Mapping Mountains – Hill Reclassifications – The 500-Metre Tops of England and Wales – Deweys

Foel y Geifr (SH 716 050) – Dewey deletion

This is one in a series of Hill Reclassification posts that detail hills whose status has altered in the listing of the Deweys.  These posts tie in with a ChangeRegister giving detail to this list and its alterations since publication in the Mountain tables book. 

Foel y Geifr (SH 716 050)

The 500-Metre Tops of England and Wales are affectionately known after their hill list compiler; Michael Dewey.  This list mixes metric and imperial height in its criteria to bookend up to the 2000ft height band and takes in all hills in England, Isle of Man and Wales that are 500m and above and below 2000ft (609.6m) in height that have 30m minimum drop.

This list formed one of a number of lists that appeared in the Mountain tables book published by Constable in 1995 and at the time of publication comprised 373 hills with 164 in England, 5 in the Isle of Man and 204 in Wales.  The Deweys have undergone extensive revision since first publication with the initial stages forming the basis of this revision given below: 

 

1995    Mountain tables published by Constable with 373 hills listed as Deweys.

 

April 2000    Strider (LDWA quarterly booklet) publishes contact details for David Purchase and Myrddyn Phillips who have found and list 24 and 14 possible new 500m tops respectively.

 

It was expanded versions of the above two lists that formed the basis of the next publication:

 

25^th May 2000    List of Possible 500 Metre Tops by Michael Dewey listing 44 hills.

 

David Purchase expands his Additional Dewey 500m Hills and Myrddyn Phillips produces lists of English 500m hills to measure and Welsh 500m hills to measure.

 

These lists formed the basis of the next publication:

 

29^th June 2000    Possible/Probable 500’s by Michael Dewey listing 77 hills.  Michael adopts following protocol; if one person proposes that a top should qualify as a 500 by personal survey, and is then confirmed by a second person, it should then be promoted to the main list.

 

April 2002    The 500+ Tops of England and Wales – The ‘New Deweys’ published in the Strider booklet and listing 66 new qualifying hills.

 

25^th May 2006    Rob Woodall republishes Michael’s main and possible/probable lists on the RHB Yahoo group file database.

 

Postscript:  Michael Dewey died on the 5^th November 2022.  His wife; Gillian wished for this list to be carried on and made provision for it to be co-authored by Myrddyn Phillips.  Michael will always be the compiler and originator, it’s just that he’s now got a co-author to safeguard and carry this list on.

Mountain tables by Michael Dewey

The details for this deletion appear below:

The name the hill is listed by in the Deweys is Foel y Geifr, and it is adjoined to the Cadair Idris group of hills which are situated in the south-western part of North Wales, and it is positioned with the B4405 road to its north-west, the A493 road to its south and the A487 road to its east, and has the town of Machynlleth towards the south-east.

This hill was not included in the original 1995 Constable publication, but with a 515m summit spot height and bwlch contouring between 480m – 490m that appear on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, the interpolated drop value was estimated sufficient for this hill to be a potential new Dewey. 

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

The above detail was noted by Myrddyn Phillips who then conducted a basic levelling survey of this hill on the 26^th June 2000, resulting in over 30m of drop.  These details were forwarded to the list author; Michael Dewey and the hill was added to the list with the date of survey given in the Remarks column accompanying the list.

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 image of Foel y Geifr (SH 716 050)

Therefore, the deletion of this hill from the The 500-Metre Tops of England and Wales list was instigated on the 26^th May 2023 and is due to LIDAR analysis first reported by the DoBIH team based on detail produced by Joe Nuttall in his surface analysis programme, resulting in a 515.6m summit height and a 486.8m bwlch height, with these values giving this hill 28.8m of drop, which is insufficient for it to be classified as a Dewey. 

 

The full details for the hill are: 

Name:  Foel y Geifr 

OS 1:50,000 map:  124

OS 1:25,000 map:  23

Summit Height:  515.6m (LIDAR) 

Summit Grid Reference:  SH 71634 05092 (LIDAR) 

Bwlch Height:  486.8m (LIDAR) 

Bwlch Grid Reference:  SH 71726 05403 (LIDAR) 

Drop:  28.8m (LIDAR) 

 

Myrddyn Phillips (July 2023)

  

Mapping Mountains – Hill Reclassifications – The 500-Metre Tops of England and Wales – Deweys

 

Meal Fell (NY 282 337) – Dewey deletion

This is one in a series of retrospective Hill Reclassification posts that detail hills whose status has altered in the listing of the Deweys.  These posts tie in with a Change Register giving detail to this list and its alterations since publication in the Mountain tables book. 

LIDAR image of Meal Fell (NY 282 337)

The 500-Metre Tops of England and Wales are affectionately known after their hill list compiler; Michael Dewey.  This list mixes metric and imperial height in its criteria to bookend up to the 2000ft height band and takes in all hills in England, Isle of Man and Wales that are 500m and above and below 2000ft (609.6m) in height that have 30m minimum drop.

This list formed one of a number of lists that appeared in the Mountain tables book published by Constable in 1995 and at the time of publication comprised 373 hills with 164 in England, 5 in the Isle of Man and 204 in Wales.  The Deweys have undergone extensive revision since first publication with the initial stages forming the basis of this revision given below: 

 

1995    Mountain tables published by Constable with 373 hills listed as Deweys.

 

April 2000    Strider (LDWA quarterly booklet) publishes contact details for David Purchase and Myrddyn Phillips who have found and list 24 and 14 possible new 500m tops respectively.

 

It was expanded versions of the above two lists that formed the basis of the next publication:

 

25^th May 2000    List of Possible 500 Metre Tops by Michael Dewey listing 44 hills.

 

David Purchase expands his Additional Dewey 500m Hills and Myrddyn Phillips produces lists of English 500m hills to measure and Welsh 500m hills to measure.

 

These lists formed the basis of the next publication:

 

29^th June 2000    Possible/Probable 500’s by Michael Dewey listing 77 hills.  Michael adopts following protocol; if one person proposes that a top should qualify as a 500 by personal survey, and is then confirmed by a second person, it should then be promoted to the main list.

 

April 2002    The 500+ Tops of England and Wales – The ‘New Deweys’ published in the Strider booklet and listing 66 new qualifying hills.

 

25^th May 2006    Rob Woodall republishes Michael’s main and possible/probable lists on the RHB Yahoo group file database. 

 

Postscript:  Michael Dewey died on the 5^th November 2022.  His wife; Gillian wished for this list to be carried on and made provision for it to be co-authored by Myrddyn Phillips.  Michael will always be the compiler and originator, it’s just that he’s now got a co-author to safeguard and carry this list on. 

Mountain tables by Michael Dewey

The details for this deletion appear below: 

The name the hill was listed by in the Deweys is Meal Fell, and it is adjoined to the Skiddaw group of hills which are situated in the Lake District in England, and it is positioned with the B5299 road to its north, the A591 road to its west and the A66 road to its south, and has the town of Keswick towards the south. 

This hill was not included in the original 1995 Constable publication, but with a 550m summit spot height and col contouring between 520m – 530m that appear on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, the interpolated drop value was estimated sufficient for this hill to be a potential new Dewey as the 0pposing 520m ring contours are extremely close together.                                                            

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

The above detail was noted by Rob Woodall and Myrddyn Phillips who worked independently but also exchanged all data, with Rob assessing the hill’s qualification on site on the 14^th November 2000.  These details were forwarded to Michael Dewey and the hill was added to the list on the 19^th November 2000.

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 image of Meal Fell (NY 282 337)

Therefore, the deletion of this hill from the The 500-Metre Tops of England and Wales list was instigated on the 29^th December 2022 and is due to LIDAR analysis conducted by Myrddyn Phillips, with this previously deduced by the DoBIH team, resulting in a 549.4m summit height and a 520.1m col height, with these values giving this hill 29.3m of drop, which is insufficient for it to be classified as a Dewey. 

 

The full details for the hill are: 

Name:  Meal Fell 

OS 1:50,000 map:  89, 90

OS 1:25,000 map:  4

Summit Height:  549.4m (LIDAR) 

Summit Grid Reference:  NY 28299 33762 (LIDAR) 

Col Height:  520.1m (LIDAR) 

Col Grid Reference:  NY 28565 33765 (LIDAR) 

Drop:  29.3m (LIDAR) 

 

Myrddyn Phillips (February 2023)

 

 

 

Mapping Mountains – Hill Reclassifications – The 500-Metre Tops of England and Wales – Deweys

Y Drum (SJ 082 378) – Dewey addition

This is one in a series of retrospective Hill Reclassification posts that detail hills whose status has altered in the listing of the Deweys and where I have had direct association with the status change.  These posts will tie in with a Change Register giving detail to this list and its alterations since publication in the Mountain tables book. 

Y Drum (SJ 082 378)

The 500-Metre Tops of England and Wales are affectionately known after their hill list compiler; Michael Dewey.  This list mixes metric and imperial height in its criteria to bookend up to the 2000ft height band and takes in all hills in England, Isle of Man and Wales that are 500m and above and below 2000ft (609.6m) in height that have 30m minimum drop. 

This list formed one of a number of lists that appeared in the Mountain tables book published by Constable in 1995 and at the time of publication comprised 373 hills with 164 in England, 5 in the Isle of Man and 204 in Wales.  The Deweys have undergone extensive revision since first publication with the initial stages forming the basis of this revision given below: 

 

1995    Mountain tables published by Constable with 373 hills listed as Deweys.

 

April 2000    Strider (LDWA quarterly booklet) publishes contact details for David Purchase and Myrddyn Phillips who have found and list 24 and 14 possible new 500m tops respectively.

 

It was expanded versions of the above two lists that formed the basis of the next publication:

 

25^th May 2000    List of Possible 500 Metre Tops by Michael Dewey listing 44 hills.

 

David Purchase expands his Additional Dewey 500m Hills and Myrddyn Phillips produces lists of English 500m hills to measure and Welsh 500m hills to measure.

 

These lists formed the basis of the next publication:

 

29^th June 2000    Possible/Probable 500’s by Michael Dewey listing 77 hills.  Michael adopts following protocol; if one person proposes that a top should qualify as a 500 by personal survey, and is then confirmed by a second person, it should then be promoted to the main list.

 

April 2002    The 500+ Tops of England and Wales – The ‘New Deweys’ published in the Strider booklet and listing 66 new qualifying hills.

 

25^th May 2006    Rob Woodall republishes Michael’s main and possible/probable lists on the RHB Yahoo group file database. 

Mountain tables by Michael Dewey

The details for this addition appear below: 

The name the hill is listed by in the Deweys is Y Drum, and it is adjoined to the Craig Berwyn group of hills, which are situated in the south-eastern part of north Wales, and it is positioned with the A5 road to its north and the B4401 road to its west, and has the village of Cynwyd towards the north-west. 

This hill was not included in the original 1995 Constable publication, as with a 579m summit spot height and a 551m bwlch spot height that appear on the Ordnance Survey 1:25,000 Explorer map it was accepted that the hill had under 30m of drop. 

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

Since the 1995 publication of this list by Constable there have been a number of Ordnance Survey maps made available online, some of these are historic 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 mapping on the OS Maps website.  This is the replacement for OS Get-a-map and it used to have contours at 5m intervals which proved 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 had bwlch contouring between 545m – 550m, with interpolation giving an estimated bwlch height of c 549m and therefore an estimated c 30m of drop. 

With this newly acquired information the hill was prioritised for a GNSS survey and this took place on the 26^th November 2020.  The summit and bwlch of this hill were surveyed by Myrddyn Phillips with Aled Williams and Mark Trengove assisting, using a Trimble GeoXH 6000 resulting in a 579.1m summit height and a 549.0m bwlch height, with these values giving this hill 30.1m of drop. 

The Trimble GeoXH 6000 gathering data at the bwlch area of Y Drum

The Trimble GeoXH 6000 gathering data at the summit of Y Drum

These details were forwarded to the list author; Michael Dewey and the hill was subsequently added to his list on 28^th November 2020.

The hill was subsequently analysed via LIDAR by Aled Williams, and on the 17^th October 2025 it was surveyed by Alan Dawson using a Leica RX1250, resulting in a 579.1m summit height and a 549.1m bwlch height, with these values giving this hill 30.0m of drop. 

 

The full details for the hill are: 

Name:  Y Drum 

OS 1:50,000 map:  125

OS 1:25,000 map:  255

Summit Height:  579.1m (converted to OSGM15, Trimble GeoXH 6000 and Leica RX1250)

Summit Grid Reference:  SJ 08247 37893 (Trimble GeoXH 6000 and Leica RX1250)

Bwlch Height:  549.1m (converted to OSGM15, Leica RX1250)

Bwlch Grid Reference:  SJ 07986 38259 (Leica RX1250)

Drop:  30.0m (Trimble GeoXH 6000 and Leica RX1250 summit and Leica RX1250 bwlch)

 

Myrddyn Phillips (June 2021)

 

 

 

 

 

 

  

The 500-Metre Tops of England and Wales – the Deweys

Y Drum (SJ 082 378) – Dewey addition

The listing to The 500-Metre Tops of England and Wales appeared in Michael’s Mountain tables book which was published by Constable in 1995.  This list mixed metric and imperial height in its criteria to bookend up to the 2000ft height band and listed hills between 500m – 2000ft (609.6m) in height with 30m minimum drop.

Mountain tables by Michael Dewey

Since publication of this list there have been a number of status changes to it. In recent years this has involved independent surveyors and the use of LIDAR.  Both have enabled an accurate re-assessment of many of the hills included in Michael’s list as well as potential new Deweys that were considered marginal on height and/or drop and not initially included. 

Michael Dewey is in receipt of the survey details relating to this hill and has confirmed its addition to his list of The 500-Metre Tops of England and Wales.

Y Drum (SJ 082 378)

 

Dewey addition:

Y Drum (SJ 082 378) was surveyed using the Trimble GeoXH 6000 whilst on a walk with Aled Williams and Mark Trengove, the hill is positioned in the north-western Berwyn and situated between Moel yr Henfaes (SJ 077 385) and Cefn Dylif (SJ 089 369).

The Trimble GeoXH 6000 gathering data at the summit of Y Drum

 

Survey details: 

Name:  Y Drum 

Summit:  579.1m at SJ 08247 37893 

Bwlch:  549.0m at SJ 08003 38256 

Drop:  30.1m 

 

Myrddyn Phillips (November 2020)