Mapping Mountains - Trimble Surveys - Stiperstones

17.12.13  Pritchard’s Hill (SJ 316 147), Kempster's Hill (SJ 318 143), Bulthy Hill (SJ 312 136), Cefn y Castell (SJ 305 133), Middletown Hill (SJ 298 130), Moel y Golfa (SJ 290 125), New Piece (SJ 295 136), New Piece (SJ 297 141) and Breiddin (SJ 295 144)

Cefn y Castell (SJ 305 133)

Freshly enthused with the prospect of determining the absolute height of many a hill can give added impetus to revisit areas that have not been visited for many a year.  It was with this added enthusiasm that I set out for some of my local hills; the Breiddin.  I’d done a circuit of all the P30’s and Subs in this compact hill group a few years ago and had always wondered if I would repeat it.  With the forecast of winter sunshine and with confidence in using the Trimble I decided that five P30’s and two Subs, including one Marilyn and two marginal HuMPs was the order of the day.

The route took me up through patches of woodland where on my last visit I’d disturbed two deer, a rare sight on hills in mid Wales, to the grassy summit of Pritchard’s Hill (SJ 316 147).  Footpaths on the map indicated that I had to venture in to the back garden of a house before walking down a track to gain the lower slopes of Kempster’s Hill.  I was soon confronted with ‘Oh you, what are you doing there!’  This was the owner of the house who had spotted me from the end of the track, I sheepishly approached and apologised for any disturbance and then spent the next ten minutes in conversation about the local names of the hills.

By now the sun was up casting lengthy shadows on the ground as patches of mist in the valley below were edging their way around bends in the River Severn.  Gaining the summit of Kempster’s Hill (SJ 318 143) the open land of Shropshire was on view with sunlight enhancing the ridge of the Stiperstones.  I surveyed the high point and look forward to the result as no absolute height appears on the map for this hill.

On the summit of Kempster's Hill (SJ 318 143) looking towards Cefn y Castell

My next objective was Cefn y Castell (SJ 305 133), otherwise known as Middletown Hill.  Passing over Bulthy Hill (SJ 312 136) I decided to give it a quick survey.  Five minutes later I packed the Trimble in its protective case and carried on up the ridge to the summit of Cefn y Castell. 
 

The Trimble ventures in to deepest, darkest England on the high point of Bulthy Hill (SJ 312 136)

Gathering data on the summit of Cefn y Castell (SJ 305 133)

The time was now approaching 10.30am and a bank of cloud had appeared skimming the upper reaches of Cefn Digoll (Long Mountain).  This soon expanded to envelop the top of Moel y Golfa and the Breiddin with wisps of cloud gently rolling down the valley either side of where I stood.

The bank of cloud enveloping the summit of Moel y Golfa

I chatted with a man walking his two dogs on the way down to a 307m sub-hill and gathered data at its bwlch and summit, before assessing the bwlch of Cefn y Castell which has a 271m spot height on the narrow road on the Ordnance Survey enlarged mapping on the Geograph website.  This area has a parking ground for cars and I decided that the safest place for the Trimble was adjacent to this area on a grass verge.  It also seemed to be the point of the critical bwlch that could be deemed as ‘natural’.

The next hill was the highest and the only Marilyn of the day; Moel y Golfa (SJ 290 125).  The last time I had visited was with Bob Kerr who was staying over during his visits to film and be interviewed on his attempt of the Seven Summits (the continental high points).  On that particular day we sought shelter just below the summit amongst trees as there was a brisk wind that would destroy the audio on the small digital camera I conduct the interviews with.  Today the summit was peaceful with the bank of cloud greying the valley and the sun breaking through to highlight the colours on the higher land.  Twas a fine time to be out on the hill.

The Trimble on the summit of Moel y Golfa (SJ 290 125)

As each summit and bwlch was visited I collected a minimum of five minutes of data and continued this process as I attempted to decipher where the critical bwlch position was for the Breiddin.  Was it beside a tree in a field or on a gravel track or in another field full of sheep with rummaging pigs alerting local farmers of my presence?  I opted for data collection beside the tree and on the gravel track and quickly headed in to the Breiddin Forest where a series of wooded green tracks and the customary forest track took me over the summit of New Piece (SJ 295 136) toward its bwlch and then the summit of New Piece (SJ 297 141) a sub P30 hill whose name was later found from Tithe maps.

The forested summit of New Piece (SJ 295 136)

Next stop was the Breiddin and its large monument named Rodney’s Pillar.  I had a good look around the base of the monument and assessed the height of the natural rock on its four sides.  This is where a level and staff comes in to its own as judging by eyesight alone is not ideal.  The Trimble was set up and activated and gathered over 13 minutes of data as I pottered around with the camera and visited a nearby panoramic viewfinder.

The Breiddin (SJ 295 144) overlooking the flat lands of the Shropshire plain

The downward route through the forest was on a good green track all the way down the ridge toward the Admiral Rodney pub to the awaiting car.  I’d been out over seven hours and collected data at sixteen points.  A Marilyn, two marginal HuMPs, a further two P30’s and two subs and all except for one critical bwlch (the one for Moel y Golfa) had been surveyed.  It proved a great day on the hill.

LIDAR image of Pritchard's Hill (SJ 316 147)

Postscript 

Since visiting 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 being prioritised for some of these hills.

Survey Result:

Pritchard’s Hill

Summit Height:  172.6m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SJ 31608 14759 (Trimble GeoXH 6000)

Bwlch Height:  151.75m (LIDAR)

Bwlch Grid Reference:  SJ 31481 14542 (LIDAR)

Drop:  20.9m (Trimble GeoXH 6000 summit and LIDAR bwlch) (100m Sub-Twmpau addition) 

Dominance:  12.08% (Trimble GeoXH 6000 summit and LIDAR bwlch)

Kempster’s Hill

Summit Height:  246.1m (converted to OSGM15) 

Summit Grid Reference:  SJ 31830 14342

Bwlch Height:  197.9m (converted to OSGM15)

Bwlch Grid Reference:  SJ 31428 13989

Drop:  48.2m

Dominance:  19.58%

Bulthy Hill

Summit Height:  291.4m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SJ 31260 13672 (Trimble GeoXH 6000)

Col Height:  275.8m (LIDAR)

Col Grid Reference:  SJ 31179 13634 (LIDAR)

Drop:  15.6m (Trimble GeoXH 6000 summit and LIDAR bwlch) 

Dominance:  5.36% (Trimble GeoXH 6000 summit and LIDAR bwlch)

Cefn y Castell (significant name change)

Summit Height:  367.8m (converted to OSGM15)

Summit Grid Reference:  SJ 30523 13332

Bwlch Height:  271.3m (converted to OSGM15)

Bwlch Grid Reference:  SJ 29697 13022

Drop:  96.5m

Dominance:  26.23%

Middletown Hill

Summit Height:  306.9m (converted to OSGM15)

Summit Grid Reference:  SJ 29869 13016

Bwlch Height:  280.5m (converted to OSGM15)

Bwlch Grid Reference:  SJ 30065 13115

Drop:  26.3m (Sub-Trichant addition)

Dominance:  8.58%

Moel y Golfa

Summit Height:  403.2m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SJ 29074 12528 (Trimble GeoXH 6000) 

Bwlch Height:  140.8m (LIDAR)

Bwlch Grid Reference:  SJ 32605 11659 (LIDAR)

Drop:  262.4m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Dominance:  65.09% (Trimble GeoXH 6000 summit and LIDAR bwlch)

New Piece

Summit Height:  321.6m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SJ 29558 13655 (Trimble GeoXH 6000)

Bwlch Height:  281.1m (LIDAR)

Bwlch Grid Reference:  SJ 29789 13876 (LIDAR)

Drop:  40.5m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Dominance:  12.59% (Trimble GeoXH 6000 summit and LIDAR bwlch)

New Piece (significant name change)

Summit Height:  320.2m (converted to OSGM15)

Summit Grid Reference:  SJ 29767 14148

Bwlch Height:  295.0m (converted to OSGM15)

Bwlch Grid Reference:  SJ 29686 14281

Drop:  25.2m

Dominance:  7.87%

Breiddin (significant name change)

Summit Height:  366.6m (converted to OSGM15)

Summit Grid Reference:  SJ 29510 14414

Bwlch Height:  260.4m (converted to OSGM15)

Bwlch Grid Reference:  SJ 29166 13081

Drop:  106.2m

Dominance:  28.96%

For details on the bwlch survey of Moel y Golfa

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