Card cutlery
The term map set (also navigation set, nautical chart cutlery, nautical cutlery ) summarizes the use of typical aids for navigation in printed nautical charts on ships . The card set is used in particular to transfer measured bearings , baseline lines and distances to a nautical chart. Then, with the help of the card set, courses and distances can be staked out in the conformal map. The classic card set is particularly suitable for use with Mercator cards.
scope
The card cutlery usually consists of the use of a course triangle , placement triangle and a compass , whereby a second course triangle is often used as a placement triangle in practice. Alternatively, an adjustable parallel ruler can be used instead of the two triangles . The use of this drawing device is particularly widespread in the Anglo-American region. A sharp pencil for the graphic transfer of information to the nautical chart and an eraser for any corrections or deletions are also required for map navigation.
use
The two course triangles and the parallel ruler are used to transfer bearings, linear stand lines and courses, i.e. directions, to the nautical chart. The scaling on the devices allows the alignment of the base of the course triangle and the legs of the parallel ruler at a certain angle to the meridians drawn in parallel on Mercator maps and a subsequent transfer to the desired map area by placing and moving with the help of the placement triangle. If the parallel ruler is used, the set angle is moved according to the correct angle by fixing one leg and then positioning the second leg. The execution of the movable connection between the two legs ensures that both legs are kept parallel over the entire range of motion and thus the set angle can be transferred to every area of the card. The map circle is used to record the distances tapped on the map edge at the level of the respective target area and to then transfer the route into the map itself.
The use of the classic card set is currently losing importance with the increasing spread of electronic nautical chart systems such as ECDIS . The functionality of the classic card set is taken over in these systems by software tools, for example the VRM (Variable Range Marker) or EBL (Electronic Bearing Line). Nevertheless, even on ships that are equipped with an electronic sea chart system, paper charts are still carried and used as a back-up in the interests of redundancy . Correct handling of the card set therefore remains an important part of navigation training in professional and recreational shipping, and relevant knowledge must be proven in the context of a card task test.
See also
Individual evidence
- ↑ Bobby Schenk: Yacht navigation. From compasses to GPS. ISBN 3-7688-1818-7 .