Chain surveying is the type of surveying in which only linear measurements are taken in the
field. This type of surveying is done for surveys of small extent to describe the boundaries of plot
of land to locate the existing features on them.
It is the method of surveying in which the area is divided into network of triangles and the
sides of the various triangles are measured directly in the field with a chain or a tape and no
angular measurements are taken.
Chains are the measuring instrument used in surveying formed by the 100 links of 4mm
galvanized mild steel wire. These links are joined by 3 circular or oval wire rings. These rings
provide the flexibility to the chains.
Every aspect of the life requires some measuring units. Measurements are used to do the
work precisely and accurately. Let it be from kitchen to office, everywhere measurements are
used. So as in engineering calculation or measurements holds a very greater role in construction
or surveying or any other aspect.
There are various units of measurements such as meters, centimeters, feets, inches, acre,
yards and the list goes on. Same as units there are various instrument used in the measurements
of any entity. One of the instruments used in measurement are chains.
Parts of Chains used in Surveying
The chain consists of many small parts used for handling or reading the measurements.
Every aspect of the life requires some measuring units. Measurements are used to do the
work precisely and accurately. Let it be from kitchen to office, everywhere measurements are
used. So as in engineering calculation or measurements holds a very greater role in construction
or surveying or any other aspect.
There are various units of measurements such as meters, centimeters, feets, inches, acre,
yards and the list goes on. Same as units there are various instrument used in the measurements
of any entity. One of the instruments used in measurement are chains.
Parts of Chains used in Surveying
The chain consists of many small parts used for handling or reading the measurements.
o At the ends chain is provided with brass handle with swivel joint so that it can be easy to roll or
unroll the chain without twisting and knots.
o At every 10th link is provided with a tally of one teeth, 20th link with a tally of two teeth and soon till 40th link. This is provided for the easy reading of measurements.
o At the center of the chain is provided with a circular talley used for easy reading.
Types of Chains used in Surveying
Depending upon the length of the chain, these are divide into following types,
1. Metric chains
2. Steel band or Band chain
3. Gunter’s chain or surveyor’s chain
4. Engineer’s chain
5. Revenue chain
A. Metric chains
Metric chains are the most commonly used chain in India. These types of chains comes in many
lengths such as 5, 10, 20 and 30 meters. Most commonly used is 20m chain. Tallies are provided
at every 2m of the chain for quick reading. Every link of this type of chain is 0.2m. The total
length of the chain is marked on the brass handle at the ends.
B. Steel band or Band chain
These types of chain consist of a long narrow strip of steel of uniform width of 12 to 16 mm and
thickness of 0.3 to 0.6 mm. this chain is divides by brass studs at every 20cm or instead of brass
studs, band chain may have graduated engraving as centimeter.
For easy use and workability band chains are wound on steel crosses or metal reels from which
they can be easily unrolled. These steel bands are available in 20m and 30m length and the width
of about 12-16mm.
C. Gunter’s chain or surveyor’s chain
Gunter chain comes in standard 66ft. These chain consists of 100links, each link being 0.66ft or
7.92inches. The length 66ft is selected because it is convenient in land measurements.
10 square Gunter’s chains = 1 Acre
10 Gunter chains = 1 Furlong
80 Gunter chains = 1 mile
D. Engineer’s chain
This chain comes in 100ft length. It consist of 100 links each link being 1ft long. At every 10
links a brass ring or tags are provided for indication of 10 links. Readings are taken in feet and
decimal.
E. Revenue Chain
The standard size of this type of chain is 33ft. The number of links are 16, each link being
2 ft. This chain is commonly used in cadastral survey.
PRINCIPLE OF CHAIN SURVEYING
The principal of chain surveying is to divide the area into a number of triangles of
suitable sides.
As a triangles is the only simple plane of geometrical figure which can be plotted from
the lengths of the three sides even if the angels are not known.
A network of triangles (triangulation) is preferred to in chain surveying.
If the area to be surveyed is triangular in shape and if the lengths and sequence of its
three sides are recorded the plane of area can be easily drawn.
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