Fife Trig Pillars

The Ordnance Survey triangulation pillar is well known to hill walkers as it often adorns a hill summit or is located very close to the summit. However, the trig pillar is much more wide spread, with the lowest in Scotland being at a height of just 2.6m above sea level. The concrete trig pillars as we know them today were constructed from 1936 through to the 1960’s as part of the Ordnance Survey’s retriangulation of Britain, At the time of their construction all pillars would have had clear views to neighbouring pillars. Sadly modern forestry and land use changes mean this is no longer guaranteed!

The pillars are often referred to as trig points but the term trig point (triangulation point) is actually much wider than the pillar so beloved of hillwalkers as it includes buried underground blocks, bolts, and prominent landmarks (and much more) all of which were used by the OS surveyors to produce accurate mapping. Trig pillars can be found and “bagged” by any enthusiastic person with some being easily accessible from the roadside. However, some of the other types of trig point require considerably more dedication.

There are 58 intact OS triangulation pillars in Fife (and two that have been destroyed). However, two of the 58 have been toppled and moved, and are currently abandoned in fields.

Each trig pillar (though there are some exceptions) is uniquely identified by means of its flush bracket number, a metal plate on the side of the pillar. This is usually a 4-digit number beginning with S. Whilst the pillar was used to measure “the shape of the land”, the flush bracket was used to determine its height (a process known as levelling). As well as trigs, flush brackets can be found on walls and buildings throughout the country and are known as benchmarks. Other types of benchmarks also exist but that is a whole different topic!

In Fife there are three fundamental benchmarks which are highly accurate benchmarks. These take the form of what looks like a mini-trig. They are small granite pillars about 12 inches high with an underground chamber. Being small, they get hidden in long grass and vegetation so can be more of a challenge to find than the usual trig pillar.

In today’s digital era, the majority of these concrete pillars, along with the benchmarks, are now redundant having been superseded by satellite based surveying. However, a number of pillars have been repurposed as “passive stations” and are used in the OS’s modern GPS network. There are three such stations in Fife and they can be identified by a wee plaque telling you it is a criminal offence to damage it! These pillars being:

In addition the fundamental benchmarks mentioned above are also part of this modern network.

In the era before satellite based surveying, the triangulation stations were used to form a network of triangles the length and breadth of the country. The pillars were used as an accurate and stable base on which could be placed the measuring equipment. By measuring the angles between points and knowing the distance of one side of the triangle, it was possible to calculate (using trigonometry) the other distances and thus produce accurate mapping. Triangulation itself was originally used in Britain in the 18th and 19th centuries (the Principal Triangulation) but the original network was somewhat inconsistent and haphazard. In 1936 the retriangulation was started and the trig pillar as we know it today was born. A diagram of the composition of a trig pillar is available on the OS blog.

Trig pillar map
NameFB numberGrid ReferenceLocation
Central Fife trigs
West LomondS1615NO 19730 06639Hill
Keir BraeS3138NT 23931 94624Forest/woods
Benarty HillS3140NT 15379 97881Hill
East AuchmuirS3142NT 22035 99898Grazing field
StrathoreS3144NT 26203 97740Field
DrumainS3149NO 20703 04521Forest/woods
Duniface HillS3153NO 35009 01085Forest/woods
DalginchS3156NO 31204 02492Grazing field
HiltonS3158NO 30514 05434Field
Rhind HillS3160NO 25632 03930Grazing field
Clatto HillS3162NO 35571 06518Forest/woods
East LomondS3163NO 24447 06094Hill
Woodbank FarmS4216NT 33953 98841Field
East Fife Trigs
Kellie LawS1611NO 51744 06458Hill
CassingrayS3150NO 48600 07659Field
Coalyard HillS3151NO 51088 00971Field
Largo LawS3152NO 42706 04979Hill
Kincraig HillS3161NT 46775 99914Rough ground
Municipal Golf CourseS4215NO 38991 01739Golf course
BruntshielsS4769NO 43302 10288Grazing field
Easter BalrymonthS4792NO 53314 14397Field
Drumcarrow CraigS4809NO 45938 13205Hill
North ClattoS4810NO 43623 15735Grazing field
LochtonS4811NO 58510 09455Field
North Fife Trigs
KilwhissS4768NO 27728 09801Destroyed
Grange HillS4770NO 25848 14442Forest/woods
Lumbennie HillS4771NO 21735 15540Forest/woods
Dunbog HillS4773NO 28710 16433Grazing field
Mount HillS4774NO 33112 16490Hill
BallomillS4775NO 33108 10908Rough ground
Myrecairnie HillS4788NO 36968 18234Forest/woods
Hill Of TarvitS4789NO 37546 12061Hill
Tay MountS4790NO 34793 22431Grazing field
Lucklaw HillS4791NO 41895 21630Hill
Normans LawS4793NO 30501 20229Hill
Craigie HillS4794NO 44535 24424Golf course
NorthfieldS4795NO 42977 28442Field
Peace HillS4823NO 38477 25535Field
Yellow HillS5918NO 15376 09139Field
Pitlour HillS5920NO 20795 12683Hill
South Fife Trigs
CraigencaltS3145NT 26115 87867Field
Orrock HillS3146NT 22361 88486Rough ground
Pilkham HillsS3164NT 18963 89597Grazing field
BankheadS3168NT 16434 85800Field
Hill Of BeathS3169NT 13768 90057Hill
Castlandhill ReservoirS3239NT 11870 82759Compound
Bogie MainsS4218NT 25735 93312Residential
Tyrie FarmS4219NT 26607 89447Field
Fleet Recreation GroundS4411NT 11181 83224Destroyed
West Fife Trigs
ThorntonS3166NT 12626 93464Forest/woods
Kingseat HillS3167NT 10468 88826Residential
GallowridgeS3201NS 97567 88120Rough ground
Kinniny BraesS3202NT 04037 84312Inaccessible
Maggie Duncans HillS3205NS 93956 90951Grazing field
Knock HillS3207NT 05349 93761Hill
Cult HillS3208NT 02691 96276Hill
Carneil HillS3237NT 03277 88806Grazing field
Dover HeightsS4412NT 12293 85531Rough ground
Pitreavie Golf CourseS4414NT 11051 85661Golf course
Keirsbeath RidgeS4416NT 12579 90068Residential

Fundamental Benchmarks

NameGrid ReferenceBenchmark Database Link
St AndrewsNO 5344 1489https://www.bench-marks.org.uk/bm1153
RosythNT 1109 8233https://www.bench-marks.org.uk/bm1142
KinghornNT 2725 8842https://www.bench-marks.org.uk/bm1092

Apart from the MOD trig, the Fife trigs present little in the way of access problems. However, many of them are in working countryside so it is important to bear in the mind the provisions of the Scottish Outdoor Access Code. In particular it is worth noting that access rights do not extend to farm yards, private gardens, quarries, and working areas. Some of the trigs are in arable fields where crops may be present and you should stick to the field edges to avoid walking on crops. If it is not possible to access the trig without walking over the crop, come back at another time of the year or view from a distance. Keep dogs under close control at all times but especially so when livestock are around.

Reaching a trig may involve squeezing through barb wire, negotiating electric fences, overgrown vegetation, inquisitive cattle, and mud! Use gates where possible and leave them as you find them. If you need to climb a gate do so at the hinged end as this reduces the risk of damage. Winter and Spring are better than late Summer and Autumn for the heavily vegetated ones.

Why not post a trig log on to the TrigpointingUK website? Record your visit, make a note of the condition you find the pillar in and any damage it has suffered, add a few notes on what route you used to reach it (helpful for people in the future) and optionally include a photograph of it. You can even give it a score out of ten! If you start visiting a large number it will be a helpful record of where you have been.

References / Further Reading: