John Holland's 1872 one man pedal power submarines

[Darwin]

I managed to take some screenshots from the documentary on the Explorer. Shows the hulk as it now exists, some artist's renderings of the internal construction (showing the ballast tank area between the inner and outer hulls), and a couple of shots of the inside of the sub.

[Florida Diver]

I know about it Darwin. The "Explorer" submarine was lost to history for a long time until a few years ago in 2001 I believe. It's builder originally offered it to the U.S. government who as usual at that time, declined it even though it was ahead of its time and could have given the U.S. a decided edge in underwater military technology. So he took it to the islands and used it in an ill fated pearl diving venture. It is what is known as an "ambient" submarine.

An ambient sub is one where the air pressure inside the sub is the same pressure as the outside water pressure. Using air pumps they were able to pump up the air pressure inside the sub so that it matched the outside water pressure. The bottom of the sub was open so they could collect the clams for pearls off the bottom of the seabed. Same principle as an open bottom diving bell. In theory, an ambient sub could have a hull as thin as a beer can because you equalize the inside air pressure to equal the outside water pressure and thus there is no outside pressure nor inside pressing against the hull, since the inside air pressure equals and cancels out the outside water pressure.

The problem is that they knew nothing at that time about safety diving tables and decompression sickness. Since the air pressure inside the sub was equal to the outside water pressure, that means even though the occupants stayed mostly dry inside the sub, they were still subjected to the increased air pressure so they built up nitrogen in their bloodsteam just as if they had been diving outside. At that time they did not understand that and the entire crew as well as the inventor/builder of the sub died as a result of decompression sickness (also known as "the bends"). Descendants of natives on the island at that time said their ancestors buried them and that they died of some kind of "fever" since the natives back then didn't know about decompression sickness and that it killed them all.

The sub was left abandoned on the beach just off San Telmov where they last left it and forgotten by history being in such a remote place and at low tide you could see the upper portion of the sub. There it sat (and sits) for approx 150 years. Slowly rumors got out to the outside world that it was some kind of midget Japanese sub from WW2. An archaeology professor who was in the general area doing other work, was asked by a college to check it out. So he went there and was able to look inside the sub at low tide. He realized its Victorian construction predated anything from Japan from WW2.

He researched it and found out it was the Explorer. A civil war era submarine that had been lost to history. There has been talk about putting nets under her and getting her out of the silt and to a museum, but the bottom of the hull is very fragile and could easily break up. So talks are still ongoing on how to recover it and preserve it without damaging her now fragile hull. In the meantime there she still sits right where the crew who all died left her approx 150 years ago.








Here's various links to articles about her.

Special Report

Sub Marine Explorer Abandoned for 142 Years in Panama: Urban Ghosts |

Panama: Sub Explorer | Waitt Institute

Newsletter 64 Will The Hunley Sink Again

Sub Marine Explorer

You can find lots more about it. Just google up "Explorer submarine".


.