Y Trichant – The 300m Hills of Wales

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 22^nd 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 1^st 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 1^st and 15^th of each month, with the sixth instalment to the Moel Siabod group of hills.  The Moelwyn Mawr group of hills will appear on the 1^st April. 

 

Y Trichant –The 300m Hills of Wales as a downloadable list in Google Doc format