Ghost trigs

[ted1]

I've added a wiki page for 'ghost' trigs: https://wiki.trigpointing.uk/Ghost_trigs
- these are instances of the familiar triangulation symbol on Ordnance Survey 'Explorer'
or 'Outdoor Leisure' series maps which are not trig pillars.

Additions/corrections would be welcome - the initial version of the list is rather
biased towards Northern England so some examples from elsewhere would give a
better balance.

[BigJ1]

Hi Ted. Some that I was aware of on older maps seem to have been amended by the OS and the trig symbol has been removed. However, the following one is still shown as a triangle on the 1:25000 but is in fact a bolt. TP15365 - Am Meallan, Grid Reference: NG 86667 33984. Hoping this helps.

[BigJ1]

Oh. And here’s another one. This time it shows on the 1:50000 but not the 1:25000. TP15473 - Glenborrowdale Grid Reference: NM 60266 61243

[BigJ1]

Oh. And another one. This time showing on the 1:25000 but not the 1:50000. TP15483 - Torr Na Fhaire Grid Reference: NM 67766 44508.

[BigJ1]

One last one. On the 1:25000 but not the 1:50000. TP15291 - Rudh Ard Bhaideanach Grid Reference: NC 41196 55865

[ted1]

Thanks! I'll add those to the wiki table. If you could provide the map details
(Landranger, Explorer, Outdoor Leisure) map number and, ideally the map's publication
date/revision letter then that would be helpful.

[tim747]

Altrincham Crem SJ 73807 89796 has a trig point symbol on Memory-Map OS 1:25k England-Wales 2026 which is not on the 1:50k.

[BigJ1]

Hi Ted. I've put together the details you asked for and included the link. I’ve taken the info from the up to date OS digital mapping as I don't really have paper maps anymore. Hope that’s OK. Cheers Big J
https://docs.google.com/spreadsheets/d/ ... p=drivesdk

[ted1]

Thanks for the feedback; wiki page updates pending (trying to clear
a backlog of other updates first).

Further examples of ghost trigs welcome!

[sheepsocks1]

On Harris, at least two (and probably more) Hydrographic Survey Stations are marked on OS maps with triangles but are actually bolts:
TP7634 Tolmachain
TP7549 Greaval