Civil Engineering Tutorial 2: Chain Surveying Fundamentals

This document is a tutorial on chain surveying, a fundamental technique in civil engineering. It covers the essential equipment like chains, tapes, and ranging poles. The tutorial explains key concepts such as triangulation, offset measurement, and reconnaissance diagrams. It details the procedures for running survey lines, including chaining, ranging, and stretching the chain. The document also differentiates between direct and indirect ranging and discusses potential errors arising from incorrect chain lengths, temperature changes, and personal mistakes. Furthermore, it outlines the suitability of chain surveying, highlighting ideal and unsuitable conditions for its application. This tutorial is designed to provide a clear understanding of chain surveying principles and practices for civil engineering students.

02. Chain Surveying CIVIL
Surveying, Measuring & Setting out Tutorial -2
Page 1 of 6
Eng. C. M. Shafraz
Introduction
• Simple Technique
• Small Plane Areas with Very Few Details
• It gives quite accurate results, if it is done carefully
• The necessary equipment for field work are;
➢ Chain or Steel Tape
➢ Linen Tape
➢ Ranging Rod/Pole
➢ Arrows
➢ Mallet
➢ Plumb Bob
➢ Pegs
➢ Cross Staff (Sometime)
Triangulation
Well-conditioned
➢ A tangle is said to be well conditioned when no angle is less than 30° or greater than 150°.
➢ An equilateral triangle is considered the best condition or ideal triangle.
ill – conditioned triangles
• A tangle in which an angle is less than 30° or more than 150°.
• It is said to be ill conditioned.

02. Chain Surveying CIVIL
Surveying, Measuring & Setting out Tutorial -2
Page 2 of 6
Eng. C. M. Shafraz
Offset Area
Perpendicular Offset Measurement
Oblique Offset Measurement
Tie Measurement to the Station/Location Sketch
The primary control points are triangulation stations.
The secondary control points are reference to the
primary control stations.

02. Chain Surveying CIVIL
Surveying, Measuring & Setting out Tutorial -2
Page 3 of 6
Eng. C. M. Shafraz
Steel Chain
Equipment
Steel Tape & Linen Tape Ranging Pole
Reconnaissance Diagram
Also called - Index Plan, Reference Sketch, Key Plan or Prospection Diagram
Procedure
1. Reconnaissance
2. Selection of Stations
3. Marking of Stations
4. Measurements (Running Survey Lines)
5. Note Keeping
Running Survey Lines
1. Chaining a horizontal line
2. Ranging a chain
3. Stretching a chain
4. Carrying the chain to next length
5. Folding the chain

02. Chain Surveying CIVIL
Surveying, Measuring & Setting out Tutorial -2
Page 4 of 6
Eng. C. M. Shafraz
Ranging of Survey Lines
• When survey line is longer than a chain length
• The process of locating intermediate points (subsidiary points) on the survey line
• Ranging a line means establishing a set of intermediate points on a straight line between two control
points already fixed on the ground
• Two type:
✓ Direct Ranging
✓ Indirect Ranging
Direct Ranging
• If the first and last points (control points or end points) are inter-visible
Indirect Ranging
• If the first and last points (control points or end points) are not inter-visible due to unevenness of the
ground or due to the long distance
• This method is also called reciprocal ranging
• Need four ranging poles
• There are two methods based on visibility of intermediate points

02. Chain Surveying CIVIL
Surveying, Measuring & Setting out Tutorial -2
Page 5 of 6
Eng. C. M. Shafraz
Indirect Ranging-Visibility from Intermediates
Errors may arise from the following
Erroneous length the chain or tape
• Sag in chain or tape
• Change of temperature
• Variation of pull
• Bad ranging
• Personal mistakes
• Carelessness of holding and making
• Non horizontalness of the tape
Cumulative Errors

02. Chain Surveying CIVIL
Surveying, Measuring & Setting out Tutorial -2
Page 6 of 6
Eng. C. M. Shafraz
Compensating Errors
Suitability of chain surveying
•Most suitable in the following cases:
✓ Ground is fairly level
✓ Area is comparatively small in extend
✓ Formation of well – conditioned triangles is easy
•Unsuitable in the following cases:
✓ For large areas
✓ For areas crowed with many details
✓ For undulation areas
✓ The formation of well- conditioned triangles becomes difficult due to obstacles like forest areas