Hogging

[Phillip Allen]

I'm just wandering if any hogging has been seen by anyone on this forum on older boats in the thirty to forty foot range.

[Rich VanValkenburg]

Yep. Our 22sqm is 38' and had a bad hog when I found it. The long overhangs need support. On top of a hog, if the cradle settles in the dirt unevenly, it can pick up a twist.

Rich

[videoguy]

well I'm starting hog a midship I guess it can happen boats and boatbuilders.

[RGM]

It's difficult to find an older boat that isn't hogged, no matter what the length. Alot of people aren't aware that their boat is hogged because they have never done a keel profile on their boat. Or they simply haul it out and slap her down on the blocking provided by the haulout facility with little attention to hull shape. For power boats it requires stretching a tight wire from stem to stern beneath or alongside the lower portion of the keel while the boat is in the water unsupported by straps or drydock blocking. You or the diver measure and record the distance from the wire to the bottom of your keel at intervals that have been previously marked out on the wire. Many people (and their boats) would benefit from having this knowledge. It would allow folks to properly block up and support their boats while drydocked or on the hard. Subjecting a boat to undue stress and strain while out of the water is tough on them. If the boat is hogged it's best to support it. Similar attention should be given to sailboat hulls even if the overhangs are modest. A marked wire can be stretched above the deck, off centerline a bit is ok, that's all you can do with a sailboat anyway. Measurements can be taken before and after a vessel is hauled. Most people would be suprised by the results.

[Bob Cleek]

Amen to what RGM just said. They all can hog to one degree or another. It's all about gravity. This is particularly so in boats with long overhangs. Some ships were actually built with "reverse hog" to compensate for the inevitable. Certainly, it tends to be less of a problem in shorter, smaller, vessels. Given the bouyancy of water, the worst of it occurs when boats are hauled, and as RGM said, when they aren't properly supported. If you want to see a picture of how NOT to leave a boat on the hard and how to just about guarantee hogging, take a look at the picures posted below of Al Mailik, that English boat from Zanzibar. (I presume the picures were taken just as she was hauled and still in the slings before they had a chance to get proper supports under her ends.)

[Ruaridh]

er... that'll be a Scottish boat, Bob...!

[Ed Harrow]

I've been thinking on this quite a bit, spurred on by a previous email from Rodger on this very topic.

So, I'm thinking that I'll make tripods to sit bow and stern, run wire (a suitable string substitute?) over them and hang suitable weight on each end, and measure from the string to various reference points. What would be suitable reference points? I was thinking perhaps stanchion bases?

This all, of course, begs the primary question, is Phoenix "right" as she sits? How much will the tweak in her keel, and the gap between the faying surfaces of the keel and grip affect this?

[mjasko1]

Accepted that hogging is inevitable but what effect does it have on sailing the boat given that the hogging is not serious. Certainly there will be some effect on the ability of the boat to sail to its potential based on the original design and possibly if bad enough on the water tightness of the hull . Most of the boats I have seen that are hogged are only slightly so and are still quite enjoyable to sail.

[P.I. Stazzer-Newt]

"Hogging" a mixture of gravel and clay

[P.L.Lenihan]

Hogging is dredging up an 8 year old thread.:D

[paladin]

Andrew...You are EVIL!

[Peerie Maa]

I between building big black things, we built three of these.
http://www.ship-technology.com/projects/thames/images/thames4.jpg

The owners agent got into a real flap. He had read the draft marks forward midships and aft, and calculated that she had developed a hog.
He only calmed down again when we walked him along the quay to where he could see how much she was heeling. :D

[richbeck]

??? Phillip Allen new member 28,083 posts ???

[Jim Ledger]

Here's a good example...

http://i104.photobucket.com/albums/m193/searover1916/Morgan3.jpg

[Peerie Maa]

??? Phillip Allen new member 28,083 posts ???

I'm told that there's a little blue pill? . . . . never mind.

[capnharv]

Hogging?

I knew a guy who had 7 El Toros, 3 C-Larks, 2 Thistles and a San Juan 23 in his yard.

Of course, he was single. . .

[P.L.Lenihan]

I know what bush-hogging is! :D

[JimD]

Do I understand that this is an older thread that's been bumped?

Lew, upper left hand corner of every post has a time stamp indicating exactly when the post was made. The original says May 20th, 2002. And I thought all 28 thousand of Mr Allen's posts were about guns in The Bilge. This proves that once, almost 8 years ago, he actually posted about a boat. Shows just how wrong I've been about him.

[Garret]

Hogging or sagging, both can mess with the beauty & sailing characteristics. The bend in the sheerline of that beautiful boat above is a sad thing to see.

As the owner of a sailboat with loooong overhangs, I do a few things:

3 blocks under the keel. Of course 2 would work, but having 3 lets me know if anything has moved/settled.

2 V jackstand supports under the bow instead of the usual one.

At least one (usually 2) extra supports aft: 1 on the horn timber just aft of the rudder (at the bootstripe) & another approx. halfway (maybe 5/8)to the transom.

Neoga (http://www.automatesoftware.com/neoga/OnTrailerAft.jpg) has about 12' aft of the rudder & at least 8' of it is not supported even when in the water - so the 2nd support is probably mostly there to make me feel better....

[Lew Barrett]

Lew, upper left hand corner of every post has a time stamp indicating exactly when the post was made. The original says May 20th, 2002. .

D'oh? So silly of me.......Thanks Jim

[Peerie Maa]

Jim,

Great shot. It certainly looks like this hull was carefully blocked to this profile and since there are no trammel lines present it's kind of hard to say with real assurance. But I would guess there is a story here and more than meets the eye. Most old wood built commercial craft do this with time due to the weight of the focs'l and poop/counter where there is no buoyancy to support them. Preparation to dock an old hull without damage should if possible include preparing the dock blocks to the keel profile.


Most lightly constructed sailing vessels and some power boats with long overhangs suffer from both Hog and Sag. On sailboats that have some years on them and tall rigs you will see hogging around the chainplates from years of continual pulling and loading on the frames, clamps and shelves if there are any.True, but fortunately the rest of the hull is usually sound.


This is not the same as Sag though. Sagging is the settling of the hull ends where it may give the appearance of being high or Hogged in the middle. Not true. Sag is the opposite of hog, where a vessel is supported by wave crests at her ends, with a trough amidships, putting the deck into compression and the bottom in tension. Design of the hull scantlings for a commercial vessel includes a calculation of both sets of stresses, by comparing the shape of the weight distribution curve and the buoyancy curve when balanced on a wave crest and over a trough. Then by integrating the curves of the resultant load you derive bending moment and shear curves.

[Lew Barrett]

Bottom line: none of these things were ever intended to last forever. It's an artifact of our era that we treasure the old wood since it's like will not be coming our way again. As time and tides have passed, the boats are at greater risk of losing their shapes simply through the continuous cycles of use, transport and repair, don't you think Nick? Only the luckiest ones and those with the right characteristics keep their shape and retain their utility for the long haul. One in a hundred.

[Peerie Maa]

Bottom line: none of these things were ever intended to last forever. It's an artifact of our era that we treasure the old wood since it's like will not be coming our way again. As time and tides have passed, the boats are at greater risk of losing their shapes simply through the continuous cycles of use, transport and repair, don't you think Nick? Only the luckiest ones and those with the right characteristics keep their shape and retain their utility for the long haul. One in a hundred.

Very true. I do remember two magazine articles about caring for old wooden commercial boats still in service. On one they were refastening her, so they were able to rake out all of the caulking, and gradually straighten her out by lowering the keel blocks. I think that on this hull they then built a steel I beam false keel to add strength and take external ballast.
The other article described a careful disposition of internal ballast to make the weight distribution of the hull and ballast better match the buoyancy curve, thereby helping the old girl to hold her shape.