Friday, 29 April 2016

Mapping Mountains – Trimble Surveys – Beacon Hill


20.04.16  Broomy Leasow (SO 093 881) and The Top (SO 092 887) 

The Top (SO 092 887)

Overlooking the mid-Walian town of Newtown and to its south are two small hills, given map heights of 317m and 327m respectively, each now consist of closely cropped grass and are no doubt grazed by those lovable little white hill wonders known as sheep.

These two hills are not crag happy marvels of ice age sculpture, but they are pleasing and quiet affairs where one is unlikely to be disturbed except for the possibility of a farmer on a quad bike or a sheep and lamb suckling in the spring sunshine.

Having parked beside a T-junction on a minor lane between the two hills and to their east I did contemplate surveying their bylchau, but decided that this may prove a lengthy exercise and that a quiet stroll in beautiful afternoon sunshine to the top of each hill was the order of the day.  I followed a public footpath before heading toward the high point of the 327m map heighted and more southerly of the two hills, the sun beat down in a refreshing way with early year clear clarity and welcome warmth.

After negotiating a fence I popped out on the summit and proceeded to assess the lay of land from a number of directions and placed the Trimble on the ground.  As it beeped its way to 300 separate datum points during its five minutes of data gathering I converted my walking trousers to shorts and exposed my legs to the first sun of the walking year.

Gathering data at the summit of Broomy Leasow

Just below the summit of the hill is a house named Little Bryn-bedwyn which I called at hoping to enquire about the name of the hill, no one was in, so I wandered down the lane, called in at another bungalow, with again no response, I then contemplated calling in at Bank farm which is situated at the bwlch for the second and last hill of the day.  Deciding to leave the farm until after visiting the summit of the hill I proceeded down the narrow lane to the south-west of the summit, as I did so a vehicle appeared and as it looked as if it may have come from Bank farm I flagged it down.  I chatted with the driver for a few minutes; Gwyn Phillips was indeed the local farmer from Bank, and as the hill that I was interested in was straight above us I pointed its way and asked if he knew a name for it, ‘Just know it as The Top’, came the reply, I asked if he had ever heard any other name for it or if he knew of a field name for where the summit of the hill is situated, and he said ‘It’s on my land, but I’ve never heard another name for it’, with that I expressed my thanks and off he sped down towards the main road.

The Top overlooking Bank farm

After meeting Gwyn I clambered over a fence and made my way to the top of the hill and proceeded to take data from two points, not surprisingly both of which I thought to be close in height.  Once data collection was complete I headed down toward Graig, which is another farm on a direct course to where my car was parked, on the way I became fixated on the colours of new growth in the hedgerow, these shot out succulently sharp and tender and alive with radiant colour, I stopped and took some photos and happily continued to my car.

Gathering data at the summit of The Top

Broomy Leasow from the summit of The Top, with the house of Little Bryn-bedwen on right and Bank farm below

Succulent new growth

Once back home I examined the online Tithe maps for field names for the two hills I’d visited, these are listed as Bryn-bedwen and Pen-y-banc in the original P30 lists that are published on Geoff Crowder’s v-g.me website, both names are taken from near farms, a practice that I now consider unsatisfactory.  The online Tithe maps are slightly complicated in nature, but with a little perseverance I pinpointed each summit field, with the more northerly one being a part of the land of Bank farm and which has no name given it on the Tithe map, this information corresponds with the knowledge that the owner of this farm has, he told me he had lived there all of his life and except for the name he referred to the hill as; The Top, he did not know another name for the hill or for the field where the summit is situated. 

The more southerly hill is given the name of Bryn-bedwen in the original P30 lists, this name came from buildings to the south-west of the summit, with the house immediately below the summit to the north-west being named Little Bryn-bedwen.  As many Welsh farms take their name from the hill, or vice versa, one may think that giving this hill the name of Bryn-bedwen is appropriate, however the naming of farms after hills or vice versa is not always the case, and appointing a name to a hill should be a task undertaken with the same dedication that many spend with the appointment of the respective hill’s numerical data.  And the use of the Tithe map can show a multitude of names, especially so for the lower heighted hills.  If a Tithe map gives a field name for where the summit of the hill is situated this is more appropriate than using that of a farm which may have no association with the hill.

The field where the summit of the 325.6m hill at SO 093 881 is situated named as Broomy Leasow on the Tithe map

In the instance of the more southerly of these two hills the Tithe map gives a rather evocative name for the summit field; Broomy Leasow.  The word leasow means pasture or meadowland, whilst broomy means covered with or abounding in broom, broom being the flowering shrub.


Survey Result:



Summit Height:  325.6m (converted to OSGM15)

Summit Grid Reference:  SO 09332 88123

Drop:  c 59m

Dominance:  18.12%  




Summit Height:  315.5m (converted to OSGM15)

Summit Grid Reference:  SO 09275 88714

Drop:  32m (300m Twmpau status confirmed dependent upon accuracy of bwlch spot height)

Dominance:  10.14%



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


Wednesday, 27 April 2016

Mapping Mountains – Trimble Surveys – Beacon Hill


20.04.16  Racecourse (SO 091 862) 

Racecourse (SO 091 862) second ridge of four and centre right of photograph

Beside the winding A 483 road as it makes its way south from Newtown toward the salubrious surrounds of Llandrindod are a number of hills, all of merit, and many seldom visited, one such hill is the Racecourse, which stands aloof of its neighbours to the north-west of the road near the conference and holiday park of Cefn Lea.

I parked just beyond the entrance to Cefn Lea on a minor lane and walked down the road hoping to find access into a deciduous wood named Glog Wood, which is situated on the western lower side of the hill.  By now the slight chill of early morning had been replaced with warmth reminiscent of summer.

A short distance down the road the adjacent bank lessened in steepness and gave me an opportunity to clamber over a fence into the wood.  Deciduous woods have a beauty all to themselves and my short sojourn through and up this one was a tranquil experience until I heard a quad bike in the adjacent field above, I walked over to a near gate and waved to the person on the bike, he parked it up and walked over to me.  Tony Ward lived locally and pointed out his old toll house next to the road, we talked about the hill and its name and I asked if he minded me visiting its top.  He knew the hill as Cefn Faes whose land the conference centre and holiday park was on.  He explained that the house of Cefn Faes was next to the entrance to Cefn Lea and told me that its high point was toward the right hand side of the field where a golf course is situated.  After thanking him I slowly plodded up the closely cropped grassy field which had a number of red flags stuck in it, indicating where budding golfing professionals were to aim their ball.  I knew from the map that the high point of the hill was on the northern side of the fence and wondered if this land was a part of Cefn Faes, further enquiries were necessary.

The top of the golf course is bounded by a thin layer of conifer trees and a double fence which proved easy to carefully clamber over, on the other side was another cropped grassy field which led to the summit of the hill.  This was definitely someone else’s land and did not belong to Cefn Faes.

I chose the spot for Trimble placement and waited the customary five minutes as it beeped away collecting its 300 datum points.  As it gathered its data I admired the view, looking out toward the high peaks of Cadair Idris, the Aran and Y Berwyn, it was indeed a beautiful day.

Gathering data at the summit of the Racecourse

After packing the Trimble away I retraced my steps down to where I had chatted with Tony and decided to walk down to the buildings next to Cefn Faes and try and gather data at the critical bwlch of the hill.  It was as if mid Wales had been transported to the sun drenched lands of southern Spain where an early afternoon siesta was taking place, as when I arrived at the bwlch all was quiet and remained so for the next fifteen minutes as I assessed the lay of land, chose the spot for Trimble placement and gathered the necessary data.

Gathering data at the critical bwlch of the Racecourse

After packing the Trimble away I called at Cefn Faes and enquired about the hill, they knew where the high point was situated and confirmed that this wasn’t on their land, they also told me that their part of the hill was known as Cefn Faes and kindly directed me down the lane to the next farm; Garth-Heilyn, who were the land owners for the part of the hill where the summit is situated.  Before heading back to my car I called at the next house down the lane and chatted with their son, who also confirmed that the land up to the boundary fence of thin conifers is known as Cefn Faes and that the high point of the hill is a part of the land of Garth-Heilyn, and that the Morris’ would be able to tell me a name for the hill.

Once back at my car I drove a mile or so down the road and parked on the lane as it makes its way through the farm of Garth-Heilyn.  As I got out of my car a large tractor came chugging toward me from an adjacent barn, Gwyn Morris pulled up and smiled, I introduced myself and explained my interest in Welsh upland place-names and asked about the high point of their hill.  As Gwyn chatted away I found it hard to hear some of what he was saying as the tractor’s engine roared away, he kindly lessened the noise but explained that he was busy and would have to carry on with his work.  However, he was only too willing to talk about the hill and told me that it is known as the Racecourse, I thought this a slightly unusual name for a hill, but not one that is unique as there are examples of places on uplands known by such names.  He said that he didn’t know why the hill is known as the Racecourse and explained that Gilfach farm used to own the land, with his family moving to Garth-Heilyn in 1935 and purchasing the land from Gilfach in 1969, and the hill was known as the Racecourse even when Gilfach owned the land.

Gwyn Morris

As Gwyn chugged off in his tractor to continue his work, Andrew Morris; Gwyn’s brother, walked around the corner and the conversation continued.  As soon as I mentioned the hill, he said ‘You mean the Racecourse.’  He also said that he didn’t know why it was called by this name, but that was the name the locals had known it by for decades and he didn’t think that the name appeared on a map.

Andrew Morris

I scribbled all necessary details in my notebook before getting back into my car and waved my thanks to Andrew as he went about his farming business and I drove back up the lane toward my next and last walk of the day.

The following day I wrote this blog post and accessed the Tithe maps online and searched for this hill.  The Tithe maps operate on a field system and are ideal for names adjoined to smaller heighted hills as usually the field where the summit of the hill is situated can be pinpointed and with a little detective work the number adjoined to a field can be cross referenced against its name.  Not all fields have names, but many in Wales do, these are historical as well as current, some names of which survive in the local community to the present day, whilst others have been lost, but the ones that do not survive the oral tradition of passing place-names down from one generation to the next will be documented on the Tithe maps of the day, and as I scrolled down the Tithe documents a name popped up on my Laptop’s screen; Race Course.  I smiled and thought how wonderful this name is, it had survived the passage of time in the local community, even when the meaning behind it had not.

Gwyn and Andrew Morris' field where the summit of the hill is situated named as the Race Course on the Tithe map
     

Survey Result:



Summit Height:  370.7m (converted to OSGM15)

Summit Grid Reference:  SO 09122 86296

Bwlch Height:  326.7m (converted to OSGM15)

Bwlch Grid Reference:  SO 09113 85925

Drop:  44.0m

Dominance:  11.87%



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




Monday, 25 April 2016

Mapping Mountains – Trimble Surveys – Pegwn Mawr


20.04.16  Pt. 436.3m (SO 062 850) 

Pt. 436.3m (SO 062 850)

During last summer I’d visited this hill and Trimbled its bwlch and summit with the result giving the hill 29.983m of drop, after discussing this result with Aled we decided to leave the hill listed as a Pedwar until a further survey could be conducted.  As the Trimble has limitations on its accuracy when the margin between 30m drop qualification is only 17mm, I knew that the ideal way to re-survey this hill would be by line survey; however I could at least take a series of data sets with the Trimble and assess the results with Aled afterward. 

The forecast for the day was ideal with only a breath of breeze and sunshine predicted during daylight hours.  Thankfully the hill is easily accessed from a minor lane to the south of its summit.  I set off walking at 8.00am down the green vehicle track that leads to the bwlch.  Looking toward the hill the sky gave a dulled pale sheen as blue merged with white on the horizon.  All round was quiet and except for an occasional farmer out feeding sheep, it remained so for the four hours it took me to take a further 19 data sets, with 9 of these being at the bwlch and 10 at the summit.

When approaching this hill from the south the critical bwlch is crossed on the way to the summit, I’d come duly prepared with ten figure grid references for the positions where I’d previously taken data from, as well as the ten figure grid references for where the 406m bwlch and 437m summit spot heights appear on the ground.

As the green vehicle track crosses the area of the bwlch the land descends on its west, whilst on its east is a stagnant reed infested pool, the water from which does not cross the track, therefore unless water flowed in to the pool from its east the critical bwlch lay either on, or beside the vehicle track.

The first data set I took at the bwlch matched the co-ordinates of my previous survey from last summer, I then spent a long time assessing the ground and placed the Trimble approximately 18 inches from this first placement and gathered another five minutes of data.  Three further data sets were repeated from this second point, each time alternating between the Trimble being placed on the ground and being placed on top of my rucksack with a 0.41m measurement offset between the internal antenna within the Trimble and the ground at the base of my rucksack.

Looking south from the bwlch with the green vehicle track heading back to my car 

Looking north from the bwlch toward the summit of the hill during one of nine data sets taken at the bwlch

After each data set was gathered from different points I marked the position of the Trimble so if need be another data set could be gathered from the same position and the resulting data then averaged.

Following these surveys I took a data set from where the 406m spot height appears on the ground and a further two data sets from the vehicle track adjacent to the spot height position, one from each side of the track.

The only remaining data set to gather at the bwlch was from the opposing easterly side of the pool, this would prove that it was lower than the track although visually it was significantly lower, I only wanted to do this if the water flowed in to the pool and not out of it, as if it did, it meant that the ground to the east of the pool is lower than the surface water.  I followed the water course from the pool and it remained still for a number of metres, until I spotted a tranquil trickle as it glistened in the early morning sun, I continued following it until the ground started going downhill, working my way back toward the pool I looked for any sign that the water course was not continuous, there was none, therefore the surface water of the pool was lower than the height of the vehicle track.

With all bwlch surveys now complete I gathered the Trimble up, packed it away and walked to the summit following the continuation of the track and finally across a field to where the rounded dome of the high point of the hill is situated.  This rounded dome is a slight ridge; whale backed in shape and aligned in a north to south direction, to its east is a visually lower ridge of same formation.

The first data set I took was from where the 437m spot height appears on the ground, this point was on a downward slope and although not necessary to conduct, it would at least give another accurate height for this particular point.  The second data set was taken from where I had placed the Trimble during last summer’s survey.  I now wanted to take a series of data sets following the flattened ridge crest working from north to south, each Trimble placement was approximately seven metres apart, with eight taken in all on the whale backed summit ridge.

As I closed the Trimble off at each of these points I placed a piece of paper on the ground with a nail inserted in it to indicate where the internal antenna had been aligned.  Leaving the paper trail in situ I then visited the visually lower ridge and took a data set from what I deemed to be its highest point.

The position where the Trimble is placed proved to be the highest point surveyed and was the last of ten data sets taken at the summit, with three placements indicated with paper running the length of the whale backed ridge in a southerly direction

Looking northward with the Trimble placed on the highest point surveyed and with the paper indicating a further four placements where data had been gathered

Only one survey remained for me to conduct and this was to the point of the hill that I now thought to be the highest.  I assessed the summit ridge from the vantage point of the visually lower ridge and decided to place the Trimble between what I deemed to be the two highest previous placements.  As the Trimble beeped away gathering its allotted five minutes of data during the last of 19 data sets I stood a safe distance away, scribbling all detail that would form a part of the spreadsheet documenting all of my Trimble surveys, and happy in the knowledge that I had done as much as I could with the Trimble to decide the fate of this hill, I gathered it up, packed it away and happily sauntered off down the hill in continuing glorious sunshine to my awaiting car below.

  
Survey Result:


Pt. 436.3m

Summit Height:  436.3m (converted to OSGM15)

Summit Grid Reference:  SO 06252 85015

Bwlch Height:  406.2m (converted to OSGM15)

Bwlch Grid Reference:  SO 06027 84366

Drop:  30.2m (Pedwar status confirmed)

Dominance:  6.92%




For the post relating to the first survey of this hill please click {here}


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


Saturday, 23 April 2016

Mapping Mountains – Trimble Surveys – Arenig


10.04.16  Bryn Mawr (SH 830 259) and Foel Ddu (SH 818 245)  

Bryn Mawr (SH 830 259)

For many years I’d wondered if I had reached the highest point of Bryn Mawr, as on my previous visit I’d stood on what my memory told me was the highest point of the hill and looked east toward another high point that was immersed in a conifer plantation.  Having no hand-held GPS I could now only go on what my memory told me and compare this to current maps, and these show the high point of Bryn Mawr with three 400m ring contours, with two of these including the furthest easterly 401m spot heighted summit within the boundary of the conifer plantation.  Had I reached the true summit or was I standing on a near 390m ring contour looking toward the high point and never actually going to it.  Armed with my Trimble it was time for me to repeat my visit and be sure that I had finally reached the summit. 

I left my car at Pont Fronwydd and followed a footpath on the north-east side of the Afon Mynach as it tumbles down from wilder higher climes to the valley below.  The morning’s chill gave a prospect of clear conditions but I knew that it would be breezy as the forecast predicted 17mph winds in lower parts.

The footpath hugged the southern part of Carreg yr Aderyn which is now swamped in conifer plantation, these swayed in the morning’s sunshine as buffets of wind blew through their branches.  The footpath joins a track higher up close to Cae Llwyd, a single house looking out on a beautiful scene of ruggedness.  Leaving the path I gained height keeping the forestry on my right.  Across the Afon Mynach the blackened profile of Foel Ddu loomed skyward, looking rather uninviting as my recollection was that pathless heather predominated on this hill.

Foel Ddu rising above the lonely house of Cae Llwyd

As I followed the forestry I checked the co-ordinates in the Trimble for the ten figure summit grid reference, after following a wet sheep path adjacent to the trees I reached their high point and peered in to them for the summit of a hill, non-existed, but behind me to the south-west a number of bumps were significantly higher than any ground in the forestry, it seemed I had reached the high point on my previous visit and that the placement of the conifer plantation is incorrect of current maps.

I surveyed the high point of each 400m ring contour in turn and positioned my rucksack on the ground, resting on its back instead of the customary base which only elevates it above the ground by an approximate 0.28m.  This would elevate the Trimble above the moorland surroundings of grass but would keep it relatively close to the ground as the wind consistently breezed through the land and positioning it any higher was running the risk of wind wobble.

Gathering data at the central 400m ring contour on Bryn Mawr

During these three surveys I stood a safe distance away from the equipment with my back braced against the chill wind and looked out on a sun bleached land of mountain top, heather, rock and beauty – a stunning place.

Craig y Benglog (SH 805 244)

The blackened profile of Foel Ddu

Happy that I had re-claimed the summit of Bryn Mawr I contemplated heading back to my car, but I also wanted to survey the critical bwlch of the hill.  This took me on to land that must surely be seldom visited except for an occasional passing farmer on a mud splattered quad bike, as few hill walkers would have the necessity to visit.

The bwlch is positioned in a wild bog of knee high tussock grass forlorn and empty, a quiet haven amongst a bed of nothingness.  For me this is one of the beauties of surveying as if not for this unusual activity and inner need to catalogue I would not visit such places, and many have a beauty all to themselves.

Gathering data at the critical bwlch of Bryn Mawr

The desolation of bwlch surveying

I could now either head back to my car, bi-passing the heathery delights of what looked like a watery bwlch adjoined to Foel Ddu and its pathless heather bound summit, or I could plod on in to the morass of wilderness.  I almost talked myself in to the former, but I just couldn’t resist the temptation and except for the wind the day was rather stunning as colour poured down on the land with succulent clear blues etched against the bleached and lonely moor whilst mountain peaks cast down upon the scene.

The connecting land between each hill proved a slow stumble as I followed a collapsed and old wall up toward the bwlch that connects Foel Ddu with Carreg Lusog.  As I arrived at its high point I looked down on to a wide, tussock and bog ridden bwlch that immerses itself in heather, this looked like fun.

I stumbled my way in to the bwlch and splashed from one bog infested tussock to another, each time I assessed the lay of land another point looked as if it was the point where the valley to valley traverse meets the hill to hill traverse.  I eventually set the Trimble up at two points, one where map interpolation suggests the bwlch to be positioned and another where I thought the critical bwlch lay.  Each survey was a wild affair as I tried to keep me, my rucksack and the Trimble out of the oozing water under each tussock.  As the Trimble did its stuff I waited and watched the light on Carreg Lusog and Craig y Benglog, each bringing back memories of past surveys.

Carreg Lusog (SH 818 264)

Gathering data during one of the surveys for the position and height of the critical bwlch of Foel Ddu

After the bog laden bwlch survey I squelched my way up on to relatively dry ground and followed a fence toward the summit of Foel Ddu.  I’d noted a ten figure grid reference for the summit from the Hill Bagging website but found that my eye judged the higher point to be a little further south, and when I arrived there I dug out a heather bound summit cairn.  I gathered data from this point and the high ground near to the grid reference I’d noted.  During this the wind whipped across the upper part of the hill.  To my north the forever blackened profile of Y Dduallt rose above the gentler but still rugged slopes of Carreg Lusog.

Y Dduallt and Carreg Lusog from the ascent of Foel Ddu

Gathering data at the summit of Foel Ddu

All that remained was to slowly stumble down the hill’s pathless northern ridge to where I’d previously followed the collapsed old wall, from here a path descended toward the track near to Cae Llwyd.

Leaving the wind-blown summits, the warmth of spring was evident as I made my way down the track, with white born lambs sitting nestled in the sunshine, eyes closed and dozing until I slowly crept up to take their photograph.





Enjoying the sunshine

Survey Result:


Bryn Mawr

Summit Height:  401.6m (converted to OSGM15) (Pedwar status confirmed)

Summit Grid Reference:  SH 83087 25918

Bwlch Height:  360.6m (converted to OSGM15)

Bwlch Grid Reference:  SH 82629 26107

Drop:  41.0m

Dominance:  10.21%



Foel Ddu

Summit Height:  465.0m (converted to OSGM15)

Summit Grid Reference:  SH 81870 24547

Bwlch Height:  377.9m (converted to OSGM15)

Bwlch Grid Reference:  SH 81730 25060

Drop:  87.1m

Dominance:  18.73%



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






Thursday, 21 April 2016

Y Trechol - The Dominant Hills of Wales - Mynydd Hiraethog


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}


Tre Pys Llygod (SH 894 687) is situated in the Mynydd Hiraethog Group of hills and is listed as one of the Lesser Welsh Dominants

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 ninth Group listed being Mynydd Hiraethog.  The Dominant Hills of Bryniau Clwyd will appear on the 19th May 2016.

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