Monday, January 4, 2010

Complicated Science, Simple Machines

Okay, we're still stuck in port. But a ship is a pretty interesting place even when it isn't going anywhere. This is where we will be going:

That's the Antarctic peninsula, just south of the tip of South America. The rainbow colors indicate the depth of the water in places that the ship has been. The pictures taped to the big map are recent images of the ice in that area. I don't know very much about ice (yet!), but I can tell you that it's very icy out there.

Once we leave port, we'll be doing a lot of complicated science. But we have to think about safety on the ship, and we'll be crossing some rough water. Here is a piece of equipment that I will need once we're working:

It's a battery charger and it's very heavy. When the ship moves, it could fall off the table and break or hit something. So before we leave port, everything gets tied down. That's where the simple machines come in! See the metal circle to the right of the charger? That's an eye hook. To get it into the table, I drilled a hole and screwed it in. But it was too hard to tighten with just my hands, so I used a lever.

I know that it's just a screwdriver, and I'm not even using it right! I apply effort to the handle, the part of the eye hook closest to the effort acts as the fulcrum, and the other side of the eye hook is the load.

Once I have an eye hook on either side of charger, I still need to use rope to tie it down. But I can't get the rope tight enough! Luckily, I can use a pulley to gain a mechanical advantage:

How is this a pulley system? I'm going to use the eye hook as my fixed pulley and that loop in the rope as my moveable pulley. And there is is, all tied down and safe:

And here you can see the pulley loop (formed by a knot called a trucker's hitch) and how the remaining rope is attached to the eye hook (using two half-hitches).

We sail at 1500 today! That's 3pm for you land-based types.


  1. Good Day Mrs. T, I envy you, your cruise to Antarctica. I am a semi-retired yacht captain working ashore, so would love to follow your research. You said you are studying ocean currents. What is your background?
    Thanks, Erik