Thoughts

• Land Surveyor

  DAVID C. GARCELON April 3, 2013 at 7:56am

  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

  DAVID C. GARCELON March 30, 2013 at 2:23pm

  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

  DAVID C. GARCELON March 29, 2013 at 8:18am

  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

  DAVID C. GARCELON March 28, 2013 at 11:49am

  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
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  Randall R.Schaff PLS September 8, 2010 at 3:19am

  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

  Jaybird June 14, 2010 at 1:00pm

  would somebody be interested in making a video tutorial on how Chaining is done?
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  MARK GREGORY HILL June 14, 2010 at 6:13am

  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

  Jaybird June 10, 2010 at 10:26am

  amazing....sure wish you had some photos from back then Phil...it 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?
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  [email protected] June 9, 2010 at 6:54pm

  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.