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Long-Range Trawler / Explorer Yacht Brands

Discussion in 'General Yachting Discussion' started by ThirdStew, Mar 17, 2020.

  1. TimL

    TimL New Member

    Mar 30, 2007
    Puget Sound
    It would be good if a naval architect/engineer responded to this chain. I would assume when a boat is designed, the NA and engineer design the vessel for the proper strength required for the size, displacement and performance. This would also be in relation to material being used. I would also assume regardless of the material used, the ultimate strength would be the same as that is what is required by the engineering, design and code requirements. For example, the same boat built in steel would have a 1/4" thick hull plating, or 3/8" aluminum plating or 3/4" fiberglass laminate. I do not think a vessel is deigned to be weaker than the same boat in a different material. Ultimately the vessel has to meet the engineering requirements for that code requirement, regardless of material. The materials might have advantages/disadvantages over each other, but the engineering tries to remove that in order to meet the same result in strength. I work for a company that does our own fabrication using ferrous and non ferrous materials. When we use aluminum, it is often thicker than if using steel as we need to match the strength of steel. This can be done if we go thicker. The problem with aluminum is stress over time and not being as compliant as steel (breaking instead of bending). I would assume fiberglass laminate could be made to have strength and ability to absorb a certain amount of energy before cracking. A materials expert in boat construction would be able to shed more light on this topic. This comes up quite a bit and it I have yet to see an engineer chime in.
  2. jsschieff

    jsschieff Member

    Apr 3, 2010
    Middletown RI/Stuart FL
    Although there are new fiberglass materials including carbon fiber that might be close to steel or aluminum in terms of resistance to collision damage, I note that Steve Dashew, who designed and built a very successful line of ocean voyaging powerboats used aluminum for his yachts.

    The Dashew Offshore FPB yachts might suit Third Stew's needs -- they are considerably faster than full-displacement trawler-types like Nordhavns. The largest Dashew FPB built before Steve Dashew closed down production was 97 feet, and there is one on the market. I believe Dashew designed a 130-footer, which could be built by a competent yard today. Dashew's boats are long and lean, not deep and ponderous, and they have made some very impressive quick, problem-free ocean passages.
  3. PacBlue

    PacBlue Senior Member

    Jan 9, 2009
    Dana Point, Ca
    Most larger boats are engineered to classification society standards. Some of those standards trickle down to smaller yachts and the EU introduced ISO standards for small craft as the Belgium’s love to regulate as if it was their birth right.

    The engineering comes down to speed, loads, expected seas, predicted impacts, skin thickness, beam structures, material selections, manufacturing expertise, owners requirements, maintenance and finally boatyard profits. Lots of trade-offs along the way. There are usually minimum structural standards to meet known/predicted loads and there are many reasons not to over-design.

    The material properties of high strength Cor-Ten steel are superior in a given thickness as well as resistant to environmental conditions. That’s why you still have 100 year old steel structures in plain view around the world. A true displacement yacht is not trying to ultimately optimize structure as they usually require some form of liquid or fixed ballast and you can minimize that to a point with a heavy hull structure as long as your stability criteria are met.

    FRP in a displacement yacht always needs an assist from dedicated ballast. There gets to be a point where thickness becomes impractical and just adds cost in material and labor. You can make a composite sandwich laminate very strong especially with infusion techniques today, but there benefit is in strength to weight like you see in sport fishers. But abrasion resistance is different than impact loads and that is the rub for displacement boats. Abrasion resistance becomes a design goal and frp laminates have their limits in this regard, even with Kevlar as you are less likely to have a “bulletproof” load than an impact tear/peel driven by the mass of the boat versus a fixed object.

    The Zopilote example goes to the core of the issue of strength-impact-abrasion resistance. The laminates in the location that failed were over built, over lapped and thick, yet met their doom on an uncharted reef in an extremely low tied situation, the perfect storm so to speak.

    And if I was engineering the ultimate global traveler and having the mind set of perfect storms in the back of my mind, my money would ultimately drift to the Cor-Ten steel hull with an aluminum or composite structure.
  4. Kapn

    Kapn Member

    Aug 31, 2009
    If you needed to choose one car to drive for the next 10 years, and you wanted the safest choice for all situations, I think it would be an armored truck. You know, similar to the kind that comes to the bank to pick up the cash.
    However, it would be hard to see out of it while driving in a scenic area. And hard to get in and out while running errands. It may not hold highway speeds without a lot of fuel burn compared to your current vehicle. Most parking lots would cause anxiety levels to increase. Parking in a garage would be nearly impossible. Exploring the downtown area in an old city would be difficult. But hands down, while discussing it on the internet, you could resolutely say that you drove the safest vehicle on the road.

    As for choosing boats, I see where an Outer Reef did the trip around South America and Tony Fleming cruised Iceland and out to Dutch Harbor in the Aleutians. Both of these types of boats and destinations carried risks greater than going by commercial cruise liner. Neither would border on reckless choices of vessels for their destinations. Both of those are designed for comfort with windows large enough to see out of, deck space to entertain and relax, twin engines and thrusters to make docking easier and wide side decks to handle lines. I think picking a mission specific boat and hoping it does everything well is where some buyers/dreamers get overwhelmed.
  5. Demani

    Demani New Member

    Jul 9, 2014
    Tampa, Florida
    I also like steel for long range cruising. I saw someone said you can poke a hole in steel, you hit anything hard enough you can poke a hole in it. In the long run though steel is still the safest material out there for long range cruisers. I'd recommend taking a look at De Vries Lentch before you make up your mind, they have an excellent reputation for over 100 years.
  6. longpig

    longpig New Member

    Apr 22, 2016
    How about Altena for some lovely Dutch trawlers and my favourite, more motor yacht than trawler, Linssen. I think you would be happy to sit and eat ya Broodjes on either of these.