I’m talking mainly about these three lighthouses - One, Two and Three.
You’ll recognize #2 as the famous La Jument Lighthouse - the one with the famous picture of a man about to get pummelled by a huge wave…
I’d just ike to know how the heck did they build these gigantic lighthouses in seemingly hellish locations. I’ve seen turbulant waters off the atlantic coast here in New England and north to Labrador. But I have also seen those same waters calm as glass. But how could an engineer and masons count on calm waters for a long enough time to build one of these huge lighthouses? What about mean high water and the high water mark? Some of these lighthouses look like they were constructed below mean high water…how’d they do that?
As I understand it, you can get a good overview of the history of lighthouse construction by taking a few minutes to read the history of lighthouses build on the Eddystone Shoals. From the first lighthouse which fell in the Great Storm of 1703, through the second, third and fourth lights. The third, in particular, seems to have pioneered many of the techniques that you’re interested in. When the support for the foundation for the third was found to be being undercut by the actions of waves and current and the fourth had to be built, it was found that the building’s foundation was too sturdy for them to economically remove or destroy.
Let me restate that: The foundation was too sturdy to be destroyed. And is still visible, today! (The stub behind the lighthouse in this picture is the third Eddystone Lighthouse.)
Here’s a couple of links with various degrees of information about the Light there.
It took seventeen years to build La Jument. I assume that they waited for calm weather, ran out and drove pilings until the weather soured, made it back to shore and waited again. Also, brick lighthouses are heavy, with thick walls. I assume that the blocks were precut on shore, and each completed course of blocks may have been able to withstand the waves until the next course could be laid.
Many lighthouses subject to the effects of erosion are built on/near barrier islands and are subject to the natural migration (littoral action) of sand. Many areas of the coastline are subject to movement and redeposit of sand through NATURAL actions outside of man’s influence. Ironically, when man is left to believe he is the cause of the erosion and takes action to prevent wave action, preventing the wave action leads to MORE erosion…or, more specifically, interference with the natural migration of sand that was naturally bound to replenish another beach/island/whatever.
Barrier islands move around. They are nothing more than glorified sand bars, and they’ve exchanged sand with offshore, nearshore and inlet locations for all of time.
Some grow, some move, some shrink…some lose sand to nearby inlets (oh crap, let’s move this lighthouse!..“oh crap, why does my inlet need dredging!”)
If a lighthouse built in 1882 and 200 yards from the beach is now surrounded by water, you need a boatload of facts before you can even begin to understand why.
