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Sri LankaWhy is the term bluetop used in surveying?
Most US Surveyors know what it is during constrction stage of dirt(another word) work,
I think dirtwork means playing with soil excavation and filling.
More clarifications required .
Thesae terms used when I was working with Zachry Dellingham,a US company here!
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Lalith,
In the USA, "blue top" is slang, a "nickname" for something many state departments of transportation, such as WisDOT (Wisconsin) have included in their specifications regarding exactly how to mark, or in this case adorn, such stakes. In Wisconsin a "blue top" is a blue colored whisker-like attachment that is added to a wooden hub which is set at the proposed grade for "subgrade" or the final earthen surface that crushed stone will be laid upon.
When the same staking process is used for the next layer of material, such as crushed stone, here in Wisconsin we call it a "red-top", or "redtopping", which uses a red whisker, rather than a blue one.
I have no knowledge on who chose which color for which layer of material, but I do see deviations from this convention in using pink whiskers and many other colors. These hub attachments are sometimes called stake-chasers.
They are 6 inches (15 cm) long. Their purpose is to allow the operator of a grading machine operator to visually estimate how much dirt he needs to cut or to place at the particular staked location.
With the advent of "machine control", or GNSS guided bulldozers, graders, and other large equipment, the term "blue-top" is becoming a bit scarce.
That's the history as I know it. I hope it helps.
Learn something new everyday huh! Nice work Scott!
In road or grading work the surveyor sets stakes and paints their tops blue to represent the required elevation. Graders then work to just cover the blue tops of the stakes. Here is another discussion which goes deeper with "Blue Tops"