Monday, 4 January 2021

Mapping Mountains – Trimble Surveys – Arenig

 

20.09.20  Pt. 513.4m (SH 760 439), Graig Goch (SH 751 440), Graig Goch (SH 752 444), Graig Goch (SH 750 447), Graig Goch (SH 749 447), Y Clochdy (SH 749 450), Pt. 516.5m (SH 745 449), Pt. 509.0m (SH 745 446) and Pt. 502.6m (SH 743 440) 

Y Clochdy (SH 749 450)

There are few small groupings of hills that are as contrastable when viewed from their east compared to their west than the grouping that takes Graig Goch as their highest.  It is this group that splits the land between the Moelwynion and the Y Migneint that then merges in to the higher Arenig.  From their east it is the moorland of tussock grass, heather and bog that is on show; this is typical Migneint territory and one to be savoured when in its realm.  From the west the crags that give the highest hill its name are on display, with attractive lakes at their base.  Even though the underfoot conditions can still be torturous it is the western aspect of these hills that show them at their best.  This contrast is greatest when approaching the lower southerly part of the Graig Goch ridge from the east.  This is when the crags only manifest when on the ridge and the lakes of Llynnau Gamallt and Llyn Bryn Du spring in to view. 

It was this eastern approach that Aled and I took today.  Meeting at the small parking area beside Llyn Dubach, we soon had our cars re-positioned with one left at the end of the track leading to the fisherman’s path and the other beside Ffynnon Eidda. 

We had a number of surveying objectives for the day which consisted of ten hills; many of these were on the Graig Goch ridge and the majority of the remainder in the land to the west beside the lakes.  Our first hill was literally just above where Aled parked his car and we were soon walking up toward its high point. 

A strong easterly breeze blew as we approached the summit, heralding the onset of autumn.  The summit of this small hill is given a 514m spot height on the Ordnance Survey 1:25,000 Explorer map and its bwlch a 503m spot height.  Both positions were surveyed.  From here pathless moor leads toward the Graig Goch ridge. 

Heading toward the Graig Goch ridge

It was slow going on the moor, picking out two landmarks we wandered toward each before resting for a few minutes and then setting off for the next.  Slowly our first hill of the hill became more distant and we reached the southern end of the ridge.  The contrast couldn’t be greater.  The great sweep of broken crags swept north before swinging north-westward with the two lakes of Llynnau Gamallt stretching below.  I hadn’t been on this hill for 16 years and the memory held from that day matched this as I stood and looked and savoured the view. 

The southern end of the Graig Goch ridge

Llynnau Gamallt

The surveys came thick and fast as we surveyed all summits and connecting bylchau before reaching the high point of the day; the summit of Graig Goch.  This is crowned by a large flattish rock with a neatly constructed cairn on it.  Soon the Trimble was set-up and beeping away collecting its individual data points. 

Gathering data at the summit of Graig Goch (SH 751 447)

Beyond Graig Goch we still had three hills to survey before dropping down to our west and the land beside the lakes.  Two of these are minor prominence tops connected to Graig Goch whilst the third is Y Clochdy; which is a fine hill and especially so when viewed from the west looking east when its bell-like profile is on grand display. 

The cold east breeze of early morning was now slowly being replaced with warming sunshine as the high grey cloud was burnt away, leaving blue skies for the remainder of the day.  Having surveyed the bwlch and summit of Y Clochdy we joined the path leading down toward the wild lands close to Llyn Bryn Du.  Here we left the path and contoured the lower westerly slopes of Y Clochdy to a small notch which proved to be the bwlch of our next hill to survey which overlooks the quiet surrounds of Llyn Bryn Du. 

I’d been surveying around these parts many years ago with my old basic levelling staff but have very little memory of it.  It was good to be back with Aled, who was ever enthusiastic to survey all small tops to add to our ever increasing data for our 500m Welsh list. 

Llyn Bryn Du with Y Clochdy beyond

The next hill was positioned just to the south of Llyn Bryn Du and before its summit we had its bwlch to assess.  This took time as the territory consisted of tussocks, heather and bog, but happy with our chosen position I set the Trimble up and we waited for the allotted data to be gathered and stored.  The summit of this hill consisted of a large rock overlooking Llynnau Gamallt, and proved another fine small hill and one well worth visiting. 

The descent to the lake was past huge rocks with massive clefts splitting their vertical faces.  Edging our way down I made a mental note not to visit this area when misty as there are few navigational aids on the ground and if whatever path exists is not found, the going underfoot would be problematic. 

Thankfully, the afternoon was proving blissful with blue skies above and descending toward the northern edge of the smaller of the Llynnau Gamallt lakes a path contoured around its shore heading toward our next bwlch to survey.  This bwlch connects with a 502m map heighted hill which is listed in the Deweys as Moel Gamallt; this hill is marginal on both height and drop and needed an accurate survey. 

As the Trimble gathered data at the bwlch I sat with Aled on a rock and waited for the allotted data to be stored.  The day had been a long one and this survey was the nineteenth and with one last summit survey afterward it was going to join the ranks of days with 20 or more surveys completed.  There had been one or two of these over the years since I bought the Trimble, but not too many. 

The fisherman's hut beside Llynnau Gamallt

After the bwlch survey was completed I packed the equipment away and we walked the short distance to the fisherman’s hut which is named Shooting Box on the Ordnance Survey map.  This hut is now showing signs of neglect with a few holes in its roof.  We looked inside and found a framed photograph of David Bowie beside mugs, frying pans and an empty milk carton.  There are few places like this amongst the Welsh hills; the ones on the higher hills are mountain refuges and a few others are fisherman’s huts, with the latter usually locked.  This was open and its darkened interior was at contrast to the unadulterated colour and warmth outside. 

Inside the fisherman's hut

Just one summit remained and it was a slow plod to its high point across more tussocks until its grassed summit was reached.  I needed to sit and rest during data collection, relaxing in the sun looking across the larger of the Llynnau Gamallt lakes to the great sweep of crags beyond.  It was a shame to leave, but as ever one must. 

Gathering data at the summit of Pt. 502.6m (SH 743 440)

All that remained was the walk down the hill’s broad easterly flank to connect with the fisherman’s path leading around the southern shore of the larger lake.  From here Y Clochdy and the cliff of Graig Goch dominated the view with its conically shaped profile set against the blue of the lake, a marvellous sight. 

Y Clochdy and Graig Goch from the southern shore of Llynnau Gamallt

It was lovely to reach the car and get my boots off and change before driving on the rutted track to the minor road and heading the short distance north to Aled’s car.  The walk had taken 8 hours 20 minutes, and although not great in length we accomplished all surveying objectives with 20 surveys taken and some special little hills visited.  A stunningly beautiful area!

 

Survey Result: 

 

Pt. 513.4m  

Summit Height:  513.4m (converted to OSGM15)

Summit Grid Reference:  SH 76032 43918

Bwlch Height:  503.2m (converted to OSGM15)

Bwlch Grid Reference:  SH 76084 44174

Drop:  10.2m

Dominance:  1.99%

 

 

Graig Goch  

Summit Height:  548.2m (converted to OSGM15)

Summit Grid Reference:  SH 75134 44061

Bwlch Height:  539.2m (converted to OSGM15)

Bwlch Grid Reference:  SH 75141 44092

Drop:  9.0m

Dominance:  1.64%

 

 

Graig Goch  

Summit Height:  576.3m (converted to OSGM15)

Summit Grid Reference:  SH 75223 44423

Bwlch Height:  564.4m (converted to OSGM15)

Bwlch Grid Reference:  SH 75201 44487

Drop:  11.9m

Dominance:  2.07%

 

 

Graig Goch  

Summit Height:  589.5m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SH 75124 44714 (Trimble GeoXH 6000)

Bwlch Height:  466m (spot height)

Bwlch Grid Reference:  SH 73957 45053 (spot height)

Drop:  123m (Trimble GeoXH 6000 summit and spot height bwlch)

Dominance:  20.94% (Trimble GeoXH 6000 summit and spot height bwlch)

 

 

Graig Goch  

Summit Height:  587.2m (converted to OSGM15)

Summit Grid Reference:  SH 75092 44781

Bwlch Height:  577.8m (converted to OSGM15)

Bwlch Grid Reference:  SH 75131 44759

Drop:  9.4m

Dominance:  1.60%

 

 

Graig Goch  

Summit Height:  585.1m (converted to OSGM15)

Summit Grid Reference:  SH 74997 44799

Bwlch Height:  577.9m (converted to OSGM15)

Bwlch Grid Reference:  SH 75073 44794

Drop:  7.1m

Dominance:  1.22%

 

 

Y Clochdy  

Summit Height:  577.6m (converted to OSGM15)

Summit Grid Reference:  SH 74972 45046

Bwlch Height:  559.4m (converted to OSGM15)

Bwlch Grid Reference:  SH 75075 45001

Drop:  18.1m

Dominance:  3.14%

 

 

Pt. 516.5m  

Summit Height:  516.5m (converted to OSGM15)

Summit Grid Reference:  SH 74568 44934

Bwlch Height:  506.0m (converted to OSGM15)

Bwlch Grid Reference:  SH 74620 44956

Drop:  10.5m

Dominance:  2.03%

 

 

Pt. 509.0m  

Summit Height:  509.0m (converted to OSGM15)

Summit Grid Reference:  SH 74586 44601

Bwlch Height:  499.7m (converted to OSGM15)

Bwlch Grid Reference:  SH 74643 44752

Drop:  9.3m

Dominance:  1.84%

 

 

Pt. 502.6m  

Summit Height:  502.6m (converted to OSGM15)

Summit Grid Reference:  SH 74376 44064

Bwlch Height:  471.0m (converted to OSGM15)

Bwlch Grid Reference:  SH 74449 44350

Drop:  31.6m

Dominance:  6.30%

 

 

For further details please consult the Trimble Survey Spreadsheet

 

No comments:

Post a Comment