13.09.19
Pen y Waun Fawr (SN 878 949), only bwlch surveyed
The view down the
Pennant gorge is unexpected and rather stunning as the ice aged glaciers have
carved a great swathe of land and left an almost symmetrical steep sided
gorge. The view can be awe-inspiring.
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| The Pennant gorge |
The land either side of
this gorge is pastoral with greened grazing fields in time giving way to
moorland. When looking down the gorge
the hill on the eastern side is known as Pen y Waun Fawr. I’d visited its summit once before in October
2003 surveying hills with my old basic levelling staff as I did so. Since these days LIDAR is now available and
the summit of this hill has subsequently been analysed by Aled Williams. However, LIDAR does not cover its connecting
bwlch, and this was my next surveying objective during a day which comprised
six roadside surveys, and all done in glorious sun drenched weather.
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| Pen y Waun Fawr (SN 878 949) |
Ordnance Survey maps
indicate that the critical bwlch for this hill is on or immediately beside the
minor road that heads north toward Bontdolgadfan. To check on the width of the road and parking
I’d accessed a Google car via my laptop the previous evening and found the
connecting bwlch for this hill was placed on the minor road. Therefore, I would have to position my car
directly over the bwlch and use the car’s roof as an improvised tripod.
Thankfully the minor
road is just wide enough to squeeze one parked car adjacent to the mature
boundary hedge and leave sufficient space for any vehicle to pass on the other
side. When I arrived I parked and spent
a few minutes wandering down either side of the car assessing the lay of
land. Contouring on the OS Maps website implies
that the critical point of this bwlch is beside a fence that heads downhill from
the west, I judged the critical point to be a few metres further south, however
the road hereabouts was relatively flat for ten metres or so.
Once I’d moved my car in
to position, I placed the Trimble on its roof and measured the offset between
its internal antenna and the ground below and proceeded to stand on my recently
bought aluminium surveying steps, which proved ideal to see the Trimble’s
screen and create the file whilst setting the equipment up to gather data.
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| The Trimble set-up position at the bwlch of Pen y Waun Fawr |
During this the road
remained relatively quiet with only an occasion passing cyclist and a rogue car
or two. Once the Trimble attained the
0.1m accuracy level before data should be logged I pressed ‘Log’ and moved the
steps to the front of the car and walked a short distance away and politely
gestured with a hand wave and smile at any vehicle that then passed. Only one pulled up to ask if I was all right,
with the presumption that my car may have broken down. I thanked them for stopping but said
everything was all right, except for the bwlch which really should have been in
the adjacent field and not on the road!
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| Gathering data at the bwlch of Pen y Waun Fawr |
There’s a surreal
enjoyment that can be found with surveying a road. It can be dangerous, to the person conducting
the survey as well as to the equipment as evidenced by the unfortunate dicing
with death the Trimble experienced when it was run over. However, the Trimble is a sturdy beast and I’ve
learnt from past experience, and now come well prepared with a car roof and
surveying steps. The surreal quality
still remains though, and this kind of activity is not one that I envisaged being
a part of my life even a few years ago.
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| Done the job and now ready to be packed away |
Once allotted data were
gathered and stored I closed the equipment down, took a few photos, packed it
away and headed down to Bontdolgadfan and the hill road toward Talerddig where
the high point of the road nestled beside a field where the next roadside
survey was to take place.
Survey Result:
Pen y Waun Fawr
Summit Height: 401.3m (LIDAR)
Summit Grid Reference: SN 87843 94922 (LIDAR)
Bwlch Height: 330.1m (converted to OSGM15)
Bwlch Grid Reference: SN 88483 94552
Drop: 71.2m
Dominance: 17.74%
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