Mapping Mountains – Hill Reclassifications – Y Trichant – The 300m Hills of Wales

Mynydd Bach (SN 992 359) – Trichant reclassified to Sub-Trichant

There has been a reclassification to the list of Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis.

LIDAR image of Mynydd Bach (SN 992 359)

This was initiated by Joe Nuttall who produced a summit analysis programme that used LIDAR with an alternative height map (DEM) allowing identification of summits and cols and thereby drops.  The resulting spreadsheet that Joe produced contains over 29600 hills.

This spreadsheet is being evaluated by DoBIH Editors and others, and for this particular hill it was Jim Bloomer who initially assessed its height and that of its adjacent peak via LIDAR analysis.

Myrddyn Phillips then evaluated this hill’s details via LIDAR analysis and confirmed its height and hence its reclassification to Sub-Trichant status.

The criteria for the list that this reclassification applies to are:

Y Trichant – The 300m Hills of Wales – 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.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13th May 2017.

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Mynydd Bach, and it is adjoined to the Mynydd Epynt group of hills, which are situated in the south-eastern part of Mid and West Wales (Region B, Sub-Region B2), and it is positioned with minor roads to its east, north and west and farther afield it has the A40 road to its south and the B4520 road to its east, and has the hamlet of Merthyr Cynog towards the north north-west.

When the original 300m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website this hill was listed as a 387m map heighted twin summit with its adjacent hill positioned at SN 992 359.   

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for these two hills could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

The LIDAR result for each hill appears below:

Lan    385.9m summit at SN 98815 36321

Mynydd Bach    385.3m summit at SN 99215 35955

As Lan is higher than Mynydd Bach it is retained as the Trichant, whilst the drop is sufficient for Mynydd Bach to be classified as a Sub-Trichant.

LIDAR image of Lan (SN 988 363) and Mynydd Bach (SN 992 359)

Therefore, the reclassification of this hill to Sub-Trichant status is due to LIDAR analysis, resulting in a 385.3m summit height and a 362.9m bwlch height, with these values giving this hill 22.3m of drop, which is sufficient for it to be classified as a Sub-Trichant.

The full details for the hill are:

Group:  Mynydd Epynt

Name:  Mynydd Bach

OS 1:50,000 map:  160

Summit Height:  385.3m (LIDAR)

Summit Grid Reference:  SN 99215 35955 (LIDAR)

Bwlch Height:  362.9m (LIDAR)

Bwlch Grid Reference:  SN 98996 36093 (LIDAR)

Drop:  22.3m (LIDAR)

Myrddyn Phillips (September 2020)

Mapping Mountains – Significant Height Revisions – 30-99m Twmpau and Y Trechol – The Dominant Hills of Wales

Mynydd Bach (SH 389 767)

There has been a Significant Height Revision to a hill that is listed in the 30-99m Twmpau and Y Trechol – The Dominant Hills of Wales, with the summit height confirmed by LIDAR analysis, and a subsequent survey with the Trimble GeoXH 6000 conducted by Myrddyn Phillips, with the latter taking place on the 28^th October 2018.

LIDAR summit image of Mynydd Bach

The criteria for the two listings that this height revision applies to are:

30-99m Twmpau - Welsh hills at or above 30m and below 100m in height with 30m minimum drop, with an accompanying sub list entitled the 30-99m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 30m and below 100m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

Y Trechol - The Dominant Hills of Wales - Welsh P30 hills whose prominence  equal or exceed half that of their absolute height.  With the criteria for Lesser Dominant status being those additional Welsh P30 hills whose prominence is between one third and half that of their absolute height, with the Introduction to the Mapping Mountains publication of this list appearing on the 3^rd December 2015.

The name of the hill is Mynydd Bach and this was derived from local enquiry and it is adjoined to the Ynys Môn group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it has the A5 and A55 roads and the village of Gwalchmai towards its south.

When the original 30—99m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was listed with a summit height of c 95m, when this list was standardised with interpolated heights and drop values also included the hill was listed with an estimated c 97m summit height based on its uppermost 95m ring contour that appears on the Ordnance Survey 1:25,000 Explorer map.

Extract from the Ordnance Survey 1:25,000 Explorer map

The details for this hill were next re-assessed when the Ordnance Survey Vector Map Local hosted on the Geograph website and which is entitled the Interactive Coverage Map became available online.  This map has a 99m spot height in the vicinity of this hill’s summit, however this spot height is placed on a covered reservoir, and as this is considered a recent man-made construct it is not taken as a part of the hill’s overall height.

Extract from the Ordnance Survey Vector Map Local hosted on the Geograph website

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

The summit height produced by LIDAR is in good accordance with that produced by the Trimble GeoXH 6000 survey, and even though the spot height that appears on the Ordnance Survey Vector Map Local hosted on the Geograph website is placed on the top of a covered reservoir, this height comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey or Harvey map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR, also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.  As heights on different scaled Ordnance Survey maps are not consistent the height given on the 1:25,000 Explorer map is being prioritised in favour of the 1:50,000 Landranger map for detailing these revisions.

Therefore, this hill’s new listed summit height is 96.5m and this was derived from the Trimble GeoXH 6000 survey, this is 2.5m lower than the 99m spot height that appears on the Ordnance Survey Vector Map Local hosted on the Geograph website and which is entitled the Interactive Coverage Map.

ills of Wales, and are reproduced below@

The full details for the hill are:

Group:  Ynys Môn 

Name:  Mynydd Bach

OS 1:50,000 map:  114

Summit Height (New height):  96.5m (converted to OSGM15)

Summit Grid Reference:  SH 38964 76773

Bwlch Height:  c 64m

Bwlch Grid Reference:  SH 40259 77918 (I)

 

Drop:  c 32m

Dominance:  33.66%

For details on the summit survey of this hill

Myrddyn Phillips (May 2019)

Mapping Mountains – Significant Name Changes – 30-99m Twmpau and Y Trechol – The Dominant Hills of Wales

Mynydd Bach (SH 389 767)

There has been a Significant Name Change to a hill that is listed in the 30-99m Twmpau and Y Trechol – The Dominant Hills of Wales, with the summit height confirmed by LIDAR analysis, and a subsequent survey with the Trimble GeoXH 6000 conducted by Myrddyn Phillips, with the latter taking place on the 28^th October 2018.

LIDAR summit image of Mynydd Bach

The criteria for the two listings that this name change applies to are:

30-99m Twmpau - Welsh hills at or above 30m and below 100m in height with 30m minimum drop, with an accompanying sub list entitled the 30-99m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 30m and below 100m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

Y Trechol - The Dominant Hills of Wales - Welsh P30 hills whose prominence  equal or exceed half that of their absolute height.  With the criteria for Lesser Dominant status being those additional Welsh P30 hills whose prominence is between one third and half that of their absolute height, with the Introduction to the Mapping Mountains publication of this list appearing on the 3^rd December 2015.

The hill is adjoined to the Ynys Môn group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it has the A5 and A55 roads to its south, and has the village of Gwalchmai towards its south.

This hill was first listed in the original Welsh 30-99m P30 list published on Geoff Crowder’s v-g.me website, under the transposed name of Bryn-teg, which is a name appearing near to the hill on contemporary Ordnance Survey maps and which I presumed was the name of the hill, it is not, it is a name of a house.

Bryn-teg

95c

SH389768

114

262/263

During my early hill listing I thought it appropriate to either invent a name for a hill, or use a name that appeared near to the summit of the hill on Ordnance Survey maps of the day.  My preference was to use farm names and put Pen, Bryn or Moel in front of them or as in this instance transpose a name on the map which I presumed to be that of the hill.  This is not a practice that I now advocate as with time and inclination place-name data can be improved either by asking local people or by examining historic documents, through this form of research an appropriate name for the hill can usually be found.

Extract from the Ordnance Survey 1:25,000 Explorer map

After visiting this hill I called at a number of houses, including Bryn-teg hoping to make place-name enquiries.  I was directed down the minor lane toward a cottage, as I headed toward the cottage a man appeared and walked toward a plot of land where his daughter was planning to live.  Gwyn Thomas lived at one of the houses I’d passed on the lane; the hill was on the other side of the road to where his daughter was planning to live and was at the back of Gwyn’s house.  I introduced myself and explained my interest in hill names and asked if he knew a name for the hill; he replied immediately and told me its name is Mynydd Bach.

Gwyn Thomas with Mynydd Bach in the background

Therefore, the name this hill is now listed by in the 30-99m Twmpau and Y Trechol – The Dominant Hills of Wales is Mynydd Bach, and this was derived from local enquiry.

The full details for the hill are:

Group:  Ynys Môn

Name:  Mynydd Bach

Previously Listed Name:  Bryn-teg

 

OS 1:50,000 map:  114

Summit Height:  96.5m (converted to OSGM15)

Summit Grid Reference:  SH 38964 76773

Bwlch Height:  c 64m

Bwlch Grid Reference:  SH 40259 77918 (I)

 

Drop:  c 32m

Dominance:  33.66%

For details on the summit survey of this hill

Myrddyn Phillips (May 2019)

Mapping Mountains – Trimble Surveys – Mynydd Twr

28.10.18  Mynydd Bach (SH 389 767)  

Visiting the summit of this hill seemed an easy affair, as logged ascents on the Hill Bagging website mainly used the access track to the north-west that leads to the two high masts and covered reservoir positioned on the summit area of the hill.  As well as giving an easy and convenient ascent it was also a short one, as it only involved a couple of hundred metres to the top.

However, as I drove up the narrow lane and arrived at the start of the track I found a high metal fence barring access, where the fence ended each side was well protected with brambles and unforgiving amounts of unsavoury undergrowth.  I parked my car for a good inspection and did consider trying to climb the locked fence, but smiled at the thought as I knew I would not be able to do this, even if wanting so, which by the way, I didn’t.

Having walked a short distance on the lane either side of the metalled fence I realised I would not be gaining access to the hill from this direction and therefore drove the short distance back down the lane to the small community of Gwalchmai and then drove north up another narrow lane which brought me to the east of the hill.  I found parking beside a gate that gave access to another track leading toward the hill, I decided to investigate.

The track led through a paddock where three horses were standing in the morning sun, one showed particular interest in me as I quietly headed up toward a mass of gorse, bracken and brambles with the summit just beyond.  This form of undergrowth is prevalent on many of the lower hills on Ynys Môn, and all that I have encountered can either be bi-passed or bashed through, but summer ascents wearing shorts is definitely not recommended!

The high ground of the paddock led me to two gates which gave access to an old stone wall and the mass of unsavoury undergrowth on the other side, but as the masts and the summit of the hill were now within reach there was only one thing for it, and within a minute or so I was over the remnants of the wall and heading through the gorse, bracken and brambles.  This conveniently led directly to the natural high point of the hill which LIDAR analysis gives as ground close to a small fenced compound where one of the masts is situated.

Within a few minutes I’d assessed the ground, stomped on a few brambles and set the Trimble up to gather data.  As the set-up position was beside the compound amongst lush vegetation I decided to gather a ten minute data set.

The Trimble set-up position at the summit of Mynydd Bach

As the Trimble quietly beeped away gathering its allotted data I roamed around the summit area, climbing the outer steps to the fenced reservoir and looking back on the Trimble which was hard to see through the mass of gorse and brambles.

Once data were gathered and stored I closed the equipment down, packed it away and tried to remember my inward route back through the unsavoury stuff.  Eventually I clambered over the old wall back on to greened land where the friendly horse wandered my way and followed me as I headed back through the paddock to my car.  All that remained was to make place-name enquiries as the hill remains unnamed on the map.

Gathering data at the summit of Mynydd Bach

The first house I called at was next to where my car was parked; the occupant was obviously in bed when I knocked on the door as when he opened it he was bare chested and still doing his trousers up, we talked for a number of minutes and he kindly directed me down the lane to the first of two small houses where he said the elderly woman would probably be able to help.

I walked down the lane toward the house with the rough and rocky slopes of the hill on my left, as I did so a man appeared and walked toward a plot of land where his daughter was planning to live.  Gwyn Thomas lived at one of the houses I’d passed on the lane; the hill was on the other side of the road to where his daughter was planning to live and was at the back of Gwyn’s house.  I introduced myself and explained my interest in hill names and asked if he knew a name for the hill; he replied immediately and told me its name is Mynydd Bach.

Gwyn Thomas with Mynydd Bach in the background

We talked for a number of minutes before I headed back up the lane after thanking Gwyn for his time.  Mynydd Bach is a proper little mountain, rough and rocky and with extensive views from its summit.  I was glad to have visited, even though the undergrowth had proven problematic, another hill bagged and just as important; another name documented.    

Survey Result:

Mynydd Bach (significant name change) 

Summit Height:  96.5m (converted to OSGM15, Trimble GeoXH 6000) (significant height revision)

Summit Grid Reference:  SH 38964 76773 (Trimble GeoXH 6000)

Bwlch Height: c 64m (interpolation)

Bwlch Grid Reference:  SH 40259 77918 (interpolation)

Drop:  c 32m (Trimble GeoXH 6000 summit and interpolated bwlch)

Dominance:  33.66% (Trimble GeoXH 6000 summit and interpolated bwlch)

For further details please consult the Trimble Survey Spreadsheet

Mapping Mountains – Significant Name Changes – Y Trichant

Mynydd Bach (SJ 051 123)

There has been a Significant Name Change to a hill that is listed in the Y Trichant, with the summit height, drop and status of the hill being confirmed by a Trimble GeoXH 6000 survey conducted by Myrddyn Phillips which took place on the 26^th January 2018.

The criteria for the list that this name change applies to are:

Y Trichant – Welsh hills at and above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub category entitled the Sub-Trichant consisting of all Welsh hills at and above 300m and below 400m in height that have 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips and the Introduction to the list and the re-naming and publication history was published on Mapping Mountains on the 13^th May 2017.

The hill is adjoined to the Y Berwyn range of hills which are situated in the south-eastern part of North Wales (Region A, Sub-Region A4), and is positioned between the Afon Banwy to the south and the Afon Efyrnwy (River Vyrnwy) to the north-east, with the A 458 road to its south-west and the small community of Dolanog which is to its east north-east. 

Mynydd Bach (SJ 051 123)

The hill appeared in the 300m P30 list on Geoff Crowder’s v-g.me website under the name of Pen-y-graig.  During my early hill listing I thought it appropriate to either invent a name for a hill, or use a name that appeared near to the summit of the hill on Ordnance Survey maps of the day.  My preference was to use farm names and put Pen, Bryn or Moel in front of them, or as in this instance, use the name of a building which I thought that of the hill.

Pen-y-graig

323m

SJ051123

125

239

This is not a practice that I now advocate as with time and inclination place-name data can be improved either by asking local people or by examining historical documents, through this form of research an appropriate name for the hill can usually be found, and in the case of this hill it was a local farmer who owns the land where the summit of the hill is situated who gave the name of Mynydd Bach.

Extract from the Ordnance Survey 1:25,000 Historical map

The local farmer is Trefor Jones who farms from Maes Celynog which is situated towards the south of the hill.  Whilst visiting this hill and its adjacent P30 I was fortunate to meet Trefor who was on his way up to the lower field of this hill in his tractor.  He stopped and we chatted for a number of minutes with him explaining that the hill is known as Mynydd Bach and it is on land that he owns having bought it off an adjacent farm.  Trefor is a Welsh speaker and gave me the translation of the hill’s name as small mountain.

Trefor Jones

Therefore, the name this hill is now listed by in the Y Trichant is Mynydd Bach and this name was derived from local enquiry.

The full details for the hill are:

Group:  Y Berwyn

Name:  Mynydd Bach

Previously Listed Name:  Pen-y-graig 

Summit Height:  324.9m (converted to OSGM15)

OS 1:50,000 map:  125

Summit Grid Reference:  SJ 05100 12325 

 

Drop:  28.5m (converted to OSGM15)

The Trimble GeoXH 6000 gathering data at the summit of Mynydd Bach

For details on the survey of Mynydd Bach

Myrddyn Phillips (February 2018)