Some Notes on the H28 design

[Jay Greer]

I received a question from the owner of an H28 Sloop rigged boat that he sails on San Francisco Bay. The question concerned the wisdom of adding either a ballon jib or a asymetrical chute to his sail inventory.
I thought that my ramblings might be of interest to the group so I am printing it here.
Jay

< I thought a bit of further comment might be of help to Ted with his sloop
rigged H28. Essentially the boat has the same jib stay length as the head
stay of the Ketch rigged boats, if indeed the mast is as the version
designed by LFH. In designing the sloop rig, Herreshoff merely added a set
of jumpers and four more feet to the height of the main mast. This means
that a balloon jib can be set on the jib stay and will then be more
efficient when working to weather in light airs as the luff will be
supported better than if set flying.

The design of the H28 is essentially a blown up version of the Herreshoff 12 1/2 that was designed by Nathaniel Herreshoff. Being of relatively shallow,
3'5" draft, the boats ability to work to weather is balanced by the
relatively generous beam of 8'9" which creates a hydrodynamic lift when
working close on the wind. This is the reason that many persons do not
believe the H28 will go to weather very well as they attempt to pinch the
boat closer to the wind than it was designed to sail. In truth, though the
boats may not look as though they are pointing well, they actually are
working up wind quite nicely. Remembering that it is luff length and not
foot length that aids in sailing up wind, head sails on the H28 work very
well when designed as a blade or 100% of the fore triangle. Again, when
working in light airs when a lighter sail is called for a high cut light air
drifter has the advantage of the full luff length combined with a light
weight clew and thereby being easier to keep full. When close reaching
there is a grey area where a mast head asymmetrical chute comes into play
and replaces the Genoa that is set on the jib stay. Here there is the added
advantage of being able to fly more area on a more efficient angle and
still take advantage of the hull form that is designed to lift to weather
when heeled.

On our own H28 "Bright Star", which is ketch rigged, I am convinced that
putting the sloop mast in place of the original shorter ketch mast and
keeping the mizzen as designed will give the advantage of the sloop combined
with the greater area for sailing down wind. Running a mast head chute on
both the main and mizzen will, in my opinion, take advantage of the very
fair hull that is one of the great advantages of this design. The only
disadvantage I can see is that we will have to reef sooner.
Fair Winds,
Jay Greer




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Messages in this topic

[Zane Lewis]

What you are talking about if much what my Dad did to his H28. Nb His one was more like 29' long i belive having been built in 1966 for the Charter trade in NZ.

He added 4 foot to the main mast and shifted the masthead stay out say 4'6" onto a bowsprit.
We had found that we did not need to reef until 18 knots or so. Now in summer we get a lot of light breezes. In the moring the sea breezes start and build up and peak at 20-25 knts between 2 and 4 pm then drop away again. Hence in anything under 12 knts she was struggling. Hence we became a Cutter riged Ketch.

My best run in that boat was 27 nm in 3 hours while Dad was down below sleeping and I had the 3 am to 6am slot. Broad reach with large following sea. That boat would just lie on her side and skid or surf. Dad came up and saw how much the masts were working and made me take some sail off.
Zane

[Jay Greer]

Sounds like the your boat became more versitile. 27nm in 3 hrs. is impressive!
How managable was the helm.
Jay

[Zane Lewis]

No real problems. She was running light as we had taken the engine, shaft, etc out while in Auckland and were heading back to Whitianga. It had been a side installation and so we had the full rudder. She sailed much better without that 120kg of engine, not counting shaft and tanks etc.
She certenly was much easyier on the helm that our 34 ft Yawl when pushing hard although the H28 was no where near as powerfull a boat, lower ballast ratio, slacker bilge, narrower and shallower.
She would just lay over on her side and just skid down the waves.
Zane

[Jay Greer]

We have had "Bright Star" out in some pretty nasty weather that causes most modern craft in our area to broach to when running on the quarter. Our own boat has yet to show any such characteristics. I am, currently, drawing up the new rig
which will incorporate a single strut jumper on the mizzen that will place the span stay connection at the mizzen masthead. This will will allow for a mizzen spinnaker to be flown in conjunction with the main spinnaker. I think this will really bring the boat to a new level when sailing off the wind.
Jay

[Larks]

Jay, have you explored your "Captains handkerchief" idea anymore? (Is that what it was called?)

[Jay Greer]

Jay, have you explored your "Captains handkerchief" idea anymore? (Is that what it was called?)

Essentialy a "Captains Handkercheif" is a square sail that can be rigged for sailing off the wind. A raffee can be set above it. Setting one up is a real idea on my part which, will have to wait while the new mast is being built. Right now, finishing my shop building is the first priority.
Jay