The first drill pipe section has the drill bit (with digging teeth) attached. The drill bit and the the first few units of drill pipe are known as the bottom hole assembly. The pipe sections for the bottom hole assembly are heavier than regular drill pipe because they go into the burrow hole at the bottom of the ocean. It takes about 12 hours of assembling the pipe and slowly lowering it down to reach the bottom at 4,000 meters. The drill bit reaches the bottom first and begins drilling!
As the drill bit burrows down into the ocean floor, the hollow section in the middle of the bit gets filled up with sediment and rock. Think of it as a giant metal straw being pushed into a birthday cake. The cake inside the straw is the core! Sediment and rock from the ocean crust travels up into a core barrel located inside the drill pipe. This core barrel is only about 10 meters (33 feet) long, and has a plastic liner to hold the valuable core materials as we drill.
Once we think the core barrel is full, we use a sinker bar to latch onto the core barrel and bring that back up to the ship. The drill pipe stays where it is, so that after we remove the full core barrell, we can immediately send a new, empty core barrell down to the ocean bottom and continue drilling with as little interruption as possible. The sinker bar has to be removed from inside the drill pipe, so someone has to travel up to the top of the drilling derrick in a chair, remove the sinker bar, and lower it back down to the ship on a rope. The core barrel gets laid down on the ship's deck, the core liner is removed, and this exciting new scientific sample is passed on to the science technicians to prepare for analysis.
