Y Trichant – The 300m Hills of
Wales
The most comprehensive and accurate listing to this height band of hills ever published
Introduction
Visiting the 300m hills of
Wales can take you on a journey the length and breadth of the country with all
major hill ranges represented. This
height band is the metric equivalent of the imperial 1,000ft and this list
produces a challenge on par with many other lists of higher hills.
The hills within this list take
in a variety of upland landscape, including land that can be considered as Mynydd; mountain and moor, and Ffridd; heath, grassland, woodland and
high pasture.
The Welsh aspect of these hills
is represented in their combined title; Y
Trichant; when translated in to English, this is the three hundred, with the full title being Y Trichant – The 300m Hills of Wales, and this listing is the most
comprehensive and accurate to this height band of hills ever published.
The
List: The listing of the Y Trichant- The 300m Hills of Wales takes
in all Welsh hills at or above 300m
and below 400m in height that have 30m minimum drop, with an accompanying sub
list entitled the Sub-Trichant, with the criteria for this sub category being
all Welsh hills at or above 300m and below 400m in height with 20m or more and
below 30m of drop.
Publication
History: This list was first
published on 22nd October 2004 on Geoff Crowder’s v-g.me website and
entitled The Welsh 300 Metre Peaks,
coinciding with Geoff’s publication the list was also published by Mike Grant
on his 5everdene website.
The next publication of the
list was in January 2005 on the RHB Yahoo Group file database, with the file
later updated in January 2006 and entitled 300-499
Man Eng Wales. This file was
uploaded by Rob Woodall who then augmented data from E D ‘Clem’ Clements into
the database.
It was the publication on the
RHB Yahoo Group file database that was later duplicated en masse by Mark
Jackson without consultation with the author, with these data forming the
equivalent part of the Tumps. This has
resulted in years of undue data divergence that is ongoing.
Maintaining
the List: The master list for
the above publications was hand written and this was used for a number of years
to then update with any additional information.
The list is now maintained in spreadsheet format, with all necessary
information appearing in the Mapping Mountains publication. Between the first publication of this list and
its latest publication on Mapping Mountains it has undergone a number of
significant updates and the timeframe for these are given below.
Significant
Updates:
2004: The original list did not use interpolation
for estimated heights and therefore accepted Ordnance Survey spot heights as
fact. With the accompanying Hills to be surveyed P20 sub list only
including hills that once surveyed stood a chance of entering the main P30
list.
2005: Drop values added with interpolated heights
used and the accompanying sub list standardised.
2012: The original list relied upon paper mapping
with the newly published Ordnance Survey 1:25,000 Explorer maps prioritised
over the 1:50,000 Landranger. The advent
of online mapping included the Ordnance Survey Vector Map Local hosted on the
Geograph website and which was entitled the Interactive Coverage Map. This mapping had many spot heights not on
other publicly available Ordnance Survey maps and enabled a full review of all
data in this list. The updating of this
list using information on this mapping formed a part of the compilation of The
Welsh P15s with all 300m Welsh hills being listed down to P14, resulting in a
comprehensive list to the Welsh 300m P20s.
2013: Numerical accuracy within hill lists has
dramatically increased compared to when Ordnance Survey paper mapping was the
tool of reference. This increased
accuracy is due to the advent of independent surveyors using survey grade GNSS
equipment and for this list it is the use of the Trimble GeoXH 6000 that has
greatly benefited the numerical data within it, with the first 300m Welsh hill
surveyed with this equipment in December 2013 and with these surveys ongoing to
the present day.
2017: In May 2017 an article was published on
Mapping Mountains giving an introduction to this list and its renaming to; Y Trichant – The 300m Hills of Wales and
mentioning future intention to publish the list in its entirety.
2018: The use of the LIDAR (Light Detection &
Ranging) technique has revolutionised hill listings resulting in a plethora of
reclassifications. My use of LIDAR
started in March 2018 and is ongoing, with this list heavily dependent upon the
accuracy produced from LIDAR analysis.
2022: The Mapping Mountains publication of Y Trichant – The 300m Hills of Wales
commences on the 1st January.
Major
Advances: Although the
criteria has remained the same the list has changed greatly since its first
publication, with the advent of independent surveyors and the use of LIDAR
enabling greater numerical accuracy.
Place name research within hill
lists has also made dramatic progress since the first publication of this list,
with local enquiry and historical research enabling greater depth and
understanding for the hill names used.
Since the advent of Mapping
Mountains in November 2013 all status changes to this list are documented in
Hill Reclassification posts on this site, with all major significant amendments
also documented.
Mapping
Mountains Publication: For
the Mapping Mountains publication of the Y
Trichant – The 300m Hills of Wales the list has been fully re-evaluated
using GNSS results produced via Trimble GeoXH 6000 and Leica surveys, available
LIDAR and the latest online mapping.
Each hill name has been considered for its most appropriate use with
Ordnance Survey historical and contemporary mapping and the Tithe map used in
conjunction with any local enquiry. The
accompanying sub list entitled the Sub-Trichant is the first standardised P20
sub list to this height band of hills to ever be published.
Y Trichant – The 300m Hills of Wales as a downloadable list in Google Doc format
The Mapping Mountains list
consists of the following:
Name: This is considered the most appropriate name
for the hill, based on local usage where this is known. The name used does not always correspond to
contemporary Ordnance Survey map spelling and/or composition or the name may
not appear on any Ordnance Survey map.
Where an appropriate name is not forthcoming for the hill, the Point
(for example; Pt. 343.1m) notation is used rather than making up a name that
has no local or historical evidence of use.
Summit Height (m): This gives the map height in metres of the
hill above Ordnance Datum Newlyn (ODN), often referred to as sea level. Where a height is quoted to a decimal place
it implies that the hill has been surveyed by GNSS receiver (survey grade GPS)
or obtained from LIDAR analysis (these heights may not match current Ordnance
Survey map heights), with the heights produced by GNSS receiver converted to
OSGM15. Where a ‘c’ (circa) appears
preceding the height it means there is no known spot height available and the height
has been estimated from contour interpolation.
1:50,000
Map: This column gives the number or numbers of
the 1:50,000 Ordnance Survey Landranger map that the summit of the hill appears
on.
1:25,000
Map: This column gives the number or numbers of the
1:25,000 Ordnance Survey Explorer map that the summit of the hill appears on.
Summit
Grid Reference: This is
the ten figure grid reference for the summit of the hill. This has either been produced by an accurate
survey via GNSS receiver or LIDAR analysis, a map spot height, hand-held GPS
via DoBIH or for interpolated heights by a centralised position in an uppermost
contour ring.
Summit
Grid Reference extracted from: Details of where the ten figure grid
reference for the summit was derived.
Drop (m): This
column details the prominence of the hill, otherwise known as drop or
re-ascent. The drop is the height
difference between the summit and the lowest connecting bwlch to the higher
parent peak along the watershed. The
letter ‘c’ before the drop figure signifies there is no spot height or surveyed
height known for either summit or more usually, the bwlch, therefore a part of
the drop figure has been estimated from contour interpolation.
Bwlch
Grid Reference: This is
the ten figure grid reference for the bwlch of the hill. This has either been produced by an accurate
survey via GNSS receiver or LIDAR analysis, a map spot height, hand-held GPS
via DoBIH or when none of the above is available by a centralised position
between converging hill to hill and valley to valley contours.
Bwlch
Grid Reference extracted from: Details of where the ten figure grid
reference for the bwlch was derived.
Bwlch Height (m): This gives the map height in metres of the
bwlch of the hill above Ordnance Datum Newlyn (ODN), often referred to as sea
level. Where a height is quoted to a
decimal place it implies that the bwlch has been surveyed by GNSS receiver
(survey grade GPS) or obtained from LIDAR analysis (these heights may not match
current Ordnance Survey map heights), with the heights produced by GNSS
receiver converted to OSGM15. Where a
‘c’ (circa) appears preceding the height it means there is no known spot height
available and the height has been estimated from contour interpolation.
Notes: This column gives additional information
relating to the hill, including headings for Place Name Information, Numerical
Data and Listing History.
Myrddyn Phillips (January 2022)
Access: This is a collection
of Welsh hills that meet set criteria and although such a list can be a
reference for people to visit the hills, for those wishing to do so they should
abide by any legal restriction and if unsure of permissible access ask
permission to visit from the respective landowner.
Risks: Hill walking
is an activity with risks and dangers, both natural and man-made. You should not attempt hills beyond your
capabilities, and should fully appraise yourself of, and prepare for, the
possible risks before attempting to visit any hill. Participants in these activities should be
aware of and accept these risks, and be responsible for their own actions and
involvement.
Thanks: With special thanks to Aled Williams for his
continued support, Mark Trengove for advice over many years, Geoff Crowder and
Mike Grant for past publication and Rob Woodall who inputted data for the list
published on the RHB Yahoo Group file database, and to the people who submit 10
figure grid references to the Database of British and Irish Hills (DoBIH) and
for DoBIH making these available for public use.
This list will appear in
instalments published at 7.00pm on the 1st and 15th of
each month, with the first instalment to the Carnedd Llywelyn group of
hills. The Glyder Fawr group of hills
will appear on the 15th January.
Y Trichant –The 300m Hills of Wales as a downloadable list in Google Doc format
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