Free Fall

We are moored in Teesside now, a major steel and coal port in the UK. Steel is a not very popular cargo. The stability of a ship is actually a matter of balance. If the center of gravity is too high, the stability becomes finally indifferent, in other words; the ship doesn't care if it's floating normally or floating up side down. If you have a full load of steel however; this is quite another story. The center of gravity is so low, that the ship will correct every disturbance in heeling immediately. The roll period is very low and rolling is unpleasantly fast. Moreover; the restoring forces to get the vessel upright are so great that, in the long run, they even might have effect on the ship's construction. Last very negative aspect is that steel doesn't float. If a ship loaded with steel sinks, it sinks like a rock. In earlier days, especially when the weather was bad, crewmembers had hardly time to leave the ship in their lifeboats. That's why free fall lifeboats were invented like you can see on this picture. If your vessel sinks, get in the lifeboat, close it and launch it.