Retarding Water

Now now, this post on the heels of the last Palin observation has nothing to do with how dumb a certain beauty-queen-turned-Facebooker is - git yer political minds outta that rut. =)

As part of my job that pays the bills, I am often asked really unusual questions, and consulted for my opinion as to "what would you do, Joe?" or "how should we handle this?". Sorta like the joke about the old guy who sent in a bill for $50,000 as to 'where to put the X' - I wish I got $50K a question, THAT would be Sweet! But I digress...

Today, I was asked "how do we check parts from this large machine that fell into a river, and stayed submerged in the center of the river (in Southern Asia) for several months, before a salvage crew could get a barge with a large enough crane up-river?" This machine was a really heavy, really expensive machine, full of investment castings and precision machined components. In my description of "what would Joe do?" I explained how the depth of the river's water and muddy bottom dampened the impact slightly, since there was no dock, or river bank, for the multi-million dollar machine to "THUD" against as it fell. The water's depth, which appeared from photos to cover the semi-truck (read as "lorrie" to the British), would have cushioned and then slowed the descent of machine as it settled into the river's bottom.

One of my less senior colleagues thought this was laughable, and scoffed at my suggestion. How could this large machine, that weighs more than several western battlefield armoured vehicles possibly be slowed by water? Simple, mass and viscosity of the media. The machine had fallen only about 40 feet (about 12 meters) into the water. At an Earthly 32.2 ft/sec^2 (or 9.81 m/sec^2) it had not picked up too much vertical velocity on it's way down. Now, compare that to the +1000 fps muzzle velocities that gun fired rounds have (50 cal, 9mm, etc) when they are test fired into water, and how the BIGGER they are, the faster they are stopped by the water - as tested by the Navy's Bureau of Ordnance. Mythbusters did this too, but I question their methods and sensationalism, as well as the silly mustache.

So yes, water can and does slow things down when something is dropped into it. Will it softly cushion and guide a multi-million dollar machine to a comfortable, damage free resting place at the bottom of a river? No, but it's better than dropping it 40 feet from a crane onto a harder surface, like a cement dock, etc. If you're gonna question my logic in a professional setting, please have your facts irrefutably straight, or be prepared to meet the stubborn Pollack genetically programmed, deep inside my psyche as your argument is dissected, completely. =)