Does anyone recognize the objects in this photo? Yes, it's the wreckage of the Norwich City from the latest video from the July expedition. You can see beams and steel plates. Quite clearly. Not covered in coral or sediment yet it has been in the water since the stern broke off in 1939. Why are we suggesting that just a few hundred feet away we have wreckage of the Electra covered by coral and sediment?
Good point Irv and one which deserves further investigation. Here's a couple of points to consider...
'At present, aluminium alloys used in shipbuilding corrode 100 times slower than steel. During the first year of operation, steel corrodes at a speed of 120 mm/year, while aluminium – at a speed of 1 mm/year.'
Which makes steel a pretty tough base to get a grip on, it's corroding faster than the coral growth is growing.
'The first studies of aluminium alloy properties were initiated in the very beginning of the century, but only by the forties did the researchers who studied the issue of aluminium corrosion in seawater discover that adding a small amount of magnesium and silicon, made aluminium resistant to salt water. Alloy 5083 is considered the base alloy of the shipbuilders; it was registered by the Aluminium Association in 1954. Although this alloy is often called the ‘shipbuilding’ alloy, it is also widely used in many other industries. Alloy 5083 initially won popularity in shipbuilding thanks to its properties, such as high strength, corrosion resistance, good mouldability, and excellent welding characteristics.'
Which excludes a 1911 steamship from contributing aluminium debris to the debris field around the Gardner seamount, that's good news. More good news would be if a chunk of the debris field was lifted and found to be aluminium, preferably Alloy 2024, introduced by Alcoa in 1931 as an alclad sheet, that would narrow down the list of suspects quite considerably Irv.
Here's a link explaining why aluminium wasn't widely used in ships until the late fifties...
http://www.aluminiumleader.com/en/around/transport/ship