Mapping Mountains – Trimble Surveys – Stiperstones

 

12.12.20  Lion Rock (SO 365 981), Saddle Rock (SO 367 984), Stiperstones (SO 367 986, previously Trimbled), Devil’s Chair (SO 368 991), Pt. 503.5m (SJ 376 003) and Lord’s Hill (SJ 381 025) 

The Stiperstones (SO 367 986)

The Stiperstones are a distinct grouping of hills positioned near the English – Welsh border, viewed as a castellated spine from near distance with their quartzite rocky tors breaking the skyline of darkened heather. 

I’d been on many of these tors in the past and surveyed the highest known as Manstone Rock in November 2014.  One of the most distinct tors is the Devil’s Chair, and it was here many years ago on one of my only two roped climbs that I fell and dangled in mid-air, until my brother, who was top roping from above, appealed to me to get back on the rock as he was holding my full body weight.  I remember the dangling sensation was fun and that the falling off the rock part was a surprise and happened all too quickly. 

Today I was out with Aled, who had proposed a two car traverse of the higher ridge surveying each substantial tor exceeding 500m as we did so, with their cols also all surveyed to ascertain drop as well as height.  To do this we needed ideal conditions with no frost or ice, a light breeze and clear visibility.  We ended up with two of the three with the chilled wind stronger than hoped, but still adequate to safely position the surveying equipment on top of each tor in turn. 

We started from the south having left one car above the small community of Snailbeach which would give us the option to include Lord’s Hill at the end of the walk.  Getting out of the car we were met by a chilled wind, which was somewhat of a surprise as the forecast predicted just a breeze.  The forecast also predicted that the sun would break through toward late morning and as we gained height on the public footpath that heads toward the first of the tors; named as Cranberry Rock on contemporary maps and also known locally as Lion Rock, the cloud base was high, but in our immediate surrounds grey, with no sign yet of brighter conditions.  However, further in to Shropshire toward the south-east blue sky dominated. 

One of the main advantages of the Trimble GeoXH 6000 is its internal antenna; this means that accurate data can be gathered without the aid of a pole and external antenna, although the equipment can also be set-up in this fashion.  Therefore, the Trimble can be positioned on the exact highest point of any hill and as its underside is rubberised the friction between it and rock is good.  But, improvisation is also sometimes required, as some rocks are pointy whilst others overlook vertical drops and so over the years of operating this equipment I’ve learned that three small rocks and the aid of a rucksack usually overcomes most rock barriers.  The summit of Lion Rock was easily overcome for surveying purposes with the aid of Aled’s rucksack, which when laid flat beside this tor’s high point enabled the Trimble to be placed safely on it with two of the three small rocks I had brought wedged at its side to stabilise it, with its internal antenna aligned and positioned on the highest point of the tor. 

Gathering data at the summit of Lion Rock

The other main advantage of the Trimble GeoXH 6000 is that it only requires a minimum of two minutes data collection to produce an accurate result; this enables a hill walk with surveys conducted on the way, rather than a survey that just concentrates on one hill.  Both have their place in the magical (but also rather weird) world of hill surveying, but for me the former is now what works best. 

We surveyed two points for the position of the critical col adjoined to Lion Rock, the first on a rare patch of grass at the northerly base of the tor and the other where the main path leading up from the visitor’s car park joins the ridge path; this again was on a large patch of grass.  By now the high greyed cloud base had broken and a gentle winter sun was piercing the land, giving refreshing light that kept with us for much of the remainder of the day. 

The next tor on the surveying agenda is known as Saddle Rock and this is positioned between Lion Rock and Manstone Rock.  From our southerly approach it looked like a jumble of scree.  Circumventing the scree we wound our way around the back of the tor and headed up to its high point which consists of another well shaped rock. 

Saddle Rock (SO 367 984)

Within a couple of minutes the Trimble was set up with its internal antenna aligned with the tor’s high point with the sturdiest of my three rocks wedged on the leeward side of the equipment to keep it stable against the westerly wind.  By the time we’d sat, chatted and enjoyed some fruit cake that Aled had brought, seven minutes of data had been collected.  Once the equipment was closed down and packed away we headed down to the connecting col.  The col adjoined to Saddle Rock proved to be in a morass of heather, it was duly surveyed. 

Gathering data at the summit of Saddle Rock

The tors were now getting bigger in size with the two most impressive ahead of us, the first of these is the high point of the Stiperstones; Manstone Rock.  Having previously surveyed its summit the Trimble remained in its case whilst we scrambled to its top, with Aled taking a more difficult line to me.  It was wonderful to be back on its summit.  This was a place I occasionally visited with friends even before starting proper hill walking.  It was a local place that locals occasionally went to, me included. 

From the summit the westerly panorama opened up with patches of snow on the main Y Berwyn ridge and the forming of a shower toward our south-west.  I’d noticed on my previous visits to many of the Shropshire hills that showers formed toward Newtown and made their way down the Kerry valley before spilling their contents on the Shropshire hills, and again this was the direction that this shower was coming from.  However, it was still a distance away and even if it caught us it wouldn’t be for a while yet. 

The view north from the summit of the Stiperstones with the Devil's Chair on the left

After Manstone Rock is the Devil’s Chair, which is the most intricate summit of these tors with three distinct tops all vying for the accolade of its high point.  Before getting to grips with its summit we had its adjoining col to investigate.  Three positions were surveyed, the first amongst heather close to the main ridge path.  The second amongst a jumble of rock before an outlying tor almost of equal height and the third directly below the up thrust of rock that constitutes the main tor of the Devil’s Chair. 

One of three positions surveyed for the critical col of the Devil's Chair

A path led us around the westerly fringe of the tor and gained height toward its northerly summit, I hoped this would prove the highest as the thought of delicately picking my balanced way across the castellated top to the other possible high points did not enthuse me.  I would have been enthused a few years ago but I’m getting old now and am not as lithe and versatile as I once was. 

Before placing the Trimble on the first of these three tops, Aled Abneyed from its high point to the other two and concluded that the central one was just as high as the northerly, but it was so close that his recommendation was that all three needed surveying. 

Scrambling on the Devil's Chair

The first was relatively easy, as the high rock was relatively broad, I could stand on it although the wind did not help me with any lingering confidence I may have had.  As I set the Trimble up and wedged it in place with two of my rocks, Aled headed off to investigate the other two tops and left me hunkered down below the equipment as it beeped away gathering its individual data points as the wind blew across the hill.  I felt happy enough though, I was relatively safe and as long as being careful with where I placed my feet when the allotted data was gathered and stored I should survive the experience.  I was still unsure about the other two tops though, they looked a little scary. 

Hunkered down below the summit of the Devil's Chair patiently waiting for the Trimble to gather its allotted data.  Photo: Aled Williams 

I remember days long gone when I, along with various friends used to enjoy many a pint in the Vaynol Arms in Nant Peris, bed down in our tents in the near campsite and head to Pete’s Eats for breakfast the following morning, before a scramble either across Crib Goch, or perhaps the Bristly Ridge or any other than tempted our fancies.  When doing this on a weekly or monthly basis one’s mind and body become adjusted to the rigours required, those daunting drops can be coped with and as long as you don’t attempt anything outside of your comfort zone everything seems to go swimmingly.  However, when those weekly or monthly scrambling expeditions become a thing of the past and suddenly spring up in front of you, you suddenly realise that the confidence and balance and head for heights that you once had, has suddenly left your mind and body.  This can be worrisome when on rock, especially so when operating an expensive bit of surveying kit. 

Gathering data at the northerly of the three Devil's Chair tops

As I packed the Trimble away Aled called me over toward the second top of the Devil’s Chair.  This required a fine balancing act down, across and then up with large drops on either side, nowhere near as fierce as from Crib Goch, but nasty enough to do serious damage if one stumbled. 

Looking past the second top toward the third top on the Devil's Chair with Manstone Rock in the background

Once at the second top I positioned the Trimble in place and sat with Aled below the equipment with my feet wedged in place in a small gap in the rock.  It was a spectacular position to be surveying in, but I soon learned that the last of the three tops was even more precarious. 

This last top looked interesting to say the least and especially so when Aled said that he’d already visited it and was happy to wait whilst I negotiated a delicate balancing and wriggling act to get to its top.  Upon reaching its high point I wondered how on earth I was going to survey it.  I was now standing with my feet wedged firmly in small gaps and when I looked down all I could see was space below and then a jumble of rocks and heather further below.  This was to my right hand side, to my left was a greater drop, but thankfully the position my body was wedged in meant that looking down to my left was hard to do, this left me with the rather unusual comfortable thought that I could not see the greater drop, but I knew it was their and it was immediately beside me.  I decided that I should not move from my wedged in position, I would have to of course, but only after the Trimble had gathered and stored its all-important data. 

By placing one small rock under the bottom of the equipment and one either side of it the Trimble could be secured in place with its internal antenna aligned to the highest part of this third Devil’s Chair top.  However, I wasn’t going to trust its present position to these rocks as the wind was constant and if either the small rock at its base slipped or the wind dislodged it, the Trimble would fall to an untimely death, therefore as it beeped away gathering data I hunkered down below it and hung on to its rear end.  I’ve only had necessity to do this on a few summits in the past, one being Manstone Rock; the high point of the Stiperstones. 

Whilst collecting data I shouted across to Aled and asked him to take a few photos as I was not going to unpack my camera in the position I found myself in.  Within a few seconds he was beside me traversing rock that I didn’t think was there and then he popped up the other side of the tor pinnacle, I wondered how on earth he’d got there as all I could see were horrendous drops in to oblivion. 

Once the Trimble was safely packed away all I wanted to do was get back on to safe terra firma.  Even the thought of the shower which was now bearing down on the hill didn’t detract from the fact that large drops and survey equipment are not comfortable bed fellows. 

The Devil's Chair from the south

A few specks of rain whisked their way over this part of the hill as we re-joined the main ridge path heading ever northward, but thankfully the main shower cloud was further to our south.  Ahead of us lay a 503m unnamed on the map, map heighted hill and before surveying its summit we now had its col to investigate.  This proved an easy affair to pinpoint and proved to be near a large cairn marking the meeting of paths. 

As col data were gathered Aled headed up to the next rock tor which rose out of the heathered depths below.  During the walk the main ridge had been scattered with people, some on the main path, others scrambling on the Devil’s Chair, couples, singles, dog walkers and a few mountain bikers, all out enjoying the favourable weather, but there seemed to be only two hill surveyors.  I sometimes find this a little odd, as it’s a very enjoyable pastime, one which I would highly recommend. 

Gathering data at the col of Pt. 503.5m

We were nearing the end part of the walk, all the daring do and vertical drops were thankfully behind us with just a soft heathered hill to survey and the option of Lord’s Hill at the end.  We took two data sets from the summit area of the 503m map heighted hill, one on a small knoll and the other close to a prominent cairn.  We favoured the former as the higher.  From here the views opened to our north with The Wrekin standing aloof as a singular up thrust whilst the valley below beckoned. 

Gathering data at the summit of Pt. 503.5m (SJ 376 003)

From the summit we headed down through soft heather to join the main path which was now a track with a multitude of mountain bikers heading up it.  This led ever downward with our shadows now elongated and accentuated against beautiful winter colour. 

Late afternoon light with Lord's Hill in the background on the left

The track led down to the minor paved road where my car was parked.  We checked the time and then looked at the connecting col for Lord’s Hill which was in a pastured grazing field beside the minor lane.  Deciding to leave this for our return we headed up the last hill of the day, accessing a track through a gate which then would its way upward. 

The summit of Lord’s Hill is in utter contrast to the others we had encountered on the walk, as it consists of closely cropped grass.  We each assessed the lay of land and after choosing placement for the Trimble it was soon set up gathering data.  I enjoyed this last hill, it felt good to tag it on at the end, even if it was at contrast to the other summits; it was a fitting end to the day’s walk. 

Gathering data at the summit of Lord's Hill

All that remained was to reverse our inward route down the track to the minor lane, and whilst I headed in to the adjoining field Aled headed to the car, directing me toward the col’s critical point as he did so. 

And at the end of the day.............

During the last of sixteen data sets gathered on the walk I stood and savoured the view as behind the survey equipment was the most beautiful yellowed sun set.  It had been an excellent day on the hill and this was an ideal way for it to end; savouring a sun set whilst the survey equipment gathered the last data set of the day. 

 

Survey Result: 

 

Lion Rock  

Summit Height:  506.7m (converted to OSGM15)

Summit Grid Reference:  SO 36539 98110

Col Height:  501.6m (converted to OSGM15)

Col Grid Reference:  SO 36569 98157

Drop:  5.1m

Dominance:  1.01%

 

 

Saddle Rock  

Summit Height:  527.1m (converted to OSGM15)

Summit Grid Reference:  SO 36732 98480

Col Height:  522.1m (converted to OSGM15)

Col Grid Reference:  SO 36783 98570

Drop:  5.0m

Dominance:  0.96%

 

 

Stiperstones  

Summit Height:  537.0m (converted to OSGM15, from previous Trimble GeoXH 6000 survey)

Summit Grid Reference:  SO 36753 98643 (from previous Trimble GeoXH 6000 survey)

Col Height:  179.0m (LIDAR)

Col Grid Reference:  SO 33951 91045 (LIDAR)

Drop:  358.0m (Trimble GeoXH 6000 summit and LIDAR col)

Dominance:  66.67% (Trimble GeoXH 6000 summit and LIDAR col)

 

 

Devil’s Chair  

Summit Height:  529.6m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SO 36838 99152 (Trimble GeoXH 6000)

Col Height:  519.6m (LIDAR)

Col Grid Reference:  SO 36828 99100 (LIDAR)

Drop:  10.0m (Trimble GeoXH 6000 summit and LIDAR col)

Dominance:  1.89% (Trimble GeoXH 6000 summit and LIDAR col)

 

 

Pt. 503.5m  

Summit Height:  503.5m (converted to OSGM15)

Summit Grid Reference:  SJ 37676 00359

Col Height:  481.0m (converted to OSGM15)

Col Grid Reference:  SJ 37329 99909

Drop:  22.5m

Dominance:  4.47%

 

 

Lord’s Hill  

Summit Height:  364.3m (converted to OSGM15)

Summit Grid Reference:  SJ 38191 02516

Col Height:  314.5m (converted to OSGM15)

Col Grid Reference:  SJ 37998 02185

Drop:  49.8m

Dominance:  13.66% 

 

 

For details on the survey of the Stiperstones

For further details please consult the Trimble Survey Spreadsheet