TrigpointingUK

ted wrote:

Manhole covers even have their own web site:
https://manhole.co.il/coverDetails.asp?c=3786

Isn't it strange what people will search for? Lumps of buried concrete for example

Another recently-added passive is TP25816 - Bedson http://trigpointing.uk/trig/25816
Comparing the OS passive station records for Newcastle Active station, we see:

Newcastle [DELETED NEWC] A1NZ2465

Type of mark: Active Last visited by OS: 06/09/1999
Flush Bracket: Not available On Landranger sheet: 88
Grid reference: NZ248650 On Explorer sheet: Not available
Access to mark: Unknown Permission required: Yes
Keys required: Yes

Coordinates of this station
Date of observation: 12/05/2000 Coordinates last checked: 06/09/1999
Planned next check: 06/09/2000

ETRS89 Cartesian ETRS89 Geodetic
X: 3667109.221 m Latitude: 54� 58' 44.8419'' N
Y: -103493.443 m Longitude: 1� 36' 59.6767'' W
Z: 5200153.199 m Ellipsoid height: 125.877 m

National Grid (converted by OSTN02/OSGM02)
Eastings: 424639.342 m
Northings: 565012.700 m
Height: 76.551 m (Orthometric height above MSL, Newlyn Datum)

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Bedson B1NZ2465

Type of mark: Surface Block Last visited by OS: 01/02/1999
Flush Bracket: Not available On Landranger sheet: 88
Grid reference: NZ246650 On Explorer sheet: 316
Access to mark: foot Permission required: Yes
Keys required: No

Coordinates of this station
Date of observation: 01/02/1999 Coordinates last checked: 01/02/1999
Planned next check: 31/01/2004

ETRS89 Cartesian ETRS89 Geodetic
X: 3667109.179 m Latitude: 54� 58' 44.8424'' N
Y: -103493.454 m Longitude: 1� 36' 59.6774'' W
Z: 5200153.167 m Ellipsoid height: 125.828 m

National Grid (converted by OSTN02/OSGM02)
Eastings: 424639.330 m
Northings: 565012.716 m
Height: 76.501 m (Orthometric height above MSL, Newlyn Datum)

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Comparing the coordinates, the 'Surface' block is 1.2cm West, 1.6cm North and 5cm lower than
the Active station which we know to be on the roof of the Bedson building.

The near-coincidence of position suggests that the block may have been replaced by the Active Station?

ted wrote:The near-coincidence of position suggests that the block may have been replaced by the Active Station?

I think that's exactly right. There are a couple of other instances where the newly added passives are within the general area of Active Stations (Teddington, I remember), and the case in Newcastle is particularly striking.

A second of these additional Passive Stations has now been found by peregrinus; the first that's a rivet on a milestone.

Bethersden