Mapping Mountains – Trimble Surveys – Carnedd Llywelyn

31.08.18  Foel Lwyd (SH 720 723) and Tal y Fan (SH 729 726)  

Tal y Fan (SH 729 726)

Today I hoped to meet Matthew Myerscough and Michael Murray as they reached the summit of Tal y Fan, the last of 190 Welsh Nuttall summits on their continuous coast to coast walk over these hills that had taken 34 days to complete.  For more details please see their Dragon’s Back Challenge website.

I’d tried to meet Matthew and Michael 15 days ago, but heavy overnight rain meant that instead of pushing on through a part of the Berwyn, whose hills I was surveying, they had taken a day off to re-group.

To complicate matters I had arranged to meet Janet Ruth Davies; a research photographer, in Capel Curig at 4.00pm, and therefore I needed to leave the summit of Tal y Fan by 2.30pm, would Matthew and Michael be on this final summit by then, all I could do was reach the summit and wait.

As I drove up the high road toward Bwlch y Ddeufaen that heads in to the northern Carneddau, the sky shone blue, a radiant colour at this time in the morning.  The route I had planned was not long, as it only took in Foel Lwyd and Tal y Fan, but I wanted to take data from each bwlch and summit to compare against that taken by John, Graham and myself with the Leica GS15 in May 2013 when we surveyed the summit of Tal y Fan, and the following day the summit of Foel Lwyd, and by Alan Dawson who in June 2017 surveyed each summit and bwlch with his Leica RX1250.

I was walking up the continuation of the narrow road to the south of Tal y Fan by just after 10.00am and hoped to complete the surveys by 1.30pm, which would give me an hour on the summit of Tal y Fan waiting for Matthew and Michael.

A car and camper van sat resting in the early morning sun in the car park at the end of the narrow road, their occupants either on the hill or still asleep, from here a track heads toward the bwlch which is dominated by two standing stones, these sentinels have stood guard for many millennia, and although the construction of pylons that cross this bwlch is an imposition that nowadays would probably not be granted planning permission, the monoliths still stand solemnly on the passage of time.  This morning they were bathed in sunshine with yellowed gorse and purpled heather as backdrop.

Looking toward Bwlch Ddeufaen

The southerly monolith

The northerly monolith

The bwlch of Tal y Fan is positioned close to these two ancient monoliths and Alan had previously surveyed it with the Leica RX1250, I wanted to gather data from his bwlch position and also from a second position approximately 100 metres distant that OS Maps indicate is a contender for the critical bwlch.

The first position was beside a bog and realising I had plenty of time until my hoped for rendezvous I decided to gather ten minutes of data.  During this a number of people passed mainly heading over the bwlch, with one person heading south-west up toward Carnedd y Ddelw.  Once data were gathered and stored I wandered through the heather toward the second position to be surveyed, and another ten minute data set was duly gathered.

Gathering data at the critical bwlch of Tal y Fan

Leaving the bwlch I made steady progress up beside the wall leading toward the summit area of Foel Lwyd, the last time I’d visited this hill was in May 2013 with John Barnard and Graham Jackson the day after filming with BBC Breakfast on the summit of Tal y Fan, and although we worked extremely well as a team on and off the hill, I can remember disagreement in the ranks even then, on this particular day the conversation was partly based on what hills we should concentrate on surveying, as although I’d invested a great amount of time and effort in to the team as well as a substantial amount of money, the hills I either wanted to survey or suggested to survey were usually dispensed with and others favoured instead.

The summit of Foel Lwyd is situated on the southern side of a stone wall and this had to be negotiated to get to it.  Stone wall and barb wired fence climbing are two intrinsic parts of hill walking that seem to be getting more difficult with the passage of time, and this one proved no different as I sat astride the wall wondering what my next move should be!

Eventually I slithered down the wall and made my way through heather toward the small rock where the summit of Foel Lwyd is positioned.  During the morning a brisk breeze blew and so I positioned the Trimble atop my rucksack which was nestled on its back, and aligned the internal antenna of the Trimble with the high point of the hill and noted the measurement offset between it and the ground below, before pressing ‘Log’ and waiting for ten minutes of data to be gathered and stored.

Gathering data at the summit of Foel Lwyd

By now I was scouring adjacent hillsides in the faint hope of spotting Matthew and Michael, unsurprisingly the distance involved meant that even if they were walking on one of the ridges I would probably not pick them out.

Away to the north the gauged out husk of Penmaen Mawr, which in its time was an impressive hill with over 100m of prominence, and due to quarrying is now two separate P30s, stood out with Ynys Seiriol (Puffin Island) behind, with its brambled summit being a test of mind and body to reach.

The two summits of Penmaen Mawr with Ynys Seiriol in the background

Ahead the rock strewn upper slopes of Tal y Fan rose domed like out of heathered surrounds, with its trig pillar pointing skyward.  My next survey was the connecting bwlch between these two hills, this is the critical bwlch of Foel Lwyd and is placed beside the stone wall.  I found placing the Trimble on top of it to be the easiest course of action, and another data set was gathered.

Tal y Fan from Foel Lwyd

Gathering data at the bwlch area of Foel Lwyd

A path leads from the bwlch through the rocky upper slopes of Tal y Fan to the ladder style close to its trig pillar and large embedded rock which is its high point.  When I arrived there was a buzz of a radio receiver and Dave; its operator, was busy connecting with a multitude of people, we only talked briefly as I wanted solitude and a sit in the brisk sun drenched breeze.  But before doing this I wanted to gather the last data set of the walk from the high point of Tal y Fan.

Gathering data at the summit of Tal y Fan

As the Trimble gathered this last data set I sat on a rock beside the stone wall and again scoured adjacent hillsides for any sign of Matthew and Michael.  Once the Trimble had gathered and stored its allotted data I closed it down, packed it away and had a bite to eat and sat waiting.  After an hour I wondered if Matthew and Michael had already been over the summit and were now heading down to the completion of their continuous walk at the coast to the north.  By 2.15pm there was no sign of them and so I gathered up the bottle of celebratory bubbly I’d brought and which was nestled in my rucksack, taped the congratulatory note I had written to its side and positioned it at the base of the trig pillar, hoping that if they were still on their way toward Tal y Fan they would at least find it.  At 2.30pm I started my descent.

The bottle of bubbly left (and found) for Matthew and Michael

Nestled out of the breeze awaiting a continuous Welsh Nuttall completion

It is only a short distance from the summit of Tal y Fan following the path down its slopes to a ladder stile close to its connecting bwlch and then onward to the narrow lane where my car was parked.  During my descent I continued to look out toward Pen y Castell which I presumed would be Matthew and Michael’s penultimate hill and wondered if they would head in a direct route from this hill to Tal y Fan, they did not, as although I missed meeting them, they found the bottle of bubbly having arrived on the summit of Tal y Fan at 4.30pm after doubling back to Drum from Pen y Castell.  It was a shame I had missed them, and their achievement in completing a continuous traverse of the Welsh Nuttalls and in the process raising £5,000 for the Llanberis and Aberglaslyn Mountain Rescue Teams is to be applauded.

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 the bwlch of Foel Lwyd.

  

Survey Result:

Foel Lwyd 

Summit Height:  600.2m (converted to OSGM15, from previous Leica GS15 survey) (significant height revision)

Summit Grid Reference:  SH 72036 72323 (from previous Leica GS15 survey)

Bwlch Height:  547.2m (LIDAR)

Bwlch Grid Reference:  SH 72647 72325 (LIDAR)

Drop:  53.0m (Leica GS15 summit and LIDAR bwlch)

Dominance:  8.83% (Leica GS15 summit and LIDAR bwlch)

Tal y Fan

Summit Height:  610.0m (converted to OSGM15, average of two previous surveys by a Leica GS15 and Leica RX1250)

Summit Grid Reference:  SH 72936 72648 (from previous Leica RX1250 survey)

Bwlch Height:  420.5m (converted to OSGM15, from previous Leica RX1250 survey)

Bwlch Grid Reference:  SH 71446 71856 (from previous Leica RX1250 survey)

Drop:  189.5m (from previous Leica RX1250 survey)

Dominance:  31.07% (from previous Leica RX1250 survey)

For further details please consult the Trimble Survey Spreadsheet