23.07.16 Mynydd Ton
(SS 949 940 [SS 947 939, position Trimbled])
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| Mynydd Ton (SS 949 940) |
I’d visited Mynydd Ton
once before in February 2003 when I followed the track leaving the A 4061
toward a forest break that gave relatively easy access toward where the 535m
map heighted trig pillar was situated.
On that day I found ground about a minute away from the trig to be
slightly higher, happy with my efforts I retraced my inward route back to my
car. Since my visit a number of Ordnance
Survey maps have become available online, including the series of old Six-Inch
maps and I believe it was Mick Moore who found a 1,769ft (539m) height on one
of these maps that is adjoined to an ancient cairn which is approximately 175
metres south-west from where the trig pillar is positioned. Therefore I wanted to re-visit the hill and the
relatively newly discovered map high point.
As I left my car in a
large lay-by near to the high point of the A 4061 the sun was out and young
children were happily waiting next to an ice cream van as sheep also queued for
any odd piece of food thrown their way.
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| The view north-east from the lay-by |
A track leaves this road
and heads up toward the forested summit area of Mynydd Ton, as I walked toward
it two trail bikes were going through the gate and sped off across the hill’s
northern flank, ahead was a car chugging its way up the track. As I gained height there were other cars parked
high on the track with a number of people flying model aircraft, I said my
‘hello’s’ and continued on the track to where it enters the forestry, I then
turned right (southward) and followed a path beside the large conifer
plantation to where a wide forest break gives access toward the map high point
of the hill.
Seemingly abandoned in
the forest break was a four by four vehicle with its front windscreen partly
smashed and its front end also badly damaged, I took a few photographs of it
and continued down the forest break wanting to see if I could find the trig
pillar that I’d previously visited, deciding that I’d had enough tree bashing
for the day from my recent visit to Mynydd Ystradffernol, I back-tracked and
headed in to another small forest break where the ancient cairn is situated and
where the 1,769ft (539m) Six-Inch map heighted summit is positioned.
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| The abandoned four by four in the forest break |
The cairn has been
re-modelled and sits atop an ancient mound, past exploration found a central
cist although this seems no longer in evidence.
I positioned the Trimble atop my rucksack deciding that the ground
immediately beside the base of the cairn was slightly higher than the solid
ground in the centre of it, and left it slowly ebbing down to its 0.1m accuracy
level before data should be logged. During this process I stood beside the trees
and waited patiently, looking out past the re-modelled cairn and ancient mound
to bright sunshine and the opposing conifers as they stared back at me. I checked the equipment’s downward progress
and once the accuracy level was attained I pressed ‘Log’ and retreated to the
periphery of the trees and waited for five minutes of data to be collected.
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| Gathering data beside the ancient cairn on Mynydd Ton |
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| The Trimble set-up position beside the ancient cairn on Mynydd Ton |
As I packed the Trimble
away I looked back at the mound and cairn and wondered if I would ever
re-visit. I then headed down the hill
and visited the connecting bwlch which was just above where I had parked my
car. I’d examined this area via a Google
car the previous evening and knew that a stone wall positioned on the south-eastward
side of the road would give the Trimble elevation above its immediate
surrounds.
Once at the top of the
road which constitutes the area of the bwlch I judged the ground at the base of
the wall to be the point of the critical bwlch and measured a 1.23m offset
between the Trimble’s internal antenna and the ground at its base and set it to
gather another five minute data set.
When it had collected its all-important data I walked the few metres
down the road to my car and drove a kilometre westward toward my last hill of
the day.
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| Gathering data at the critical bwlch of Mynydd Ton |
Survey Result:
Mynydd Ton
Summit Height: 534.2m (converted to OSGM15) (significant height revision and
summit relocated to its previously listed position; 534.4m at SS 94931 94059) 534.4m (converted to OSGM15, from subsequent Trimble survey)
Summit Grid Reference: SS 94791 93954 (based on Trimble survey with
the summit now relocated to SS 94931 94059) SS 94931 94059 (from subsequent Trimble survey)
Bwlch Height: 443.1m (converted to OSGM15)
Bwlch Grid Reference: SS 93953 94456
Drop: 91.1m (based on Trimble survey, 91.3m based on
summit relocation and Subhump status confirmed) 91.3m (from subsequent Trimble survey)
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