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Impassable cliff 201

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This page contains content from ISOM2000   This page contains content from Ashby Mapping  Ski-O symbol  Mountain Bike-O symbol   revision 05/00

Specifications

201 Impassable cliff

An impassable cliff, quarry or earth bank (see 106) is shown with a 0.35mm line and downward tags showing its full extent from the top line to the foot. The tags may be omitted if space is short, eg. narrow passages between cliffs (the passage should be drawn with a width of at least 0.3 mm). The tags may extend over an area symbol representing detail immediately below the rock face. When a rock face drops straight into water making it impossible to pass under the cliff along the water's edge, the bank line is omitted or the tags should clearly extend over the bank line.

Colour: black.

Line width 0.35mm (tag 0.12mm)

tag length 0.5mm (minimum), spacing 0.5mm

ISOM 1990 Definition

As ISOM 2000 but tag line width was 0.125mm

OCAD Methods

Defined as line symbol 201.0, and 201.1 for the tagless symbol.

As this is a line object it can be drawn with any tool. If the bézier tool is used, care must be taken as tag spacing and angle is dependent on location of nodes and handles. See bézier topic for more information.

OCAD default definition

The default definition specifies a gap between tags of 0.75mm, compared with the ISOM specified distance of 0.6mm. Variation is allowed in the specification, see the Variations in Symbols topic for details.

Drawing Considerations

Unlike the smaller crag symbol (Passable rock face 203), it is not permissible to have an isolated tagless impassable cliff. Use OCAD symbol 201.1, the plain black 0.35mm line, where there is no space for the tags.

Pictorial Descriptions

- BOF Rules, Appendix One

A rock slope steeper than 45 degrees.

1) If the cliff has a tight curve or sharp angle the tags tend to overlap. The solution is to cut out the central part of the curve and replace it with a plain black line. Use the default 201.1, impassable cliff.

2) Longer tags are sometimes needed. Use a black 0.12mm line, the distinct cultivation boundary symbol (414) is suitable.

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International Specification for Orienteering Maps produced by the International Orienteering Federation
OCAD produced by Hans Steinegger Software. © 1988-1999 Hans Steinegger. ® OCAD is a registered trademark of Hans Steinegger
This document has been written and coded by Peter Hornsby of Ashby Mapping
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Produced for the Ashby Mapping internet site on 20 November 1997 and 1 December 1999  ©1997-2000 Ashby Mapping
Revised 28 December 1999, 23 March 2000