The 6th floor features a Ships & Navigation corner under the theme of crossing the sea.
Navigation means moving a ship safely and efficiently from one point to another. Since ancient times, people have spent an enormous amount of time searching for ways to calculate where they were and where they were heading on the vast ocean with no landmarks to serve as a guide.
A device to determine direction is this cylindrical object with a golden cap called a compass.
More precisely, it is a magnetic compass that always points to the north, and has been used since ancient times. It is sealed in liquid so that gradations can be easily read even aboard a rolling ship. A more accurate compass is called a gyrocompass, but as a magnetic compass rarely breaks down and consumes no electricity, its installation is required of each vessel as a vital device for navigation to provide direction.
Seamen, at sea with no landmarks, have known since ancient times that they could locate where they were by observing the sun and stars in the sky.
This black, strange measuring instrument is a device called a sextant. It is used to calculate position from the sun or stars. Latitude can be calculated from the altitude measured by the sextant, and the exact location in relation to the earth can be obtained from the longitude derived from an accurate clock called a chronometer and astronomical almanac. At present, the exact location on the earth can be obtained via satellite-based GPS that is also used in car navigation; however, every ship still carries a sextant.
An instrument called a log measures the ship's speed and distance traveled. A long time ago, speed and distance were measured by a hand log like that displayed here. A hand log was comprised of a rope and fan-shaped plate that was let out at certain intervals while measuring the time with an hourglass; the distance and speed of a ship were measured by the length of the rope let out.
The knots were marks to measure the length of the rope and have come to be used as the speed unit of a ship. One knot is a speed of one nautical mile per hour, which is equivalent to 1.852 kilometers per hour.
At present, ship speed can be measured more accurately by using an electromagnetic log and a satellite.
Thus, the exact location of a ship can be derived if the distance and direction are obtained, and this is why it has always been so important to know the exact speed and direction.
This spacious room filled with machinery is a pilothouse, commonly called a bridge. Here, the equipment and machines required for maneuvering a passenger boat of approximately 60,000 tons are reproduced and set up in exactly the same way as in an actual boat.
Look at the center. In the old days, a big wheel used to sit here, but now the wheel has become the small handle you now see. On the left is an engine telegraph to convey engine-related instructions to the engine room, and on the right is the radar and an anti-collision device.
A big table placed in the center toward the front is called a chart table. A chart provides vital information for navigation, including the depth of the sea, geological data of the seabed, lighthouses, and routes. The red-circled spot is where the Museum of Maritime Science is located.
To become a sailor, one must study at a specialized school and pass a national examination. The ships that are used to train these students at public nautical schools are called training ships and belong to the National Institute for Sea Training.
This ship with beautiful white sails is the most famous of all Japanese training ships, the Nippon Maru. It was built in 1930 and served for 55 years to train a number of sailors. After its retirement, it is quietly spending the rest of its life in Yokohama where it is preserved and displayed. Its mission of onboard sailing training was assigned to the new Nippon Maru to continue the education of today's sailors.
Well, how did you like this tour of Museum of Maritime Science? I hope you enjoyed it.
You may not often see ships in your daily life, but I hope that what you have seen today helps to remind you of how important ships are to our daily lives.
This finishes the audio guide.
Please go down the stairs to the 5th floor, and then take the elevator down to the first floor. Kindly return the audio guide unit to the front desk.
Thank you once again for visiting the Museum of Maritime Science, and I hope we can serve you again in the future.
Oct. 7, 2002