Mapping Mountains – Trimble Surveys – Cilfaesty

10.03.15  Cefn Hepreas (SO 267 787), Llanfair Hill (SO 255 785), Llanfair Hill (SO 254 794), Pt. 425.6m (SO 243 802) and Stoney Pound Hill (SO 234 808)   

Llanfair Hill (SO 254 794)

Another foray to the beautiful Shropshire hills, this time to the west of Clun.  I parked on the grass verge a few metres to the east of Springhill Farm (SO 255 808) where three or four cars can just be squeezed away from the narrow lane that overlooks the River Clun to the north.

The first hill I wanted to visit was Cefn Hepreas and I had planned to use footpaths that headed downhill toward a farm named Burfield, but as I had a last study of the map I decided to walk on the lane toward Llanfair Hill and use the Jack Mytton Way, which is a 150 km (93 mile) long distance path, and contour around the northern bulk of Llanfair Hill.

As I set off the sounds and warmth of spring permeated the quiet Shropshire hills, there’s always an awakening this time of year with new growth and sounds not seen or heard since the autumnal months. 

Just to the east of the lane the earthen bank of Offa’s Dyke reared up, in some parts it was overgrown with gorse and heather, but mainly it was just of grass.  The Dyke is named after Offa, the 8^th century King of Mercia who is reputed to have ordered its construction.  In its time it delineated the lands of Anglican Mercia from those of the Welsh kingdom of Powys.  Its construction must have taken many years and it is one of the ancient historical jewels of Britain.

The earthen embankment of Offa's Dyke delineates the old boundary of Anglican Mercia and the Welsh kingdom of Powys.  Nowadays this part of the dyke overlooks the sleepy Shropshire countryside

I turned off the lane just beyond Springhill Cottage onto the Jack Mytton Way, this headed east and straight through part of the Dyke as it snaked its way up and over the landscape.  When constructed the Dyke was in parts 20m (65ft) wide (including its flanking ditch) and 2.4m (8ft) high.  As I walked up it and peered out and watched it forever meander onward I wondered what the ancient landscape must have once looked like and how the kingdoms of Britain were separated by its construction.

Beyond the Dyke my chosen route skirted the northern flank of Llanfair Hill and swung southward toward Cefn Hepreas, in part this route was on a good path, and then through muddy fields with friendly horses before I crossed a boggy stream and walked up the steepening slopes to the summit of the first hill of the day.

As the Trimble gathered data from what I judged to be the high point of Cefn Hepreas I sauntered a few metres down the hill to take photos of Rock Hill (SO 278 792) which stood across an intervening valley.

Gathering data at the summit area of Cefn Hepreas with Rock Hill in the background

Once the Trimble had been packed away I walked down to the connecting col with Llanfair Hill, which proved to be a methane gassed bog, and the more I walked up and down trying to judge the place where the hill to hill and valley to valley traverse met, the more methane was discharged from its boggy realm.  Once I picked my spot I stomped the reed grass down and set the Trimble up, by now my watch had stopped so I catalogued the time of each survey from the clock in the Trimble.

Somewhere in the bog is the Trimble gathering data at the col area of Cefn Hepreas

The view of Cefn Hepreas from its connecting col

The next hill I wanted to visit was Llanfair Hill which is given a 432m summit spot height on Ordnance Survey maps, about 1 km south of the 432m point the Ordnance Survey also spot height another point with a height of 431m with a 430m trig pillar also close to this point.  Because of the margin of uncertainty applied to the surveying method the Ordnance Survey use to obtain their beige coloured spot heights, it means that the lower spot heighted hill could in fact be higher on the ground, because of this I wanted to survey each of these three points. 

As the Trimble gathered data at the 431m map heighted point, followed by the high ground beside the trig I looked out toward where the 432m map height point on Llanfair Hill is situated and visually dismissed these first two points as being lower.  As data were gathered I stood and waited, listening to the spring song of Skylarks as they heralded the changing season.

Beyond the trig a track heads north adjacent to the Dyke, which looked impressive against the blue of sky as its rounded shape bulged out of the land.  There are one or two gates that give access to the Dyke from this track and before using the second one which would give access to the top of Llanfair Hill I chatted with one of the local farmers who was delivering a number of sheep from his wagon out onto their grazing field.  We chatted for a few minutes and he kindly told me where the gates were positioned so I could visit the summit of Llanfair Hill.

Offa's Dyke with the summit area of Llanfair Hill in the background

Delivering sheep to their grazing field

Considering the relative expansive nature of the summit area of Llanfair Hill, its high point is easily identified, and once five minutes of data were collected I re-traced my steps back through the gates onto the track which led down to the hill’s connecting col.  I’d driven a Google car up this track the previous evening and noted that the more easterly option for the col looked lower when compared to the more westerly option with each having a small 395m contour ring between them.

Gathering data at the summit of Llanfair Hill (SO 254 794)

Both options were Trimbled but each required patience as the Trimble took an age to attain its 0.1m accuracy before data can be logged, with the second more westerly option for the col taking over 25 minutes for it to slowly creep down to the required accuracy.  During this I chatted with a local couple who were out walking their dog and enjoying the day’s sunshine.

The critical col of Llanfair Hill (summit at SO 254 794)

I met another couple as I headed up the connecting track to my next hill of the day; they were from Cornwall and spent much of the conversation passing comment on how wonderful the Shropshire countryside was.  The next point surveyed was the summit of a 400m Sub-Four and I placed the Trimble on a flattened mole hill and waited for the allotted data to be gathered.

Gathering data at the summit area of the 400m Sub-Four

This hill’s connecting col is adjacent to the old farm of Stoney Pound and is due north-west of its summit, driving the Google car around these lanes had indicated that the critical col was placed on the road.  When I arrived I assessed the lay of land and placed the Trimble on one corner of the crossroads and began my long wait.  I stood beside a large tree close to the Trimble and hoped that this quiet corner of Shropshire would remain so for the next few minutes.  I checked the Trimble every few minutes as its required accuracy slowly crept down to 0.1m.  The accuracy figure shown in the Trimble ‘bounced’ back up twice, indicating that satellite coverage was not ideal, this was expected as there were a number of mature trees and hedges all in close proximity to where it had been placed.  However, I was in no rush.  Two cars passed, one drove into the drive of Stoney Pound and I stood beside the Trimble when it did so, the second pulled up next to me and I chatted with the driver and explained what I was doing as he went into the adjacent field and re-appeared with a number of dead moles.  After a long wait the magical figure of 0.1m appeared on the Trimble’s screen and I quickly pressed ‘Log’ and waited for five minutes of data to be collected.

Risking its life AGAIN - gathering data at the critical col of the 400m Sub-Four

Just one hill and survey remained and that was the high point of the day; the 437m map heighted summit of Stoney Pound Hill.  I walked up the lane from the crossroads and gained access to the summit over a gate.  By the time data were collected a slight chill has settled on the land, I packed the equipment away and headed back over the fields to the lane.

Last survey of the day - at the summit of Stoney Pound Hill

I now had just over a mile to walk back on the lane to my car.  This was cut short as a car pulled up and offered me a lift, I accepted.  The person who kindly offered me a lift was Wayne Smith and we chatted about the hills, Wayne has completed the 600m summits of Wales as listed by Terry Marsh in his excellent guides.

As Wayne dropped me off we stood beside my car admiring the hills and chatted about all manner of hill related stuff, Wayne left with a scrap piece of paper full to overflowing with names, websites and publishers of hill lists.

Before leaving, Wayne showed me the book he had written to ‘The Drovers’ Roads of the Middle Marches’ which is published by Logaston Press, check the book out on Amazon, it receives five stars from everyone that has reviewed it.  As we stood and chatted Wayne pointed out that the lane we were standing on was an old drover’s road and these usually headed from west to east.

Highly recommended for those wanting walks to historical routes through the hills

The author of the book - Wayne Smith

It had been another very enjoyable day in the hills with first visits to another three of The Fours and one Sub to add to the total, and meeting Wayne was an ideal end to my latest foray to the Shropshire hills.     

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 some of these hills being prioritised over that produced by the Trimble GeoXH 6000.

Survey Result:

Cefn Hepreas

Summit Height:  412.4m (LIDAR)

Summit Grid Reference:  SO 26727 78732 (LIDAR)

Col Height:  366.9m (LIDAR)

Col Grid Reference:  SO 26301 78758 (LIDAR)

Drop:  45.5m (LIDAR)

Dominance:  11.02% (LIDAR)

Llanfair Hill

Summit Height:  430.6m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SO 25594 78509 (Trimble GeoXH 6000)

Col Height:  415.3m (LIDAR)

Col Grid Reference:  SO 25209 78802 (LIDAR)

Drop:  15.3m (Trimble GeoXH 6000 summit and LIDAR col) 

Dominance:  3.54% (Trimble GeoXH 6000 summit and LIDAR col) 

Llanfair Hill

Summit Height:  432.2m (converted to OSGM15)

Summit Grid Reference:  SO 25480 79432

Col Height:  394.0m (converted to OSGM15)

Col Grid Reference:  SO 25060 79639

Drop:  38.2m

Dominance:  8.84%

Pt. 425.6m (significant name change)

Summit Height:  425.6m (LIDAR)

Summit Grid Reference:  SO 24371 80264 (LIDAR)

Col Height:  397.5m (LIDAR)

Col Grid Reference:  SO 23931 80943 (LIDAR)

Drop:  28.1m (LIDAR)

Dominance:  6.60% (LIDAR)

Stoney Pound Hill (significant name change)

Summit Height:  438.3m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SO 23445 80810 (Trimble GeoXH 6000)

Col Height:  376.9m (LIDAR)

Col Grid Reference:  SO 22872 80617 (LIDAR)

Drop:  61.5m (Trimble GeoXH 6000 summit and LIDAR col) 

Dominance:  14.03% (Trimble GeoXH 6000 summit and LIDAR col) 

 

  

For further details please consult the Trimble survey spreadsheet click {here}