Concrete Boat

dwhite1031

Petty Officer 2nd Class
Joined
Apr 14, 2009
Messages
130
Re: Concrete Boat




Did Hurricane Ike do any further damage to the SS Selma and is she still in place?​
 

freelancer

Petty Officer 1st Class
Joined
Jun 2, 2009
Messages
300
Re: Concrete Boat

Remember one in Philadelphia Harbor in the early 90s; it was a green sailboat around 100 ft long. It lasted about three seasons as an excursion boat and was then taken to somewhere in New England. Haven't heard about it since.
 

lowell7963

Seaman Apprentice
Joined
Jun 18, 2009
Messages
48
Re: Concrete Boat

I graduated from WVU and the civil engineers each year had contests to build a concrete "boat".

On a second note, I knew a guy that tried to pour a concrete pad for a boat launch. Poured in on the shore then pushed it into the river. Guess what she floated off, well not totally on top of the water, but ended up not where he wanted it. Lot's of trapped air even in a slab of concrete.

Last story, many years ago,before plastic, I know of a guy that put a concrete septec tank in the ground, replaced the dirt, but did not fill the tank. A huge rain came an lo and behold, emerging from the earth was a floating septic tank.
 

Bilgamesh

Petty Officer 2nd Class
Joined
Jun 16, 2009
Messages
173
Re: Concrete Boat

It does seem counterintuitive that a big slab of concrete can float. However, consider that a modern aircraft carrier weighs 97000 tons.

Archimedes Principle: "Any object, wholly or partly immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object."

Bouyancy is a function of density.

"A ship will float even though it may be made of steel" (concrete in this case), "because it encloses a volume of air, and the resulting shape has an average density less than that of the water."

Amazing!
 

OldePharte

Chief Petty Officer
Joined
Aug 17, 2008
Messages
633
Re: Concrete Boat

SNIP - On a second note, I knew a guy that tried to pour a concrete pad for a boat launch. Poured in on the shore then pushed it into the river. Guess what she floated off, well not totally on top of the water, but ended up not where he wanted it. Lot's of trapped air even in a slab of concrete. SNIP -

Across from us is a public boat ramp. Since the lake levels can fluctuate, every so often, a trailer would fall of the end of the ramp when the lake was low. So the DNR came in late in the winter, cut across all 4 lanes, and pushed the existing sections further into the water and then poured a new 10 foot section, effectively extending the ramps 10 foot further out.

And yes, the ramp gets used 12 months a year. I do have some photos of fishermen launching in a snow storm and play ice breaker to get out of the cove to the ice-free main channel. When the ice gets too thick, the DNR brings in a motor grader with a front plow to break up the ice around the ramps. This February, he ran the machine into the water to just before the cab. My first thought was that he was getting ready to take a very cold swim, but he obviously knew what he was doing.
 

esobofh

Petty Officer 2nd Class
Joined
Jun 3, 2009
Messages
116
Re: Concrete Boat

Absolutely!

Ferro cement boats can be wonderful masterpieces!

My friend (now 81) built himself two amazing sail boats - one 60' and on 40' using the ferro cement method. It is labour intensive, but the results are amazing (if you know how to finish the cement well).

Just looking at his boat, you couldn't tell that it was cement.. it looked exactly as a fibreglass boat would, until you knocked on the hull. They are solid, beautiful boats that are still sailing strong today (40 years later).

If I had money, time and the patience I would certainly consider building a cement boat. They are like any boat though.. improperly built, or improperly maintained, and they will bite you some way or another.

My friend ran aground on his boat and punched a 6" whole in the hull - the fix was to mix some concrete on the spot, apply, let dry, and away he went!

google ferro cement.. you can see alot of construction blogs and step by step pictures.
 

witenite0560

Petty Officer 1st Class
Joined
Sep 6, 2008
Messages
216
Re: Concrete Boat

Just FYI, the ice/sawdust mixture was known as Pykrete. It was the invention of a guy named Pyke. There was a plan to build a floating, mobile airfiield out of it, complete with below surface level work and living spaces. A model was built on a lake in Canada and I believe it took over two years for it to melt away. The effects of shell fire, torpedo or bombing was negligible. It was so big and the ice just cratered and refroze. Surface craters could just be filled in and refrozen. The expense and change of the tide of war put it to bed.
 

LadyPN1

Recruit
Joined
Dec 31, 2010
Messages
1
Re: Concrete Boat

There's a lot of history on concrete boats and ships on the internet. But what first intrigued me is there is one here in Bethlehem, PA. It was brought here by a boat salesman sometime after WWII. I don't know much about it or what he planned to do with it. He had it up on a wooden drydock near his sales shop. But when I-78 was constructed, he moved his business but left the concrete boat there. In the winter, when the leaves are off the trees, you can still see it beyond Rt. 378 going South just past the I-78 overpass. It's easier to see, however going north on 378 just before the I-78 overpass - but only in winter. I believe the old wooden drydock it was on rotted away and dropped the boat on it's side - but it is still there.
 

DaNinja

Lieutenant
Joined
Jun 11, 2008
Messages
1,407
Re: Concrete Boat

Welcome to 2010, Lady.
Oh, Happy New Year!
It's almost 2011 here.
 

StevenSalmon

Recruit
Joined
Jan 14, 2011
Messages
1
Re: Concrete Boat

There are remnants of a concrete ship on the shore of the beach near Santa Cruz Ca. I walked on the deck several years ago. I think the story was that it was used at a time in WWII when available metal was used for warships.

2_concrete_ship_large.jpg


Check this: http://www.concreteships.org/

This was the SS Palo Alto built in 1919 as a tanker. She was one of many concrete cargo carriers build during WW I. She was in San Francisco until 1930 until she was towed to Rio del Mar and used as a night club until the depression. There is also the story that she was in service when driven ashore by a storm but that is a romance. She was still showing orange paint during the '50's when I last saw it, it has also broken since then.
 

tswiczko

Master Chief Petty Officer
Joined
Feb 15, 2009
Messages
838
Re: Concrete Boat

I worked with a man several years back who said he built ship out of concrete during WWII and also built some mulberry harbors, but as to the fact of that I can not confirm.

He has since past away so I can not get any Information as to the ship yards he worked to confirm this. I have heard of other stories of this so I will assume it is true.
 

jayhanig

Master Chief Petty Officer
Joined
Jun 27, 2010
Messages
836
Re: Concrete Boat

I seem to recall one out of either Carolina Beach or Wrightsville Beach, NC back in the early 80s called the Sea Mint. IIRC it was in the 26-40 foot range. Truthfully, I just can't remember but I'm certain I saw it. The reason I remember was because of its distinctive name being so appropriate: everybody on board laughed when we heard it. It looked like a nice sport fisherman for offshore use.
 
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