planing sail boat hulls

Discussion in 'Boat Design' started by wayne nicol, May 4, 2018.

  1. wayne nicol
    Joined: Dec 2009
    Posts: 139
    Likes: 4, Points: 18, Legacy Rep: 34
    Location: Queen Charlotte islands, B.C.

    wayne nicol Senior Member

    excellent, thanks guys for the input. i have long been interested in the interceptors, and messed around a bit with them, in as much as tieing a 1/2" rope around tight just forward of the transom, and noted the difference.
    also read about their improved efficiency over trim tabs.
    looked at the commercially available options too- some nice units out there.
    i would assume , one uses and trims them by feel, much like one does trim tabs, by applying trim in increments, while monitoring bow angle , speed and motor rpm's , finally settling in the sweet spot for conditions and requirements ?
     
    Last edited: May 7, 2018
  2. Niclas Vestman
    Joined: Aug 2017
    Posts: 128
    Likes: 15, Points: 18
    Location: Malmoe, Sweden

    Niclas Vestman Senior Member

    This actually might be my first post, after reading and "peeping" for a long time. So first of all Hi, and a big thanks to all generous experts and gurus for your invaluable and plentiful contributions! And for those interested in the subject, check out HJS webbpage. Google sass design. It's a treassure of design inspiration and insight. Espescially regarding hull designs for a wider rage of speeds (both displacement and planning) while remaining efficient and showing good seakeeping characteristics. Btw very nice rendering. Double foils should be perfect for safety in this case, ideally with kick up functionallity. I suspect that cavitationplate-mounted foils on the outboards would probably be needed to keep an efficient trim angle.
     
    rwatson likes this.
  3. wayne nicol
    Joined: Dec 2009
    Posts: 139
    Likes: 4, Points: 18, Legacy Rep: 34
    Location: Queen Charlotte islands, B.C.

    wayne nicol Senior Member

    thanks Niklas.
    after all the naysayers i have faced over the years, i have finally found someone who has something positive to work with>
    and with him, its not just theory, he has built and tested model, and done tests on full size boats.
    he certainly is very progressive and advanced.

    he has some amazing designs on his website, and in fact I have been communicating with Jurgen, and am hoping to get him to do some hull design work for this project.
    What i found really fascinating, was his powerboat design, with the video of it running in a big chop against a traditional single chine deep V powerboat, and his boat (that had a way flatter hull), far outperformed the deep V. Not pounding nearly as much!
    seems to blow all the old theorists out of the water.
     
  4. Ike
    Joined: Apr 2006
    Posts: 2,471
    Likes: 334, Points: 83, Legacy Rep: 1669
    Location: Washington

    Ike Senior Member

    I just want to reinforce Wayne Nicol's comment about conditions here in the PNW. There are inlets and bays here that even large powerful powerboats cannot transit when the tidal current is at its max. (look up Deception Pass) Yes, it do rain a bit, and there are lot of pilothouse sailboats and most power boats here much over 20 feet have a cabin or some kind of shelter. It's just the way boats are built here. Not all of us like getting cold and wet. Especially for folks who like to fish. Unfortunately the best salmon runs also occur in the fall and winter and not in the few sunny months. To illustrate his comments about deep water, my folks had property on Hood Canal. Our beach was very flat and when the tide went out was several hundred yards wide. But at the lowest tide if you walked ten feet out into the water you fell off the ledge and the water depth dropped to 90 feet. A little farther out it dropped to 300. Submarines could actually run submerged in Hood Canal. (no that's not a joke, I have seen them surface) I do have some concerns about his concept but most of those have been answered already. I have never been a big fan of Macs, but not for the same reasons. They have been involved in an inordinate number of swampings and capsizings. Frankly, be darn careful using that water ballast and make sure everything is working properly..
     
  5. rwatson
    Joined: Aug 2007
    Posts: 5,866
    Likes: 299, Points: 83, Legacy Rep: 1749
    Location: Tasmania,Australia

    rwatson Senior Member

    I've only heard of two that hit the news, one fatality, and even then the boat stayed on the surface.
     
  6. Ike
    Joined: Apr 2006
    Posts: 2,471
    Likes: 334, Points: 83, Legacy Rep: 1669
    Location: Washington

    Ike Senior Member

    They were rarely in the news. But at the Coast Guard Office of Boating Safety we got the reports and half a dozen or more consumer complaints none of which rose to the level where we had to intervene. As far as I know the one you mentioned was the only fatality. Almost all of them involved the ballast system. I wrote some letters to the manufacturer, they dealt with it but none every rose to the level to require the maker to do a recall. The one we did get involved was a capsize. But I looked up my old correspondence (yeah I kept that, it's all digital) and after an investigation it appeared that the owner could have been at fault, or maybe not. Maybe a valve was leaking. Too much time had passed and it was not possible to make a positive determination based on the evidence. if there was a leaky valve it had been fixed. The manufacturer claimed to have inspected the boat and everything was working correctly. But the owner was convinced it was a leaky valve. So we wrote a letter to Macgregor and to the owner and closed the file. Not very satisfactory but unfortunately at that point there was not much we could do. However we did get complaints about shoddy workmanship, but all that was warranty stuff and not covered by Fed Regs. If I recall right the fatality involved a child. A group was taking special needs children for a sail and the boat capsized but it wasn't any fault of the boat. I did a search and found this. Occured in 2011 long after I retired. Gust of wind caused fatal sailboat capsize https://www.cbsnews.com/news/gust-of-wind-caused-fatal-sailboat-capsize/
     
  7. rwatson
    Joined: Aug 2007
    Posts: 5,866
    Likes: 299, Points: 83, Legacy Rep: 1749
    Location: Tasmania,Australia

    rwatson Senior Member

    So, after 36,000 Macs sold over the years, you got half a dozen complaints, and one fatality where the findings implicated an inebriated skipper ?

    Thats doesnt seem to be "an inordinate number of swampings and capsizings."

    If you peruse the Mac owners website, I have never come across a serious incident - though these people will be a more experienced group I am sure.
     
  8. Ike
    Joined: Apr 2006
    Posts: 2,471
    Likes: 334, Points: 83, Legacy Rep: 1669
    Location: Washington

    Ike Senior Member

    Take into consideration the time period I am speaking of was in the late nineties. There are 10 recalls listed on the CG website, most of them are minor stuff like incorrect Hull ID nos, and labels. One is a capsize due to a valve leaking. (I handled that one) One is a leaky fuel tank. (one of my colleagues handled that and he said it was a warranty problem. Why it's listed as a recall beats me.) Another is a leak. Doesn't say what. (I hadn't been hired yet so I don't know what the circumstances were)

    None of the consumer complaints rose to the level of recall so they are never seen by the public. Part of looking for what the law calls "a defect that creates a substantial risk of injury or death" is watching for trends. If you start getting consumer complaints there may be a trend in them. May be is the operative word here. There may not be. If you see a trend then you take it farther and start communicating with the builder, and maybe sending someone to look at the boats and the factory. As far as I recall we got nothing after the first spate in the mid to late 90's. So MacGregor must have done something right. As you say, the only fatality was probably due to alcohol, but that is a matter for the local PD that responds. We only looked at boats. Is there something wrong with the boat that could injure or kill in a sudden and unforeseen way?

    I retired in 2004. Since then I have seen nothing, and there is nothing after 2000 on the CG database. So I can only assume (dangerous word) that MacGregor dealt with their customers and fixed whatever the problems were. But from what I saw if the owner was not careful with the valves unwelcome things could happen. How many boat owners actually read their owner's manuals? Maybe you and I do but from what I have seen we are the minority.
     
  9. rwatson
    Joined: Aug 2007
    Posts: 5,866
    Likes: 299, Points: 83, Legacy Rep: 1749
    Location: Tasmania,Australia

    rwatson Senior Member

    That's usually the key, experience and conscientiousness.

    I wouldn't be surprised if any small trend to capsize was ameliorated by the addition of 120 kilos of permanent ballast that occured after the fatality.

    All in all, I don't think that the Macs have any real reason to be criticised on safety grounds.
     

  10. wayne nicol
    Joined: Dec 2009
    Posts: 139
    Likes: 4, Points: 18, Legacy Rep: 34
    Location: Queen Charlotte islands, B.C.

    wayne nicol Senior Member

    i really cant comment about the safety issues, my boat is a 2012 model- the last year the macs were built in California- before his daughter took over and moved it to Florida.
    i remember reading about that incident with the liferaft being blown into the rigging, causing the knockdown.

    But yes there are many things on the boat, from a quality perspective that i am not happy with, i fully understand his business model, and being a low entry-level price boat. but some things we just have to change- i would not consider these mods or comfort improvements. My question has always been, why not just put the right thing on in the first place- surely the upgraded product, would be a lot cheaper for the consumer, instead of paying for it twice, but rather to pay only once at purchase.
    eg: the shrouds are too light, cheap plastic thru- hulls - with no stopcocks and not double clamped, the cheap appointments on the trailer- with tongues rusting out- because they are not galvanized etc etc.

    However, the overall concept is something i really like.
    i love sailing, and when i get on my 15' commodore- i can scream around the bay here- we love it, but for family, and fishing and gunkholing/camping, the mac is awesome.
    its trailerable, it deals with our time constraints, we can power when we have too, and sail when we want too.

    sure, its a compromise boat- but whats wrong with owning a compromise boat?
    heck, our wives had to compromise when they married us :)

    this new design is progressing well, and with some incredible new input, we are going to be able to build a boat, that performs better than the mac, and is more ideally suited to our own needs.
    thanks fellas! :)
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.