Mapping Mountains – Hill Reclassifications – 200m Twmpau

Gribin (SH 675 168) – 200m Sub-Twmpau reclassified to 200m Twmpau

There has been confirmation of a reclassification to the 200m Twmpau list due to LIDAR analysis conducted by Myrddyn Phillips, with the criteria for this list being:

200m Twmpau - Welsh hills at and above 200m and below 300m in height with 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau with the criteria for this sub category being all Welsh hills at and above 200m and below 300m in height with 20m and more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

This hill was listed in the Hills to be surveyed sub list when the original Welsh P30 hills were published on Geoff Crowder’s v-g.me website as it was thought not  to meet the criteria then used for the main P30 list; however this list has now been standardised and interpolated heights and drop values also included, resulting in this hill being listed with an estimated c 39m of drop, based on an estimated c 211m summit height and an estimated bwlch height of c 172m based on bwlch map contouring between 170m – 180m.  The details for this hill were later amended when the Ordnance Survey Interactive Coverage Map hosted on the Geograph website became available online and it was then listed with a 211m summit height based on the spot height appearing on this map.

Extract from the Ordnance Survey Interactive Coverage Map hosted on the Geograph website

The name of the hill is Gribin and it is adjoined to the Cadair Idris group of hills, which are situated in the south-western part of North Wales (Region A, Sub-Region A3), it is positioned overlooking the A 493 road which is to its north and has the small community of Arthog towards the south-west and the town of Dolgellau towards the east.

The summit and upper southern section of the hill is a part of designated open access land and a public footpath leads toward this from the west south-west of the hill, with another option for an ascent following a public footpath from the north-east of the hill.

The confirmation of the reclassification of Gribin to 200m Twmpau status is due to LIDAR analysis conducted by Myrddyn Phillips.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

 

The 1m DTM LIDAR analysis gives the hill the following details:

Name:  Gribin

Summit Height:  209.3m

Summit Grid Reference:  SH 67559 16814

Bwlch Height:  169.7m

Bwlch Grid Reference:  SH 67588 16670

Drop:  39.6m

LIDAR image of Gribin

Therefore, the 209.3m LIDAR analysis for the summit position at SH 67559 16814 and the 169.7m LIDAR analysis for the bwlch position at SH 67588 16670 gives this hill 39.6m of drop, which confirms its reclassification to 200m Twmpau status.

The full details for the hill are:

Group:  Cadair Idris

Name:  Gribin

OS 1:50,000 map:  124

Summit Height:  209.3m (LIDAR)

Summit Grid Reference:  SH 67559 16814 (LIDAR)

Bwlch Height:  169.7m (LIDAR)

Bwlch Grid Reference:  SH 67588 16670 (LIDAR)

Drop:  39.6m (LIDAR)

Myrddyn Phillips (May 2018)

Mapping Mountains – Significant Height Revisions – The Fours

Tindale Law (NT 859 108)

There has been a Significant Height Revision to a hill that is listed in The Fours initiated by LIDAR analysis conducted by Myrddyn Phillips.  The Fours is the title for the list of 400m hills of England and is co-authored by Myrddyn Phillips and Aled Williams with the 2^nd edition of the booklet containing this list published by Mapping Mountains Publications on the 24.04.18.

The criteria for the list that this significant height revision affects are:

The Fours - English hills at and above 400m and below 500m in height that have a minimum 30m of drop.

The name of the hill is Tindale Law and it is situated in Region 33; Scottish Border to the River Tyne, and is positioned overlooking the River Coquet which is to its west, north and east and has the small community of Barrowburn towards the east.

As the hill is not a part of designated open access land permission to visit should be sought, for those wishing to do so a public footpath crosses near to the critical col and the summit is then only a short distance to the north.

Prior to LIDAR analysis this hill was listed with 60m of drop based on the 423m summit and 363m col spot height that appear on the Ordnance Survey Interactive Coverage Map hosted on the Geograph.

Extract from the Ordnance Survey Interactive Coverage Map hosted on the Geograph website

The summit height produced by LIDAR analysis is 420.959m, this is not a dramatic height revision when compared to some revised heights, but it does come 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 by LIDAR analysis, 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 analysis of LIDAR.  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 summit height is 421.0m and this was produced by LIDAR analysis, this is 2.0m lower than its previously listed height of 423m which appears as a spot height on the Ordnance Survey Interactive Coverage Map hosted on the Geograph website.

The full details for the hill are:

Cardinal Hill:  Thirl Moor

Summit Height (New Height):  421.0m (LIDAR)

Name:  Tindale Law

OS 1:50,000 map:  80

Summit Grid Reference:  NT 85953 10829 (LIDAR) 

  

Drop:  58.5m (LIDAR)

Myrddyn Phillips and Aled Williams (May 2018)

Mapping Mountains – Hill Reclassifications – The Fours

High Nook (NY 120 189) – 400m Sub-Four deletion

There has been a deletion from the listing of The Fours due to LIDAR analysis conducted by Aled Williams.  The Fours is the title for the list of 400m hills of England and takes in all English hills at and above 400m and below 500m in height that have a minimum 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.

Accompanying the main list of The Fours are three categories of sub hills, with this hill being deleted from the 400m Sub-Fours.  The criteria for 400m Sub-Four status are all English hills at and above 400m and below 500m in height that have 20m and more and below 30m of drop. 

 

Prior to LIDAR analysis this hill was listed with 21m of drop based on the 488m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and the 467m col spot height that appears on the Ordnance Survey Interactive Coverage Map hosted on the Geograph website.

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

Extract from the Ordnance Survey Interactive Coverage Map hosted on the Geograph website

The name of the hill is High Nook and it is situated in the Central and Western Fells of the Lake District and is placed in Region 34, Section 34B, with its Cardinal Hill being Great Gable (NY 211 103).  The hill is positioned on the north-easterly ridge that descends from Gravel Fell and has the Highnook Beck to its north-west and the Whiteoak Beck to its east.

As the summit of the hill is a part of designated open access land it can be approached from a number of directions, with a public footpath leading toward the hill from the north, however this hill can easily be combined with adjacent hills to make an extended walk.

The deletion of High Nook from 400m Sub-Four status is due to LIDAR analysis conducted by Aled Williams.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

Aled’s LIDAR analysis gives the hill the following details:

High Nook

Summit Height:  486.0m

Summit Grid Reference:  NY 12033 18915

Col Height:  466.1m

Col Grid Reference:  NY 11922 18855

Drop:  19.9m

LIDAR image of High Nook

Therefore, the 486.0m LIDAR analysis for the summit position at NY 12033 18915 and the 466.1m LIDAR analysis for the col position at NY 11922 18855 gives this hill 19.9m of drop, which is insufficient for it to retain its 400m Sub-Four status.

The full details for the hill are:

Cardinal Hill:  Great Gable

Summit Height:  486.0m (LIDAR)

Name:  High Nook

OS 1:50,000 map:  89

Summit Grid Reference:  NY 12033 18915 (LIDAR)

Drop:  19.9m (LIDAR)

For the additions, deletions and reclassifications to The Fours reported on Mapping Mountains since the December 2013 publication of the 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 (May 2018)

Mapping Mountains – Significant Name Changes – The Fours

High Forest (NY 492 143)

There has been a Significant Name Change to a hill that is listed in The Fours, with this being announced when the 2^nd edition of The Fours was published by Mapping Mountains Publications on the 24^th April 2018.

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

The Fours – English hills at and above 400m and below 500m in height that have 30m minimum drop.  Accompanying the main list of The Fours are three categories of sub hills, with this hill listed as a 400m Sub-Four.  The criteria for 400m Sub-Four status are all English hills at and above 400m and below 500m in height that have 20m and more and below 30m of drop.  

The list is co-authored by Myrddyn Phillips and Aled Williams, with the 1^st edition of the list having been published by Europeaklist in December 2013 and by Haroldstreet in January 2014, with the 2^nd edition of the list published by Mapping Mountains Publications and by Haroldstreet on the 24^th April 2018.

The hill is situated in the Eastern Fells of the Lake District and is placed in Region 34, Section 34C with its Cardinal Hill being High Street (NY 440 110).  The hill is positioned with the expanse of Haweswater Reservoir to its west, and has the small community of Burnbanks towards the north-east.

When the listing that is now known as The Fours was originally compiled this hill appeared under the name of Kit Crag, this was also the name it appeared as when the list was uploaded to the RHB Yahoo group file database.  Subsequently the hill was listed as Naddle High Forest in the 1st edition of The Fours when the list was published by Europeaklist in December 2013. 

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

Prior to publication of the 2^nd edition of The Fours enquiries were made with two well-known Lake District guide book authors, resulting in the name of Naddle High Forest considered as ‘very possibly correct’, and the advice that ‘one would need to talk to genuine locals and shepherds to give definitive answers’. 

Therefore, as there is no definite confirmation of Naddle High Forest being an appropriate name for this hill, the name this hill is now listed by in The Fours is High Forest, which is the name appearing nearest the summit of this hill on a number of different scaled Ordnance Survey maps.  

The full details for the hill are:

Group:  High Street

Name:  High Forest

Previously Listed Name:  Naddle High Forest 

Summit Height:  435m

OS 1:50,000 map:  90

Summit Grid Reference:  NY 49245 14308

  

Drop:  c 28m

Myrddyn Phillips and Aled Williams (May 2018)

Mapping Mountains – Hill Reclassifications – 200m Twmpau

Pt. 296.1m (SH 694 169) – 200m Sub-Twmpau addition

There has been confirmation of an addition to the 200m Twmpau list due to LIDAR analysis conducted by Myrddyn Phillips, with the criteria for this list being:

200m Twmpau - Welsh hills at and above 200m and below 300m in height with 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau with the criteria for this sub category being all Welsh hills at and above 200m and below 300m in height with 20m and more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

This hill was not listed in the Hills to be surveyed sub list when the original Welsh P30 hills were published on Geoff Crowder’s v-g.me website as it did not meet the criteria then used for this category of hill; however this list has now been standardised and interpolated heights and drop values also included, resulting in this hill being listed with 26m of drop, based on the 297m summit spot height and the 271m bwlch spot height that appear on the Ordnance Survey Interactive Coverage Map hosted on the Geograph website.

Extract from the Ordnance Survey Interactive Coverage Map hosted on the Geograph website

As the name of the ffridd taking in this hill’s summit has not been confirmed the hill is being listed by the point (Pt. 296.1m) notation and it is adjoined to the Cadair Idris group of hills, which are situated in the south-western part of North Wales (Region A, Sub-Region A3), and the hill is positioned with the A 493 road to its north and has the town of Dolgellau towards its east.

As the hill is a part of designated open access land an ascent from a variety of directions is feasible, with a minor road towards its east and a public footpath towards its north and a bridleway towards its south probably giving the easiest option for ascent.

The confirmation of the addition of this hill to 200m Sub-Twmpau status is due to LIDAR analysis conducted by Myrddyn Phillips.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

The 1m DTM LIDAR analysis gives the hill the following details:

Name:  Pt. 296.1m

Summit Height:  296.1m

Summit Grid Reference:  SH 69444 16921

Bwlch Height:  271.0m

Bwlch Grid Reference:  SH 69406 17012

Drop:  25.0m

LIDAR image of Pt. 296.1m

Therefore, the 296.1m LIDAR analysis for the summit position at SH 69444 16921 and the 271.0m LIDAR analysis for the bwlch position at SH 69406 17012 gives this hill 25.0m of drop, which confirms its addition to 200m Sub-Twmpau status.

The full details for the hill are:

Group:  Cadair Idris

Name:  Pt. 296.1m

OS 1:50,000 map:  124

Summit Height:  296.1m (LIDAR)

Summit Grid Reference:  SH 69444 16921 (LIDAR)

Bwlch Height:  271.0m (LIDAR)

Bwlch Grid Reference:  SH 69406 17012 (LIDAR)

Drop:  25.0m (LIDAR)

Myrddyn Phillips (May 2018)

Mapping Mountains – Significant Name Changes – Y Pedwarau

Waun Sidan (SO 250 726)

There has been a Significant Name Change to a hill that is listed in the Y Pedwarau, with the summit height, drop and status of the hill derived from LIDAR analysis conducted by Aled Williams and subsequently confirmed by a survey with the Trimble GeoXH 6000 which took place on the 19^th April 2018.

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

Y Pedwarau – Welsh hills at and above 400m and below 500m in height that have 30m minimum drop.  The list is co-authored by Myrddyn Phillips and Aled Williams, with the introduction to the Mapping Mountains publication of the list appearing on the 30^th January 2017.

The hill is adjoined to the Beacon Hill range of hills, which are situated in the north-eastern part of Mid and West Wales (Region B, Sub-Region B1), and is positioned between the B4355 road to the north-east and the A488 road to the south-east, and has the small town of Tref-y-clawdd (Knighton) to the east.

Waun Sidan (SO 250 726)

The hill appeared in the 400m P30 list on Geoff Crowder’s v-g.me website under the partly invented name of Downes’s Dingle Hill, with an accompanying note stating; Name from dingle to the South. 

Downes's Dingle Hill

406m

SO250726

137/148

201

Name from dingle to the South.

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 dingle and add the word 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 historical 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

Since publication of these P30 lists on Geoff Crowder’s v-g.me website there have been a number of Ordnance Survey maps made available online, some of these are historical such as the series of Six-Inch maps on the National Library of Scotland website, whilst others are current and digitally updated such as the Interactive Coverage Map hosted on the Geograph website.  Two of the historical maps now available are the Ordnance Survey Draft Surveyors map which formed the basis for the Ordnance Survey One-Inch ‘Old Series’ map, and it was the former of these maps that name the hill as Waun Sidan.

Extract from the Ordnance Survey Draft Surveyors map

The Draft Surveyors maps consist of the preliminary drawings made by the Ordnance Survey’s surveyors between the 1780s and 1840 and formed the basis for the first publicly available One-Inch map.  They were drawn at scales of six inches to the mile for areas considered of particular military significance and down to two inches to the mile for other areas.  Fair copies were then produced from these preliminary drawings to one inch to the mile and then copper plates were prepared for printing.  The Draft Surveyors maps for the whole of Wales are now available online and they form an important part in the study of Welsh upland place-names as they bridge the time frame between the late 18^th century and the mid-19^th century when the Ordnance Survey produced their first One-Inch maps.

Therefore, the name this hill is now listed by in the Y Pedwarau is Waun Sidan, and this was derived from the Ordnance Survey Draft Surveyors map.

The full details for the hill are:

Group:  Beacon Hill

Name:  Waun Sidan

Previously Listed Name:  Downes’s Dingle Hill

Summit Height:  407.8m (converted to OSGM15)

OS 1:50,000 map:  137, 148

Summit Grid Reference:  SO 25022 72649

Drop:  31.5m (converted to OSGM15)

The Trimble GeoXH 6000 gathering data at the summit of Waun Sidan (SO 250 726)

For details on the survey of Waun Sidan

Myrddyn Phillips and Aled Williams (May 2018)