Solid Hull that floats?

[cannedgravy]

Hi everyone,

I don't post much on here but I wanted to get some feedback on something that has been 'floating' in the back of my mind since I was a child.

I'm a huge fan of the Lego pirate ships and all lego boats for that matter. Particularly the series of boats that float with the use of one solid plastic hull piece. In the beginning these hulls were rather small and have grown larger over the year; the "City Lines" cargo ship being the largest solid plastic hull piece made by Lego.

Now I've been a long time fan of the grand lego ships since the Black Seas Barracuda and as a child I always wanted to be able to have the grand ship float along side me while swimming in our family pool. I know many lego builders would shun at having their lego get wet but Lego is a near indestructible toy and it would be fun I think! kids would get a kick out of it.

So I was thinking of something similar to this:

As you can see the hull would be a rather large solid plastic brown piece but compatible with Lego bricks. I have never seen anything accomplished with this and I may have to make a prototype myself. What does everyone think of this idea? Would you be interested in a solid lego galleon hull? Perhaps the float-able hulls could be sectioned into pieces thus allowing the creator to make the hull shorter or longer depending? I just think there could be a lot of fun with this if only it existed.

[Matthias]

My old Playmobilship allways overturned . But I saw a picture of the Imerial Flaggship 1 or 2 years ago floating in the Northsee. Therefore it is not impossible to make todays Lego ships floating.

[cannedgravy]

I would like to see that imperial flagship floating that you mention. I have one Playmobil ship that does REALLY well in the water and stay upright even in rough water. The key is to make the hull just wide enough with a low but centered ballast. I'd imagine the LEGO version would be similar in design.

[Immo]

(...) I saw a picture of the Imerial Flaggship 1 or 2 years ago floating in the Northsee. Therefore it is not impossible to make todays Lego ships floating.

I guess using some silicone (possible to be later removed without spoiling any bricks) would seal the hull of a Lego ship. I guess even using abundant 2x4 bricks would seal it decently enough. The problem is ballasting the thing so the point of weight would be as low as possible.

[Captain Becker]

I think that set number 7075 Captain Redbeard´s Pirate ship that came in the 4+ Juniors theme was able to float if I remember correctly. Also it comes whit a motor in some limited sets.

The same pieces also come whit the Harry Potter Drumstrangs ship but it doesn't have the middle section on it.

Captain Becker

[kurigan]

Since you're talking about kids and play you may say this isn't what your looking for. However, cb4 did manage to brick build a hull which can float if the bricks can be sealed water-tight. Check it out:

http://www.eurobricks.com/forum/index.php?showtopic=79732

[ejred]

For years I've been wanting to see if I could work out a built hull that could float without gluing.

My theory is to build the hull with a large compartment in the base, put a heavy weight in the bottom, and then fill the rest of the compartment with sealed air bags or something like that. But I've never taken the time to try it yet. Has anyone done it?

Edit: or, based on the previous post, has anyone sealed the *inside* with a sheet of plastic, rather than the outside as demonstrated in those test pictures?

Edited January 15, 2016 by ejred

[kurigan]

To my knowledge the only two builders here who have perused this method are cb4 (the likely originator) and Frank Brick Wright. Neither are regulars on the forum any longer nor was either trying to make a floating hull. Cb4’s “sea trial” seemed more of a curiosity after the fact. The success of it, however, was a direct result of the initial goal in the development of this method. That was: to recreate the metrics of the actual thing, to scale, in Lego, and there by produce a superior model. The end result was so effective that the thing would thing actually float and in the same manner as its real world inspiration.

For my part I’ve always theorized that one could sandwich a sheet of plastic between the two or more layers of plates which make up the outside of the hull but foresee a few problems which would likely not make it an ideal solution for this proposal. For one, it would stress the bricks having that extra material smashed in-between studs. To some this is acceptable for the sake of pushing the limits of the system, but to others is an unacceptable abuse of Lego. You would also have to keep the sheet intact throughout with special attention paid to the amount of stress stretching it between plates would create. It seems it would be too delicate a process to trust to children.

My best idea, though I’ve never put the bricks together to try it, would be ballast in the form of a steel rod (likely suspended below the keel like an RC model) and below deck cavities filled with closed cell foam. There would still be a bilge from the less than water tight connections but it might still work the same.

Now as for the original proposal, I only came on with this because I think it’s a good idea. Personally I just don’t like, well… pre-fab anything (almost). I feel it limits scope and creativity, but for the kids, I suppose that’s another thing. It’s certainly something worth perusing, perhaps as a prototype for an actual Lego brand set in the future. I think the easiest way to prototype this would be with 3D printing. Get someone onboard who can model with the necessary skills and start hashing out a design.

One suggestion, leave some provision in the design to add ballast outside the hull like the x149.

Notes:

AndersT’s method in fundamentally similar but with a different basis for the frame work. His employs a more gradual stepping out technique while the cb4 makes use of hinges.