Sunday, 17 April 2016

Mapping Mountains – Trimble Surveys – Fforest Glud


08.04.16  Glog Hill (SO 222 690), Weston Bank (SO 199 702), Pt. 394.0m (SO 186 701), Pt. 407.7m (SO 180 692), Dunn’s Rhos (SO 177 684), Llysin Hill (SO 168 683) and Pt. 426.8m (SN 186 685)   

Llysin Hill (SO 168 683)

To the north and west of the small community of Bleddfa are a number of hills that are either given over to arable crops or in the main sheep grazing, some still retain their moor and heath origins in places, but greenery of pasture predominates.  However, the land close to Bleddfa has a quiet feeling to it with hills that are rounded in shape and pleasing to visit.  This land also has one particular hill that desperately needed Trimbling.  This hill was originally listed under the invented name of Pen Fraichwen and only included in the Welsh 400m P30 list due to a basic levelling survey.  This hill also has three positions vying for where its critical bwlch is placed; each needed surveying as did its summit and these when combined with a number of other hills would make a good circuit from Bleddfa.

I parked just off the A 488 next to a stand full of bedding plants with an accompanying honesty box.  As I sorted my gear and laced up my boots a man approached and we chatted for a number of minutes, he was collecting the money in the box and I checked on where the footpath was that I wanted to take up to the first hill of the day.  We walked up the lane together and said our good buys as I branched off following the path to a foot bridge spanning the stream that descends from St Michael’s pool.

The small community of Bleddfa

The path continued up the hillside and I eventually left it and headed for the summit of Glog Hill, using gates to gain access in to fields.  On my way I came across a sorry scene; a sheep lying on its side, seemingly unable to right itself, as I grabbed a hand full of wool and lifted it up to place it down on its legs I noticed that there was blood on its head, the poor thing had had its eyes pecked out.  I wondered what to do, there was little I could, I talked to it gently and made sure that it was sitting on its belly, at least that way it could munch on grass if it still had the strength to do so.

Leaving the poor sheep I aimed for the high point of Glog Hill and when I reached it I checked the placement of the Trimble from different directions, happy that it was placed on the summit I pressed Log and waited for the customary five minutes of data to be gathered.

Gathering data at the summit of Glog Hill

After packing the Trimble away I retraced my steps back to the poor sheep and down the hill’s broad western ridge following a fence line which connected with my inward right of way.  This brought me toward Pitch Hill; a small lump of a hill, on one side or the other of Pitch Hill is the critical bwlch for Glog Hill, each position was Trimbled.

Beyond this bwlch was my next hill which is listed as Weston Bank, as I approached I could hear a vehicle on the hill and sheep dogs barking.  The summit of Weston Bank is positioned between two thin conifer plantations and nearing the first I spotted a person standing beside a gate, this was the gate giving access to the summit.  The person was a young girl and she told me that they were out feeding the sheep; I asked if she minded me visiting the summit and she said that this was OK.  By the time I arrived at the high point the vehicle was coming back up the hill, I waved and it headed my way.  I explained what I was doing and engaged the driver in a conversation about the name of the hill, she got on the radio to her husband and as I set the Trimble up to collect summit data he arrived in another vehicle.  Rob Dougan asked me to be careful around the sheep, explaining that mothers can easily be separated from their lambs at this time of year.  We chatted for a number of minutes and he pointed to where Weston Bank is situated and gave me another locally known name for the hill.  After telling him my onward route he suggested I walk through the adjacent turnip field to connect back with the public footpath which continues toward a paved minor lane.

Rob Dougan out feeding the sheep


Just fed and ready to help with the surveying

As Rob and his wife drove off I packed the Trimble away, walked through the turnip field and down a track to the corner of the lane and then branched off south-westward following a rutted track toward a building where a number of cows stared back at me, these were on the path which was enclosed at this point, not wanting to edge my way past them I headed in to the adjacent field and made my way to the first of the three positions where the critical bwlch for the hill originally listed as Pen Fraichwen is situated, we now have this hill listed under the point notation (Pt. 407.7m).

I found the first potential bwlch for Pt. 407.7m to be positioned under a small tree next to a fence, which wasn’t ideal.  As the Trimble ebbed down to its 0.1m accuracy level before data should be logged I walked to the edge of Pen-y-clawdd Pool which nested against the rounded and grassy hillside.  A track passes this small lake as it heads down to the near farm of Pen-y-clawdd and I was aware that a quad bike or Landrover could appear at any minute, but the whole of the area was quiet and remained so whilst the Trimble gathered its data.

The first of the three bylchau surveyed proved to be the critical one for Pt. 407.7m


Pen-y-clawdd Pool

Above the lake and track is a small hill which has an uppermost 390m ring contour on Ordnance Survey maps, this hill is a potential new 390m Sub-Pedwar and I proceeded to survey two points for its summit, watching a Red Kite fly off from a near sheep carcass as I did so.

Red Kite, ever majestic

Beyond this small hill was the second potential bwlch position for Pt. 407.7m, this was situated at the top of a track.  I placed the Trimblle on top of my rucksack to give it elevation above its surroundings and measured a 0.40m offset between its internal antenna and the point of the bwlch.  As it gathered data I stood on the adjacent hillside and let my mind wander whilst looking out on the patterns of trees marching through glowing green fields.

The second potential bwlch position for Pt. 407.7m proved to be the critical bwlch for a 14.3m drop and 394.0m high intermediary bump


Tree patterns on a green landscape

The next point to survey was the summit of Pt. 407.7m, this hill had been included in the list now known as Y Pedwarau for the last 13 years and the Trimble surveys conducted during the day would decide its fate.  The summit is positioned next to a fence and after Trimbling it I wandered down to the third potential position for its critical bwlch.  This is positioned in a field and was relatively easy to judge where its critical point lay.

Gathering data at the summit of Pt. 407.7m


The third potential bwlch position for Pt. 407.7m proved to be the critical bwlch for Weston Bank

As the afternoon was ideal for surveying with just the faintest of breeze with clear conditions and intermittent sunshine I decided to head for Dunn’s Rhos, which is listed as a 390m Double Sub-Pedwar with a 395m map heighted summit and c 26m of drop.  I spent an inordinate amount of time at its bwlch, taking three data sets in all and forever trying to work out where its critical bwlch was positioned, and in the process conducting my 1,000th Trimble survey related to a hill (outside of datum point surveys).  All of this was done in a closely cropped grassy field next to a minor road; I spent much of the time at this bwlch either on my knees or stomach assessing the lay of the land, during this time not a single car passed.  Tis quiet country hereabouts.

Dunn's Rhos centre left and Llysin Hill cenre right

After gathering data at the summit of Dunn’s Rhos I headed toward Llysin Hill which has a fine profile with steeply wooded southern slopes and an elongated south-west to north-east aligned broad summit ridge.  Between me and its summit was its bwlch, this was duly surveyed and I then slowly plodded up a track which leads to within a few metres of its summit.  By now the breeze had picked up and when the sun disappeared behind cloud there was a chill in the air.

Gathering data at the critical bwlch of Llysin Hill


Gathering data at the summit of Llysin Hill

Leaving the summit of Llysin Hill I retraced my steps back down the track toward its connecting bwlch and followed the right of way around Dunn’s Rhos to the minor lane which gave access to the lower slopes of my last hill of the day.  This hill is another that is unnamed on current Ordnance Survey maps and therefore we have it listed under the point notation (Pt. 426.8m).

Pt. 408m from the ascent of Pt. 426.8m

As I plodded up its slopes a quad bike zoomed up a lower track to feed the sheep who had looked pensively at me whilst I surveyed the third potential bwlch position of Pt. 407.7m, otherwise all was quiet.  After gathering data at the summit I wandered down to its critical bwlch which is positioned on or near to the top of the A 488.  This section of road has a number of spot heights on the Ordnance Survey enlarged mapping on the Geograph website, I found that the valley to valley traverse is positioned either side of the road and crosses it beside a gate, this is where I positioned the Trimble on top of my rucksack and watched as a number of cars hurtled past it.  The Trimble looked fairly safe and I wondered why I had not used this set-up position in Mold many a month ago when it was run over by a car.

Gathering data from the summit of Pt. 426.8m


Gathering data at the critical bwlch of Pt. 426.8m

After five minutes of data were gathered I packed the Trimble away and headed down the road and found the onward green track for my descent route back to Bleddfa, passing a woolly haired Shetland pony on the way.

A friendly Shetland pony

It had been another good day on the hill with 19 data points surveyed and the outcome of the hill listed as Pt. 407.7m teetering on the edge of Pedwar oblivion.  



Survey Result:


Glog Hill

Summit Height:  406.6m (converted to OSGM15)

Summit Grid Reference:  SO 22288 69079

Bwlch Height:  357.2m (converted to OSGM15)

Bwlch Grid Reference:  SO 20956 69962

Drop:  49.4m

Dominance:  12.16%




Summit Height:  416.9m (converted to OSGM15)

Summit Grid Reference:  SO 19915 70279

Bwlch Height:  378.3m (converted to OSGM15)

Bwlch Grid Reference:  SO 18002 69004

Drop:  38.6m

Dominance:  9.26%



Pt. 394.0m

Summit Height:  394.0m (converted to OSGM15)

Summit Grid Reference:  SO 18686 70106

Bwlch Height:  379.6m (converted to OSGM15)

Bwlch Grid Reference:  SO 18397 69858

Drop:  14.3m

Dominance:  3.64%



Pt. 407.7m

Summit Height:  407.7m (converted to OSGM15)

Summit Grid Reference:  SO 18077 69277

Bwlch Height:  379.5m (converted to OSGM15)

Bwlch Grid Reference:  SO 18847 70099

Drop:  28.3m (Pedwar reclassified to 400m Sub-Pedwar)

Dominance:  6.93%



Dunn’s Rhos

Summit Height:  393.5m (converted to OSGM15)

Summit Grid Reference:  SO 17711 68435

Bwlch Height:  369.1m (converted to OSGM15)

Bwlch Grid Reference:  SO 17972 68420

Drop:  24.4m

Dominance:  6.21%



Llysin Hill

Summit Height:  425.7m (converted to OSGM15)

Summit Grid Reference:  SO 16830 68396

Bwlch Height:  354.5m (converted to OSGM15)

Bwlch Grid Reference:  SO 17397 68602

Drop:  71.2m

Dominance:  16.73%



Pt. 426.8m

Summit Height:  426.8m (converted to OSGM15)

Summit Grid Reference:  SO 18696 68582

Bwlch Height:  366.7m (converted to OSGM15)

Bwlch Grid Reference:  SO 18732 68227

Drop:  60.2m

Dominance:  14.10%



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




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