Types of chains

a. Metric chain

• The chains are made in length of 20 and 30 meters .
• To enable the reading of fractions of a chain without much difficulty, tallies are fixed at every five-meter length and small brass rings are provided at every meter length, except where tallies are attached.
• Connecting links between two large links are oval in shape, the central one being a circular ring.
• The length of the chain is marked over the handle to indicate the length and also to distinguish from non- metallic chains.
• The length of each link is 0.2 m (20cm) in 20m chain is provided with 100 links and 30 m chain divided into 150 links.

The advantages of the chain are:

(i) It is very suitable for rough usage

(ii)It can be easily repaired in the field

(iii) It can be easily read.

b. Gunter’s Chain

• It is also called surveyor‟s chain. The Gunter‟s chain is 66 ft. long and is divided into 100 links. Therefore, each end link is equal to 0.66 ft. long.
• It is very convenient for measuring distances in miles and furlongs and for measuring land when the unit of area is an acre, on account of its simple relation to the mile and the acre.

10 Gunter’s chains – 1 furlong

80 Günter’s chains- 1 mile

10 square Guntur’s chains – 1 acre

c. Revenue Chain:

• The revenue chain is commonly used for measuring fields in cadastral survey. It is 33 ft. long and divided into 16 links.

d. Engineers’ Chain:

• The engineer’s chain is 100 ft. long and is divided into 100 links each link is equal to 1 ft.
• The construction details are same as that of a Günter’s chain. It is used on all engineering surveys.
• The distances measured with the engineer’s chain are recorded in feet and decimals.