Week 3

This exercise introduces topographical surveys. The aim is to produce a detailed map of an area clearly defining changes in terrain, fixed objects, and boundaries. An area will be marked out with 4 pegs/rods and each corner is labelled Station ABCD, the survey requires 6 chain lines, AB, AC, AD, BC, BD, CD which should be the perimeter and diagonals.

Equipment Required

Process

1) Set the 4 stations out in a sensible place, ensure an area is located which has enough to survey. The stations need to be approximately 20M apart in a rough square.

2) Draw a very simple map of your stations with key landmarks, and give the stations their names, A, B, C and D

3) Stretch a chain from A to B

4) Write Station A at the top of the book.

5) Working towards station B, record any changes in terrain, fixed objects, or boundary lines within 3M of the chain on either side.

6) When station B is reached record it and its distance from A on the chain

7) Repeat the process for the other 5 chain lines

Example Features

Boundaries and Fences, Long features should be recorded with enough detail to be able to draw it accurately. For example, taking a reading every 3M at right-angle to the Chain

Buildings, Buildings should be recorded to the corners where possible, and for long sides or curved faces multiple readings should be taken to ensure an accurate drawing can be made.

Objects, Objects like street furniture should be recorded with 2 readings off the chain at least 2M apart to the approximate centre of the object. Simple notes should be made about the object for identifications purposes.

Trees, Trees should be recorded with at 2 measurements from the chain at least 2M apart. The readings should be to the approximate Centre of the tree and the Span and Girth should be recorded alongside this.

How to Write in the Chain Survey Book

Example Book Layout

Practical Video Guide