Monday 31 August 2020

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


Craig y Benglog (SH 805 244) – 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 forthcoming Change Register giving detail to this list and its alterations since publication in the Mountain tables book.

Craig y Benglog (SH 805 244)

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:

25th 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:

29th 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.

25th 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 Craig y Benglog, and it is adjoined to the Arenig group of hills which are situated in the central part of north Wales, and it is positioned with the A470 road to its west and the A494 road to its east, and has the town of Dolgellau towards the south-west.

This hill was not included in the original 1995 Constable publication, but with an uppermost 520m ring contour and bwlch contouring between 490m – 500m 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 was then joined by Rob Woodall to conduct a basic levelling survey of this hill on the 27th October 2001, resulting in 110ft / 33.5m of drop.  These details were forwarded to the list author; Michael Dewey and the hill was added to the list on the 2nd November 2001.

At the bwlch of Craig y Benglog during the GNSS survey of the hill

As this hill qualified for the Dewey list through a basic levelling survey it was prioritised for a GNSS survey, and this took place on the 26th January 2009.  The summit and bwlch of this hill were surveyed by John Barnard, Graham Jackson and Myrddyn Phillips using a Leica 530, resulting in a 525.3m summit height and a 492.7m bwlch height, with these values giving this hill 32.6m of drop, and therefore confirming its Dewey status.


The full details for the hill are:

Name:  Craig y Benglog

OS 1:50,000 map:  124, 125

OS 1:25,000 map:  23

Summit Height:  525.3m (Leica 530)

Summit Grid Reference:  SH 80504 24416 (Leica 530)

Bwlch Height:  492.7m (Leica 530)

Bwlch Grid Reference:  SH 80428 24506 (Leica 530)

Drop:  32.6m (Leica 530)


Myrddyn Phillips (August 2020)




Sunday 30 August 2020

Mapping Mountains – Summit Relocations – The Fours – The 400m Hills of England


Rushy Knowe (NY 681 820)

There has been a Summit Relocation to a hill that is listed in 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 detail on contemporary maps produced from Ordnance Survey data.


This spreadsheet is being evaluated by a number of people, including Ronnie Bowron, who passed the details of this hill for evaluation.

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

The FoursThe 400m Hills of England.  English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main listing of The Fours are three categories of sub hills, with this hill being listed in the 390m Double Sub-Four category, the criteria for which are all English hills at or above 390m and below 400m 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 2nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24th April 2018.

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

The name the hill is listed by is Rushy Knowe, and it is adjoined to Sighty Crag group of hills, which are situated in the north-eastern part of England (Region 33 Scottish Border to the River Tyne), and it is positioned with a minor road and Kielder Water to its north, and has the village of Bellingham towards the east.

When the 2nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, this hill was listed with an estimated c 28m of drop, based on the 397m summit spot height positioned at NY 677 817 and an estimated c 369m col height based on interpolation of 10m contouring between 360m – 370m that appear on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map.

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

The details for this hill have now been re-assessed against Ordnance Survey data hosted on the Magic Maps website, and this mapping gives a 398m spot height on the summit area of this hill positioned at NY 681 820.

Extract from the Magic Maps website

This new summit position and interpolation of col contouring were also re-assessed against the OS Maps website.  This is the replacement for OS Get-a-map and has contours at 5m intervals which are proving 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 re-assessment resulted in the estimated col height for this hill being amended to c 371m, with this based on interpolation of 5m contouring between 370m – 375m.

Extract from the OS Maps website

The above detail comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the hill’s high point is in a different field, or where a number of potential summit positions are within close proximity and the highest point is not where previously given, or when it is positioned to a different feature such as in a conifer plantation, or when the high point of the hill is placed within a different map contour, or when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be 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 listed summit height of this hill is now 398m and its new position is NY 68108 82036, 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 350 metres north-eastward from where the previously listed summit is positioned.


The full details for the hill are:

Group:  Sighty Crag

Name:  Rushy Knowe

OS 1:50,000 map:  80

Summit Height:  398m (spot height)

Summit Grid Reference (new position):  NY 68108 82036 (spot height)

Col Height:  c 371m (interpolation)

Col Grid Reference:  NY 67304 81373 (interpolation)

Drop:  c 27m (spot height summit and interpolated col)


Myrddyn Phillips and Aled Williams (August 2020)



Saturday 29 August 2020

Mapping Mountains – Significant Name Changes – Y Trichant – The 300m Hills of Wales


Lan Cilpebyll (SN 988 363)

There has been a Significant Name Change 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 confirmed by LIDAR analysis.

LIDAR image of Lan Cilpebyll (SN 988 363)


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 prioritised Trichant status.

The criteria for the list that this name change 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.

The hill 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.

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

The hill appeared in the original Welsh 300m P30 list published on Geoff Crowder’s v-g.me website under the name of Mynydd Bach and listed as a 387m map heighted twin summit with its adjacent hill positioned at SN 992 359.  With the name of Mynydd Bach being appropriate for the adjacent hill but not necessarily for this hill.


Mynydd Bach387mSN992360160188Two tops of same height - other at SN988363


As this hill comprises bounded land the Tithe map was consulted.  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 798 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 Lan (of the farm) Cilpebyll in the apportionments, with the details on the Tithe map appearing in the parish of Merthyr Cynog and in the county named as Brecon.

Extract from the apportionments

The land associated with Mynydd Bach does not have a number given it on the Tithe, this signifies that this land was not tenanted and therefore viewed as Common land with the consolidating or extending of land holdings in to larger areas compared to that of the Tithe, and these larger areas of land would include land communally farmed under the open field system.  As such, this land had its own individual name which can be thought of as that of the hill; Mynydd Bach.  Whereas, the land named as Lan (of the farm) Cilpebyll on the Tithe was tenanted and took in a smaller patch of bounded land as indicated on the Tithe.

Therefore, the name this hill is now listed by in the Y Trichant – The 300m Hills of Wales is Lan Cilpebyll , and this was derived from the Tithe map.


The full details for the hill are:

Group:  Mynydd Epynt

Name:  Lan Cilpebyll

Previously Listed Name:  Mynydd Bach

OS 1:50,000 map:  160

Summit Height:  385.9m (LIDAR)

Summit Grid Reference:  SN 98815 36321 (LIDAR)

Bwlch Height:  310.4m (LIDAR)

Bwlch Grid Reference:  SN 98629 37385 (LIDAR)

Drop:  75.5m (LIDAR)


Myrddyn Phillips (August 2020)






Friday 28 August 2020

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


Moel yr Wden (SH 780 356) – 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 forthcoming Change Register giving detail to this list and its alterations since publication in the Mountain tables book.

Moel yr Wden (SH 779 353)

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:

25th 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:

29th 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.

25th 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 Moel yr Wden, and it is adjoined to the Arenig group of hills which are situated in the central part of north Wales, and it is positioned with the A4212 road to its north-west, the A470 road to its south-west and the A494 road to its south-east, and has the village of Trawsfynydd towards the west.

The Name: Moel yr Wden is a transposed name as local enquiry confirms that it is applicable to a 520m upper contour map heighted hill positioned to the west of this, the qualifying Dewey, with the name placement on the Ordnance Survey 1:50,000 Landranger map being appropriate.

This hill was not included in the original 1995 Constable publication, as with a 560m uppermost contour and bwlch contouring between 530m – 540m that appear on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and with the opposing 540m contours relatively close together, this implied this hill was unlikely to have sufficient drop to qualify for this list. 

Extract from the Ordnance Survey 1:50,000 Landranger map

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

Although the above was noted by Myrddyn Phillips, a basic levelling survey of this hill was conducted on the 21st July 2000, with a surprising result of 112ft / 34.1m of drop.  As this result was at odds with Ordnance Survey contouring, Michael Dewey was informed, but it was decided not to promote this hill to Dewey status and wait for the result of a second survey of this hill.

The second basic levelling survey of this hill was conducted on the 27th October 2001 by Myrddyn Phillips and Rob Woodall, resulting in the same drop value as the first; 112ft / 34.1m.  These details were forwarded to the list author; Michael Dewey and the hill was added to the list on the 2nd November 2001.

Graham Jackson and Janet Jackson during the line survey of Moel yr Wden

As this hill qualified for the Dewey list through a basic levelling survey and as this was at odds with Ordnance Survey map contouring, it was prioritised for a line survey, and this took place on the 31st March 2008.  The line survey consisted of two teams; Graham Jackson and Janet Jackson who concentrated on the drop value of Moel yr Wden, and John Barnard and Myrddyn Phillips who line surveyed from the 619m map heighted summit of Gallt y Daren (SH 778 344) to the bwlch position of Moel yr Wden, this resulted in 34.1m of drop with the summit of Moel yr Wden being 572.9m in height dependent upon the accuracy of the 619m spot height atop Gallt yr Daren.  This survey confirmed this hill’s Dewey status.

The Leica 530 set-up position at the summit of Moel yr Wden
The Leica 530 set-up position at the bwlch of Moel yr Wden

As the resulting height of Moel yr Wden was still at odds with its 560m uppermost Ordnance Survey contour the hill was prioritised for a GNSS survey.  This was conducted by John Barnard, Graham Jackson and Myrddyn Phillips on the 25th November 2008, resulting in a 572.3m summit height and a 538.2m bwlch height, with these values giving this hill 34.0m of drop, confirming that the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map are missing an uppermost 570m ring contour.


The full details for the hill are:

Name:  Moel yr Wden

OS 1:50,000 map:  124

OS 1:25,000 map:  18, 23

Summit Height:  572.3m (Leica 530)

Summit Grid Reference:  SH 78012 35618 (Leica 530)

Bwlch Height:  538.2m (line survey relative to summit height)

Bwlch Grid Reference:  SH 77981 35395 (Leica 530)

Drop:  34.1m (line survey)


Myrddyn Phillips (August 2020)