Announcement

Collapse
No announcement yet.

Staying Fit at Sea

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #31
    As far as I can tell it runs roughly along the lines of....
    At static even keel when you set off the bow automatically dips (we are talking bulbous bows here) therfore you are using energy / fuel to drive the nose down, if you trim by 1-2mtr by the head then there is NO SIGNIFICANT increase in this trim at "cruising speed" therfore you arent using engine power and therfore fuel puching the nose down.

    Also the prop can work in better water as the hull kind of casts a shadow (if you get my meaning)

    And they spent quite a bit of time and effort on the testing, with all thier "class" hulls ie ones where there is a goodly few of them in a run and even they admit it is counter intuative....but the numbers dont lie now we just need to redesign the ships so that all the bunker tanks have forward AND aft suctions ditto cargo holds bilge locations.

    the real saving is of course on a long run, hopping around europe or chinese coast dosnt show up put trans-pac or Sing__>Suez then it's worth it....lets face it even a 1% saving per day is $$$$ especially when you multiply it by number of boats etc etc......no wonder the bean counters need to lay down in a darkend room
    Trust me I'm a Chief.

    Views expressed by me are mine and mine alone.
    Yes I work for the big blue canoe company.
    No I do not report things from here to them as they are quite able to come and read this stuff for themselves.


    Twitter:- @DeeChief

    Comment


    • #32
      Ah I can understand that. And yes I know what your trying to say about the propeller, working in a static water area, rather then being caught in the flow and unusual currents bouncing down the side/bottom of the hull. The only thing of course is closer the prop is to the surface, more chance of cavitation and also in the case of my vessel where we have anti-cavitation propellers as it has a shallow bottom, they'd end up coming up out of the water more and also i do wonder in worse weather if it would stress the hull structure more.

      Very true about tank suctions, but my ship rolls so much you can never completely empty the tanks normally until you are just coming into port anyway.

      I think in a lot of applications if they just used swath hull design more everyone would be happy, finacially and comfort! There is a very good program by the discovery channel floating about somewhere on this.

      http://en.wikipedia.org/wiki/Small-w...area_twin_hull

      ....

      Comment


      • #33
        cant see 11000teu twin hull canoes taking off though
        Trust me I'm a Chief.

        Views expressed by me are mine and mine alone.
        Yes I work for the big blue canoe company.
        No I do not report things from here to them as they are quite able to come and read this stuff for themselves.


        Twitter:- @DeeChief

        Comment


        • #34
          Weights obviously an issue, although in theory you could still design one, would be good for a engineering cadets dissertation/final project, cough cough, but I am still shocked at how little the military use tried and proven catamarans, and now they have swath which is even better, I think it has something to do with relunctant to send the work overseas for building ships, as the best cats come from Incat in Australia, and probably couldn't be built in the UK in the Royal Navys case. There is already one cruise ship of swath type, a few ferries, some top end research vessels, and some coast guard vessels though.

          MV Asia Star is a cruise ship run by Asia Cruises. It has a unique twin-hull/SWATH design and its gross tonnage is 20,050 tonnes. It is stationed in Hong Kong. It was formerly known as the Radisson Diamond, and built in Finland It has 12 decks and 170 guest rooms, displacing over 11,500 tons when fully loaded.


          ....

          Comment


          • #35
            I can see the advantages of multi-hull designs, but significant design work would be needed to make them viable for cargo carrying or as large passenger ships. They're very well suited as ferries and I believe both Incat and Austal have constructed ships for the military, but where would the cargo go? Or, in the case of cruise ships, where would all the usual below-the-waterline accommodation go?
            sigpic
            Hello! I'm Chris. I'm away a lot so I'm sorry if it takes me a while to reply to messages, but I promise I'll get back to everyone. If it's urgent, please email me directly at [email protected].

            Need books, Flip Cards or chartwork instruments? Visit SailorShop.co.uk!

            Comment


            • #36
              Not to mention that they are awful to look at...

              Comment


              • #37
                I like the look of them...but as for cargo ships rememeber a box boat is just a big empty patch of water surrounded by steel with (now a days) just 1 engine, 1 rudder etc all on the ceter line. Big slow speed deisels are still more efficient / practicle for this application (latest B&W ME series max rpm=79) BUT for cruise and ferry I can see makes perfect sense, already use multi engined diesel electric / geared drive chains so no real issue.

                As already mentioned though all that "stuff" we keep below the waterline needs to be found a new home


                /me just realised we are way off topic from "staying fit at sea"!
                Last edited by Chiefy; 2 August 2011, 12:15 AM. Reason: add more spelling mistakes
                Trust me I'm a Chief.

                Views expressed by me are mine and mine alone.
                Yes I work for the big blue canoe company.
                No I do not report things from here to them as they are quite able to come and read this stuff for themselves.


                Twitter:- @DeeChief

                Comment


                • #38
                  Most the machinery space can be under the waterline still, the whole point is, it is the area directly on the waterline that effects stability, not the area used above or below it. Good photos of how much space there is in a smaller swath craft's pod, bear in mind it is long and thin the pod, in this case a super yacht...

                  http://www.yachtsilvercloud.com/SSC/construction.htm

                  If they wanted more power for the same space used, something like the incats Ruston 20RK270 would produce a lot of power for size. 7080kW per engine in fact.


                  The real problem is not enough creative companies wanting to trial some new design ship, most companies just want to make profit using a tried and tested system, such as the incats now are.

                  2 stroke swath? Now thats a new scale of ideas, maybe even nuclear powered aircraft carrier swath? I do wonder how much research has been done into it, and been kept secret, much like the future NASA space shuttles.

                  And yes this is very off topic hehe, should probably be moved to another thread! Sorry!
                  ....

                  Comment


                  • #39
                    ive came to the solution that i will take skipping ropes and 1kg weights for doing easy aerobic exercises to keep up tone/cardio, no point in becoming a body builder when your away. even a set of boxing gloves and pads is a more enjoyable way than lifing weights, use the time to turn yourself into a fighting machine. just incase.

                    Comment

                    Working...
                    X