What is Chain Surveying | Principles of Chain Surveying | Types of Chains Used in Surveying | Principle of Chain Surveying | Procedure of Chain Surveying | Obstacles in Chain Surveying
Baseline, Tie line, Check line, Main survey stations, Tie Stations, Location sketches of survey station
Two men are required to measure the distance between two places A and B by a chain.
One man who grabs the ends of the chain and pulls it forward is called the forerunner and the other, the one that is called the back end of the chain.
The precursor is given a drawing bar and 10 arrows when measuring by a chain.
A knob in the groove inside the handle of the succeeding chain holds the handle of the chain exactly as it is mounted, pressing it down the heel of the foot, and pulling the chain from the forearm to the perpendicular line to the line AB.
Then, with the instructions to the succeeding precursor, the trajectory moves line AB to the left or right, until the straight line connecting the points A and B is reached.
When the drawing is done correctly, the forearm points to the ground where the forearm is fine, with two lines cutting off each other, with the help of a forward shaft or if the ground is hard.
Then the handle of the forearm chain instantly grabs the chain with both hands and pulls it exactly above the mark on the ground.
Now the precursor takes one of the ten arrows held by it and knocks it in the semicircular groove provided at the outside of the handle of the chain.
These arrows indicate the end of a chain. Now the forward chain is pulled forward
And when the next arrow is dropped, it stops the pioneer from moving forward. Then he will be there for himself
And when the next arrow is dropped, it stops the pioneer from moving forward. Then he will be there for himself
The arrow drawn in the groove of the handle of the chain holds the handle in a manner that fits exactly between the two-legged and draws the forearm to the line AB by drawing as described above.
Then pull the leading chain straight and end at it. Moves the arrow as described above.
He then pulls the chain forward and lifts the lost arrow in the ground before the successor moves behind it.
In this way, the process of quantification is repeated until it reaches position B.
The precursor is usually given 10 arrows at the beginning. Since the precursor picks up the lost arrow successor, the number of arrows should be ten at any given time.
By doing so, it is not possible to forget the length of the entire chain by measuring the distance.
The number of chain-lengths measured by the arrow that comes to the successor is calculated.
When all 10 arrows are moved to the successor, they note the field and give it to the forearm, thus measuring the distance.
Finally, when the portion of line AB whose length is less than one entire chain remains to be measured, it is precisely drawn to measure the leading chain B reads the distance in front of the link and reports the successor in the field.
Subsequent drawings have to be made when measuring distances, and the measured distances have to be noted in the field book.
Thus his responsibility is more than the foregoing.
Therefore, experienced and intelligent surveyors should be entrusted with the task of succession. Procedure Chain Surveying
A well-formed triangle should be drawn along the line connecting the survey location.
The main survey line should be as low as possible.
Surface and the open area should pass through till baseline is formed.
The main survey line should pass through the details and until they are made parallel so that the vertical is shortened.
Each triangle must have a lock line.
There should be as little difficulty as possible in placing and drawing the length of the survey line.
All survey lines should pass through the flat ground.
On high-traffic roads, the survey line should pass over one side of the road so as not to cause frequent interruptions in the measurement, as well as not to disturb the vehicles.