H34 - Shortening the mast

[Guillaume C.]

Has anyone shortened their long stick on a Hunter 34?

I am planning to do some offshore passage and this is a solution that would help a bit to reduce the tenderness of the design.

Very rough calculation indicate that by loosing 4' of fat at that height is equivalent of 700# in the keel at small angle of heel (then around 400# at max RM). The mast would be shortened from the base so as to lower the center of gravity of the mast (lower the spreaders). Structurally this would not be a problem but proper tuning will require some calculations(not done)

Obviously in light air I would curse myself to have done this, but as soon as the wind pick up enough for reefing, the boat would actually perform better as it would have the same sail area with less weight (and associated inertia...) doing nothing up there.

To lessen the drawback, the boom would be lowered close to deck level and raising toward to cockpit, lowering the center of effort of sail while not reducing the area very much. Forward is less of a problem as bigger sail (spi...) can be raised earlier when needed

note: I am changing the rigging and sails anyway.

Any experience, thought, whatever?

 

[kloudie1]

Back in the day, when the 34 was new, it was not unusual for some folks here on the Gulf Intercoastal Waterway to have 4-6 feet cut out of the mast in order to clear some bridges around Destin, Fl, and Navarre Beach in Fl.. There were some other bridges as well but some have been replaced with the new standard of 65 feet. There are still some of those boats around.. I haven't sailed on one, so I can't comment .. Most were shoal draft .. and motored a lot in light air. No real downside except as you've noted..

 

[Steve Dion]

What is wrong with reefing the main?

A second option would be to purchase a smaller mainsail!

Am I missing something here?

I think the down side is you have probably reduced the potential value by several thousand dollars and/or reduced the number of people that would be interested in purchasing the vessel in the future.

 

[Ken Kindrick]

Methinks that you are getting "paralysis by analysis".

 

[David in Sandusky]

Unintended consequences

Changing your boats basic design will usually lead to unforeseen problems. But you can be sure that you are decreasing the value of your boat, which has a well earned reputation for going to weather, especially in light winds.

I agree with Steve. Put away your hacksaw, and go see a good sailmaker. Get comfortable reefing the main, and make sure you have the right reef points. Put your effort into rigging for and acquiring a trysail - a proven value for heavy weather offshore.

Also, have the sailmaker check your mainsail. Heeling instead of driving ahead is a normal symptom of a blown out main. (I know the h-34's reputation for being tender, but that high aspect ratio tall rig is so efficient at all wind speeds.)

 

[Guillaume C.]

Thanks for the comments

Just to be clear, I do not want to reduce the sail area and performances of the boat, I actually want to increase the average performances when cruising offshore

If most of my cruising would be upwind in light air or when choosing only the bests days to sail, then the actual rig design is very well suited (high aspect ratio is favourable upwind, and in light air the high CE(sail) and CG(mast) are not a problem)

But in more likely cruising conditions, more windy and the least possible time going upwind, the requirement for rig change a bit: the high aspect ratio is not optimal anymore and lowering the CE(sail) & CG(mast)allow to keep the sail up in stronger wind than would be possible with the original rig

Basicly as soon as we are not carrying the full sails, then a shorter mast will actually perform slightly better. For example at 30 degree of heel, if you loose 25 pounds 2 foots from the masthead, it has the same effect as having 130 pounds on the rail.

Of course this is nothing new, saving weight high in the air is a big priority in racing boat. This is why aluminum mast are tapered in the highest part and why for a same design, if a racer use an aluminum mast instead of carbon, it is overall better to make it shorter. Raked boom are common as well to lower the CE...

An added benefit is that the lower CE would slightly reduce the tendency for weather helm...

So I guest the important question would be: what % of time do you carry full sails ? I do not have that much sailing time on the Hunter 34, but the experience I had was that I rarely needed the full mainsail & genoa when doing the ''delivery'' (when you do not choose your weather window)

Cheers,
Guillaume

 

[dehler25]

I am in the market for a new boat and one that I looked at had shortened the mast, I instantly subtracted ten grand from the value compared to others that were not modified so. It's just a consideration.

 

[Fast Ed]

G.C.
I would definitely not shorten the mast. I suggest adding a baby stay to the rig instead, and having a staysail made. The baby stay would run to the aft edge of your anchor locker. One issue for the B&R rig is that the forestay is the only thing holding the rig up! With the swept back spreaders, there are 7 wires pulling against the forestay. The boat also has a really long 'J' dimension. The foredeck is really big enough to be a cutter.
I have not actually done this to my boat, but I would if I planned to cross an ocean.
Fast Eddie

 

[Guillaume C.]

Yes, while the mast shortening is just a possibility, adding a baby stay is definately on the project list.

On the H34 the anchor locker is kind of "hanging" from the deck, so I dont see it as an especially good anchor point.

I will probably add a tranverse beam inside the v-berth cabin, lying against the deck liner (any space between liner and actual deck to be filled) and extending on both side up to the hull/deck junction. Small part of the deck liner "lip" (wich cover the carpet end) will need to be cut away.

I have not studdied yet the rigging details, most importantly the need or not to have flying backstay at the baby stay attachment point. While most rig would need them, the 30deg sweptback spreaders might be well enough for the task. If anyone has checked this already (by a naval architect or rigging company?) please let me know

 

[JWC]

I knew a guy who had an 85 H45 who installed an inner forestay for a staysail and he used the spreaders instead of running backstays without a problem. He said the designer (Bergstrom?) told him it was OK as the swept back nature of the rig was adequate. However I had a 34 and took it offshore plenty and our solution was a small, flat jib, high cut clew, about 80% of J and 80% of the luff. Worked really well in 15 knots and up, just keep reefing the main. You will need to put in a third reef with a bit of hardware outside the boom.

 

[heart of gold]

Guillaume, I am very interested in the addition of a cutter stay as well. I think that I would leave the mast alone for the light winds up to 15 knots its very advantages and even during a crossing this will come in very handy. The addition of the cutter stay I think would be the very best of both worlds both in heavier weather and light winds. This is on my project list as well. I've been thinking of running a ss or bronze rod right through the chain locker and out the nose of the hull to another ss plate. Would this not be the strongest solution? I would really like to see how yours turns out. Cheers,

 

[VINN]

im sure it would be a bad idea to cut the mast down on a h34 because of all the other possible options available. for some its an asset. the ideal sail varies due to changeable weather conditions for any sailboat. many experienced sailors carry at least a 1,2 and 3 headsail commonly known as a 150, 130, and a 106%. the gaps can be filled in with reefing the main or jib for comfortable handling. you can also have a# 4 built with a shorter luft, some 4 feet shorter than the top of the mast to decrease the leverage of the sail plan. for maximum performance you want to carry a headsail thats about 10% over canvassed to handle the lulls, and easy enough to bleed off the extra power in gusts with the main and traveler. my 106 feels great at 15k app without a crew. with a shorter luft and non overlapping foot 18 kts app might work. just need to experiment. a cutter rig would be great if you could store it when unused so it would not foul the jib when tacking during a race...

 

[Jared1048]

im sure it would be a bad idea to cut the mast down on a h34 because of all the other possible options available. for some its an asset. the ideal sail varies due to changeable weather conditions for any sailboat. many experienced sailors carry at least a 1,2 and 3 headsail commonly as a 150, 130, and a 106%. the gaps can be filled in with reefing the main or jib for comfortable handling. you can also have a# 4 built with a shorter luft, some 4 feet shorter than the top of the mast to decrease the leverage of the sail plan. my 106 feels great at 15k app. without a crew. with a shorter luft and non overlapping foot 18 kts app might work. just need to experiment. a cutter rig would be great if you could store it when unused so it would not foul the jib when tacking during a race...

Agreed 100%....The combination of sails and shape are the real issue you should be focusing on and not care about the mast height. Your looking at the problem backwards.