Adjusting height of boom on Ericson 39

[bbboat]

Hi all,
Hope someone has either a clear answer or strong opinions on this one.

After 4 long years, we have a rig back on our E39 , which was originally set up for racing. Now we're in the process of modifying the rig to make it easier for the two of us to cruise.

In putting the boom back on, we realized that the boom was originally set at about 8-feet off the deck. The racing measurement stripe and hoisting the sail confirms this. I double-checked the measurements, and the "I" measurement (at 52.04') minus the "P" measurement (at 44.04') gives a difference of 8-feet, which would be the distance from the deck to the boom.

I guess 8-feet high is fine if you're racing with the original gooseneck, topping lift, downhaul and boom slide that lets you drop the boom below sailing height to flake the sail. However, we want to ditch this oversized dinghy arrangement in favor of a fixed gooseneck, lazy jacks and a rigid vang. A boom where the gooseneck is permanently 8-feet up in the air would be nearly impossible to sail with safely.

Our rigger is recommending fixing the boom height at about 4-feet to 4.5-feet off the deck, which would make the boom and mainsail easy to tend, plus it would make the boat less tender with our original-spec sail, since the sail area would drop a few feet. He also argues that if we were so inclined, the lower boom height would let us add more sail area when it comes time to buy a new main.

In the cockpit, this new boom height is still plenty high enough to accommodate the bimini and dodger we want to install.

My question is: Are we missing anything? Are there any downsides to this new arrangement (apart from the risk of getting clobbered by the boom, which is the case on 99% of all sailboats out there anyway)?

Thanks!
Dan

 

[HughHarv]

Boom height

Sounds like your rigger is giving you sound advice. I have an Ericson 39 project boat that has the boom located about the same elevation above the deck as you mention. I know cause I replaced the pin at the gooseneck attachment with one hand while holding the boom in the crook of the other arm. Sorry I didn't measure the height more accurately. Even at this elevation, the boom is high above the cockpit sole and I had to step up on the lazarette to reach up to it.

 

[Martin King]

By all means fix it in place. This was one of the first mods I did
when I owned a 39. That sliding gooseneck may have been ok
in it's day (although I have my doubts) but is downright hazardous on a
short handed cruising boat. I remember cursing that arrangement
when I got clobbered going underneath the boom at the same time a crew
member cut loose the main halyard.

Martin

 

[Sven]

Dan,

In putting the boom back on, we realized that the boom was originally set at about 8-feet off the deck.

When I got the E39 drawings one of the first thing I noticed was the slope of the boom in the flushdeck sailplan. (The boom does not slope in the flushdeck model with a clubfooted cutter design.) The boom slopes down appreciably from the mast towards the stern, probably by a foot or more. I wish there was more definition in the picture I took but you can probably still see it.

I can't help but wonder if that was to beat some arcane measurement rule.


-Sven

 

[Guy Stevens]

Drop it down so the height in the cockpit fits you.

Then put a bigger mainsail on so that the boat does even better in light air, which if you are cruising is about 85% or more of the time.

Fix the boom in place, and get rid of that stupid 1970 pivoting system. (I have photos to show how to do both if you need them.. Contact me off channel).

A good set of lazy jacks which are only deployed when the sail is being dropped is next. ( I will send you a reprint of my article which used to be on the web site at boat us... If you would like.)

If your crew is not too strong and has a problem raising or lowering the sail with the existing slides then go to a strong track system which makes it way easier. (Dropping it too fast can become an issue with this)

Then put on a rigid boom vang if you don't have one. Garhauers are the best and cheapest around.

Also now is a good time to look at that old traveler if it is still on the boat. They were not very good to begin wiht (Nicro Fico with wheels that never did roll well). Time to replace it with either a Garhauer (Worth the wait if you can be patient, or a Harken if you have to have it now....)

Then take the boat out and be amazed at how much better it sails....

(Then you will probably figure out that you need a bit more rudder if the rudder mod has not been done... But that is another story, and you can sail for a long time without the rudder mod... But you will like it a lot when you finally break down and make the rudder bigger. DO NOT GO WITH THE FOSS MISTAKE.... Another thread....)

If you want any photos or input on any of this, contact me back channel... I only have about 50,000 miles on a E-39..... So I might not have a solution to all the problems......

Guy

 

[Sven]

Guy,

(Then you will probably figure out that you need a bit more rudder if the rudder mod has not been done... But that is another story, and you can sail for a long time without the rudder mod... But you will like it a lot when you finally break down and make the rudder bigger. DO NOT GO WITH THE FOSS MISTAKE.... Another thread....)

Would a search on FOSS MISTAKE show me the way to that other thread ?

No, we're not ready to take on a rudder mod, but I'd like to know about it anyway.

Thanks,


-Sven

 

[bbboat]

Thanks!

Thanks everyone for such quick replies! Guy I'll contact you off-channel for those details. Confirms what I suspected. We had already had the gooseneck swivel deleted before the boom went back up.

Now we'll set the boom at 4.5 feet off the deck - for now just a pin above and below the track to hold it in place, or is that not enough?

Ironically, it was the lazy jacks that started this discussion. We put them on, only to immediately realize that, at 8-feet up, the lazy jacks worked great, but when it came time to lower the boom to put stuff away, the jacks acted like a second topping lift! Lowering the jacks to drop the boom, of course, let the sail flop all over the deck, making the jacks completely useless. Fixing the boom will solve that one.

The previous owner installed all new Harken traveler and mainsheet gear, and we saw the Garhauer rigid vang at the Annapolis boat show and really like it - a good value!

We'll have to wait on the STRONG track and new mainsail. One day...

As for the rudder, we already went with the Foss modification a few years back - basically it's a Cal 40 rudder on our old rudder stock. So far it's made a huge improvement in boat handling. Next year will be the real test.

It's a big reassurance knowing that, even with a 32-year old boat, we have such a great support system with this website. Thanks again.

 

[Martin King]

I can't help but wonder if that was to beat some arcane measurement rule.

Exactly right, Sven. Known as a droopy boom, it gave you a little
extra unrated sail area under the IOR mk1.

Martin

 

[Seth]

All good advice from Martin, Loren, et al..

And Guy, of course.....
Just so you keep the dimensions correct, "I" (or "IG") is measured from the top of the jib halyard sheave to the "base of I" (or from the top of the spin halyard sheave for "ISP") which is not on the deck anywhere near the mast partners, but is lower, and near the chainplates-in very rough terms it is about 1" below the deck at about the location of the upper diagonal shroud chainplates-out by the rail.

You should still set the boom where you want it above the deck of course, and I would go ahead and build the next mainsail taller-you will be faster all the time except upwind in heavy air, and you can always reef for that.

Slightly nitpicky I know, but this is a common misconception about how "I" is measured..I minus P is not the boom height above deck if using the partners (deck cutout) as a reference..Also, P is from the top of the main halyard sheave to the TOP face of the boom (unless modified by re-locating the top band or boom height for rating reasons)...
Cheers!
S:nerd: