etc. I have also spoken to a few other racers about sail trim, weather helm, etc. Then I have tried to apply this advice to my E38. I have been told that I should be able to trim the sails so the wheel is neutral or just a bit of weather helm and this will be the fastest/lowest drag, etc. My E38 just doesn't like that! No matter what I do the boat really seems to like about a 1/4 turn into the wheel, maybe 1/3rd turn at most. When I do this the boat jumps, literally, and picks up almost 1kt in speed. This is all going to weather/close hauled in 16-20kts true. 130 genoa and a full batten main. My theory is the E38 is designed like this. The boat heels, increases waterline, the offset foils generate more lift, etc. She really seems to like being sailed with the leeward toerail at least 6 inches above the water to having the toerail right at the water. I have tried sailing the boat more upright its just not as fast. Heeled over she just seems to find her groove and lock in. The only thing I have not tried is to move the traveller to windward in these conditions while easing the mainsheet to leeward with the intent of really twisting off the top of the mainsail. My main doesn't like to twist and this maybe due to the full battens? I can see how this state of trim is possibly due to the current suit of sails. I can see how the theory of keeping the rudder as close to centerline as possible will minimize drag however it just doesn't appear to work on my boat! The rig is tuned correctly, the rake is as recommended in numerous posts. Regarding speeds well I can't say for sure since my knotmeter is dead. All I have is GPS SOG. I am seeing 5.7-6+kts SOG close hauled in 16-18kts true. Sailed upright I see 5kts or less. Would she be faster if I can figure out how to trim so that the rudder is more on centerline? I have no idea. I also notice that off the wind, beam reaching or even broad reaching, 120* or so, that the rudder needs to be held 1/4 turn to leeward to hold her on course. Again, trying to trim otherwise seems to slow her down. So what say the Ericson faithful? I'm not complaining, the boat seems just fine to me. I am just trying to understand why its not responding to the recommendations of some experienced sailors. RT

 

[wurzner]

Rob

I'm not questioning the numbers you have posted, but will share my experiences. I do not think I could comfortably carry my 130 in 20 knots of wind and that is with a new main and hydraulic backstay....I'd be way over powered. Also, I see better upwind speeds than you posted and frequently find that when I put my 105 up, I get better speed than with the 130 and have learned to reef earlier. In the conditions you mentioned, I would expect to see closer to 6.5 to 7 knots and that is with a smaller headsail or a reef. In 20 knots with a full sail plan, short of having a lot of weight on the rail makes driving pretty tough. I do agree that 1/4 turn or more of weather helm does not appear to compromise performance too much and having the boat heeled a little does not seem to impact performance..

shaun
E38-200

 

[Frank Langer]

Rob, just a few thoughts before the more experienced others chime in....I have had the same experience on our E30+, finding she sails best with the wheel turned about 1/4 to the 3:00 position. I am quite good at sail trim, so made all the right adjustments, and was still puzzled as to why I had to turn the wheel so much to keep her headed right--yet going at 7 knots in 14 knots windspeed. I know the books suggest that the rudder should be turned about 3 - 4 degrees to provide lift without too much braking from having it turned too much.

I recently put the wheel to the 1/4 turn at the dock and looked at how much it turned the rudder, expecting the rudder to be turned fairly sharply. But I was surprised to see that it was turned only about a rudder width from centre line. While I don't know how many degrees this is, it was less than I had expected, and makes me think that this may be quite normal.

I also had the recent experience of sailing in about 10 knots wind with my full mainsail and full 125 degree furling headsail fully open--the wind was steady and the boat was so well balanced (with the rudder at the 1/4, 3:00 position) that I was able to sail in a straight line with no hands on the wheel, ie. absolutely balanced helm. I know that many will say one should always have weatherhelm so the boat will round up as a safety factor, and my boat will normally do this; but under the right conditions she will "sail herself" as she rounds up very slightly, falls off slightly and repeats this in a nice straight line as mentioned.

So I have stopped worrying about this, and am just enjoying how well she sails. While I'll look forward to what others have to say on this, I am really pleased with how our E30+ sails, with wheel at that position and heeled about 15 degrees. (At times she's also really fun to sail with the rail in the water, but I know that the experts will say that she would sail better with less heel--and though they are right, fun is important too!).

I know that the E38 is different from the E30+, but interesting that we seem to be having the same observations about performance.

Frank

 

[rwthomas1]

Its hard to say on the speed issue. Since the knotmeter is inoperative I have to rely on GPS speed. This can be unreliable in terms of absolute numbers however it seems to work fine if I am just noting the trend in speed when I make a change. The bottom of the boat is pretty fuzzy right now so I would be willing to guess that is costing a knot, maybe less or maybe more. I knocked off what I could 3 weeks ago but there was sea grapes and other muck an inch deep in some spots. Fixed prop too. Figuring wind speeds is dicey too as the anemometer is not subtracting the boat speed. So if I am seeing 20-22kts when driving to weather, maybe 40* off the wind at 6kts then I figure I am really seeing 15-17kts true? I have reduced sail in these conditions and it doesn't make the boat any faster, mostly slower. When the boat is "in the groove" as I describe above I can literally walk away from the wheel, it will sail itself. This only happens when sailing close to the wind though. Above 20kts true the first reef is in the main and the 130 is rolled to the first mark. It was a bit gusty yesterday so I didn't bother reefing even though some gusts were in that range. Another thing to remember is my E38 has an added keel bulb of unknown weight. I would guess that this makes the boat less tender than the standard shoal draft? It make in fact be on of the reasons my boat sails the way it does? It is no longer as the designer intended? Like I said, I am looking mainly for feedback on the sailing qualities. Hope others chime in. RT

 

[Chris Miller]

tenderness

Hey Rob,
The 38's are very tender compared to a lot of other boats (like that C&C)... it's just in their nature. We find that twisting off the genoa by moving the cars back to the point that we can sheet the foot to the rig and still get the top to open up a little brings the power a little lower and helps stability. Then I leave it alone and sheet the bejezus out of the main and just play the traveler while the Capt. has the helm. When the weather helm gets to be too much, I drop the trav until only the leach is working and the rest has a big bubble-at which point the boat will settle out. then trav up for more power when needed. That way you don't flog your main as much (by having the leach working), we can still point and stay in control, and I get to do something (trimming the trav) while the wife is driving.

That's what works for us, I'm sure lots of other experience will pop up here.

Chris

 

[JohnK]

I am seeing 5.7-6+kts SOG close hauled in 16-18kts true.

This jives with the US Sailing polar diagrams done for the E38 here. The summary page (page 25) shows that for a true wind of 16 knots, boat speed is 5.98 knots, apparent wind is 20 knots, apparent angle is 33 deg., and heel is 19 deg. Just another data point to consider.

 

[ted_reshetiloff]

I think the keels on these 38s have a lot to do with what we are all looking at here. The upwind characteristics in 18-20 TWS will be pretty different when you look at my 6.5' fin, Chris' 5.5' wing, and RT's bulb of unknown spec. My experience has been closer to Shaun's in that at 18-20 true I am not going to be able to carry my full genoa (150 for me) and main. At that speed I am likely to be on my first reef with the #3 (100%) up. If I don't have any crew on the rail I will sheet the 3 with the car a little aft of neutral so the top set of tails are breaking on the inside with the bottom 2 sets both even. Main will be sheeted hard with the traveler lowered and quite a bit of vang on. Out haul/reef line flat, luff tension on both sails quite tight to eliminate any wrinkles. Hydraulic backstay is powered up to about 1800-2k lbs to yield 3-4 inches of headstay sag and 5-6 inches of mast bend. The main may have a little "happy bubble" but all leech tails will be flying. At that setting I am getting a pretty solid 7kts of boatspeed at 30* apparent. If I take it down to 33-35* speed jumps to 7.2 -7.3. Probably about 1/4 turn on the wheel.

Possibly most importantly is: if I am turning the wheel more than 1/4 turn I am overpowered and need to adjust trim (leads or tension) or shorten sail. I try to avoid sailing the boat with the rail buried. The occasional puff that sends a little water on the lee side okay but nothing more than that. I may see that the boat is going faster but VMG will be hurting for sure with all the leeway you will make heeled that much.

If I am sailing with 8-10 guys on the rail in race mode (18-20 tws)I will likely be with the same headsail but probably not the reefed main. Less vang, higher traveler, jib leads so all 3 sets of tails break at the same time, happy bubble, someone playing the traveler to keep the heel and wheel angle's manageable. So I'm more powered up with the crew obviously but still shoot for the same heel and wheel angles. Boatspeed with crew is likely 7.2 at 30* 7.4 down a bit. I will often feather in the puffs up to maybe 26-27 until speed drops then bring it back to the groove. Likely sail things a bit fuller and more powered up if we have a lot of chop to deal with.

 

[footrope]

Effect of fuzz and propeller type?

Hi Rob,

You may have several things that seem to reduce your speed, but it is hard to compare GPS SOG to boatspeed through the water. I have the 6' 6" fin, a 3-blade feathering prop, and I like 1/8 to 1/4 turn of weather helm - I think that is where my boat stabilizes and the main and jib pull the best. I have the 100-110% working jib and leach battens on the main. With a reasonably clean bottom and 12+ knots wind I see 6-7 knots boatspeed, but it is hard to stay above 7 knots for some reason, when going upwind. I consciously try to get the boat pointing between 35 and 40 deg off the wind, according to my gauges.

I agree with the others that more than 1/4 turn weather helm means I'm overpowered and need to drop the traveler, trim, or reef. I don't have a backstay adjuster and I think my mast is at about zero rake. I keep forgetting to measure that. Have you posted a photo of your keel? I can't imagine it's so big that the drag needs to be considered.

1/4 turn of the wheel is not much rudder angle, but in gusts, when I have to wind in another 1/4 turn, the forces go up substantially. More than 1/4 turn seems to be unnatural for the boat/rudder design.

 

[rwthomas1]

From what I am reading here I am not far off the mark. I don't feel the boat is overpowered sailed the way I am describing. At 18-20kts it is pretty close but not quite overpowered yet. At least it feels that way. I will have to look at the rudder with 1/4turn and see how much angle this really is. I will also agree that anything past 1/4 turn does seem to indicate that the boat is overpowered and the steering input forces increase noticeably. It is difficult to use GPS as the only measure of speed. I just try to use it for trends, not absolutes. The way I see it, a feathering prop, squeaky clean bottom and maybe a new main would easily add a full knot. That would put me right about where everyone else seems to be. I will keep playing with tune and looking for improvements. Thanks all! RT

PS, anyone want to guess what the modified keel bulb might weigh? Its very likely a Mars Metal bolt on lead setup.

 

[u079721]

1/8th wheel to weather

My two cents worth here is that we used about 1/8th wheel to weather when hard on the wind, moving up to 1/4 in gusts. That's with a 130 genny, and a shoal draft keel, which could certainly make a difference in the balance.

 

[Lawdog]

e 38 weather helm

It appears that your keel was originally a 6'6" keel but was cut down when the Mars appendages were added. I looked at doing the same thing to my deep keel and talked to Mars and saw similar pictures showing the same type of bulb configuration. They told me that the bulbs weight was 800 lbs., and that the piece of the keel being cut off was somewhere around 200 and 300 lbs depending upon how much I shortened my keel. They also showed that the newer keel stiffened the boat and added a few tenths of speed but did not allow the boat to go to windward as close as before.
I just raced my 38 in the MS Regatta in Portland, ME last Sat. where winds exceeded 43.4 on my WS for the highest gust reported, with averages of 30kts common. I had a double reefed 9.5 oz main and 50% jib, if that, and was regularly suffering broaches (maybe 5 to 6 times) over the 10+ mile course. My arms are still in pain from the huge amount of weather helm. I do not have an adjustable backstay that I think would have helped dramatically in those conditions. Pictures are available if I can figure out how to atach them

Neal
Enterprise

 

[Lawdog]

here's a few shots from the day

 

[e38 owner]

Weather helm e 38

When my e38 was out of the water I measured the amount of rudder angle compared to the recommendation in the NORTH SAILS TRIM BOOK and found that according to my wheel 1/4 turn is about right. My wheel is the ys Wheel. Other boats in our yacht club with different wheels, boats and gear ratios found that 1 spoke was about right. 1/4 seems to work for me

Ps I have the deep keel. The photos above appear to have the mars bulbs added to the the shoal draft keel. The shoal draft keel appears to be larger from bow to stern.


Great photos

Finally a question for the group. I have found that once the headsail if reefed to a certain point , maybe (20% from full) that the effect of reefing more has little effect on the performance of the boat due the high center of effort, poor sheeting angle, and fullness of the sail. I am still at a loss of what to do in conditons that warrent less headsail, but where a change of headsails is not practical. Often when sailing in gusty conditions my prefered sail combo is 130 and no main. However I have never done this when racing and heading for the windward mark

 

[ted_reshetiloff]

e-38 owner has touched on something I discovered this summer on my 38. I used to reef in the order of roll up/reef genny first, then main first reef, then more genny roll up, then main second reef etc. I found that the boat goes a lot better if I lose the main first. So go to first reef early, then second, then no main and roll up genny last. The boat sails very well with just a full headsail, but the headsail needs to greater than 100% or you cant point. I find with just my #3 and no main the boat develops too much lee helm. When I do roll up the genny I always move the car fwd. With my full 150 the car is about 10" from the aftmost end. When I am reefed to about 120 my car is between the opening port in the head and the aftmost fixed port. At 100% the car is in the middle of the aftmost fixed port. As you reef more headsail you need to move the car fwd or you will have a tough time retaining any shape in the sail and the leech will be dumping everything.

 

[NateHanson]

It's also been my experience that boats that size balance pretty well with full genoa and no main. I guess the CE of a sail that size is so far aft that it doesn't develop any lee helm, even when it's the only sail flying.

However, I wouldn't recommend reefing in the order that you mentioned, leaving a full genoa and no main in 25 or 30 knots of wind, because the mainsail provides a lot of support to the mast in heavy seas. With only a big headsail and no main in heavy wind and seas (assuming you don't have running backstays), you can often see the mast pumping back and forth a bit, and I think you are at risk of busting the spar, if it were to get out of column in those conditions with so much pressure on the headstay.

Just my 2c. I'd reduce down to full genoa and 2nd reef, but I wouldn't douse the main in heavy air until the genoa was substantially reduced.

(Of course, I'm not talking about bobbing along single-handed on a calm day with just the genoa and no main because you're lazy. That's still fine if it means you don't have to put down your beer. I'm just talking about the stinky weather. )

 

[Don Taugher]

Hi Rob:

I have a 38 with the 6'6" keel and the Mars bulb, which looks like yours. The specs of the boat said the bulb was 500 lbs. I generally sail in the 15 + knot range and enjoy having the extra weight below.

Don Taugher
38-200 # 263

 

[ted_reshetiloff]

I see no risk to the spar on the E-38 of sailing with jib only if the rig is properly tuned. The problem suggested is typically only a problem for frac rigged boats. If you are getting a lot of pumping in the spar you need to tighten your lowers. I have carried genoa only up to 30kts apparent with no more than slight pumping. Certainly not enough to concern me about the rig. My friend has a frac rigged boat though and even with running backs his mast will pump a lot under a jib only setting. We added check stays to fix that.

 

[u079721]

....leaving a full genoa and no main in 25 or 30 knots of wind, because the mainsail provides a lot of support to the mast in heavy seas. With only a big headsail and no main in heavy wind and seas (assuming you don't have running backstays), you can often see the mast pumping back and forth a bit, and I think you are at risk of busting the spar, if it were to get out of column in those conditions with so much pressure on the headstay. QUOTE]


As in all things dealing with sail trim I will defer to Seth, but my understanding of the danger of running under headsail alone is not really wind-induced mast pumping, but rather the lack of support to the mast if you should bury the bow into a wave and practically bring the boat to a stop. The cases I have read of where a boat was dismasted while running under just headsail all invovled falling into a trough and having the mast snap from the shock.

 

[NateHanson]

That's right steve. I meant that in heavy seas I've seen the mast pump without the main up.

I can't recall motoring in those conditions (with no sails up) so I can't say whether the jib matters or not, but I figured the pumping would be more dangerous when the mast had lots of compression on it from a loaded headstay.

Where's Seth to set us straight???

 

[rwthomas1]

FWIW, I keep trying to improve the sail trim of my boat and it has been quite successful. I checked the rudder deflection at 1/8 to 1/4 turn on the wheel and its actually quite small. I suspect that the steering ratio of the YS setup is quite different from other boats. At a 1/4 turn the trailing edge is only deflected 1 1/2" or so. Not much at all. I have been concentrating on trimming the sails to balance the boat with the slight wheel turn dialed in. This has resulted in the best combination so far. The knotmeter all of a sudden decided to work intermitantly. Nice to have that back even intermittently. Anyway, I feel I just figured the E38 out after almost 2 seasons of fumbling. Thanks for the input. RT