Tuesday 11 November 2014

Mapping Mountains – Trimble Surveys – Stiperstones


05.11.14  Stiperstones (SO 367 986) and Nipstone Rock (SO 356 969)  

Nipstone Rock (SO 356 969) and the Stiperstones (SO 367 986)

The Stiperstones is one of the jewels of Shropshire, its quartzite rocky torred summit ridge being a distinctive landmark for many miles around.  The area is designated a National Nature Reserve and is classed as a Site of Special Scientific Interest.  It is a place that I’ve visited many times, always enjoyed but rarely investigated as although close to where I live it is the pull westward to inner Wales that interests me more.

Having surveyed the critical col earlier in the day, I parked in the large car park at SO 369 976 and headed northward on the main path upto the highest point.  The last time I’d been this way was with Bob Kerr as we prepared to do two filmed interviews on his seven summits attempt prior to him going to Everest.

Gathering data at what I judged to be the col of the Stiperstones

The path is a green haven amongst copious amounts of heather, when cresting the ridge it becomes rock invested as it diverges from its north-western direction to a northerly, passing a jumbled rock outcrop before heading up toward Manstone Rock and the high point of this part of Shropshire.  

This rock tor is impressive in shape with a broken vertical eastern side giving way to an easier angled western side sloping down to hillsides comprising heather and the lowlands beyond.  Its angled shape is accentuated by the summit trig pillar which stands aloof of the natural rock, cemented in place looking out on all below.

The summit tor of the Stiperstones

I knew that this survey may proof difficult as some of the natural rock surrounding the trig pillar was pointed and the drop in most directions was precipitous down onto bounder fields.  I did not want to test the Trimble’s strength against a twenty foot vertical drop onto boulders but I did want to find out how high this hill is, as Ordanance Survey maps give it a 536m summit height, whilst the OS Trig Database give the adjoined flush bracket a height of 537.362m.  When listing The Fours we used the Stiperstones as a Cardinal Hill and listed it as being 537m high.  I hoped a secure placement could be found for the Trimble, one where its life would not be cut short.

I approached the rock tor from the north having walked the length of its eastern face, the tor can be ascended on good rock scrambles but with a camera and Trimble I wanted an easier and less exciting way to the high point.  By the time I stood on top the sky was ablaze in blue.

The eastern profile of the Stiperstones summit tor

There were two options for the highest natural rock; one was relatively flat and on the northern side and adjacent to the base of the trig pillar’s plinth, whilst the other contender was on the south-east side of the plinth base and about one metre from it.  I stepped back carefully and looked at both with the trig central in view; the one on the right looked slightly higher.  This is the pointed rock on the south-easterly side of the trig pillar.  Unfortunately this rock has a big drop directly beneath it.  I wondered if the Trimble would retain its position if its internal antenna was aligned with its highest point; there was only one way to find out.

The Trimble was placed on the rock to the right of the trig pillar plinth

As I placed the Trimble on the rock I was all too aware that one slip and it may be crushed on the rock below, so as I set it up I crouched beneath and held its rear end and the sound of each data point seemed to manifest in more panic from its owner.  During data collection two people passed below the rock tor and shouted up asking if I was all right as I was hunched up in a ball with one arm extended toward the upper rock with a big drop immediately below me.  I laughed and thanked them for their concern and tried to explain what I was doing.  I met them later as I headed toward Nipstone Rock, they had both completed the 600m Terry March Welsh listed hills but probably had never encountered a rolled up hunched person seemingly in difficulty perched over a vertical drop and unmoving. 

As the five minutes of data collection was completed, I switched the Trimble off and edging backward I quickly took a number of photos and then grabbed it and put it back in its case.  The underside of the Trimble has a rubberised surround which is ideal for rock placement as the friction between rubber and rock means that the equipment can gather data when almost positioned vertically.  However, slimy rock is not ideal as the rubber surround easily slips.  Thankfully today the rock was dry and the Trimble survived, but I still had Nipstone Rock to visit and I hadn’t got a clue what the summit of that rock tor was going to be like.

Perched over a big drop the Trimble gathers data from the summit of the Stiperstones

I made my way down from the trig pillar on the southerly side of the rock tor and re-joined my inward path and continued southward when it headed back to the car park.  Ahead lay more rock tors and two climbers sorting their gear on the top of one.  There are many small climbs on these tors; some are documented in ‘Rock Climbs in the West Midlands’ by Doug Kerr which is published by Cicerone Press.

The southern side of this ridge proved a delight with a narrow path amongst heather passing rock outcrops with a lowering sun in front casting gently greyed and blue tinged silhouettes of hills.

The path led down to the road I had driven on earlier when making my way from the survey of The Cold Piece to the survey of Walker’s Bank.  On the opposite side of the road the footpath continued on to a closely cropped grass field with the attendant house of Upper Knolls Farm overlooking what is the critical col for Nipstone Rock.  It was Nipstone Rock that was my next objective.

I assessed this col before continuing, as its survey could wait until I retraced my route back to the lane.  The footpath continued into a wood and out again onto open hillside, this part of the hill had recently been reclaimed from the intrusion of a conifer plantation and had an interpretive notice board proclaiming the virtues of the Back to Purple project.  The 1960’s conifer plantation was felled in 2001 and 2006 and Hebridean Sheep introduced to eat the seedling trees sprouting on the bare ground after the conifers were felled.  The title of the project refers to the habitat of moor and heath and the heathered hillsides taking over from wooded plantations. 

The Nipstone Nature Reserve is on land that has been re-claimed from conifer plantation

The Hebridean Sheep must have done a good job as I didn’t come across one sapling tree or rotting tree slump, remarkably this land is now luxuriant in heather and relatively easy to walk through.  It also has a large outcrop of rock which I wanted to measure the height of, this is Nipstone Rock which had been in my mind for most of the day as I didn’t even know if I could get to the top of it, let alone survey it.

As I left the path through the wood Nipstone Rock loomed on the horizon to my right, I bi-passed it and walked through the heather to its adjacent hill which I also wanted to survey.  Both this and the outcrop of rock have uppermost c 445m ring contours on current Ordnance Survey maps with the heathery adjacent hill to Nipstone Rock having a 1461ft height given it on an old Ordnance Survey 1:10,560 map.  When compiling The Fours Aled and I had debated which to list as the prioritised summit; rock outcrop or heathery summit, we’d opted for the former.

When I arrived on the heathery summit I came across a pile of large rocks that looked as if they may be the high point of the hill, I gave most a good kick and all moved, I proceeded into the heather and came across a small embedded rock which I judged to be the high point of the hill, set the Trimble up, collected five minutes of data, relaxed in the afternoon sun and peered out toward Nipstone Rock.

Gathering data at the c 445m map high heathery summit adjacent to Nipstone Rock

Next objective: Nipstone Rock

As I arrived at the base of Nipstone Rock its sides could now be seen to give relatively easy access to its high point, this still required hand on rock and proved a welcome distraction from the heather clad hillsides I’d been walking on for the last hour.  Although I hoped the very highest point would give good protection for the Trimble as again, the drops in most directions were dramatic and would test the life span of the machine if the breeze picked up and catapulted the equipment thirty foot down to the rocks below.

Nipstone Rock (SO 356 969)

The very highest point proved not ideal, near to it a slightly lower rock gave ideal placement for the Trimble but the high point meant that a strengthening wind may catch the Trimble from below and topple it over to the rocks beneath.  I tried my utmost to place it as firmly as I could with its internal antenna aligned to the very highest point and once the 0.1m accuracy had been attained I pressed ‘Log’ and nestled myself in a comfortable notch below and tried not to look up, all I could hear was the steady rhythmic sound of the machine as each epoch second of data collection was gathered. 

Gathering data at the top of Nipstone Rock

Peering out toward Corndon I was only too aware that grasses growing out of the rock just beneath me were waving in the wind, I just hoped that the sound of the Trimble collecting data would continue and not be cut short by a crashing noise as it slithered off its perch to the rocks below.

Looking out toward Corndon

As the five minutes of data collection finished I scrambled back to the top, switched the equipment off, quickly took some photos, packed the Trimble away and scrambled back to the bottom of the rock.  Just one survey remained and that was the critical col for Nipstone Rock.

It's a long way down from the top of Nipstone Rock

I retraced my steps through the heather and the footpath through the wood to the closely cropped grassy field adjacent to the narrow lane, and as the sun cast out from the blue sky I tried to discourage the local sheep from making friends with a data gathering Trimble.

Gathering data at the critical col of Nipstone Rock

Once packed away I re-joined the narrow lane and happily made my way toward the car, to the south the shadows on green hills made gentle patterns as late afternoon November light accentuated their contours.  It had been a very fulfilling day.

Late afternoon November light

LIDAR col image of the Stiperstones (summit at SO 367 986)


Postscript:

Since the survey of these hills full LIDAR coverage is now available.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height and positional data that is now freely available for England and Wales.  Consequently the numerical details for these hills have been analysed using this technique, resulting in the LIDAR height and position for the col of the Stiperstones being prioritised over that produced by the Trimble GeoXH 6000.  



Survey Result:


Stiperstones 

Summit Height:  537.0m (converted to OSGM15, Trimble GeoXH 6000)
   
Summit Grid Reference:  SO 36753 98643 (Trimble GeoXH 6000)

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)





Nipstone Rock 

Summit Height:  447.0m (converted to OSGM15) (significant height revision)
   
Summit Grid Reference:  SO 35668 96957

Col Height:  423.9m (converted to OSGM15)

Col Grid Reference:  SO 36160 97549

Drop:  23.0m 

Dominance:  5.15%




For details on the 2nd visit to the Stiperstones


For further details please consult the Trimble Survey Spreadsheet 



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