Mapping Mountains – Trimble Surveys – Y Garn

25.05.23  Esgair Llwyn Gwyn (SN 885 790) 

Esgair Llwyn Gwyn (SN 885 790)

Out with Mark Trengove today visiting a Pedwar to the west of Llangurig, which is one of only a few Pedwarau in the northern part of Mid Wales that I had until today not visited.

For me it was a relatively late start as it was past 3.00pm when we set off from the car park on the southern periphery of the small village of Llangurig.  The predicted high cloud soon pushed in over the land, the hills remained clear, but the dry heat of recent days was now replaced with mugginess. 

Llangurig

Our route followed the course of the Afon Gwy (River Wye) on its southern bank for a few minutes before the bridleway leading up the eastern ridge of Esgair Llwyn Gwyn veered south-westward and gradually gained height.  Except for a few people walking beside the river the only other people we saw during the afternoon were a couple descending the ridge close to Llwyn-gwyn farm who were doing a part of the long distance Wye Valley Walk.  We stopped and chatted for a few minutes before continuing uphill. 

Mark heading toward Llwyn-gwyn farm

The outskirts of Llwyn-gwyn farm

Nearing the summit of Esgair Llwyn Gwyn the manicured green of grazing fields gave way to the reed grass and moorland surrounds of the upper hill.  We were soon on the summit wandering around trying to discern its highest point for Trimble placement; LIDAR analysis give three summit positions of equal height, all within a few metres of one another.  Having chosen the spot for Trimble placement I set the equipment up to gather data. 

Nearing the summit

The last bit of uphill

The summit area of Esgair Llwyn Gwyn consists of patches of rough grass and high reed grass, for such examples I usually prioritise the Trimble result over that of LIDAR, as comparison of results show the latter consistently higher than the former; implying difficulty with the LIDAR model when encountering tussock grass and reed grass. 

Gathering data at the summit of Esgair Llwyn Gwyn

LIDAR image of Esgair Llwyn Gwyn (SN 885 790)

During data collection Mark headed toward a trailer where he happily sat for a bite to eat.  I joined him once the Trimble had gathered and stored data.  We chatted and laughed as I sat on a part of the trailer which made it move similar to a swing, with the whole thing moving up and down with the slightest movement. 

Heading down toward the bwlch

Leaving the summit surrounds Mark used his hand-held GPS to head down to the connecting bwlch with the ten figure grid reference produced via LIDAR zeroing us in to the critical point.  However, once we were down near the bwlch we headed toward where we thought the critical point lay without the aid of the grid reference produced by LIDAR.  Once there we then consulted the grid reference, we were about 10 metres away, which proved a good estimate considering the area of the bwlch and its surrounds. 

Gathering data at the bwlch of Esgair Llwyn Gwyn

As I set the Trimble up atop my rucksack and noted the offset between its internal antenna and the ground at its base, before creating the file for data collection and once the 0.1m accuracy level was attained before data should be logged, I set it to gather data and watched as Mark headed through the reed infested mayhem of the bwlch toward a lone small tree before hopefully continuing toward what we planned as our descent route via the Pant Gwyn Hill ridge.  As Mark headed in the direction of greener ground and our path leading to the ridge he veered leftward and continued down through the tussock laden bog of the bwlch.  I wondered what he was doing, and only found the reason for this once I had packed the equipment away and stumbled my way through the tussocks and bog down toward him. 

Through the bog

The reason for continuing down through the bog instead of heading toward our planned path and descent route was one of a barb wired fence.  These pests are getting harder to cross as I am getting older.  The older fences I can stride over, but the newer taunt ones require climbing, which nowadays I do not enjoy.  Mark now has a pair of dodgy knees and barb wired fences are something to definitely avoid and I’m afraid one of these stretched across our planned onward route and necessitated a diversion down through copious amounts of reed infested bog. 

The expanse of bog and rough ground at the bwlch

Eventually the bog was overcome and we reached drier and easier ground.  As Mark headed up to a section of collapsed fence, I continued to contour using what looked like an old water course, this headed toward a wood which gave variety to our unplanned descent route.  We met at the far side of the wood. 

Looking back toward the bog from just within the wood

All that now remained was a slow wander back in the early evening light down our inward route past the farm of Llwyn-gwyn and the continuation of the track beside the river and the small section on the minor road leading to the car on the outskirts of Llangurig. 

Nearing the end of the walk

We rounded the day off with an excellent meal in The Raven in Welshpool, which gave a welcome last couple of hours to enjoy good food and continued good conversation; it proved a fine way to end an excellent day. 

 

Survey Result:

 

Esgair Llwyn Gwyn

Summit Height:  435.9m (converted to OSGM15) (significant height revision)

Summit Grid Reference:  SN 88577 79070

Bwlch Height:  402.3m (converted to OSGM15)

Bwlch Grid Reference:  SN 88120 78849

Drop:  33.6m

Dominance:  7.71%

 

 

For further details please consult the Trimble Survey Spreadsheet

 

  

Mapping Mountains – Trimble Surveys – Y Garn

 

22.06.21  Banc Lletysynod (SN 720 740), Banc Penygwernydd (SN 728 741), Banc (SN 723 729), Grogwynion (SN 720 725) and Pen y Bryn Mawr (SN 705 732, not Trimbled) 

Banc Penygwernydd (SN 728 741)

I’d looked at combining these hills since visiting others in the vicinity after one of last year’s lockdowns was lifted.  Then I’d investigated hills to the north-west and enjoyed the quiet surrounds with narrow country lanes leading between the hills, all of which made a lasting impression.  Today I’d planned a route taking in five P30s and as the last summit was forested, with just four to be Trimbled. 

It was a glorious journey to the hill with mist enclosing the Severn Valley until past Llanidloes, where blue sky crept in to the scene to dominate the western horizon.  I was parked and walking by 7.25am and was soon wandering up a long grassed field aiming for the rising profile of my first hill of the day; Banc Lletysynod. 

As height was gained a slight breeze whisked across the land, for me this was welcome as even this early in the morning warmth was evident.  Except for a distant cloud bank toward the west the skies were an azure blue; a succulent colour that pulled me ever upward. 

One of those unusual sights amongst the Welsh hills

As I rounded the northerly flank of Banc Lletysynod a mass of Range Rovers came in to view.  They were lined up, one after another on both sides of a track that led toward a number of buildings where even more Range Rovers were parked.  I was later told that these were mainly used for parts for Eastern Europe.  They made for one of those unusual sights when amongst the Welsh hills, and one that I find rather heartening as this land is not a manicured landscape, it is one lived in and loved with all its beauty and sometimes unusual elements. 

LIDAR image of Banc Lletysynod (SN 720 740)

Prior to this visit I had examined these hills via LIDAR, producing heights and positions for each summit and bwlch.  Therefore, with accurate height data all I wanted to survey were the summits, leaving bwlch heights and positions to that of LIDAR. 

LIDAR image of Grogwynion (SN 720 725)

The high point of Banc Lletysynod was easily found amongst fresh and greened fern and the Trimble was soon set up gathering its allotted data.  During data collection I peered eastward toward my second hill of the day; Banc Penygwernydd and followed the course of a track up to a fence and then onward beside fir trees to the open hill, it seemed an easy enough route. 

Gathering data at the summit of Banc Lletysynod

Once data were gathered and stored I closed the Trimble down, packed it away and sauntered down the hill aiming for the track which crosses what the map indicates as a drainage channel.  The ascent was in shade and the long grass dew laden.  The higher I got glimmers of early morning sunshine shimmered through near trees, until I reached a large field and the upper part of the hill beyond.  I again, veered toward the northerly flank to then swing south for the final ascent.  The summit of Banc Penygwernydd consists of closely cropped grass and as I set the Trimble up a herd of sheep peered my way from the adjacent field. 

Banc from the summit of Banc Lletysynod

As the Trimble was ebbing down to the 0.1m accuracy level before data should be logged, a quad bike appeared heading my way, I waved across toward it and was soon in conversation with Ivor Hopkins; the farmer from Penygwernydd. 

Ivor Hopkins of Penygwernydd farm

During our conversation I checked the Trimble and then re-positioned it to face east, Ivor said he needed to check on some sheep and would be back in five to ten minutes.  As the quad bike disappeared I pressed ‘Log’ and left the Trimble gathering data until Ivor reappeared.  We chatted for 15 minutes or so about the hills, the Trimble, the names of the hills and my onward route.  He told me where the gates were positioned for my downward progress and said he was now off to cut grass for silage. 

The view north from the summit of Banc Penygwernydd

Gathering data at the summit of Banc Penygwernydd

Descending from the summit of Banc Penygwernydd the greened and inviting profile of my next hill was a dominant feature to my south, this hill’s uppermost enclosed land is named Banc on the Tithe map.  Its summit was about a mile away as the crow flies and I soon connected with the gates that Ivor had mentioned, these brought me back to the minor road that I had travelled on earlier in the morning. 

Banc from the descent of Banc Penygwernydd

I now wandered up another minor road to where a public footpath headed eastward following the course of the ridge crest toward the high point of Banc.  This part of the walk was a delight as the country hereabouts is quiet and all I had for company was birdsong, which invitingly radiated across the land. 

Banc Penygwernydd (SN 728 741)

Banc Lletysynod with Banc Cwmnewydion beyond

By the time I neared the summit of Banc the cloud bank which was evident further to the west had pushed inland and the vivid blue skies of the early morning were suddenly gone.  The summit of Banc consists of an attractive rock outcrop and I had fun aligning the Trimble with the very highest part of rock, whilst balancing its rear on two very small flat stones that enabled it to sit in place for the five minutes of data collection. 

Gathering data at the summit of Banc

The onward route was now south-westward toward Grogwynion which also has the name prefixed with that of Castell on contemporary Ordnance Survey maps, and as this latter name implies it has an ancient hill fort at its summit, the terraces of which were on grand display from this northerly vantage point. 

Grogwynion (SN 720 725)

Below the hill is the farm of Pengrogwynion and I was soon walking through the farm yard with two happily barking farm dogs approaching me.  I’d read reports on the Hill Bagging website of the friendly farmer and even though this was encouraging I would have knocked on the front door anyway, which I soon did.  Wendy answered the door and we were soon in conversation about the hill, farming, my route, the ancient hill fort, the Welsh language, the meaning of being Welsh and where she originated; Liverpool, which was a surprise as she is a fluent Welsh speaker.  Wendy told me that the name of the hill is Grogwynion with the word Castell purely signifying the ancient hill fort as being the castle of the hill of Grogwynion.  She told me about their farm and its original name and where this related to.  We were soon joined by Caredig, who I later met on the walk descending from my last hill of the day.  Before leaving I asked permission to visit the hill and explained I wanted to survey it, this was duly granted.  Wendy told me the best way up and where the original entrance to the settlement was thought to be positioned.  I thanked them for their time and waved by goodbye’s, soon stopping to talk to one of the friendly farm dogs who was lying on a near wall basking in the remnants of sun that pieced the high cloud. 

Caredig and Wendy of Pengrogwynion farm

Wendy had told me to head up beside a water tank next to a rock just off of the narrow gravelled track that leads to the farm.  This gave access to a fenced area that led up to the open hill.  This hill is recommended to visit for its position and profile.  It has a steepening summit cone and gives excellent views north-eastward toward Banc and the continuation of its south-easterly ridge toward Banc Maen Arthur and across the intervening southerly stream valley toward the forested realms of Mynydd Bach. 

Banc from the summit of Grogwynion

After setting the Trimble up to gather its allotted data, I happily sat below the equipment looking out to the continuation of the gravelled track leading from Pengrogwynion as it meandered westward, gaining height toward the narrow minor road that led toward the few houses nestled beside it that constitutes the community of Brynafan. 

Gathering data at the summit of Grogwynion

I could easily have spent longer at the summit of Grogwynion but I still had one summit to visit, but as this was forested the Trimble could now remain in its case as LIDAR gives a height for the summit and dependent upon tree coverage any form of data collected by the Trimble may have a high degree of measurement uncertainty applicable to it. 

The onward route

On my way up the gravelled track I occasionally stopped to look back at Grogwynion; a fine hill nestled amongst many others that are also similar in nature.  The gravelled track soon reached the paved minor road and once past the houses at Brynafan I followed a track leading toward the small reservoir on the right hand side of the road that headed up toward the forestry edge. 

The small reservoir leading to the forested summit of Pen y Bryn Mawr

A foot stile indicates the way in to the forestry, a good path then leads to a forest track.  As I neared the track I heard a car pass, which surprised me, dust was still in the air as I walked directly over the track to the mature trees beyond.  The car was heading toward a house, which I came across on my later descent which is nestled against the north-easterly corner of the forest, with the track being the access road to the house. 

Prior to entering the forest I’d activated the Trimble and taken a compass reading toward the summit.  However, even without the aid of a compass the high point was easy to find.  The summit of this hill is placed in a wide forest ride that has a fallen or felled tree straight over it.  The forest ride is full of tree debris.  I visited both sides of the fallen tree and checked the Trimble co-ordinates against those produced by LIDAR, it was 1 metre out on the easterly and 4 metres out on the northerly,  I was at the summit, which didn’t surprise me as ground descended from this point in all directions. 

The Trimble marks the spot - at the summit of Pen y Bryn Mawr

Reversing my inward route out of the forest I was soon sitting on the foot stile enjoying a late breakfast of a boiled egg.  My route down now followed the periphery of the forest and the continuation of the fence to a track.  On my way I was surprised to find a house nestled in the corner against the conifers.  As I continued away from the forest and down beside a fence a Landrover appeared in the adjacent field, it made a beeline toward me and I waved over toward it.  It stopped beside the fence and I soon scampered up the intervening bank to the fence and smiled when I saw who was getting out of the vehicle, it was Caredig from Pengrogwynion farm. 

He’d come to check on the sheep in the field, this being a part of the land adjoined to his farm.  We talked for 20 minutes or so.  He told me that he has cancer, but still tries to get out to do daily tasks around the farm and is aided my his nephew.  We talked at length about his life and how fulfilling working in the outdoors is, and how the quality of outdoor life was emphasised by the recent and ongoing pandemic and the resulting lockdowns.  I told him of my canal walks during the first lockdown and how the access this gave me to immediate countryside was a great joy during a time that the distance to the hills meant that few were accessible. 

Caredig Thomas of Pengrogwynion farm

Eventually Caredig said he would have to go as he had a few other things that needed doing, but I could have easily stayed there a while longer listening to and talking with him. 

After a short distance farther down the field I turned left on a track which led to the paved minor lane which in time would lead me back to my car.  On the way I listened to birdsong, an ever present and welcome background sound that reverberated around the land.  This was interspersed by the call of a cockerel.  The latter reminded me of walking the middle hills leading to the Marshyangdi valley and the Annapurna circuit and sanctuary trek, where the call of an early morning cockerel was the usual wakening experience.  I spent the next ten minutes of so encountering delightful flash backs to images from Nepal. 

It had been another good day on the hill, when do you ever encounter a bad one, seldom if at all.

 

Survey Result: 

 

Banc Lletysynod

Summit Height:  290.2m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SN 72010 74093 (Trimble GeoXH 6000) 

Bwlch Height:  246.9m (LIDAR)

Bwlch Grid Reference:  SN 71913 74275 (LIDAR)

Drop:  43.3m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Dominance: 14.92% (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

 

Banc Penygwernydd

Summit Height:  325.95m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SN 72816 74132 (Trimble GeoXH 6000)   

Bwlch Height:  269.2m (LIDAR)

Bwlch Grid Reference:  SN 72926 74808 & SN 72928 74809 (LIDAR)

Drop:  56.7m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Dominance:  17.41% (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

 

Banc (significant name change)

Summit Height:  316.3m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SN 72380 72987 (Trimble GeoXH 6000)   

Bwlch Height:  285.1m (LIDAR)

Bwlch Grid Reference:  SN 72097 73104 (LIDAR)

Drop:  31.2m (Trimble GeoXH 6000 summit and LIDAR bwlch) (Sub-Trichant reclassified to Trichant)

Dominance:  9.87% (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

 

Grogwynion (significant name change)

Summit Height:  288.6m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SN 72068 72507 (Trimble GeoXH 6000)   

Bwlch Height:  255.8m (LIDAR)

Bwlch Grid Reference:  SN 71921 72581 (LIDAR)

Drop:  32.7m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Dominance:  11.35% (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

 

Pen y Bryn Mawr

Summit Height:  341.6m (LIDAR)

Summit Grid Reference:  SN 70567 73222 (LIDAR) (summit relocation confirmed)   

Bwlch Height:  222.8m (LIDAR)

Bwlch Grid Reference:  SN 72170 73551 (LIDAR)

Drop:  118.8m (LIDAR)

Dominance:  34.77% (LIDAR)

 

 

For further details please consult the Trimble Survey Spreadsheet

 

 

 

 

 

Mapping Mountains – Trimble Surveys – Y Garn

10.05.17  Curnau Mawr (SN 751 750), Craig Lan Las (SN 758 747), Pt. 413.9m (SN 767 751) and Lan Lwyd (SN 761 752)

Craig Lan Las (SN 758 747)

I wanted to take advantage of the settled weather in the west of the country before predicted low pressure systems brought their more unsettled conditions toward the end of the week, and decided to visit four hills to the south-east of Pontarfynach (Devil’s Bridge).  I’d contemplated visiting these hills for a number of years but had never done so, when studying maps and potential ascent routes I’d always thought that an ascent from the Arch on the former Hafod estate would be the best, but as Aled’s continuing analysis of LIDAR data had found a new 390m Double Sub-Pedwar in Curnau Mawr (SH 751 750) an ascent of this hill and its adjacent 400m Sub-Pedwar of Craig Lan Las would make a good circuit from the west when joined with the two Pedwar hills to the north-east with the Nant Brignant being central on this small horseshoe.

There aren’t many options to park a car for convenient access to the public footpath that leads toward Curnau Mawr, but thankfully a pull-in spot next to a letterbox was ideal.  As I walked up the earthen track the sky radiated blue and with just a breath of breeze the prospect for the day ahead and the surveys I planned on conducting was excellent.

I left the track and walked up the closely cropped grassed south-western slopes of Curnau Bach to the trig pillar positioned close to the fence boundary where a conifer plantation swamps the northern side of this and its adjacent hill; Curnau Mawr.

Ordnance Survey maps give Curnau Mawr a small 390m uppermost contour ring straddling the forest boundary fence, whilst LIDAR data gives the high point as 391.4m and approximately 23 metres to the south of the edge of this contour ring in amongst land between 380m – 390m.  When I approached it was obvious that the LIDAR position for the summit of this hill was correct.

Having set the Trimble up on top my rucksack I stood back whilst it gathered its customary five minutes of data and looked toward my next hill; Craig Lan Las, the underfoot conditions were wilder on this hill with bleached tussocks portraying what is common on the Elenydd hills.

Gathering data at the summit of Curnau Mawr

Surveys would come one after another on this walk with four summits and three or four bylchau to visit, and the first of these bylchau lay just to the east and firmly implanted in a bog.  All of the points I planned on surveying had been analysed with LIDAR data by Aled and I had come prepared with each ten figure grid reference, but I also wanted to independently assess each survey position and compare these to where LIDAR data indicated each should be, and on the critical bwlch for Curnau Mawr my estimated bwlch position was within a few metres of where LIDAR indicated the true bwlch was, I trusted LIDAR and placed the Trimble at the point that Aled had noted.

Gathering data at the critical bwlch of Curnau Mawr

After packing the Trimble away I slowly made my way up the steepening western slopes of Craig Lan Las to two tops, each high point consists of thick grass with the bleached and dry land of tussock grass all too evident all around.  I took data sets from each top, both attractive slender affairs in a land of flatly rounded summits.

Gathering data at the first and slightly lower of the two tops of Craig Lan Las

Gathering data at the second and slightly higher of the two tops of Craig Lan Las

Beyond the summit of Craig Lan Las lay its connecting bwlch with Lan Lwyd, this proved a delight and consisted of heather, tussocks and an odd rouge conifer gaining growth in a big bog.  Approaching the bwlch I had a good view of how the land slightly rose toward where the valley to valley traverse met and headed that way, some of the underfoot conditions proved unusual as my leg occasionally disappeared down beyond where I thought the ground lay, this place must be seldom visited as any prospective hill bagger would no doubt circumvent the delights of this bog.  I used the Trimble as a hand-help GPS and let it guide me toward the spot where LIDAR data placed the critical bwlch, once there I set the Trimble up on top of my rucksack and proceeded to sit on a clump of relatively dry heather as it gathered five minutes of data.  My view from the heather was one where the Trimble was only just visible as the heather and bog had almost swallowed the whole of my rucksack.

Lan Lwyd with the connecting bwlch (bog, a big bog, a bigger than a big bog) between it and Craig Lan Las looking decidedly unwelcoming

The view of the Trimble from my heathery perch

Gathering data at the critical bwlch of Craig Lan Las

During this first part of the walk I had contemplated my way down, should I backtrack the way I had come or leave the adjacent summit of Lan Lwyd until the last and follow its western ridge to connect with a track leading toward the conifer plantation beside the Nant Brignant, I decided on the latter as I didn’t want to visit the tussock laden bog again.

Once out of the bog I followed a green vehicle track toward the bwlch connecting Lan Lwyd with another Pedwar to its east, it was blissful to be on good walking ground again, but it had also been good to experience a small part of wildness that these hills now only have in small patches as much of their land has been reclaimed for grazing.

Pt. 413.9m from the green vehicle track that approaches its bwlch

The green track turned in to a graveled track at the bwlch and after the Trimble had gathered another five minute data set, this time perched on top of a thick gate post with a 1.36m measurement offset between its internal antenna and the ground below, I continued following the course of the track toward the summit of the next hill which is given the point notation as it is unnamed on Ordnance Survey maps and local and historical research has not yet unearthed an appropriate name for it.

Gathering data at the critical bwlch of Pt. 413.9m

I proceeded to take two data sets, one from the hill’s southern top which is placed in a closely cropped grazing field and one from its higher northern top which is placed in a felled forest consisting of scrub undergrowth intermingled with the remains of felled trees.  As the Trimble gathered data I looked below me and the Arch beside the B 4574 road was only a few minutes’ walk away, this is where the critical bwlch for Lan Lwyd (the highest and last of the four hills I planned on visiting during the day) lay, and as the track descending to the conifer plantation next to the Nant Brignant originates next to the Arch I could follow it after collecting data beside the road.

Gathering data at the summit of Pt. 413.9m

With this revised descent route now firmly established I packed the Trimble away and retraced my route back on the track toward the summit of Lan Lwyd, the high point was beside a section of land set aside with daffodil bulbs, as indeed were swathes of the hill’s south-eastern slopes.  Once the customary data set was gathered I regained the track and followed it down to the B road and the arch.

Craig Lan Las from nearing the summit of Lan Lwyd

Gathering data at the summit of Lan Lwyd

The Arch was constructed in 1810 by Thomas Johnes of Hafod to commemorate the Golden Jubilee of George III.  The road used to pass under the Arch, but after a lorry damaged hit and damaged it the road has now been diverted, creating what LIDAR data gives as a new position for the critical bwlch of Lan Lwyd.

Beside the Arch is a large car park and a number of trails heading off in to adjacent woodland, it’s usually a sleepy place, especially so on a blue skied day when the pace of life seems to slow even in a place where the pace of life is probably forever quiet and slumbered.

Initially I judged the low point on the hill to hill traverse to be on the southern side of the old road a couple of metres to the east of the span of the Arch, the Trimble took ten minutes or so to attain its 0.1m accuracy level before data should be logged, during this time I chatted with a couple who had just completed one of the marked trails through the woodland, after they headed toward their car I spent quite some time looking at the lay of land between the old and new road and the earthen embankment between, most of the time I judged the old road to be lower, but the LIDAR grid reference gave the southern part of the new road as that for the critical bwlch.  It was only after I used my camera viewing window as a level that the new road looked slightly lower than the old road, I then placed the Trimble beside the new road and hoped that any passing car would avoid a Trimble fatality.

Gathering data at the first and slightly higher of the two bylchau of Lan Lwyd

Considering where the Trimble was placed it achieved its 0.1m accuracy level relatively quickly and as it beeped away gathering its 300m allotted datum points only one car passed which was fortunate both for satellite coverage and for the safety of the equipment.

Gathering data at the second and slightly lower and critical bwlch position of Lan Lwyd

Looking back at the Arch and the bwlch of Lan Lwyd

This was the eleventh and last survey of the day and I packed the Trimble away happy in the knowledge that these hills had now been analysed with LIDAR data and surveyed with the Trimble with a mass of resulting data to salivate over!

The track proved a delight to follow as it made its way over the broad and undulating western ridge of Lan Lwyd, and down toward the old farm house of Brignant-uchaf, this is now left to the elements but is still relatively intact although a part of its roof has recently given in to age and struggle.  Today the old house nestled in its stream valley a forgotten edifice where once people would have worked and played.  I looked through an open window inside to debris, a fire place sat forgotten amongst the remains of an iron bed frame with a wall and the ceiling gaping open.  It was bathed in welcoming sunlight today, similar to a multitude of other lonely Welsh farm houses dotted across the land, some still active, others laid bare and slowly rotting, today the remains of Brignant-uchaf is a relic to times now gone.

Craig Lan Las from the track leading to the old farm house of Brignant-uchaf

Brignant-uchaf is now abandoned to the elements

Inside the living room of Brignant-uchaf

Brignant-uchaf

The track left the old farm house and I followed it through a gate and in to the conifer forest where it ended in a large gravelled area, the continuation of the path through the woodland was narrow and welcome and bathed in afternoon warmth and eventually brought me out on to open lower hillsides, where another track emerged taking me down to the B 4343 and a short walk on its tarmacked surface back to my awaiting car.

The path through the forest

Survey Result:

Curnau Mawr

Summit Height:  391.4m (converted to OSGM15, Trimble GeoXH 6000)  

Summit Grid Reference:  SN 75154 75006 (Trimble GeoXH 6000)

Bwlch Height:  369.8m (converted to OSGM15, Trimble GeoXH 6000) and 369.8m (LIDAR)

Bwlch Grid Reference:  SN 75342 74906 (Trimble GeoXH 6000) and SN 75330 74919 (LIDAR)

Drop:  21.6m (Trimble GeoXH 6000 summit and Trimble GeoXH 6000 and LIDAR bwlch) (390m Double Sub-Pedwar addition) (Sub-Trichant addition)

Dominance:  5.52% (Trimble GeoXH 6000 summit and Trimble GeoXH 6000 and LIDAR bwlch)

Craig Lan Las

Summit Height:  439.8m (converted to OSGM15)

Summit Grid Reference:  SN 75828 74735

Bwlch Height:  414.7m (converted to OSGM15)

Bwlch Grid Reference:  SN 76025 74951

Drop:  25.2m

Dominance:  5.73%

Pt. 413.9m

Summit Height:  413.9m (converted to OSGM15)

Summit Grid Reference:  SN 76757 75119

Bwlch Height:  381.7m (converted to OSGM15)

Bwlch Grid Reference:  SN 76691 75174

Drop:  32.2m

Dominance:  7.78%
 

Lan Lwyd

Summit Height:  445.4m (converted to OSGM15)

Summit Grid Reference:  SN 76171 75270

Bwlch Height:  378.0m (converted to OSGM15)

Bwlch Grid Reference:  SN 76517 75545

Drop:  67.4m

Dominance:  15.13% 

 

For further details please consult the Trimble Survey Spreadsheet