Wednesday, 27 May 2020

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

Stanky Hill (SO 163 764) – 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.

The bwlch of Stanky Hill

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 Stanky Hill, and it is adjoined to the Radnor Forest group of hills which are situated in the north-eastern part of Mid Wales, and it is positioned with the B4355 road to its north, the A483 road to its west and the B4356 road to its south, and has the village of Bugeildy (Beguildy) towards the north-east.

This hill was not included in the original 1995 Constable publication, but with a 506m summit spot height and bwlch contouring between 470m – 480m 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 considered for Dewey status.  However, as the Ordnance Survey 1:50,000 Landranger map also shows a 407m spot height on the area of this hill’s bwlch this hill had not been considered for automatic entry to this list.

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

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

The above detail was noted by David Purchase and Myrddyn Phillips who worked independently but also exchanged all data.  On the 30th April 2000 Myrddyn Phillips conducted a basic levelling survey (BLS) of this hill, resulting in 103ft / 31.4m of drop.  These details were forwarded to the list author; Michael Dewey and the hill was added to the list on the 8th May 2000.

As the margin of uncertainty for the BLS method of surveying over terrain such as that on Stanky Hill is approximately +/- 1.5m and as the resulting 31.4m of drop was near the minimum 30m qualifying drop value, this hill was prioritised for a GNSS and level and staff line survey, and this took place on the 16th February 2012.  The summit and bwlch of this hill were surveyed by John Barnard, Graham Jackson and Myrddyn Phillips with assistance from Aled Williams, using a Leica 530 with 60 minutes of data gathered at each point.  During data collection the hill was also line surveyed from bwlch to summit and back to its bwlch, resulting in the drop value for this hill being ascertained from a further two different forms of surveying.

At the bwlch of Stanky Hill

The survey resulted in a 506.7m summit height and a 476.4m bwlch height, with these values giving this hill 30.3m of drop, which also matched that ascertained from the level and staff line survey, and confirmed this hill’s Dewey status. 

The full details for the hill are:

Name:  Stanky Hill

OS 1:50,000 map:  136, 148

OS 1:25,000 map:  214

Summit Height:  506.7m (Leica 530)

Summit Grid Reference:  SO 16390 76419 (Leica 530)

Bwlch Height:  476.4m (Leica 530)

Bwlch Grid Reference:  SO 16861 76416 (hand-held GPS during survey)

Drop:  30.3m (Leica 530 and level and staff line survey)

Myrddyn Phillips (May 2020)

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