Mapping Mountains – Hill Reclassifications – The Fours – The 400m Hills of England

Burners Hills (NY 942 172) – 400m Sub-Four deletion

There has been a deletion to the listing of the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Burners Hills (NY 942 172)

The criteria for the list that this deletion applies to are:The Fours – The 400m Hills of England.  English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are three categories of sub hills, with this hill being deleted from the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Burners Hills and it is adjoined to the Cross Fell group of hills, which are situated in the northern Pennines, and it is positioned with the B6276 road to its north-west, the A66 road to its south and the B6277 road to its east, and has the town of Barnard Castle towards the east.

When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, this hill was not classified but was listed with an estimated c 17m of drop, based on the 404m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 387 col height based on interpolation of 5m contouring between 385m – 390m that appeared on the OS Maps website. 

Extract from the Ordnance Survey 1:25000 Explorer map

The mapping on the OS Maps website is the replacement for OS Get-a-map and had contours at 5m intervals which were consistently more accurate compared to the 5m contours that sometimes appear on Ordnance Survey 1:25,000 Explorer maps and used to appear on the online Vector Map Local.  This mapping is digitally updated and had altered since the details for this hill were re-evaluated for the 2^nd edition of the booklet published in April 2018, as the col contouring was now between 380m – 385m.  This is not a one off, as a number of examples have been noted where the contours on this mapping have subsequently changed since first being evaluated.  This re-assessment resulted in an estimated c 383m col height and when coupled with the 404m summit spot height, these values gave this hill an estimated c 21m of drop and it was subsequently listed as a 400m Sub-Four. 

Extract from the interactive mapping that used to be hosted on the OS Maps 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.

Therefore, the deletion of this hill from 400m Sub-Four status is due to LIDAR analysis, resulting in a 403.1m summit height and a 383.2m col height, with these values giving this hill 19.9m of drop, which is insufficient for it to be classified as a 400m Sub-Four.

 

The full details for the hill are:

Group:  Cross Fell

Name:  Burners Hills

OS 1:50,000 map:  91, 92

Summit Height:  403.1m (LIDAR)

Summit Grid Reference:  NY 94228 17203 (LIDAR)

Col Height:  383.2m (LIDAR)

Col Grid Reference:  NY 94255 16900 (LIDAR)

Drop:  19.9m (LIDAR)

 

For the additions, deletions and reclassifications to The Fours – The 400m Hills of England reported on Mapping Mountains since the December 2013 publication of the 1^st edition of this list by Europeaklist please consult the following Change Registers:

 

The Fours

 

The Fours – 400m Sub-Four

 

The Fours – 390m Sub-Four

 

The Fours – 390m Double Sub-Four

 

Myrddyn Phillips and Aled Williams (January 2023) 

Mapping Mountains – Summit Relocations – 100m Twmpau

 

Pt. 141.4m (SN 416 592) 

There has been a Summit Relocation to a hill that is listed in the 100m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from detail on contemporary maps produced from Ordnance Survey data and LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Pt. 141.4m (SNN 416 592)

The criteria for the list that this summit relocation applies to are:

100m Twmpau - Welsh hills at or above 100m and below 200m in height that have 30m minimum drop, with an accompanying sub list entitled the 100m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 100m and below 200m 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. 

The 100m Twmpau by Myrddyn Phillips

The hill is being listed by the point (Pt. 141.4m) notation as an appropriate name for it either through local enquiry and/or historic research has not been found by the author, and it is adjoined to the Mynydd Bach group of hills, which are situated in the western part of South Wales (Region B, Sub-Region B1), and it is positioned with the coast to its north, minor roads to its west and south-east, and the B4342 road to its south, and has the town of Ceinewydd (New Quay) towards the west.

When the original Welsh 100m P30 list was published on Geoff Crowder’s v-g.me website, this hill was listed with a 141m summit height, based on the spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and which is positioned at SN 41695 59277. 

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

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.

LIDAR analysis gives the highest ground on this hill as 141.5m positioned at SN 41667 59283.  However, this is a part of a raised field boundary and protocols dictate that as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill. 

LIDAR summit image of Pt. 141.4m (SN 416 592)

The height produced by LIDAR analysis to the natural summit of this hill is 141.35m and is positioned at SN 41655 59248, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies to when the high point of the hill is positioned in a different field, to a different feature such as a conifer plantation, within a different map contour, a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is considered a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

Therefore, the height produced by LIDAR analysis to the natural summit of this hill is 141.35m and is positioned at SN 41655 59248, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 40 metres westward from where the 141m spot height is positioned and 35 metres southward from where the high point of the raised field boundary is positioned. 

 

The full details for the hill are: 

Group:  Mynydd Bach 

Name:  Pt. 141.4m 

OS 1:50,000 map:  146

Summit Height:  141.35m (LIDAR) 

Summit Grid Reference (New Position):  SN 41655 59248 (LIDAR) 

Bwlch Height:  c 113m (interpolation) 

Bwlch Grid Reference:  SN 42778 58551 (interpolation) 

Drop:  c 28m (LIDAR summit and interpolated bwlch) 

 

Myrddyn Phillips (January 2023)

 

 

Mapping Mountains – Significant Height Revisions – Y Trichant – The 300m Hills of Wales

Banc Hafodau (SN 703 802) 

There has been a Significant Height Revision to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Banc Hafodau (SN 703 802)

The criteria for the list that this height revision 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 13^th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

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

The name the hill is listed by is Banc Hafodau, and it is adjoined to the Banc Llechwedd Mawr group of hills, which are situated in the northern part of South Wales (Region B, Sub-Region B1), and it is positioned with the A44 road to its north and a minor road to its south, and has the village of Ponterwyd towards the east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list with a summit height of 346m, based on the spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map. 

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

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. 

LIDAR summit image of Banc Hafodau (SN 703 802)

LIDAR analysis gives the summit height of this hill as 343.4m and this 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 summit 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.

Therefore, the new listed summit height of this hill is 343.4m and this was derived from LIDAR analysis, this is 2.6m lower than the previously listed summit height of 346m which appears as a spot height on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map. 

 

The full details for the hill are: 

Group:  Banc Llechwedd Mawr 

Name:  Banc Hafodau 

OS 1:50,000 map:  135

Summit Height (New Height):  343.4m (LIDAR)                                                           

Summit Grid Reference:  SN 70334 80277 (LIDAR) 

Bwlch Height:  303.1m (LIDAR) 

Bwlch Grid Reference:  SN 71465 80258 (LIDAR) 

Drop:  40.3m (LIDAR) 

 

Myrddyn Phillips (January 2023)

 

 

 

 

 

 

 

  

Mapping Mountains – Trimble Surveys – Moel Hebog

10.12.22  Ynys Tywyn (SH 571 385) 

Ynys Tywyn (SH 571 385)

Ynys Tywyn is easily accessed from the centre of Porthmadog, it is one of those small hills that pays dividends, with little ascent being rewarded with extensive views.  I had visited once before in December 2014 when along with Aled we decided upon an easy hill as the forecast winter rain was bearing down on us.  On that occasion its summit was Trimbled.

That ascent was part of many that Aled had organised as we continued our investigation of Traeth Mawr; the flatlands to the immediate east of the Cob.  The Cob is the embankment built on the outskirts of Porthmadog to keep the sea from heading inland at high tide.  When it did so, the islands of Traeth Mawr must have been a wonderful sight, poking their wooded summits above the sea.  These now landlocked islands can still be accessed, although many are rough underfoot, but they are also rewarding to investigate. 

Plaque on wall at the start of the walk

Today we were in the company of a film crew from the Cynefin programme which is broadcast on S4C.  They were concentrating on the area surrounding Porthmadog and in particular the Cob.  They had approached Aled to be a part of this programme having found his article on Traeth Mawr published on Mapping Mountains, suggesting that a visit to one of these islands with the Trimble in tow would be good to film.

I drove to Aled’s and arrived at 7.10am having experienced slow progress on much of the route due to a dusting of snow on the road.  The journey was particularly beautiful as moonlight highlighted silhouetted hills that shone back under their covering of snow. 

Aled with the film crew from the Cynefin programme on S4C; Heledd Cynwal, Aled Davies-Jones, Lleucu Gruffydd and Rhys Thomas

We met Lleucu and Heledd; the producer and presenter in the centre of Porthmadog before having an early morning paned.  Afterwards we were joined by Aled and Rhys; the director/cameraman and cameraman respectively.  By now a mixture of winter rain and occasion hail was descending from above.

The walk to the top of Ynys Tywyn is only short, following a path through its wooded slopes to the impressive slanting rock that constitutes its summit.  The upper part of the hill had a sprinkling of frost on it adding winter colour to the scene.

It is not my intention to go in to any great detail of the filming in this article as a future On Location with S4C post will document this.  We stayed on top for almost two hours with Aled being filmed explaining the process behind using an Abney level and the Trimble. 

Porthmadog with winter showers pushing inland from the coast

During this I happily listened to the proceedings from the background enjoying being out on this small island, which nowadays is connected to the town of Porthmadog by the Cob.  I spent much of the time watching the play of light as winter showers pushed inland from the coast.

In the distance snow-capped peaks occasionally emerged from their winter shroud, with the upper part of Cnicht springing out of the grey misted scene with its pyramidal summit profile looking ever impressive.  However, many hills were obscured with deep grey cloud penetrating their depths. 

Snow-capped hills

For a relatively small hill Ynys Tywyn certainly has a dramatic and expansive view.  The workings of the film crew would occasionally be interrupted by the hoot emanating from the steam train as it chugged its way across the Cob, bellowing smoke across the harbour surrounds. 

At the summit of Ynys Tywyn with Aled explaining the fineries of the Trimble

The last shots were of Aled explaining the fineries of the Trimble and then it was time to head down.  For Aled the filming would go on for the rest of the day, but for me it was time to head home before the roads froze and darkness fell. 

 

Survey Result: 

 

Ynys Tywyn 

Summit Height:  21.8m (converted to OSGM15) (from previous Trimble GeoXH 6000 survey)

Summit Grid Reference:  SH 57192 38506 (from previous Trimble GeoXH 6000 survey)

Bwlch Height:  N/A (sea level)

Bwlch Grid Reference:  N/A (sea level)

Drop:  21.8m (from previous Trimble GeoXH 6000 survey) (30–99m Double Sub-Twmpau addition)

Dominance:  100.00% (from previous Trimble GeoXH 6000 survey)

 

 

For details on the survey of Ynys Tywyn

For further details please consult the Trimble Survey Spreadsheet   

  

Mapping Mountains – Significant Name Changes – 100m Twmpau and Y Trechol – The Dominant Hills of Wales

 

Cae Pen Das Eithin (SN 483 590) 

There has been a Significant Name Change to a hill that is listed in the 100m Twmpau and Y Trechol – The Dominant Hills of Wales, with the summit height, bwlch height and their locations, the drop, dominance and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Cae Pen Das Eithin (SN 483 590)

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

100m Twmpau – Welsh hills at or above 100m and below 200m in height that have 30m minimum drop, with an accompanying sub list entitled the 100m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 100m and below 200m 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. 

The 100m Twmpau by Myrddyn Phillips

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.  The list is authored by Myrddyn Phillips with the Introduction to the start of the Mapping Mountains publication of this list appearing on the 3^rd December 2015, and the list is now available in its entirety on Mapping Mountains in Google Doc format. 

Y Trechol - The Dominant Hills of Wales by Myrddyn Phillips

The hill is adjoined to the Mynydd Bach group of hills, which are situated in the western part of South Wales (Region B, Sub-Region B1), and it is positioned with the A482 road to its north and minor roads to its west, south and east, and has the town of Aberaeron towards the north-west.

The hill appeared in the original Welsh 100m P30 list on Geoff Crowder’s v-g.me website, under the transposed name of Allt Llanerchaeron, which is a prominent name that appears to the north of this hill on the contemporary Ordnance Survey 1:25,000 Explorer map and does not necessarily apply to land where the summit is situated.

Allt Llanerchaeron

172m

SN483590

146

198/199

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 that appeared on the Ordnance Survey 1:25,000 Explorer map and presume it 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

As the summit of this hill comprises bounded land the details for it were examined on the Tithe map.  The term Tithe map is generally given to a map of a Welsh or English parish or township and which was prepared after the 1836 Tithe Commutation Act.  This act allowed tithes to be paid in cash rather than goods.  The Tithe maps gave names of owners and occupiers of land in each parish and importantly for place-name research they also included the name of enclosed land.  This enclosed land is usually based on a field system, however not every field is given a name, but many are and especially so in Wales. 

Extract from the Tithe map

The enclosed land where the summit of this hill is situated is given the number 203 on the Tithe map, this can be cross referenced against the apportionments; it is these apportionments that give the name of the owner or occupier of the land as well as the name of the land.  The land where the summit of this hill is situated is named as Cae Pen Das Eithin in the apportionments, with the details on the Tithe map appearing in the parish of Llannerch Aeron and in the county named as Cardigananshire. 

Extract from the apportionments

Therefore, the name this hill is now listed by in the 100m Twmpau and Y Trechol – The Dominant Hills of Wales is Cae Pen Das Eithin, and this was derived from the Tithe map. 

 

The full details for the hill are:

Group:  Mynydd Bach

Name:  Cae Pen Das Eithin

Previously Listed Name:  Allt Llanerchaeron   

OS 1:50,000 map:  146

Summit Height:  171.8m (LIDAR) 

Summit Grid Reference:  SN 48325 59003 (LIDAR) 

Bwlch Height:  101.3m (LIDAR) 

Bwlch Grid Reference:  SN 48788 58275 (LIDAR) 

Drop:  70.5m (LIDAR) 

Dominance:  41.04% (LIDAR)

 

Myrddyn Phillips (January 2023)