I guess most outdoorsy folk will be familiar with the ubiquitous triangulation (trig) pillars scattered across the hilltops of Britain. They were erected (over 6,000 of them) in the 1930s as part of a major project to refine the accuracy of the Ordnance Survey mapping.
Most trigs are angular tapered pillars, around four feet high, made of concrete, but others, including examples in our own area, are faced with stone, and in Scotland some are cylindrical. All have an identification plate and a resting place, the ‘spider’, for a surveyor’s theodolite to be placed securely on top.
Serious mapping of Britain had started in the eighteenth century for military purposes – the Board of Ordnance was in effect the Ministry of Defence of its day – using the mathematical properties of triangles to create an accurate mesh of defined points across our island. The first baseline for that original exercise is now buried under the sprawl of London Heathrow Airport.
Today the pillars are obsolete; satellite observations and other modern techniques are used to update and refine maps. Some trigs have disappeared altogether, others are buried in brambles or shielded by trees, so their view of the surrounding reference points used for the surveying work is completely lost.
But for hillwalkers they still make a useful landmark (since they are shown on maps) to confirm one’s location on a misty day, or as a clear objective when hiking to the top of the fells. However, a word of warning; they are not always on the exact peak. In a few cases this is because the true summit is not easily reached – I can think of a Tor on Bodmin Moor in Cornwall where you need bouldering skills to safely get to the absolute top (and even getting to the trig is a bit of a clamber).
Elsewhere, it’s because a highest point is in the middle of a plateau and doesn’t give a good view to the next reference location.
This is the case on quite a few of our Yorkshire hills, both Great Coum near Dent and Baugh Fell above Garsdale for example, while Fountains Fell only has trigs on its outlying shoulders of Knowe and Darnbrook. And the pillars are not always very high up – there is one in the East Anglian fens which is actually one metre below sea level!
For we Settleites, our three nearest trig points make destinations for very pleasant outings. Closest to the town (and highest of the three at 440 metres above sea level) is the pillar on Warrendale Knotts which is a short scramble off the Dales High Way and can be linked with a visit to the Victoria Cave. It gives great views up Ribblesdale and across to Ingleborough.
The second local favourite is Smearsett, easily reached from the footpath from Little Stainforth over to Wharfe and Crummack Dale. A walk here can be combined with refreshment at Elaine’s in Feizor or at the Knight’s Table. Both these points are amid our craggy and dramatic limestone scars.
A slightly gentler option is Hunter Bark above Mearbeck to the south of the town. Take the train or bus down to Long Preston then ramble over the Pennine Bridleway back to Settle. The trig is just a few yards west of the route with a great outlook across to Pendle and Bowland. All these trig points are on Access Land and close to designated rights of way so there are no issues with getting legitimately to the exact location.
If you do puff up the trail to any of these splendid vantage points, spare a thought for the men who, over eighty years ago, carted tools and cement up to the heights to build the pillars, and the surveyors who followed with bulky surveying equipment, to make Britain probably the best mapped nation in the world.
Top Photo: The summit of Warrendale Knotts seen from the Dales High Way
