Mapping Mountains – Trimble Surveys – Arenig

25.10.14  Cefn Caer Eini (SH 985 403), Pt. 368.9m (SH 991 412), Caer Eini (SJ 000 412) and Mynydd Mynyllod (SJ 002 395)

Caer Eini (SJ 000 412)

Towards the outskirts of Y Bala between the Afon Dyfrdwy (River Dee) and the summit of Foel Goch and its adjacent hills is a land of quiet moorland summits interspersed by the seldom visited lakes of Llyn Caer Eini and Llyn Mynyllod.  The name of each lake has direct connection to hills that rise from their shores and look down on their waters.

Although the hills situated near these lakes are bounded by fences they portray a feeling of openness, part of this feeling is due to hillsides predominantly consisting of heather.  Today the heather had turned from its late summer bud to a swaying mass of foliage in tune with the direction and strength of the wind.  It blew as one, almost being an entity all to itself.

I’d often wondered about visiting these hills but had never done so.  The opportunity to investigate their inner depths arrived by email and was sent by Aled, who wondered if I fancied a wander taking in a survey or three.  Quickly the hills and route with an extension if time, weather and inclination permitted had been decided upon.

We met at 9.30am and left one car in a large lay-by at SJ 003 407 and proceeded to drive to the start of the walk at SH 980 401 where a car can be parked on the grass verge at the end of the paved road.  From here a track led toward the first summit of the day.

This parking spot is at 350m which meant that there was only about 19m of ascent to our first summit of the day.  Before setting off we sat in Aled’s van chatting about a forthcoming Europeaklist publication that should be published in the next month or so.  We also peered out of the car’s front window at a decidedly grey and inhospitable scene where southerly showers swept across the land turning everything in their path a deep grey of wet and murk.  The scene was pretty yuck and we waited until the yuckiness seemed to have gone and the sky turned a lighter shade of mucky grey and off we went.

Within a few moments we were heading toward the summit of Cefn Caer Eini which is given a summit height of 369m on contemporary Ordnance Survey maps.  It also has a twin 369m summit a kilometre away, separating their heights was something I’d wanted to do ever since first listing them over eleven years ago, the advent of Leica and Trimble equipment now gives this opportunity – YYIIIIPPPPPP!!

Heading toward the first of the two 369m map heighted tops

By the time we arrived on the first 369m map heighted summit of Cefn Caer Eini the southern and western sky was full to overflowing with rain, the Trimble was quickly positioned on the obvious high point which is an embedded rock, it attained its 0.1m accuracy before data can be logged relatively quickly and I turned my back to the rain and looked north to friendlier weather.

Gathering data on the summit of Cefn Caer Eini

Once the Trimble had collected its five minutes of summit data we headed toward the second 369m map heighted hill, by now the shower had skimmed across the landscape and the sun cast out from behind a bulbous and imposing deep grey mass of sky.  The whole area of land where we were took on an autumnal glow where colour seemed to pop out into an illuminated mass of gold, green and blackish grey. 

The view west from between the two 369m map heighted summits

Five minutes of colour before the next shower sped in

Shadowed distant hills

Shadowed distant hills contrasted with brackened foreground as the grey of sky shone and pieced a freshness of colour around us.  The light lasted for five minutes or so and was quickly replaced as the next mass of milky grey swept in from the south replacing the colour wonder with another wet wind swept shower.

Fierce shower greys

Bathed light of a rainbow

The second top was soon reached and the high point judged and once the Trimble was in position and gathering data we looked out across the forgotten Cwm Main stretching into the distance and bathed by the enriched colour of a rainbow.

Gathering data from where I judged the summit of Pt. 368.9m (SH 991 412) to be positioned

LIDAR image of Pt. 368.9m (SH 991 412)

The next shower approaches as rainbow light is cast down into Cwm Main

The rainbow stayed with us as we headed for the critical bwlch of Caer Eini which is a marginal P30 with a listed drop of 31m.  Its bwlch is positioned in a wasteland of heather and I placed the Trimble to where I judged its critical point lay.

Gathering data at the bwlch of Caer Eini

LIDAR bwlch image of Caer Eini

I soon re-joined Aled once the Trimble had gathered its bwlch data and we continued to the summit of Caer Eini.  The summit area of this hill in another fine example of an ancient hill fort, we approached it via its southern entrance, with the northerly one probably being the main point of entry when first constructed.  The ramparts are impressive with a 6ft elevation between ditch bottom and the top of the earthen bank.

Hard to give a title to this one........ a rainbow

The summit of Caer Eini is crowned with a neat and well-constructed cairn, the land at the base of the cairn has a number of rocks, most were given a good firm kick to see if they moved, all did except for one, which unexpectedly was not the largest.  The Trimble was soon on its high point and gathering data.

I enjoy the time when each data point is logged and the Trimble ushers a beeping sound, it’s time to furiously scribble all necessary notes including margin of positional uncertainty, number of satellites the equipment is logged onto, time at which data started to be logged, terrain where the equipment is placed, time of overall data collection, name of hill and if the data collection is at a summit or bwlch.  However, this time can also be one of reflection or it can be one of admiration.  Today it was spent with the latter as the cairn atop Caer Eini became framed by the continuing presence of a rainbow which cast its delicate arch of colour across the north-western sky.

Gathering data at the summit of Caer Eini

As we left the summit and headed back toward the bwlch the next grey mass of shower cloud sped its way toward us and by the time we neared a conifer plantation above the minor road that runs parallel with the busy A494 the rain was upon us, but thankfully standing beside the fence next to the wood shielded us from the worst of the wet stuff.

The descent down to the minor road was a slippy affair on slothy mud.  Our route then took us across a couple of fields and onto the busy road which we walked on for a couple of minutes before heading up on a good path toward Mynydd Mynyllod which at 395m on the map would be our high point of the day.

The path gained height at a gentle gradient and led up to the higher heather clad slopes, as we left the path it was only five minutes of gentle stomping and the summit was reached.  The Trimble nestled amongst the heather almost hidden from view and data were gathered.  We contemplated investigating a hill to the south-west but this could be left for another day when this area could be approached from a different direction giving another perspective to this lovely land.

The Trimble heather bound on the summit of Mynydd Mynyllod

We descended on part of our inward route and then headed off on an overgrown green track which took us back to Aled’s awaiting van.  However, the surveying was not over for the day as I wanted to investigate the bwlch for Mynydd Mynyllod which is placed on or near to the busy A road close to or on a cross roads at the small community of Bethel.

Aled drove to the crossroad and I jumped out and walked up the road toward the direction of Y Bala, the 271m spot height that appears on the Ordnance Survey 1:25,000 Explorer map is positioned on the main road as it is intersected by the small lane from Bethel.  When out of the van and looking at the area of the bwlch it was evident that the critical bwlch is placed slightly westward from where the spot height appears on the ground.  Thankfully the critical bwlch was not on the busy A road otherwise Aled may have had to stop the traffic during Trimble collection.  The critical bwlch was found to be in a field adjacent to the road and it received the customary good Trimbling.

Gathering data at the critical bwlch for Mynydd Mynyllod

Once Aled had dropped me off at my car I drove toward Y Bala and into heavy rain that continued up onto Y Berwyn, it seemed we were fortunate to only experience wind-blown showers.  It proved a great day out on hills that give a welcome solitude.  

Survey Result:

Cefn Caer Eini

Summit Height:  369.2m (converted to OSGM15) 

  

Summit Grid Reference:  SH 98530 40303

Bwlch Height:  286.6m (LIDAR)

Bwlch Grid Reference:  SH 97035 39953 (LIDAR)

Drop:  82.6m (Trimble summit and LIDAR bwlch)

Dominance:  22.37% (Trimble summit and LIDAR bwlch)

Pt. 368.9m

Summit Height:  368.9m (LIDAR)

   

Summit Grid Reference:  SH 99136 41259 (LIDAR)

Bwlch Height:  344.2m (LIDAR)

Bwlch Grid Reference:  SH 99216 41144 (LIDAR)

Drop:  24.7m (LIDAR) (Sub-Trichant addition confirmed)

Dominance:  6.69% (LIDAR)





Caer Eini

Summit Height:  365.7m (converted to OSGM15)

   

Summit Grid Reference:  SJ 00048 41275

Bwlch Height:  334.4m (LIDAR)

Bwlch Grid Reference:  SH 99599 41003 (LIDAR)

Drop:  31.3m (Trimble summit and LIDAR bwlch) (Sub-Trichant reclassified to Trichant)

Dominance:  8.56% (Trimble summit and LIDAR bwlch)

Mynydd Mynyllod

Summit Height:  393.7m (converted to OSGM15) (390m Sub-Pedwar status confirmed) 

  

Summit Grid Reference:  SJ 00230 39523

Bwlch Height:  272.1m (converted to OSGM15)

Bwlch Grid Reference:  SH 98722 39722

Drop:  121.6m 

Dominance:  30.89%

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