© John Talbot. No images may be copied, downloaded or reproduced without prior written permission.

Explanation of Types

Type Description Examples
Flush Bracket These are rectangular metal plates affixed to triangulation pillars, walls, buildings etc. If they are not affixed to a triangulation pillar they are often referred to as Non-Pillar Flush Brackets (NPFB). They are about 6" x 3" in size and the location of most of them is known through Ordnance Survey (OS) records. Each Flush Bracket (FB) has a unique serial number which makes them highly 'collectable' and there are several numbering types.  
  One to four figure number
The earliest FBs you can find and date from 1912-1921. Numbered from 1-3000. A few can be found on triangulation pillars.
Introduced in the 1920s these are found on pillars and as NPFBs. There are two sub-types, S below the number and S left of the number.
First appeared in 1936. Unlike S-series brackets numbers below 1000 do not have leading zeroes. Used extensively in Scotland and never found on triangulation pillars.
Just sixteen brackets used in London in the early 1930s.
  Five figure number
These are effectively S-series brackets above S9999 where they ran out of room for the S (S-below was discontinued as the S interfered with the measuring equipment).
Projecting Bracket An early type of metal bracket used for a short time before the introduction of flush brackets. They are all the same and have no unique attributes. Reading, Greyfriar's Church
OSBM Bolt Used alongside the G-series of flush brackets these are placed where there wasn't a convenient building or wall to provide a vertical surface on which to affix a flush bracket. They are domed metal bolts about 1" (50-60mm) in diameter fixed to horizontal surfaces engraved with OSBM and the benchmark symbol. Caban Coch Dam
Cut Bench Mark By far the most common type. Used and made from the 1800s to around 20 years ago. You won't have to walk (or drive) very far in any village, town or city in Britain before you spot one of these. Chiseled into stone, brick or wood on all sorts of vertical structures. A familiar horizontal levelling line with a three line arrow pointing towards it (usually upwards). Each one is unique depending on the mason who cut it, some are plain, some decorated. Some roughly cut, some exquisitely cut with high accuracy. Some small, some huge. Wallingford, 60 High Street
Cut Bench Mark with Bolt Old and rare these have a metal bolt screwed either alongside the horizontal cut of a cut bench mark or at the point of the cut arrowhead. Usually has what appears as a screwhead horizontal in the head of the bolt. These are highly prized by benchmarkers. Dorchester Abbey
Rivet Usually found on horizontal surfaces these are cut marks with a small metal domed brass rivet at the apex of the cut arrowhead marks. Swyncombe, Icknield Field
Pivot Fairly rare these are used on horizontal surfaces such as soft sandstone, where the insertion of a rivet would break away the stone. They consist of a small hole or depression cut to take a pivot, a steel ball bearing of 5/8" diameter (16mm). In use, the pivot is placed in the depression and the levelling staff held on top of the pivot. Sutton Bridge
Fundamental Bench Mark These are the key to the whole levelling of the UK. Granite blocks with large domed metal caps. Just like an iceberg this is just the tip of a fairly extensive underground structure. Highly accurate height stations still used today as the baseline to levelling. Conwy
Triangulation Pillar Familiar to anyone who walks in the British countryside, these can often (but not always) be found at hilltops. Most have a flush bracket affixed to one side. Huntingland

Triangulation Pillar

Hinksey Halt Footbridge
2987 - White Horse Hill
S1522 - Cutsdean Hill
S1627 - Great Ormes Head
S1633 - Holyhead
S1652 - Barton Stacey
S1693 - Fullerton
S1834 - Beachy Head
S1892 - Britwell Hill
S1984 - Chalk Farm
S2141 - Massingham
S2414 - Waden Hill
S2477 - Stoke Hill
S2479 - Mount Joy
S2517 - Wroxall Down
S2521 - St Catherines Hill
S2526 - East Garston
S2532 - Matcham Park
S2590 - Pentridge Hill
S2716 - Lyndhurst
S3006 - Calton Hill
S3121 - Oswestry Station
S3147 - Lickey Hill
S3545 - Black Pill
S3569 - Hips Heugh
S3689 - Night Fold Field
S3697 - Ross Castle
S3700 - Hurst Hill
S3738 - Blewburton Hill
S3763 - Huntingland
S3874 - Fox Hatch
S3986 - Wilmington Hill
S4365 - Gog Magog
S4472 - Hertford Heath
S4511 - Waddesdon Hill
S4667 - Down Hill
S4734 - Fitty Hill
S4781 - Dunnet Head
S4909 - Nuffield
S5074 - Coton
S5279 - Beeston Hill
S5293 - Battle Hill
S5529 - The Begwns
S5540 - Brightwell Barrow
S5724 - Lowbury Hill
S5725 - Farnborough
S5727 - Compton
S5726 - Lough Down
S5729 - Grims Ditch
S5730 - Pit Plantation
S5731 - White Hill
S5796 - Penrallt-Y-Gardde
S5798 - Kings Bush
S5826 - Fore Down
S5828 - Steventon Hill
S5882 - Rogues Lane
S5907 - Crafts Hill
S5952 - Sutton
S6076 - Woolsbarrow Camp
S6168 - Greenmoor Hill
S6207 - Monument Hill
S6244 - Hill Farm Winchelsea
S6489 - Winshields
S6678 - Duncansby Head
S6764 - West Farm
S6778 - Great Tew
S6936 - Greenham
S7157 - Broom Farm
S7288 - Herstmonceux
S7294 - Hermon
S7305 - Parys Mountain
S7307 - Pendefig
S7324 - Mynydd Bodafon
S7328 - Aberffraw
S7330 - Bryn Euryn
S7542 - Castle Rising
S8068 - High Bridge Farm
S8142 - Lands End
S8635 - Oakington
S9325 - Breck
S9369 - Monk Field
10639 - Noup Head
10640 - Mull Head
10644 - Whitelet
10646 - Langskaill
10677 - Wideford Hill
10738 - Dunwich Common
10814 - Gayfield
10850 - Glimps Holm
11155 - Littlebury Hedge
11492 - Transit Meridian
11666 - Solar
11798 - Inkpen


All the bench marks I have logged. See my profile on the Bench Mark Database.

Show Help

By Type

Explanation of Types
Flush Bracket(188)
Projecting Bracket(6)
OSBM Bolt(10)
Cut Bench Mark(1285)
Cut Bench Mark with Bolt(73)
Fundamental Benchmark(8)
Triangulation Pillar(93)
 Show All(2270)

By Year

2018 (153)
2017 (253)
2016 (386)
2015 (409)
2014 (256)
2013 (120)
2012 (21)
2011 (78)
2010 (54)
2009 (84)
2008 (79)
2007 (248)
2006 (16)
2005 (39)
2004 (72)
2003 (2)