Thursday, 9 June 2016

Mapping Mountains – Trimble Surveys – Pembrokeshire Islands


15.05.16  Carn Ysgubor (SM 699 246), Carn Llundain (SM 696 234), Foel Fawr (SM 705 225) and Pt. 23.8m (SM 706 236)

Foel Fawr (SM 705 225)

Ynys Dewi (Ramsey or Ramsey Island as tautologically given on current Ordnance Survey maps) is the fourth largest island in Wales after Ynys Môn (Anglesey), Ynys Gybi (Holy Island) and Skomer.  It lies off the Pembrokeshire coast in south-west Wales and is positioned on the northern side of St Brides Bay.  Its name is testament to its association with Dewi Sant (Saint David) as is association with that of his confessor; Saint Justinian, as it is from St Justinian’s that boat trips to the island depart.

I’d chosen a perfect day for my visit as when I awoke the chill of a starlit night had brought unbroken blue sky and a welcome warmth to the air by the time of the 10.00am departure.  The only boat company with permission to land passengers is Thousand Island Adventures, and for those interested in contacting them, their telephone number is 01437-721721.

The RNLI Lifeboat station at St Justinian's, St David's


Boarding the boat to Ynys Dewi (Ramsey)

As the boat pulled out from the bay Ynys Dewi looked tantalisingly close, elongated in shape from north to south it has three hills of note that I wanted to visit and Trimble, two are over 100m in map height, whilst its southerly outlier; Foel Fawr has a drop very close to 30m and therefore its resulting Trimble data was of particular interest.

The northern part of Ynys Dewi from the east


The eastern profile of Carn Ysgubor

The boat trip only takes a few minutes and once docked we clambered off and made our way up steps and a paved track to an outlying building where Sarah gave us an introductory and informative talk about the island, this came with a pamphlet by the RSPB which included a map of the island with the pathways shown in blue and red, this proved a helpful addition to the Ordnance Survey 1:25,000 map I had brought, on which paths are hard to distinguish from the placement of near contour lines.  On my way to the outlying building I noted that there were two lumps of rock and earth adjacent to where the boat had docked, if time permitted I thought I should Trimble both on my return for the 4.00pm departure, the furthest east was an island now joined to the rest of Ynys Dewi by the steps and track, whilst its adjacent neighbour looked slightly lower in height and was joined to the mainland by an approximate 1.5m – 2m high pebbled bit of land.

Once Sarah had told us all about the island I followed the continuation of the track as it made its way up to the aptly named ‘The Farmhouse’, from here the track turned in to a delightful green path leading past walled enclosures and over radiantly green fields to the steepening slopes of my first hill of the day; Carn Ysgubor.

Carn Ysgubor stands as the island’s northern outlier and given a map height of 101m, according to the map its connecting bwlch to its higher neighbour; Carn Llundain is narrow with its valley to valley contours almost meeting, and as I approached it I noted that there were two places where its critical bwlch may be positioned, both would need Trimbling.

Carn Llundain above Aber Mawr from its connecting bwlch to Carn Ysgubor

Beyond the bwlch the path continued upward through twigs of moorland surrounds which on such an island was a welcome addition to its vegetation.  The summit of the hill is crowned by a largish cairn with embedded rocks around its periphery; I thought two points needed Trimbling, each on opposite sides of the cairn and both of similar height.  As the Trimble gathered the second of these summit data sets the first people appeared on the horizon, I sauntered over and explained what I was doing and they kindly waited until the five minutes of allotted data had been gathered.

The set-up position for the first data set taken from the summit area of Carn Ysgubor


The set-up position for the second data set taken from the summit area of Carn Ysgubor

Leaving the summit I quickly retraced my steps back to the bwlch and positioned the Trimble on top of my rucksack at the first position that needed Trimbling.  As the equipment gathered its all-important data I stood below it and took in the scene of cliffs and blue sea.

Gathering data at the critical bwlch of Carn Ysgubor

The vantage point of these two positions for critical bwlch gave me superb views back to Carn Ysgubor being flanked by its immediate southerly cliff face, a towering face of verticality edged against the tranquil waters of Aber Mawr and a contrast to the relative salubrious surrounds of its summit.

Carn Ysgubor (SM 699 246)

To my south Carn Llundain bulged up beyond the immediate greenery of field which filled the foreground, this was my next hill and at a map heighted 136m, the highest point of the island.  The path leading to it from this connecting bwlch was an absolute delight; it was a sheer pleasure to be on it as no one else was around, except for one distant picnicker cast adrift on a grassy ridge above a horrendous vertical drop to the sea below. 

A lovely place for a picnick


Carn Ysgubor stands proud and framed by the blue of sea and sky

As the warmth of the sun beat down I continued on the path, past small hill meadows of tiny wild flowers as gulls and ravens and an occasional chough with its distinct red coloured legs darted past me, it was good to be here, and as the day continued I thought about these places, these island places, their distinct habitat and their inner feeling, that feeling that they give, and I considered their essence, and wondered about an apt description that I would give if anyone was inclined to ask, and I decided upon one word, a word that summarises my feelings, that word is – uplifting.

The red-billed Chough

Nearing the summit of Carn Llundain I checked my watch, it was nearing 12.00 midday and as I touched the large cairn and trig pillar on the summit the next boat leaving St Justinian’s was approaching the island, on board were Adrian and Ayako, who planned on catching me up as I Trimbled my way around the island.  They had four hours on the island and the three of us were booked on the 4.00pm departure.  I hoped that the next survey would not take long as I still had Foel Fawr to investigate and those two lumps of rock and earth next to where the boat docked.

The 12.00 midday boat to Ynys Dewi with Adrian and Ayako on board

I scratched around the base of the summit cairn for quite some time, and not wanting to disturb it I did not investigate its inner realms, but happy that I’d found the highest embedded rock at its base I positioned the Trimble on top of my rucksack above it and set it to gather data.  Wanting to position the front of the Trimble landward it meant that it was positioned between the cairn and trig pillar but its 0.1m accuracy level before data should be logged was achieved remarkably quickly and after 300 data points were collected I switched it off, packed it away and walked over to the lower 128m map heighted southerly summit and drank in the view.  By now the early morning sunshine had turned hazy, but it was still a wonderful day to be out in such a place.

Gathering data from the summit of Carn Llundain

On my way to the southerly summit I spotted two roe deer lower on the hill’s eastern slope, almost camouflaged against the dulled colour of heather, they stood peering up at me, with an occasional flick of their heads as they nibbled on some juicy tit-bit.

A narrow path led from the lower southerly summit back to the main path and down toward the south-westerly spit of land that pokes out to sea.  The main path bisects hereabouts with one branch heading eastward toward the harbour and the other hugging the coastline ever southward, I opted for the path beside the coast and followed it to the top of a minor bump which was covered in delicate blue flowers and gave views toward Foel Fawr.

The next stretch of path was magical as Foel Fawr rose pyramidal against a backdrop of impressively shaped islands with Ynys Gwelltog particularly daunting, a great lump of beautifully carved steep rock capped with a greened summit, beyond was Ynys Cantwr and Ynys Bery, all invitingly close in distance but much farther away in reality, all a dream for budding ascensionists with one if not two distinctly doable.

The impressive Ynys Gwelltog


The view from the southern part of Ynys Dewi is particularly spectacular with (L-R) Foel Fawr, Ynys Gwelltog, Ynys Cantwr, Midland and Ynys Eilun in the background


From every viewpoint Ynys Gwelltog is impressive

I’d envisaged the connecting bwlch between Foel Fawr and Carn Llundain to be difficult to pinpoint and imagined it swamped in heather, but even from afar it was easy to see that its critical point was positioned on the eastern side of the area that took in the whole of the bwlch, and as I walked toward it this is what I found.

I gathered data from two positions a few metres apart and both on the valley to valley traverse, the ground hereabout has small undulations and therefore exact pinpointing of the critical bwlch to inch perfect would be hard to prove even with a level and staff.

Gathering data at the bwlch of Foel Fawr

Ahead lay the summit of Foel Fawr, a hill that is currently listed as a Pellennig and Sub-Twmpau with c 29m of drop.  Its profile between bwlch and summit leads me to believe that it has over 30m of drop, but the human eye is not the best to judge such things.

The south-westerly side of Foel Fawr gives a good ascent route with spectacular views


Another impressive view of Ynys Gwelltog

Once at the summit I found two small rocks that vied for the accolade of highest point, with the one nearer to a very large drop to the sea below being the one I favoured for the summit.  Because of its proximity to a large and horrible death via the dastardly bottomless drop in to the sea I decided to set the Trimble up on its dog lead, this can be clipped to its hand strap and enables me to hold it at a safe distance and positon myself under its internal antenna and yet still manage to save it if it was either blown overboard or dislodged from its alignment with the tip top and highest bit of rock, thus becoming airborne and in the process attempting to base jump down in to the bottomless depths.

The Trimble set-up position at the summit of Foel Fawr


My view of the dog lead during the first five minute data set at the summit of Foel Fawr

By the time that the safer second summit survey was being set-up a fellow walker was approaching on the path to the summit, I’d chatted with this person earlier in the day, and she kindly waited whilst five minutes of data were gathered.

Gathering data during the second data set on the summit area of Foel Fawr

Only the two lumps of rock and earth beside the landing place remained to visit and I wondered if I should ask permission to do so, as they were both off piste as far as fellow visitors were concerned. 

I came across Sarah on the path as I headed toward the harbour and explained what I hoped to do; I don’t think my directional detailing helped in pinpointing the exact places I wanted to survey so thought it wise to make further enquiries at The Farmhouse.  Approaching the house I spotted three roe deer beside the path, I back-traced to watch and photograph them, they are slender beasts, proud looking and robustly delicate.

Roe Deer with Carn Llundain in the background


One of the small herd of Roe Deer on Ynys Dewi (Ramsey)


Roe Deer with Carn Ysgubor in the background

As I rounded the corner next to the house the Warden was working beside the outlying building, I walked down and said my hello’s and explained the fineries of surveying and pointed up toward the slender summit of Ynys Fach, which is the easterly of the lumps of rock and earth, I was told that it is off limits as a canoeist fell to their death whilst on top taking photographs, I explained that I’m used to knife edged ridges and had a head for heights, but no charm on my part could persuade them otherwise.  However, I was given permission to visit the lower of these two lumps, and after a relaxing half hour in the sun on a bench outside of The Farmhouse, and after the Warden had told me that the higher and most easterly of the two lumps; Ynys Fach, is also known locally as The Axe, as according to legend this was the last point where St Justinian used his axe after creating the Bitches, I sauntered down the track and clambered up to the top of the lower lump.  This unfortunately doesn’t have a local name, although it is quite prominent to the eye.

Once on the summit I positioned the Trimble on top of my rucksack above the high point of earth and prayed that a gust of breeze would not deposit it in the ocean as it was positioned straight above an almighty drop.  As it gathered data Adrian came bounding up to meet me, he and Ayako had had a great time on the island but said that he’d had to run to bag Foel Fawr as four hours on the island proved insufficient.  When Adrian arrived we peered over toward the higher Ynys Fach and estimated that it was an approximate 1.5m – 2m higher than the summit being Trimbled.  Once five minutes of data were collected I packed the Trimbe away and sauntered down the small hill with Adrian.

Gathering data from the summit of Pt. 23.8m


The Trimble set-up position at the summit of Pt. 23.8m

All that remained was to wait for the boat to load its awaiting passengers on board and head back to St Justinian’s and the mainland.  As I walked toward the boat I took a few last photos of Ynys Fach and its great sweep of carved rock before getting on the boat, Ayako was already aboard having enjoyed her stay on the island and agreed that four hours was insufficient to visit all summits and fully investigate Ynys Dewi.

Ynys Fach which is also known locally as The Axe (SM 707 237)


Leaving Ynys Dewi


Ynys Fach


Ayako and Adrian

It had been a great few days investigating the hills and islands positioned around the Pembrokeshire coast and after saying my goodbye to Adrian and Ayako I quickly sorted my gear and car, and set the direction firmly eastward towards the delights of Worcester.



Survey Result:


Carn Ysgubor

Summit Height:  102.4m (converted to OSGM15)

Summit Grid Reference:  SM 69953 24603

Bwlch Height:  51.2m (converted to OSGM15)

Bwlch Grid Reference:  SM 70106 24328

Drop:  51.2m

Dominance:  49.99% (Lesser Dominant reclassified to Dominant [pre OSGM15]) (Dominant reclassified to Lesser Dominant [post OSGM15])    



Carn Llundain

Summit Height:  135.8m (converted to OSGM15)

Summit Grid Reference:  SM 69609 23456

Drop:  135.8m

Dominance:  100.00%



Foel Fawr

Summit Height:  72.0m (converted to OSGM15)

Summit Grid Reference:  SM 70542 22567

Bwlch Height:  41.9m (converted to OSGM15)

Bwlch Grid Reference:  SM 70511 22665




  
Pt. 23.8m

Summit Height:  23.8m
 
Summit Grid Reference:  SM 70677 23686


Dominance:  92.44%









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