TrigpointingUK

Hi All,
Newbie here, just registered onto the site after finding it a while ago.
Here's a question which after a search around the site I could not find an answer too:
Is there such a thing as an official list of the date of construction of pillars or the placement of bolts etc?
Thanks,
Rocky

Hi and welcome !

Each trig page (maybe with a few exceptions) on TPUK has (near top of page) the relevant data for that trig, extracted from the OS archive, showing the Computing date (soon after construction) and Levelling date. e.g. http://trigpointing.uk/trig/6194 Stockerston computed in 1938. The data extract table has a hyperlink for the OSGB36 trig archive spreadsheet, leading to the Trigonomy group files area (need to subscribe if you've not already - free of charge). Might need to search around the files area a little to find the spreadsheet. I'm pretty sure there's construction dates somewhere, in the one the files...

HTH!

Hi Peregrinus,
Thank you for the information, I have requested to join the group.
Regards,
Rocky

Hi Rob,

Each trig page (maybe with a few exceptions) on TPUK has (near top of page) the relevant data for that trig, extracted from the OS archive, showing the Computing date (soon after construction) and Levelling date. e.g. http://trigpointing.uk/trig/6194 Stockerston computed in 1938.

I've never properly understood what the OS mean by computing date in this context. Does this refer to
the processing of observations taken from the trig in order to establish its grid reference?

Its also puzzling that, in the example of Stockerston that you refer to, the levelling date is exactly
25 years after the computing date. I suppose this would be a revision or check on the calculations for
the trigs elevation and not an example of OS gross inefficiency


Regards
Ted

ted wrote: I've never properly understood what the OS mean by computing date in this context. Does this refer to
the processing of observations taken from the trig in order to establish its grid reference?

Yes I assume so. They'd collect their observations, do lots of complicated-looking distribution of errors then come up with a location

ted wrote: Its also puzzling that, in the example of Stockerston that you refer to, the levelling date is exactly
25 years after the computing date. I suppose this would be a revision or check on the calculations for
the trigs elevation and not an example of OS gross inefficiency

No idea!

Rob