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Endangered Art of Chaining Hub is for, Land Surveyors United members to discuss the Gunter's Chain and the endangered art of chaining in the land surveying profession. Share your best experiences and tips for chaining in land surveying.

Gunter's chain (also known as Gunter’s measurement) is a distance measuring device used for surveying. It was designed and introduced in 1620 by English clergyman and mathematician Edmund Gunter (1581–1626). It enabled plots of land to be accurately surveyed and plotted, for legal and commercial purposes. Gunter developed an actual measuring chain of 100 links. These, the chain and the link, became statutory measures in England and subsequently the British Empire.
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Glossary of Antique Surveying Tools

I found this helpful glossary of Antique Surveying Tools [via] which may come in handy for those who are interested in learning the old school methods.  Anybody have any pictures of these by chance? ABNEY HAND LEVEL - Measures vertical angles. ALIDADE - Used on a Plane Table to measure vertical and horizontal angles & distances. ALTAAZIMUTH INSTRUMENT - Measures horizontal and vertical angles; for position "fixing". ASTRONOMIC TRANSITS - Measures vertical angles of heavenly bodies; for…

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The Endangered Art of "Chaining" in Land Surveying


The Chain  
This is an example of a "chain" that is normally 66' long consisting of 100 links.  A "chain" of 66' can also be described as being 4 poles of 16.5'.

Other tools used by a surveyor to measure distance can be a steel tape of lengths of up to 500' and the modern electronic distance measuring devices that can measure distances in excess of several miles with the use of reflector prisms.

In fact, the first men to land on the moon left behind a grouping of reflector prisms that allowed surveyors and scientists to measure the distance from the earth to the moon to an accuracy of just a couple of feet.


Invented by clergyman Edmund Gunter, the surveyor's chain made it possible to accurately measure distances and acreage in an era before global positioning satellites permitted mapping from space. The surveyor's chain made it possible for Lewis and Clark to map the Louisiana Purchase and lay out cities, townships and railroads. Here's an explanation of the measurements and how to use them.

Basic Units

Step 1

Equate a standard surveyor's chain, or Gunter's chain, to 66 feet or 22 yards. There are also half-length chains of 33 feet. Equate an engineer's chain, or Ramsden's chain, to 100 feet.

Step 2

Divide a surveyor's chain into 100 links, equal to 0.66 feet, or 7.92 inches. Gunter's original chain was made with 100 links, a half-chain with 50. A Pennsylvania surveyor's chain, while 66 feet long, is made with only 80 links.

Step 3
Convert a measurement in surveyor's chains into rods by multiplying by 4, into furlongs by dividing by 10 and into miles by dividing by 80. Convert a length in surveyor's chains to meters by multiplying by 20.1168 and into kilometers by multiplying by 0.0201.

Tips and Warnings

An acre of land is equal to 10 square chains. A square mile is equal to 640 acres or 6,400 square chains (80 chains on each side, 80 x 80 = 6,400).

By 1785 law, only Gunter's 66-foot chain was allowed for land surveying work.


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  • Land Surveyor

    In the early 1800's two "King's Surveyors" were found dragging a chain through the Maine forests. They were asked "Why are you pulling that chain through our forest?"  "Have you ever tried pushing  a chain?" was the answer.

    David C. Garcelon

  • Land Surveyor

    Did you know that the length of a Cricket Pitch is 22 yards (66 feet) long (the distance down the center of the cricket field between the wickets).  Another irony of the English influence on the length of the chain !!

    David c. Garcelon

  • Land Surveyor

    I believe it was Professor J.B. Johnson who pointed out that if you had a 100 link chain with three loops connecting each link (808 wear surfaces) that if you had 0.005 inches of wear on each wear surface your chain would be measuring 4 inches short for each full chain measured; i.e. actual distance of  66 feet would measure 65.66 feet (99.5 links) long. That is why the better chains had the ability to be adjusted for length at each handle. It is also why John Grumman developed the "Grumman Patent "Chain" for, believe it or not, surveying in cities.

    David C. Garcelon

  • Land Surveyor

    Chain surveying was taught even in books on Geodesy prior to 1900.

    The texts that taught it in the 18th and 19th centuries are too many to mention. John Whitelaw Jr's1902  text on surveying begins with "Chapter 1-Chain Surveying" and is 59 pages long with many illustrations.

    I wonder, Randall, when you talk about "throwing a Chain" if you mean "Throwing a chain tape".. In my early days I did a lot of forestland surveys and we would use a 66 foot (1 chain) band tape

    with babbitt metal at every foot mark..we would call it a "chain tape" because of its length or a "drag tape" because we would take it off of its reel and drag it along the ground between measurements (so we wouldn't have to "Throw" it or wind it back onto the reel).

    David C. Garcelon

  • I grew up in the field, my Dad was a PLS and an Engineer, I dragged a "chain" everywhere when I was kid. I was a head chainman when I became tall enough to plumb high. Anyone remember throwing a chain ? Ever see a left handed chainman do it ?
  • GEO Ambassador
    would somebody be interested in making a video tutorial on how Chaining is done?
  • I don't mean to burst your bubble but the correct conversion of chains to a mile is to multiply 80 chains rather than divide. I am almost 55 now and have worked in the field of surveying since I was 12 years old. Those were only a few brief work experinces until I graduated from high school in 1973 and have been employed in the field ever since. I have been licensed since 1998 and used what was called a "chain" although it was truly an engineers chain. In reality it was a 100 foot steel tape of which there are a few types. We called it chaining and the term chaining pin was used but it was not made up of links like the original Gunthers chain. It is my understanding that the original geodetic surveyors would sometimes use taping "stools" as well as a tension guage and thermometer. There are many corrections that must be applied when accurately chaining that were not used or really necessary when the gunther chain was the only device available. I doubt there are any surveyors still alive that have used a true Gunthers chain to much extent and very few of the new generation are skillful at even using a plumb bob for anything other than a spear. Since the advent of the distance measuring devices it is not very productive to teach anyone or even use a "chain" or steel tape. I will occaisionally use a steel tape for measuing certain things within less than 100 feet. I remember feeling very confident that our measurements were highly accurate but since have remeasured some of the more lengthy lines with a modern total station and realized how inaccurate the measurements really are, sometimes being a foot or two off when they were 3000 to 5000 feet in length. I would like to pose a simple question for the members and ask for comments on why the "chained" measurements consitently check as being short when measured with a distance meter or total station?
  • GEO Ambassador
    amazing....sure wish you had some photos from back then would be interesting if we could make a series of tutorial videos on How to Chain Measure...the problem is....where do we get a chain?
  • In the late summer of 1971 it was hotter than blazes as we ran traverse in Quang Tri Province, Vietnam. Our survey chief was known to us as Indian Territory because he was famous for saying, "Saddle up, boys, we're headed for Indian Territory!"

    He came from setting up range poles out in front of us to check on our most recent measurements. The traverse legs were measured with a 30 meter steel tape using chaining pins. The crew reported distance and the recorder reported the last angle I turned. Indian Territory said, "That distance is wrong. You dropped a pin." They asked how he knew. His response was that he stepped off the distance and knew what it ought to be.

    They made the mistake of telling him he could not know they were wrong by stepping off the distance. The end result is that we all got to practice chaining that traverse leg and were sent back to chain it again when we did not match each other well enough to suit him.

    I learned a lot of good lessons that day. I was 19 years old, cocky, and bullet proof. But I learned that old man was serious and correct when he made bold statements. He taught me exactly what it meant to bet my life on the accuracy of my measurements.
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