![]() ![]() These circles are not to be confused with latitude and longitude, or with any sort of compass reading, which are not relative to the vehicle, but to the magnetic and spin axes of the Earth.įor maritime and aviation applications, the clock bearing is almost always a relative bearing i.e., the angle stated or implied is angular distance from the longitudinal axis of the vessel or imaginary vessel to the bearing. In navigational contexts, the bearing must be stated as 3 digits: 010 (not so in other contexts). Thus, directly to port is at 270 degrees. Angles grow larger in the clockwise direction. The convention is that of analytic geometry: the y-axis at zero degrees is the longitudinal axis of the vehicle. One bearing, or point, is termed an azimuth. The clock system is easily converted into a 360 degree system for more precise denotation. In warfare the clock system is especially useful in drawing attention to enemy locations. If the clock number for the observed vessel does not change, it is on a collision course for the observer vessel, as vessels that pass by must change relative bearing. A quick clock number can be shouted by a lookout, whereas after a calculation and comparison of compass points, which might be unknown anyway, it might be too late for the vessel to avoid danger.Īs an example of a standard use, the clock position of every approaching vessel is monitored. The angular distance between adjacent clock numbers is 30 degrees, a round unit that simplifies mathematical juggling. The clock numbers are relative to the direction in which the vessel points. The vessel can be pointed in any direction. "Relative" means that it does not state or imply any compass directions whatsoever. This is a system of denoting impromptu relative bearing widely used in practical navigation to give the position of an observed object readily and comprehensibly. It has general application to circumstances in which the location of one object with respect to another must be systematized. ![]() The clock system is not confined to transportation. For example, 12 o'clock means directly ahead, 3 o'clock means directly to the right, 6 o'clock means directly behind, and 9 o'clock means directly to the left. Neglecting the length of the vessel, and presuming that he is at the bow, he observes the time number lying on the line of sight. In this analogy, the observer imagines the vessel located on a horizontal clock face with the front at 12:00. The observer then measures or observes the angle made by the intersection of the line of sight to the longitudinal axis, the dimension of length, of the vessel, using the clock analogy. These quarters may have specialized names, such as bow and stern for a vessel, or nose and tail for an aircraft. The vehicle must be considered to have a front, a back, a left side and a right side. The XII position is true north.Ī clock position, or clock bearing, is the direction of an object observed from a vehicle, typically a vessel or an aircraft, relative to the orientation of the vehicle to the observer. Points of a 12-hour clock Horizontal sundial of 1812 matching the clock positions in Roman numerals on the outside dial to the points of a compass rose on the inside dial. JSTOR ( June 2020) ( Learn how and when to remove this template message).Unsourced material may be challenged and removed. Please help improve this article by adding citations to reliable sources. ![]() This article needs additional citations for verification.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |