Concrete Ships

[Northern Spy]

Ferro-cement is ideal in salt water - the effect of osmosis is to help pull the water OUT of the cement, which cures it. This process continues FOREVER as the cement gains in strength, though it becomes immeasurable after a number of years.

Keith

Yup. I've got compressive strength for cores for many years of the Powell River Hulks. Keeps getting stronger and stronger.

Chloride intrusion wise, some hulks actually do much better than the ACI 100 recommendations for modern concrete construction. Lots of engineers and scientists scratching their heads on that one. They figure it has something to do with the paste matrix from the materials the used to construct.

 

[High Wire]

Before:
http://media-cache-ak0.pinimg.com/736x/dc/e6/aa/dce6aab611860763d6c8e722f08dda35.jpg

After quite a few years:
http://cbsphilly.files.wordpress.com/2013/05/concrete-ship-_jlloyd.jpg?w=420&h=315

 

[Northern Spy]

The sistership of the Atlantus is still floating at Powell River.

Keeping a ship afloat, instead of intentionally grounding, tends to increase it's lifespan.

Other intentionally grounded concrete ships in Bimini, California, Oregon, Hawaii, Kwajalein Atoll, Normandy, Cuba, Texas, and Virginia aren't fairing so well either.

Oxymoronically, the intentionally sunk concrete ships in Chuuk Lagoon and Guam are well preserved.

The other floating concrete ship I am aware of is tucked away in a cay in Belize, still functions as a tanker, and is used to store molasses.

So, if you own a concrete ship, in summary: Floating, good. Grounded bad. Sunk, OK.