Short Answer:
In surveying, different types of chains are used for measuring distances accurately. The main types include:
- Metric Chain – A chain measured in meters, commonly used in modern surveys.
- Gunter’s Chain – A 66-foot-long chain used for land measurement.
- Engineer’s Chain – A 100-foot chain used in engineering surveys.
- Revenue Chain – A 33-foot chain used for land records and agricultural surveys.
- Steel Band Chain – A flexible steel strip used for high-accuracy measurements.
Each chain type is selected based on the surveying needs and required accuracy.
Detailed Explanation:
Chains are one of the simplest tools used in chain surveying to measure distances between points. They consist of a series of metal links connected to form a specific length. Different types of chains are used depending on the type of survey and level of precision required.
- Metric Chain:
- The most commonly used chain in modern surveys.
- Available in 5m, 10m, 20m, and 30m lengths.
- Each link is 20 cm long, making it easy to read measurements.
- Used for general land surveys, road projects, and small construction works.
- Gunter’s Chain (Surveyor’s Chain):
- 66 feet (20.12 meters) long, divided into 100 links.
- Designed for measuring land areas in acres.
- Used in old land surveys, especially in the United States and Britain.
- Not commonly used today but important in historical surveys.
- Engineer’s Chain:
- 100 feet (30.48 meters) long, divided into 100 links.
- Used in engineering and construction surveys.
- Provides better accuracy than Gunter’s chain.
- Suitable for large-scale projects like highway and dam construction.
- Revenue Chain:
- 33 feet (10.06 meters) long, divided into 16 links.
- Used in land revenue and agricultural surveys.
- Commonly used in India for property boundary surveys.
- Less accurate than other chains but suitable for rural land records.
- Steel Band Chain:
- Made of thin steel strips instead of links.
- Available in 20m to 30m lengths.
- More durable and provides higher accuracy than linked chains.
- Used in precision surveying and large-scale engineering projects.
Conclusion:
Different types of chains are used in surveying based on accuracy requirements and project needs. Metric chains are widely used today, while Gunter’s and revenue chains are important for land records. Engineer’s chains and steel band chains are used in construction and high-accuracy projects. Choosing the right chain ensures reliable and precise land measurements.