Sunday, 25 March 2018

Mapping Mountains – Trimble Surveys – Cadair Idris

17.02.18  Ffridd Tyddyn Bach (SH 656 139), Ffridd Tyddyn Mawr (SH 654 140), Ffridd Las (SH 660 139) and Ffridd Bellau Nant y Gwyrddail (SH 665 139)

Ffridd Bellau Nant y Gwyrddail (SH 665 139)

With the weather forecast giving drizzly wet conditions for tomorrow’s walk celebrating Rob Woodall’s completion of the Welsh mainland Tumps, I thought it wise to take advantage of today’s weather and visit these hills to get the surveys out of the way before tomorrow’s festivities.  This would enable me to survey these hills without a time constraint and also concentrate on the land to the west of Llynnau Cregennan and the minor road leading to the car park, as a small bump needed confirmation as a 200m Sub-Twmpau.

Whilst driving west toward Dinas Mawddwy the weather closed in and rain increased in strength, thankfully this ceased by the time I drove through Dolgellau toward my parking spot close to Llynnau Cregennan.  I hadn’t been this way in a number of years and it is another one of those secluded places nestled at the base of much higher hills, but still with an inner beauty all its own.

The higher satellite peaks of Cadair Idris were bathed in low lying cloud as I set off toward the first hill, and across the Afon Mawddach the southerly ridge of the Rhinogydd were again embedded in low cloud which remained steadfast during the following three hours, whilst the lower heighted hills I planned for today were glimmering free of cloud, with early morning sunshine occasionally illuminating their slopes.

Early morning cloud and colour

I wanted to survey three hills, two of which were planned for Rob’s walk tomorrow, the other was the confirmation of the 200m Sub-Twmpau, this hill is unnamed on the map and has three uppermost 270m map ring contours with the furthest north-westerly ring contour having a 274m spot height on the Ordnance Survey Interactive Coverage Map hosted on the Geograph website.

Reaching the first of these 270m ring contours I set the Trimble up on the ground and as it gathered its allotted five minutes of data I stood back and admired the profile of Pared y Cefn Hir, a hill that was the first to be surveyed using the Leica GS15 when still with John and Graham, this is a wonderful hill, rather Scottish in nature, one whose stature defies its relatively lowly height.  This morning the wisps of low cloud were still stubbornly hugging its higher ridge, but its mid and lower slopes were illuminated in early colour, and set against the waters of Llynnau Cregennan it gave a wonderful sight.

Gathering data at the summit of Ffridd Tyddyn Bach (SH 656 139)

Pared y Cefn Hir - a sublime hill

Prior to visiting these hills I’d looked at the Tithe map for boundaries between each and farm land allocation as I hoped to visit at least one farm later in the day and confirm names for each.  The Tithe map gave the land boundary for these three 270m ring contours split between Tyddyn Bach and Tyddyn Mawr, two farms positioned to the north of the hill, with just the latter named on current maps.  These land boundaries consisted of walls, between each was land probably seldom visited by the hill walker, and yet it was stunning in simplicity with wall, bog and hill all contrasting and giving substance to the view.  Land boundaries by their nature are impositions upon the land, they are territorial markers of ownership or grazing rights, they seldom enhance land, as the wild nature of open land will testify, and yet on this morning, the boundaries of walls seemed to justify their existence, they seemed set, permanent and unmoving, an indicator of an old traditional, and one that added perspective and history to this place.

The walled and bounded Ffriddoedd

As I gathered the Trimble after the morning’s first survey I headed northward toward the next 270m ring contour, this was visually lower than the third where the 274m spot height is adjoined, but as I had no time constraint and the weather favourable I thought I’d gather another data set to be completest.

Gathering data at the summit of the second and central 270m ring contour

This second high point proved to be an embedded rock with a small gorse bush smothering it, once five minutes of data were stored I headed toward the higher of the three ring contours and set the Trimble atop my rucksack and waited for the next data set to be gathered.

Gathering data at the summit of Ffridd Tyddyn Mawr (SH 654 140)

Before heading to the next hill I wanted to take at least two data sets from the positions that map contouring indicates are the possibilities for the critical bwlch position of this hill, the first of which was on a green path at the base of a bump, the second of which was in a bog close to the minor road as it skirts the western fringe of the double lakes.

Surveying the bwlch of Ffridd Tyddyn Mawr

After this second bwlch survey I started the ascent of the 279m map heighted hill which is directly above the minor road and the hill that Rob planned on finishing on tomorrow, whilst doing so I looked back at the bog I had just surveyed and decided I should take another data set from its northern extremes, so I backtracked down the hill, set the Trimble up and as it gathered data I noticed a farm vehicle parked outside Ffridd Boedel; a small farm house beside the minor road, and after the Trimble was packed away I knocked on its door, no one was in, but I hoped when here the following day to meet the farmer and ask about the names of these hills.

It was only a short walk, albeit steep, to the high point of what I learnt the next day is the hill known as Ffridd Las, this is the hill Rob planned on finishing on and as the Trimble was set on the ground aligned with the high point of the hill and beeped away gathering its five minutes of data I snook off to a convenient gorse bush and hid a small bottle of Champagne for tomorrow’s celebration.

Gathering data at the summit of Ffridd Las
Zoom in and you can just see the top of the small bottle of Champagne left in the gorse bush for the celebration of Rob's completion of the Welsh mainland Tumps the following day

Leaving the summit of Ffridd Las I headed south to the minor road at the hill’s base and walked the short distance toward a gate, beyond which was my car, from close to this a path heads across the connecting bwlch, this was the point for the next survey.  Before setting the Trimble to gather its next data set I assessed the lay of land from a number of directions and decided that beside this narrow path was as good as any.

Ffridd Las from the south

Approaching Ffridd Bellau Nant y Gwyrddail

Gathering data at the critical bwlch of Ffridd Las with Ffridd Bellau Nant y Gwyrddail in the background

Before visiting the summit of the third hill I wanted to gather data at its connecting bwlch, this is positioned to the north-east of its summit and so I walked on a moorland track and skirted the summit to its north, using gates to access the grazing pasture where the bwlch is situated.

The view north-east from the bwlch of Ffridd Bellau Nant y Gwyrddail

All that remained on this walk was the last survey, the summit of which is situated on land known as Ffridd Bellau Nant y Gwyrddail; which when translated in to English can mean the far off ffridd of Nant y Gwyrddail, with Nant-y-gwyrddail being a farm situated SH 671 143.  This hill’s summit proved a wonderful spot with views stretching down the stream valley toward Llyn Gwernan, across Llynnau Cregennan toward Pared y Cefn Hir and in to the mass of higher hills surrounding Cadair Idris.

Llynnau Cregennan from the summit of Ffridd Bellau Nant y Gwyrddail

Gathering data at the summit of Ffridd Bellau Nant y Gwyrddail

It was a fitting place to end this part of the morning’s surveying activities, but I still had time for one more survey which meant a small drive around the corner of the minor road, but this will be detailed in a separate post.

Survey Result:

Ffridd Tyddyn Bach (significant name change)

Summit Height:  272.0m (converted to OSGM15)

Summit Grid Reference:  SH 65693 13963

Bwlch Height:  259.4m (LIDAR)

Bwlch Grid Reference:  SH 65599 13975 (LIDAR)

Drop:  12.6m (Trimble summit and LIDAR bwlch)

Dominance:  4.66%

Ffridd Tyddyn Mawr (significant name change)

Summit Height:  273.2m (converted to OSGM15)

Summit Grid Reference:  SH 65486 14081

Bwlch Height:  251.2m (LIDAR)

Bwlch Grid Reference:  SH 65928 13997 (LIDAR)

Drop:  22.0m (Trimble summit and LIDAR bwlch) (200m Sub-Twmpau addition)

Dominance:  8.06%

Summit Height:  278.5m (converted to OSGM15)

Summit Grid Reference:  SH 66076 13984

Bwlch Height:  247.8m (converted to OSGM15)

Bwlch Grid Reference:  SH 66369 13783

Drop:  30.7m (200m Twmpau status confirmed)

Dominance:  11.02%

Ffridd Bellau Nant y Gwyrddail (significant name change)

Summit Height:  280.0m (converted to OSGM15)

Summit Grid Reference:  SH 66542 13906

Bwlch Height:  244.6m (converted to OSGM15)

Bwlch Grid Reference:  SH 66859 14241

Drop:  35.4m

Dominance:  12.64%

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