CHAIN SURVEYING
1. What is the fundamental difference between surveying and leveling?
In surveying the measurements are taken in horizontal plane, but in leveling they are taken in the vertical plane.
2. What is the fundamental difference between plane surveying and geodetic surveying?
In Plane surveying, the curvature of the earth is not considered. But in Geodetic surveying, the curvature of the earth is considered.
3. What do you mean by terms “topographical map” and cadastral map?
A map which shows the natural features of a country such as rivers, hills, roads, railways, villages, towns, etc. is known as topographical map, and one which shows the boundaries of estates, fields, houses, etc. is known as a cadastral map.
4. What is the main principle of surveying?
The fundamental principle of surveying is to work from the whole to the part.
5. How is a chain folded and unfolded?
In order to fold the chain, a chainman moves forward by pulling the chain at the middle so that two halves come side by side. Then he places the pair of links on his left hand with his right hand until the two brass handles appear at the top.
To unfold the chain: A chain man holds the two brass handles in his left hand and throws the bunch with his right hand. Then one chain man stands at a station holding one handle and another chainman moves forward by holding the other handle.
6. In a chaining operation, who is the leader and who is the follower?
The chain man at the forward end of the chain who drags the chain is known as the leader and the one at the rear end of the chain is known as the follower.
7. While chaining a line, if you have to measure through a steep sloping ground, what method should you apply?
The stepping method.
8. Two stations are not intervisible due to intervening high ground. How will you range the line?
The ranging is to be done by the reciprocal method.
9. What do you mean by normal tension?
The tension at which the measured distance is equal to the correct distance (i.e; when sag correction is neutralized by pull correction) is known as normal tension.
10. What do you mean by RF?
The ratio of the distance on the drawing to the corresponding actual length of the object is known as RF.
11. What is the difference between plain scale and diagonal scale?
The plain scale represents two successive units. The diagonal scale represents three successive units.
12. What is hypotenuse allowance?
When one chain length is measured on slopping ground then it shows a shorter distance on the horizontal distance is known as the hypotenusal allowance.
13. How many ranging rods are required to range a line?
At least three ranging rods required for direct ranging and at least four for indirect ranging.
14. What is the length of one link in a 20m chain?
The 20m chain is divided in to 100 links. So, one link is 0.2m. i.e; 20cm. long.
15. What is the Principle of chain surveying?
The Principle of chain surveying is triangulation.
16. What do you mean by triangulation?
The method of dividing an area into a number of triangles is known as triangulation.
17. Why is the triangle preferred to the quadrilateral?
The triangle is preferred just it is a simple figure which can be drawn by just knowing the lengths of its sides.
18. What is the disadvantage of using ill – conditioned triangles?
The apex point of an ill conditioned triangle is not well defined and sharp. This may cause some confusion while marking the actual point correctly on the map.
19. What is reconnaissance survey?
The preliminary inspection of the area to be surveyed is known as reconnaissance survey.
20. What is an index sketch?
During reconnaissance survey a neat hand sketch is prepared showing the frame work of the survey. This sketch is known as index sketch.
21. What is base line of survey?
Base line is the back bone of the survey. The frame work of the survey is prepared on this line.
22. How is the north line of the chain survey map fixed?
The north line of the chain survey map is fixed by taking the magnetic bearings of the base line by prismatic compass.
23. Suppose you are asked to conduct a chain survey in a crowded town what would you say?
In chain survey, whole area is to be divided into a number of triangles. But the formation of triangles is not possible in a crowded area. So I would reject the proposal.
24. What should be the maximum length of the offset?
The maximum length of the offset should be within the length of the tape used. Generally it should not be more than 15m.
25. How is a station marked on the ground?
The station is marked on the ground by a wooden peg and with a cross on the station point.
26. What is the need of a reference sketch?
If the station peg is removed by some one the station can be located accurately with the help of measurements shown in reference sketch.
27. How will you set up a perpendicular with the help of only a chain and tape?
By forming triangle in the ratio 3:4:5 using the chain and tape.
28. Who are the leader and follower when a line is being chained?
The chain man at the forward end of the chain who drags the chain is known as the leader. The one at the rear end of the chain is known as the follower.
29. Why does the field book open lengthwise?
If the field book is opened lengthwise, it becomes easy to maintain the continuation of a chain line.
30. Why is the scale always drawn in the map?
The paper on which the map is drawn may shrink or expand due to various reasons. If the scale is plotted on the map, then it is also reduced or enlarged proportionately. So the distance on the map measured by this scale remains unaltered.
31. What is it necessary to provide tallies in a chain?
Tallies are provided in a chain for the facility to counting some fractional length of the chain, when the full chain length is not required.
32. What do you mean by the term ideal triangle?
An equilateral triangle is said to be ideal.
1. What is the fundamental difference between surveying and leveling?
In surveying the measurements are taken in horizontal plane, but in leveling they are taken in the vertical plane.
2. What is the fundamental difference between plane surveying and geodetic surveying?
In Plane surveying, the curvature of the earth is not considered. But in Geodetic surveying, the curvature of the earth is considered.
3. What do you mean by terms “topographical map” and cadastral map?
A map which shows the natural features of a country such as rivers, hills, roads, railways, villages, towns, etc. is known as topographical map, and one which shows the boundaries of estates, fields, houses, etc. is known as a cadastral map.
4. What is the main principle of surveying?
The fundamental principle of surveying is to work from the whole to the part.
5. How is a chain folded and unfolded?
In order to fold the chain, a chainman moves forward by pulling the chain at the middle so that two halves come side by side. Then he places the pair of links on his left hand with his right hand until the two brass handles appear at the top.
To unfold the chain: A chain man holds the two brass handles in his left hand and throws the bunch with his right hand. Then one chain man stands at a station holding one handle and another chainman moves forward by holding the other handle.
6. In a chaining operation, who is the leader and who is the follower?
The chain man at the forward end of the chain who drags the chain is known as the leader and the one at the rear end of the chain is known as the follower.
7. While chaining a line, if you have to measure through a steep sloping ground, what method should you apply?
The stepping method.
8. Two stations are not intervisible due to intervening high ground. How will you range the line?
The ranging is to be done by the reciprocal method.
9. What do you mean by normal tension?
The tension at which the measured distance is equal to the correct distance (i.e; when sag correction is neutralized by pull correction) is known as normal tension.
10. What do you mean by RF?
The ratio of the distance on the drawing to the corresponding actual length of the object is known as RF.
11. What is the difference between plain scale and diagonal scale?
The plain scale represents two successive units. The diagonal scale represents three successive units.
12. What is hypotenuse allowance?
When one chain length is measured on slopping ground then it shows a shorter distance on the horizontal distance is known as the hypotenusal allowance.
13. How many ranging rods are required to range a line?
At least three ranging rods required for direct ranging and at least four for indirect ranging.
14. What is the length of one link in a 20m chain?
The 20m chain is divided in to 100 links. So, one link is 0.2m. i.e; 20cm. long.
15. What is the Principle of chain surveying?
The Principle of chain surveying is triangulation.
16. What do you mean by triangulation?
The method of dividing an area into a number of triangles is known as triangulation.
17. Why is the triangle preferred to the quadrilateral?
The triangle is preferred just it is a simple figure which can be drawn by just knowing the lengths of its sides.
18. What is the disadvantage of using ill – conditioned triangles?
The apex point of an ill conditioned triangle is not well defined and sharp. This may cause some confusion while marking the actual point correctly on the map.
19. What is reconnaissance survey?
The preliminary inspection of the area to be surveyed is known as reconnaissance survey.
20. What is an index sketch?
During reconnaissance survey a neat hand sketch is prepared showing the frame work of the survey. This sketch is known as index sketch.
21. What is base line of survey?
Base line is the back bone of the survey. The frame work of the survey is prepared on this line.
22. How is the north line of the chain survey map fixed?
The north line of the chain survey map is fixed by taking the magnetic bearings of the base line by prismatic compass.
23. Suppose you are asked to conduct a chain survey in a crowded town what would you say?
In chain survey, whole area is to be divided into a number of triangles. But the formation of triangles is not possible in a crowded area. So I would reject the proposal.
24. What should be the maximum length of the offset?
The maximum length of the offset should be within the length of the tape used. Generally it should not be more than 15m.
25. How is a station marked on the ground?
The station is marked on the ground by a wooden peg and with a cross on the station point.
26. What is the need of a reference sketch?
If the station peg is removed by some one the station can be located accurately with the help of measurements shown in reference sketch.
27. How will you set up a perpendicular with the help of only a chain and tape?
By forming triangle in the ratio 3:4:5 using the chain and tape.
28. Who are the leader and follower when a line is being chained?
The chain man at the forward end of the chain who drags the chain is known as the leader. The one at the rear end of the chain is known as the follower.
29. Why does the field book open lengthwise?
If the field book is opened lengthwise, it becomes easy to maintain the continuation of a chain line.
30. Why is the scale always drawn in the map?
The paper on which the map is drawn may shrink or expand due to various reasons. If the scale is plotted on the map, then it is also reduced or enlarged proportionately. So the distance on the map measured by this scale remains unaltered.
31. What is it necessary to provide tallies in a chain?
Tallies are provided in a chain for the facility to counting some fractional length of the chain, when the full chain length is not required.
32. What do you mean by the term ideal triangle?
An equilateral triangle is said to be ideal.
