What is chain surveying?

Answer 1

Chain surveying is a traditional method of land surveying used to measure and map large areas of land. It is one of the simplest and oldest surveying techniques, dating back to ancient times. In chain surveying, the primary measuring instrument used is a chain, hence the name.

The main steps involved in chain surveying are as follows:

1. **Selection of Stations:** The surveyor selects prominent points on the ground, known as survey stations, which form the main control points for the survey.

2. **Triangulation or Baseline:** The surveyor establishes a baseline, which is a straight line connecting two nearby survey stations. Triangulation may also be used to extend the survey to areas beyond the baseline.

3. **Chain Measurement:** The chain, a measuring tape, or a tape measure is used to measure distances between survey stations and other features on the ground. The chain used in chain surveying is typically 66 feet (20 meters) long and divided into 100 links, each 0.66 feet (20 centimeters) long.

4. **Offsets:** To survey features that are not directly on the survey line (such as buildings, walls, or trees), the surveyor takes offsets perpendicular to the survey line to the features.

5. **Angulation:** The angles between the survey lines are measured using a compass or theodolite to determine the direction of the lines relative to a reference direction (usually the north direction).

6. **Plotting:** The surveyor plots the measurements and angles on a field book and later transfers the data to a map or plan, creating a scaled representation of the surveyed area.

Chain surveying is suitable for relatively flat terrains and small to medium-sized survey areas. However, it has limitations, especially when dealing with hilly or irregular terrains. Errors can occur due to sagging or stretching of the chain, uneven ground, and inaccuracies in measuring angles and distances.

Modern surveying techniques, such as total stations and GPS (Global Positioning System), have largely replaced chain surveying for large-scale surveys due to their higher accuracy, efficiency, and suitability for various terrains. However, chain surveying remains relevant for small-scale, low-accuracy surveys and educational purposes to understand the principles of land surveying.

Answer 2

Chain surveying, also known as linear surveying, is a basic method of land surveying used to measure and map small and relatively flat areas. It is a simple and traditional technique that involves the use of chains or tapes to measure distances and basic instruments to measure angles. Chain surveying is often used for small-scale surveys such as creating maps for agricultural fields, small plots, or subdivisions.

Here's how chain surveying works:

1. Measurement of Distances: In chain surveying, distances are measured using chains (typically 66 feet or 100 feet) or steel tapes. These chains or tapes are laid out along the linear features of the land being surveyed, such as property boundaries or roads. The total distance is obtained by chaining together multiple segments.

2. Measurement of Angles: Basic angles can be measured using a compass, theodolite, or other simple instruments. These angles are used to determine the direction of the surveyed lines and to calculate the layout of the land.

3. Stations and Offsets: The surveyed area is divided into smaller segments called "stations." At each station, measurements are taken to locate nearby features or boundaries, and perpendicular lines known as "offsets" are measured to mark points of interest.

4. Plotting: The data collected during the survey is used to create a scaled drawing or map of the surveyed area. The positions of boundaries, features, and angles are plotted on the map to create an accurate representation of the land.

Advantages of Chain Surveying:

• **Simplicity:** Chain surveying is straightforward and requires minimal equipment and training.

• **Accuracy:** In relatively small and flat areas, chain surveying can provide accurate measurements for basic mapping purposes.

• **Low Cost:** It is a cost-effective method, making it suitable for smaller projects with limited budgets.

Limitations of Chain Surveying:

• **Limited Coverage:** Chain surveying is not suitable for large or complex areas, as it becomes challenging to maintain accuracy over extended distances or rugged terrains.

• **Human Errors:** The accuracy of measurements in chain surveying can be affected by human errors, such as miscounting chain links or inaccurate readings.

• **Lack of Precision:** Chain surveying may not provide the level of precision required for detailed engineering projects or high-precision mapping.

In modern surveying, more advanced methods such as total stations, GPS, and aerial surveys have largely replaced chain surveying for larger and more complex projects. However, chain surveying remains a valuable technique for smaller-scale surveys and in situations where advanced technology is not readily available or necessary.

Answer 3

chain surveying is the branch of surveying in which only linear measurement are made in field. none of angular measurement are taken.