Monday, 29 February 2016

Mapping Mountains – Significant Height Revisions – Y Pedwarau


Cwm Cynydd Bank (SO 061 726)

This is the twenty sixth post under the heading of Significant Height Revisions, and the Trimble survey that resulted in this height revision was conducted on 18th February 2016.

The resulting significant height revision was conducted in the hills of the Pegwn Mawr range in mid Wales, during a walk taking in one 300m Twmpau and three Pedwarau, with some of these hills immersed in part of the conifer plantation that takes in land to the north of Abaty Cwm Hir (Abbey Cwmhir).

The hill is situated in this woodland, but can be accessed from open hillside and forest tracks to within a few metres of its summit which is positioned in mature conifer plantation and situated just to the north of a broad path.  The hill is situated to the north of the small community of Abaty Cwm Hir (Abbey Cwmhir) and to the south-east of the small community of Bwlch y Sarnau.

The name of the hill is Cwm Cynydd Bank and prior to the Trimble survey it was listed as a Pedwar with its summit height of 450m taken from the Ordnance Survey 1:50,000 map.  This height equates to the old imperial height of 1,477ft that is given on the Ordnance Survey 1:25,000 Historical Map which originates from the series of Ordnance Survey old Six-Inch maps.  This height appears near to or on the broad path that gives access to this hill’s summit and which traverses its broad north-east to south-west ridge.

When surveying this summit I waited a long time for the accuracy level of the Trimble to attain its 0.1m before data should be logged, during this time I assessed the lay of land around the summit and tried to keep warm.  I estimated the summit of the hill to be at least 3m higher than the path where the centralised imperial height appears on the old Six-Inch map. 

Therefore this hill’s new summit height is 454.9m (converted to OSGM15) which is 4.9m higher than its previously listed height of 450m and 14.9m higher than the uppermost 440m ring contour that appears on current Ordnance Survey 1:25,000 maps.



The full details for the hill are:


Cardinal Hill:  Brondre-fawr Hill

Summit Height:  454.9m (converted to OSGM15)

Name:  Cwm Cynydd Bank

OS 1:50,000 map:  136, 147

Summit Grid Reference:  SO 061 726

Drop:  83.9m (converted to OSGM15)


Gathering data from the summit of Cwm Cynydd Bank (SO 061 727)

For details on the survey of this hill please click {here}


Myrddyn Phillips and Aled Williams (February 2016)



Saturday, 27 February 2016

Mapping Mountains – Trimble Surveys – Pegwn Mawr


18.02.16  Tyfaenor Park (SO 070 715), Cwm Cringlyn Bank (SO 072 725), 

Cwm Cynydd Bank (SO 061 726), Cwm Cynydd Bank (SO 053 724, not 

Trimbled) and Little Park (SO 051 717, not Trimbled)  

Cwm Cynydd Bank (SO 061 726)

The delights of forested tops are an acquired taste, these delights I am still unsure of, as on occasion when immersed in a conifer plantation I am prone to wonder why I am doing what I am doing, this is particularly prevalent when brambles are present, and these when combined with wind felled trees add a little gruesomeness to proceedings.  The latter part of today’s walk combined all of the above and proved to be a fine example of hell on a hill.

I set off from Abaty Cwm-hir (Abbey Cwmhir) having parked in front of the resplendent looking St Mary’s Church, immediately behind the church the framed and rounded forested hill of Little Park rose to the blue sky above.  I hoped that this hill would be my last of the day, but this was dependent upon a number of forest tracks being accessible.

Little Park with St Mary's Church in the foreground

Heading east on a minor paved road and then a narrow lane toward Llwyn-onn, the morning’s mist ebbed its last as sun’s warmth diligently worked on the frost laden land.  I left the narrow lane and followed a track toward Brynmoel and chatted with a couple walking their dogs before taking to the fields beyond.

A track led down from the fields back to the minor road before I branched up a lane to the old farm house of Tŷ-faenor (Dyfaenor), which no doubt gives its name toward the first hill on my route; Tyfaenor Park.  As I walked up the steep track beyond the farm, snowdrops sparkled out of their rooted den.  These beautiful plants are one of the first signs that warmth and the heralding of seasonal change is upon us, but today winter’s chill was still in the air, and as I made my way up through a series of foot stiles and gates toward the summit of Tyfaenor Park a slight breeze blew the sun’s warmth leaving gloved hands to operate the Trimble.

The late winter Snowdrop

The summit of Tyfaenor Park is easily identifiable and soon the Trimble was beeping away collecting its allotted 300 points which is equivalent to five minutes of data.  During this time I took a series of photographs, looking across the Clywedog Brook to the elongated shape of Llywy, a 466m map heighted Pedwar, and one which I have yet to visit.  To my west the forested summit of Great Park seemed relatively easily attainable from its reclaimed green and high pastured adjacent land.  The view to my north-west showed the ravages of conifer plantation as the summit of Cwm Cynydd Bank was completely swamped by trees.  Lastly, the continuation of land to my immediate north led to the next summit on my walk; Cwm Cringlyn Bank, thankfully free of conifers and framed by a number of sheep happily grazing in the morning’s sunshine.

Llywy (SO 054 704)

Great Park (SO 059 717)

Gathering data at the summit of Tyfaenor Park

Cwm Cringlyn Bank (SO 072 725)

Once the Trimble was packed away I quickly walked down to the connecting bwlch, assessed the lay of land, chose the spot for the critical bwlch and positioned the Trimble on top of my rucksack to give it elevation above its immediate surrounds.  As it gathered data I watched a number of sheep heading down the northern slopes of Tyfaenor Park as the sun illuminated their white fleeces from behind.

Gathering data at the critical bwlch of Tyfaenor Park

By the time I’d walked up to the summit of Cwm Cringlyn Bank the blue sky to the west had been overtaken by a mass of grey murk that slowly crept its way across some of the higher summits.  After the Trimble had done its stuff I quickly packed it away and scampered off following a path north-west toward my forest adventure.  By the time I entered the forest the first drops of snow were falling, adding an ethereal atmosphere to my suddenly darkened habitat.  I considered attempting to gather data just inside the forest at the bwlch of Cwm Cringlyn Bank but quickly abandoned the idea and set off following a muddied path to a near forest track.

Gathering data at the summit of Cwm Cringlyn Bank as the snow showers mass

By the time I reached the forest track the noise of vehicles became evident; I marched on and hoped that I wouldn’t encounter any forest workers.  Close to where the path leaves one of the forest tracks and heads confidently toward the summit of my next hill; Cwm Cynydd Bank, I started to come across a number of cars and trucks parked on the forest track.  The entrance to my summit path was cordoned off with tape signifying that workings had, or were taking place somewhere in the vicinity of the summit, I quietly walked around the tape and up the muddied path as a large forest truck stacked full of felled trees rumbled its way across the track I had just left.  Seemingly my presence had remained undiscovered and I continued walking up the path as the noise of the forest workings progressively became distant.

The path leading toward the summit of Cwm Cynydd Bank (SO 061 726)

This part of the hill had recently been worked as a number of stacked tree trunks lay across the hillside and the path was a muddy affair with vehicle tracks evident.  The path conveniently headed straight up the eastern broad ridge of Cwm Cynydd Bank and just bi-passes the hill’s high point, which is a few metres north of the path and within mature plantation.  The only spot height appearing for this hill on any current publicly available Ordnance Survey map is 450m which appears on the 1:50,000 Landranger map, so I hoped to gather at least some data to compare the Trimble height with that of this spot height.

My patient wait at the summit of Cwn Cynydd Bank was a long affair, I had set the Trimble up on my rucksack which itself was sitting atop a tree stump, with the overall measurement offset between the position of the internal antenna within the Trimble and the base of the tree stump measured as 0.73m.  I waited, and waited, and slowly became colder and colder, I paced to and fro trying to retain some body heat and took to standing in a patch of sunlight as it broke through the canopy of trees and bathed warmth in to the forestry.  Eventually I pressed ‘Log’ and gathered a few minutes of data.

Gathering data at the summit of Cwm Cynydd Bank (SO 061 726)

It had taken a long time to come away with my prized possession of summit data and I did not want to repeat this lengthy wait again, so when I walked down to the connecting bwlch with the adjacent 444m map heighted hill at SO 052 725 I decided to set the Trimble up at this bwlch and waited five minutes or so, but when the accuracy level was still too high to log data, I closed it off, packed it away and continued following the forest track and then path to what I thought to be the summit.  The summit of this hill was subsequently analysed with LIDAR data by Aled Williams producing a height of 451.4m at SO 05342 72437 (please refer to the following Hill Reclassifications post for full details).  I then had an option to double back and follow the main forest track toward the bwlch connecting with my last hill of the day; Little Park, or continue down on a path toward the area of the self-same bwlch.  I chose the latter and popped back out in to sunshine where tracks and paths meet to the north of the 401m map heighted summit of Y Glog.

The next part of the walk was where the real fun started, as I walked up the track to my east and left it where the connecting bwlch to Little Park lay to my south.  This bwlch is now positioned in mature forestry which proved easy to walk through, but ahead were signs of wind-blown trees, fallen at a variety of angles and all prostrate with their slender tops facing eastward.  I tried to keep to their western side and bi-passed their uprooted ends thinking that the eastern side of the ridge would be similar to an assault course.  As the upper part of the hill rose in front I decided that I would have to go for it, a big mistake, as tackling the uprooted and fallen trees became a nightmare of tangled undergrowth which quickly got out of hand with the unwelcome addition of a copious amount of brambles, my progress became sloth like as I tried to head straight up only to find that this was impossible, therefore I tried following the length of each fallen tree and forlornly attempted to then zig zag between them, the whole upper part of the hill was a stack of bramble, wet rotted tree branches, moss, fallen conifers and mayhem.  However, bit by bit I made progress and neared a high point which was within a few metres of where the spot height for this hill appears on the ground, but even getting to it was a task as I circumnavigated it to try and find a way in, brambles extended at all angles and became a major problem, I eventually barged my way through and stood on the top,  unfortunately Trimbling it proved an impossibility and I wish I’d taken a photo, but I didn’t, as I wanted to push farther in to the assault course and see if any other high ground existed to my south, I tried this for a few minutes and found that my perseverance was ebbing, before I stopped I looked to my south and peered through a canopy of fallen trees and brambles and could see nothing higher, and so decided that I must now try and get back to the safety of the forest track.  My backward route was much easier as I decided to loose height to my west and get below the wind-blown trees and then bi-pass their delights on the western side of the hill.  Before leaving the brambles I took a couple of photos looking back toward the summit, neither do the upper part of this hill justice, as its whole upper section seems to be made out of fallen trees and brambles.  I wish others going this way good luck, and if approaching from the forest track to this hill’s north I would highly recommend keeping relatively low on the western side of the summit and then when aligned with it, heading straight up toward it, and not attempting an ascent direct from its connecting bwlch, this is full of silliness and stupidity, and yet after the event I was glad that I had done it as some form of unusual pleasure had been gained!

The joys of Little Park

Looking back toward the summit of Little Park

It took me 45 minutes to get from the relative safety and comfort of the forest track to the hell of the summit and back again.  Once on the forest track I dusted myself down, prized out a large hanging bramble which had attached itself to my hair, and continued down toward where a path headed off downhill on the eastern side of Y Glog.

As I followed this path down the forested top of Little Park rose in a sun drenched and rather beautiful way, looking a teense innocent and attractive, but also standing bold as brass, unwavering in its simplicity, as nowadays it is a hill made out of trees, with its high point being a summit made out of fallen trees.

The upper southern section of Little Park

The south-eastern aspect of Little Park

In time the path led down to where my car was parked, as I arrived a man appeared walking up the road with a rucksack on, we chatted for a number of minutes and showed one another our routes on a printed off segment of a map he had.  He’d had a battle with a bog and we both smiled when I told him I’d had a battle with some trees.

I left the village of Abaty Cwm-hir (Abbey Cwmhir) and drove north to Bwlch y Sarnau and then east to where the critical bwlch for Cwm Cynydd Bank (summit at SO 061 726) is positioned.  As the Trimble gathered its last data set of the day positioned on top of my rucksack beside a minor road, I watched sheep inquisitively watching me from an adjacent field.  Once five minutes of data were gathered I packed the Trimble away and headed toward the car and home happy in the knowledge that another four P30s had been bagged, with three of them being Pedwarau to add to my ever increasing total. 

Gathering data at the critical bwlch of Cwm Cynydd Bank (summit at SO 061 726) 

  
Survey Result:



Summit Height:  383.1m (converted to OSGM15)

Summit Grid Reference:  SO 07078 71589

Bwlch Height:  350.4m (converted to OSGM15)

Bwlch Grid Reference:  SO 06990 71894

Drop:  32.7m (Trichant status confirmed)

Dominance:  8.54%



Cwm Cringlyn Bank

Summit Height:  423.2m (converted to OSGM15)

Summit Grid Reference:  SO 07215 72545

Drop:  55m

Dominance:  13.00%



Cwm Cynydd Bank (significant name change)

Summit Height:  454.9 (converted to OSGM15) (significant height revision)

Summit Grid Reference:  SO 06116 72668

Bwlch Height:  370.9m (converted to OSGM15)

Bwlch Grid Reference:  SO 04667 74183

Drop:  83.9m

Dominance:  18.45%



Cwm Cynydd Bank

Summit Height:  451.4m (LIDAR data)

Summit Grid Reference:  SO 05342 72437

Bwlch Height:  416.4m (LIDAR data)

Bwlch Grid Reference:  SO 05788 72576

Drop:  35.0m (LIDAR data) (400m Sub-Pedwar reclassified to Pedwar)

Dominance:  7.75%



For further details please consult the Trimble survey spreadsheet click {here}



Thursday, 25 February 2016

Y Trechol - The Dominant Hills of Wales - Moelwynion


Hill Lists – Cymru / Wales

Y Trechol - The Dominant Hills of Wales

Introduction

To access Y Trechol - The Dominant Hills of Wales list please click {here}


Moelwyn Mawr (SH 658 448) is situated in the Moelwynion Group of hills and is listed as one of The Dominant Hills of Wales

Listings of hills in Britain have progressed since Sir Hugh Munro first compiled a list to the Scottish 3,000ft mountains that eponymously now bear his name of the Munros.  Since Sir Hugh’s list was first published in the 1891 Scottish Mountaineering Club Journal the concept of how to differentiate one hill from another has developed with this association now mainly relying upon what is referred to as prominence.  This term is also known as reascent and drop, with this being the height gain between summit and connecting bwlch to the higher parent peak via the watershed.

Although differentiating one hill from another mainly relies upon prominence, it is not the only tool used to do so, as such criterion as distance, and height and prominence combined have also been used.  But prominence is now the main criterion used to differentiate one hill from another.

The concept of prominence was first investigated by the early hill list authors such as Corbett and Moss who employed the use of a single ring contour in their listings.  This system for cataloguing hills relied upon maps of the day that were based on ring contours at 50ft intervals, therefore a hill may be included that had a 5ft prominence or less because it had a separate ring contour, this is an obvious failing in this system.

However, Corbett had initialised the concept of objective judgment in how to make this all important differentiation between one hill and another, whereas Munro relied upon subjective judgment when he differentiated between his Separate Mountains (Munros) and their Subsidiary Tops (Munro Tops).

This objective judgement took its next stage forward when Carr and Lister used a 100ft criterion to differentiate one hill from another in their book to ‘The Mountains of Snowdonia’ which was published in 1925 by John Lane The Bodley Head Limited of London.  This use of 100ft by Carr and Lister can be considered as the first objective height differentiation and therefore the first use of how we now view the term prominence.

Although, as mentioned previously, there have been other use of criterion to differentiate one hill from another, there is a definite line between how the use of prominence has evolved, this line can be viewed as a link, but this link does not have many connecting parts to it, and up until the Dominant listing that this Introduction details, that connecting part only involved one link, and that is Relative Height, and now the second connecting link of Dominance has been added.

The difference between Prominence and Relative Height can be summarised as the following, with the explanation of Dominance then following:


Prominence is applied to hills whose qualification also depends upon minimum height.


Relative Height is applied to hills whose qualification is just dependent upon a minimum prominence.


Dominance is applied to hills whose prominence equal or exceed half that of their absolute height.


For those that are not initiated with the intricacies of hill list criteria the above explanation can sometimes be a difficult concept to understand, but the essence being is that Prominence is used as part of a criteria in conjunction with another criterion which is usually Minimum Height, whereas Relative Height is normally used as a singular criterion that is not dependent upon any form of minimum height except for that stipulated for its relative height, whereas Dominance relies upon the relationship between the hill’s prominence and its absolute height and is part of a criteria in conjunction with another criterion which is Minimum Height.

The first use of what we now refer to as Relative Height in a published hill list was by Eric Yeaman in his ‘Handbook of the Scottish Hills’ which was published in 1989 by Wafaida.  However, the term Relative Height was coined by Alan Dawson for the Marilyns which were first published in ‘The Relative Hills of Britain’ book by Cicerone Press in 1992.

These two publications dispensed with the concept of Prominence with Eric Yeaman using 100m of Relative Height as the main part of his Scottish list and Alan Dawson using 150m for his British list.

The next link in this small chain that takes in Prominence and Relative Height is Dominance, and therefore Dominance can be viewed as the next step in the evolutionary process of Prominence.

Dominance is a new concept for a published list to hills within Britain and to the knowledge of the author was first used for hills within Britain in early 2009 under the working title of ‘The Ultra Prominent Summits of Wales’, this title was shortened to the UPPs and was later changed to ‘The Dominant Hills of Wales.’  The change of name was instigated after a discussion with Mark Trengove who pointed out that the same concept of Dominance had been used by Eberhard Jurgalski in written format in 2001 and in published format in 2004, and as the 5,000ft prominence world peaks are known as the Ultras, their title having been shortened from the Ultra Prominent Peaks, it was sensible not to use a working title that was similar to another list that used different criteria.  Therefore, the title of Y Trechol - The Dominant Hills of Wales became the norm and the term of Dominance used to describe it, with the term Y Trechol being the Welsh for ‘The Dominants.’

The concept of Dominance was independently conceived by the author and was not copied from Eberhard as until discussing the concept of this list with Mark Trengove, I had not heard of Eberhard Jurgalski, but the term ‘Dominance’ follows Eberhard’s lead, as this is the norm when dealing with terms such as Prominence and Relative Height, each in turn were coined by someone and then they have become terms used by many.

To fulfil the qualification of a hill being Dominant its prominence has to be first known.  Therefore a Dominant list cannot be compiled unless the Prominence of each hill is known beforehand, and for a country such as Wales there are many hills that qualify under a stipulated minimum prominence of 30m.  I thought it wise to follow this minimum prominence figure as this had been previously used in a number of listings, these are briefly detailed below.

For Wales these 30m minimum prominence based lists were first published over a period of 20 years from 1984–2004.  These listings were reliant upon data produced by Terry Marsh, Michael Dewey and Myrddyn Phillips.  However, although all the lists produced by these people specified a minimum drop of 30m none of them listed the actual drop figure; this was added at a later date.  During this time listings to the majority of these hills were also independently produced by E. D. ‘Clem’ Clements whose work appeared on the RHB Yahoo Group database.

The theory of Dominance was conceptualized shortly after all the drop values were added to my hand written Master Lists and the 100m height bands expanded upward to include all P30 summits in Wales.  This Dominance criterion was conceptualized at approximately the same time as that of Remoteness, with both taking form from the same question – ‘what else can be considered once prominence values are given to all hills?’  Once this question was asked the theory of Dominance sprung in to my mind and that of Remoteness soon followed.

The Remoteness list was later published on Geoff Crowder’s v-g.me website in 2011, and updated and co-authored with Aled Williams and published by Europeaklist, Haroldstreet and Mapping Mountains in April 2015.  But until now the Dominance list has never been published.


Before detailing what Y Trechol - The Dominant Hills of Wales list consists of it may be prudent to detail the qualification for the main list:

Those P30 hills whose prominence equal or exceed half that of their absolute height.

Also included is a list to the Lesser Welsh Dominants, these are the additional P30 summits whose prominence is between one third and half that of their absolute height.



To access Y Trechol - The Dominant Hills of Wales list please click {here}



The list consists of the following:

Group:  Each hill appears under their Group, this is the group / range that the hill is a part of.  For example; Carnedd Llywelyn (SH 683 643) is part of the hill group known as the Carneddau.  The Groups are arranged from north to south on a west to east orientation.  The names of the Groups used in this list have received extensive input from Aled Williams.

Name:  This is considered the most appropriate name for the hill with respect to the information available to the author.  Sometimes the name used does not correspond to current Ordnance Survey map spelling and composition or the name may not appear on any map.  Where no appropriate name has been discovered for the hill from any source, the Point (for example; Pt. 78m) notation is used rather than making up a name that has no local or historical evidence of use.  The Welsh place-names that appear in this list and that were sourced from Ordnance Survey mapping are reproduced as simple compositions, with hyphenated and compound names reduced to the component elements.  It must be noted that this process will on occasion result in loss of pronunciation information and as such, is not ideal.  However, this protocol has been implemented in order to simplify the composition due to the inappropriate and inconsistent hyphen use that Ordnance Survey maps are prone to.

Dominance:  This is the Dominance of the hill’s height between bwlch and summit (its prominence) over that of its height from sea level (Ordnance Datum Newlyn) to its bwlch.  The Dominance is given as a percentage.

Region:  There are three Regions in Wales; North Wales, Mid and West Wales, and South Wales.  The Regional split of Wales used in this list has received extensive input from Aled Williams and will be detailed on the Mapping Mountains blog at a later date.

Sub-Region:  There are a number of Sub-Regions in Wales and those used in this list have received extensive input from Aled Williams and they will be detailed on the Mapping Mountains blog at a later date.

1:50,000 Map:  This column gives the number or numbers of the 1:50,000 Ordnance Survey Landranger map that the summit of the hill appears on.

1:25,000 Map:  This column gives the number or numbers of the 1:25,000 Ordnance Survey Explorer map that the summit of the hill appears on.

Grid Reference Summit:  This is the ten figure grid reference (10FGR) for the summit of the hill.  This has either been produced by an accurate survey, a map spot height or when neither is available by a centralised position in an uppermost contour ring.  When the accurate survey has been conducted independent of the Ordnance Survey a (S) for ‘survey’ will appear adjacent to the 10FGR, a (TP) if the 10FGR is taken to a ‘trig pillar’, a (B) if the 10FGR is taken to a ‘bolt’ or a ‘block’, a (L) if the 10FGR is taken to the position of a ‘levelled’ height on old maps, a (HH) if the 10FGR is taken from a ‘hand-held’ GPS unit, a (SH) if the 10FGR is taken to a ‘spot height’ either on current or old maps and an (I) if the summit position has been ‘interpolated’ from contours.

Height (m) Summit:  This gives the map height in metres of the hill above Ordnance Datum Newlyn (ODN), often referred to as sea level.  Where a height is quoted to a decimal place it implies that the hill has been surveyed by GPS / GNSS receiver (these heights may not match current Ordnance Survey map heights).  Where a ‘c’ (circa) appears preceding the height it means there is no known spot height available and the height has been estimated from contour interpolation.

Grid Reference Bwlch:  This is the ten figure grid reference (10FGR) for the bwlch of the hill.  This has either been produced by an accurate survey, a map spot height or when neither is available by a centralised position between converging hill to hill and valley to valley contours.  When the accurate survey has been conducted independent of the Ordnance Survey a (S) for ‘survey’ will appear adjacent to the 10FGR, a (L) if the 10FGR is taken to the position of a ‘levelled’ height on old maps, a (HH) if the 10FGR is taken from a ‘hand-held’ GPS unit, a (SH) is the 10FGR is taken to a ‘spot height’ either on current or old maps and an (I) if the bwlch position has been ‘interpolated’ from contours.

Drop (m) Summit to Bwlch:  This column details the prominence of the hill; this is commonly referred to as ‘drop’ or ‘reascent’.  The drop is the height difference between the summit and connecting bwlch to the higher parent peak along the watershed.  The letter ‘c’ before the drop figure signifies there is no spot height or surveyed height known for either summit or more usually, the bwlch, therefore a part of the drop figure has been estimated from contour interpolation.

Drop (m) – Bwlch to ODN:  This gives the map height in metres of the bwlch above Ordnance Datum Newlyn (ODN), often referred to as sea level.  Where a height is quoted to a decimal place it implies that the bwlch has been surveyed by GPS / GNSS receiver (these heights may not match current Ordnance Survey map heights).  Where a ‘c’ (circa) appears preceding the height it means there is no known spot height available and the height has been estimated from contour interpolation.

Notes:  This column gives details relevant to the hill.


With special thanks to Aled Williams and Mark Trengove for their continued support and to Eberhard Jurgalski for taking Dominance to the masses.  Thanks are also due to the people who submit 10 figure grid references to the Database of British and Irish Hills (DoBIH) and for DoBIH making these available for public use.


This list will appear in biweekly or monthly instalments with the seventh Group listed being the Moelwynion.  The Dominant Hills of Moelfre Uchaf will appear on the 24th March 2016.

To access Y Trechol - The Dominant Hills of Wales list please click {here}





Sunday, 21 February 2016

Mapping Mountains – Trimble Surveys – Cleeve Hill


13.02.16  Spring Hill (SP 115 348)  

The summit of Spring Hill (SP 115 348)

The criteria used to define a hill are an interesting concept; that need for definition, the need to quantify and make sense, a need to create order.  Nowadays defining one hill from another usually relies upon prominence; prominence being the minimum height gain between summit and connecting col along the watershed.  Over recent times Prominence has evolved in to Relative Height and also Dominance, the intricacies of which are not for this blog post.  These concepts give order to an otherwise unruly mass of never ending bumps on the landscape, their use can define hill separation, and in their own right are eloquent and simple, and they are also ingenious as their use fulfils the unusual need for definition.

However, dependent upon one’s inclination a summit listed under the criterion of Minimum Prominence, Relative Height and Dominance can be no more than a few minutes’ walk from the nearest public road, this can be thought of advantageous in many instances, and of course the convenience of the nearest public road to the summit of the hill can be nullified if wanting a more extended walk from an adjoining valley, but the convenience of public roads should not be underplayed as bagging mentality sometimes dictates that the nearest one to the summit is the one from which the walk starts.

Using near roads to bag summits can be fun, but sometimes it's not too physically taxing.  Perhaps this is one of its appeals?

Other definitions to define hills can add mileage to a bagger’s mentality; Y Pellennig – The Remotest Hills of Wales, is an example, as this listing qualification partly depends on the summit of the hill being a minimum 2.5 km from the nearest paved public road.  Although this form of definition is a welcome one, it is a rarity. 

And so we come to today’s little wander, which took 22 minutes in all to walk to the summit, assess the lay of land, set the Trimble up, measure its offset, wait for it to attain its 0.1m accuracy before data should be logged, gather five minutes of data, pack the equipment away and wander back down next to the edge of a muddy field to the awaiting car, and in the process get stung my nettles. 

Gathering data from the summit of Spring Hill

It was a pleasant 22 minutes as the walk was literally grabbed out of a planned afternoon visiting the Cotswold town of Broadway, with a planned visit to Broadway Tower which is an unusual structure built on a ridge overlooking the fertile and eloquent towns of the Cotswolds.  It was only after being told that the tower was positioned on a ridge that I went looking for the high point of this ridge, online, and it turned out to be a mile or so south of the tower, adjacent to a stone wall, in a field.

When there, the breeze blew, the sky was grey, rain spotted which turned to wet snow later, the cold edged into my fingers and I stood awaiting the last of the 300 points allotted for the Trimble to gather, looking down at my red plastered muddy wellies as the chill breeze continued.  During this Lou waited patiently in the car playing Candy Crush and slowly got cold, I thanked her afterward for being patient as the wants of the male of the species is sometimes an unusual thing to encounter.

Those 22 minutes were fun and the chill was invigorating, the data gathering part seemed periphery to this appeal for the need to bag a summit where one was not expected to be bagged, the mud, nettles, steel tape for measurement offset, unusual yellow and black surveying implement, breeze blown rain drops and chilled fingers all added to the novelty.  It was fun and was followed by the refinement of Broadway and its shops and deli’s.  


Survey Result:


Spring Hill

Summit Height:  319.5m (converted to OSGM15)

Summit Grid Reference:  SP 11510 34803

Drop:  121m

Dominance:  37.87%



For further details please consult the Trimble survey spreadsheet click {here}







Saturday, 20 February 2016

Mapping Mountains – Trimble Surveys – Rhos


10.02.16  Mwdwl Eithin (SH 829 682)  

The summit of Mwdwl Eithin (SH 829 682)

Having visited Ffridd Uchaf (SH 864 606), Foelas Fechan (SH 854 596) and Moel Maelogen (SH 848 613) I had a spare hour before a prearranged appointment in St Asaph, and as I arrived back at my car after descending from the summit of Moel Maelogen I examined the map and picked Mwdwl Eithin as a likely candidate for a quick visit, and at a map height of 389m adjoined to its summit trig pillar, it also had an outside chance of being elevated to the 390m Sub-Pedwar ranks.

I parked on the edge of the B 5113 beside a sheepfold and walked a short distance back down the road to a gate which gave access into a rising field, as this land is not a part of open access I put my head down and walked as quickly as I could up the field adjacent to a fence until out of sight of the road.

Once safe from any onlookers I headed through a small water trench to a gate which was festooned with barbed wire, I quickly clambered over and marched further up the field until the remains of the first of this hills two Tumuli came into view.  Beyond was a fence junction, and further still was the high point of the hill, which constitutes a large ancient Tumulus with a trig pillar perched at its top.

As I set the Trimble to gather data the sun broke through a cloud bank to the west which was hugging the summits of the higher Eryri peaks, light cascaded down on to the wet surrounds with shadows now elongated as the afternoon was drawing out toward early evening. 

Gathering data at the summit of Mwdwl Eithin

The last hour of a winter's day giving striking light over Mwdwl Eithin

Once five minutes of data were collected from the summit I waded back through the water laden field to a lower point between the two Tumuli and gathered another five minutes of data.  The low sun was still illuminating the land and adding interest to the puddles of water on the field, and I stood taking a number of photographs with a darkening sky overhead and sunbursts picking out patches of water with their customary silvery sheen.

Gathering data from the second but lower high point with the summit of Mwdwl Eithin in the background

Looking beyond the second and lower high point to the remains of one of two Tumuli on the summit area of Mwdwl Eithin

Gathering data from the second and lower high point with the summit of Mwdwl Eithin in the background

All that remained was to pack the Trimble away, scamper back down the field to my waiting car and change out of my partly wet and muddy clothes into something resembling dry comfort and head toward my appointment in St Asaph.


Survey Result:


Mwdwl Eithin

Summit Height:  389.0m (converted to OSGM15)

Summit Grid Reference:  SH 82902 68283

Drop:  c 136m

Dominance:  34.96% (Lesser Dominant status confirmed)



For further details please consult the Trimble survey spreadsheet click {here}