Tuesday, 23 May 2017

1,000 Welsh P30s – Mapping Mountains – Trimble Surveys – Pumlumon

1,000 Welsh P30s

Mapping Mountains – Trimble Surveys – Pumlumon

15.04.17  Bryn y Fan (SN 931 884)

What is a P30 and where do they come from?

P30 is an abbreviated term for hills that have 30m minimum prominence, with the ‘P’ standing for ‘Prominence’ and the ‘30’ standing for 30m.

For the uninitiated the terminology within hill listings and their chose of criteria is sometimes hard to fathom, hoping that the following explanation does not add to uninitiated confusion I will try and explain what prominence is.

Simply put, prominence is the vertical height gain between col and summit.  A fuller explanation for prominence is the height difference between the summit and the col connecting the hill to the next higher summit along the watershed.

Prominence is a relatively new term in use within Britain, with its use having been adopted from prominence based groups in America.  The term prominence is also referred to in Britain as ‘drop’ and reascent’, with the former being the drop in height from summit to col, and the latter being the reascent in height from col to summit.

The use of prominence as part of criteria in a hill list gives the list compiler the tool to differentiate between one hill’s inclusion and another, otherwise if solely based on a minimum height criterion a list compiler would have to resort to subjectivity to differentiate between one hill’s inclusion and another.  By using prominence objectivity is prioritised over that of subjectivity.

The use of prominence has dictated the majority of hill lists over many years, and although list compilers have experimented with many other forms of qualification, including remoteness and dominance, the popularity of using prominence speaks for itself; it works and produces listings that are easily understood and popular for the hill bagger.

The origins of P30s

The use of prominence was established with some of the early hill list compilers such as John Rooke Corbett (1) and Edward Moss (2) who used a single ring contour from maps of the day to differentiate between one hill’s inclusion and another.  The use of a single ring contour was soon developed by Carr and Lister (3) into using a minimum prominence of 100ft which was described as the following; ‘if it rose by more than 100 feet above the lower ground connecting it with any greater height’.  By using P100ft Carr and Lister had paved the way for this imperial height to subsequently be used by its nearest whole numbered metric equivalent of 30m, however the timeframe between each was 59 years with each list being specific to hills in Wales.

It was 1925 when Carr and Lister used P100ft as part of their criteria and 59 years later in 1984 the use of P30m was first employed by Terry Marsh (4); the use of P30m has subsequently been used by many list authors including Michael Dewey (5), Alan Dawson (6), Myrddyn Phillips (7), Clem Clements (8) and Mark Jackson (9).  By doing so each in turn is following an imperial height value that has been metricised, there is an erroneous quaintness about this that seems to predominate many British listings, as the use of imperial measurement is now only used by a few nations worldwide and yet we British still rely upon it even when listing hills using metric measurement!

However, even though the use of P30 is now standard amongst many British based hill list compilers there is also a fundamental quality to such hills, as a minimum of P30 just seems to be right, as it produces sufficient hills in most lists to give an adequate challenge for prospective completers and gives an adequate height rise to differentiate between hills and an adequate ascent for the hill bagger.  And although P50 hills have their supporters it seems that P30 hills are here to stay.

Pushing the boundaries

Listing hills can easily become an addiction; there is eloquence to the procedure, a fulfilment of purpose as each height band and contour checked produces another qualifying hill to be listed.  This procedure is time consuming, yet it can be therapeutic in its complicated simplicity.  The use of P30 in this procedure has produced listings that have stood the test of time; with listing down to P30 pushing the boundaries of map study which took many years of laborious work and which was conducted by a few dedicated people. 

A brief synopsis of published lists using minimum of P30 follows:

Terry Marsh – Welsh P30s at and above 600m in height

Michael Dewey – English, Manx and Welsh P30s at and above 500m and below 2,000ft (609.6m) in height

Alan Dawson – Scottish, English and Welsh P30s at and above 600m in height (accumulated from various personal listings).

Myrddyn Phillips – English, Manx and Welsh P30s at and above 400m and below 500m in height.  Welsh P30s at and above 30m and below 400m in height.

Clem Clements – Scottish, English and Welsh P30s at and above 300m in height and below 600m in height.

It was the above listings by Michael Dewey, Alan Dawson, Myrddyn Phillips and Clem Clements that formed the bulk of the Tumps that Mark Jackson duplicated when he collated the Tumps (thirty metre prominences and upward) in 2009.  This is the list that finally pulled together all of the other P30 lists and grouped them under one title, the end product was approximately 16,800 hills that is seemingly getting greater in number as new hills are added on a near weekly basis.  

Personal achievement

When Wales was mapped down to P30 level it opened the door to a complete mainland completion, and as a country Wales lends itself to this as with just over 2,300 mainland and island P30s, and with many of the latter having their own access difficulties, the challenge to complete each and every mainland P30 is feasible and will no doubt, one day, be completed.

I started bagging Welsh P30s in 2000 when I concentrated on the Deweys, however this was more a Dewey bag rather than a P30 bag, in 2002 my attention then turned to the listing of Pedwar hills, but again this was more a list bag rather than a P30 bag.  However, each of these lists and their higher counterparts of the Welsh Hewitts are mere sub lists within the whole.  When the remaining lists to all the Welsh P30s were finally published in 2004 I knew that a mainland completion was feasible, and although I did wonder if I could attain such a thing my approach was one of chipping away in preference to outright concentration on one specific task.  Other things, such as life, occasionally gets in the way of major hill bagging activity, but my total crept ever upward and toward the end of 2015 I decided to check all my bagging journals against all my updated lists and re-visit any hill whose known high point had subsequently moved since I visited, and also survey a number of hills whose status was marginal. 

This re-checking and re-visiting continued for a number of months and my bagging activity nudged my total upwards into the 960s, I then started to plan a September 2016 finish for my 1,000th Welsh P30.  But life and events got in the way as a high speed shunt by a van when I was waiting at temporary traffic lights ended with me in A&E with whiplash and periphery injuries, this kept me off the hills for a number of weeks and when I got back onto them I ended up with a knee injury which has just been diagnosed as a tear to my rear shock absorber which key-hole surgery will hopefully rectify.  These minor scuffles with a mid-life body and the added bonus of a probable cracked rib sustained when protecting my right knee whilst getting out of the bath and slipping with the resulting full weight of my body falling onto the side of the bath, ribs first, meant that any 1,000th Welsh P30 completion was put on indefinite hold.  And when my body partly recovered I was met by Aled Williams’ enthusiastic analysis of LIDAR data when the status of many P30s in Wales was being swapped and deleted on what seemed to be a nightly basis, it took all my concentration just to keep up with any current total I had achieved and as I crept ever closer to the 1,000 magic mark I had to ask Aled to stop sending me LIDAR results otherwise he may reclassify a hill to P30 status that I had already visited and my 1,000th celebratory completion would become no more than an arm chair tick.

With Aled restraining himself and with my Welsh P30 total in the 990s I visited local hills and pushed my total upwards to 999.  I’d decided to keep Bryn y Fan for my 1,000th Welsh P30 as it looked like a fine hill with expansive views and has a good path to its summit and a large car park at its base; it is also relatively close to where I live.  I set the date of 15th April for the walk and a time of 12.00 noon to meet, this was over the Easter bank holiday weekend and I hoped that the weather would be favourable and that any rain would keep away for the couple of hours spent on the hill.

On the hill – Bryn y Fan – completing 1,000 Welsh P30s

My last personal celebration on a hill was in 2002 when I completed a monthly calendar round of the Welsh Nuttalls and immediately followed this with the completion of my 16th round of the Welsh Nuttalls.  Later that same year I also completed the Welsh Deweys, otherwise the only completion celebrations I have attended have been those of friends.

Leading up to the 15th April I sent a number of emails to friends asking if they would like to attend and again hoped for good weather, and as the preceding days led toward the 15th it seemed that a 24-hour weather window was going to give dry, albeit blowy and chilly weather for the Saturday with the preceding day and following day both plagued with rain.  I woke early on the 15th and whilst doing work on my blog noticed a dark cloud outside, five minutes later it was drizzling and 30 minutes later it was raining, this wasn’t forecast!

When Lou arrived the rain had stopped, however after picking Huw and Debs up we had showers most of the way driving through Newtown and Llanidloes, it seemed the celebration was going to be a damp affair.

Pulling in to the large car park beside Bwlch-y-gle dam at the base of Bryn y Fan I recognised the figure walking down the road; it was Alex who had just completed his 1,000th Welsh P30 a few minutes earlier, waiting in the car park were Charlie Leventon and Mark Trengove and within a few minutes David Purchase and Ed had also arrived.  Soon Carole Engel and Alan Greenwood, and Jeff and Enid Parr were parked and getting their boots on, the contingent were almost complete and as the last few windswept rain drops fell Darrin arrived and made our 14 strong party complete.

Preparing to set off (L-R); Charlie, Lou, Debs, Huw, Ed, Alex, Mark, Enid, Jeff, Carole, Alan and David

Although grey skies were ever near the few raindrops that fell as we gathered to set off was the last rain of the day and what could have been a very soggy affair turned out to be dry, which is all I had hoped for.

A good green track led down under the earthen sides of the Bwlch-y-gle dam and swung southward before heading north-east up the slopes of Bryn y Fan.  The track proved slightly muddy in its lower part but the strong breeze had dried the ground higher up. 

Dodging the mud

It was good to be with friends who I had had the pleasure of doing so many hill walks with, some of them such as David, Jeff, Enid and Carole I only see once a year or so, others like Charlie and Ed live locally so are only a phone call away from getting out on the hill.  As we rounded the corner of the track before heading upward Mark suggested doing an interview on top, and although I’d brought my digi-camcorder I’d left it in my car with little intention of filming proceedings, but upon Mark’s suggestion I became enthused and dashed back to get it, when I re-joined the track a number of people were already heading upward out of site whilst Charlie waited beside a gate and we subsequently brought up the rear, slowly making our way up the zig zagging track as it gained height and the view opened up.

The start of the uphill

Charlie Leventon

Below us Clywedog glimmered as patches of whiteness developed in the sky and across the valley the shapely profile of Bryn y Tail gleamed back toward us, by now the view had opened up and any shower clouds were distant and the prospect of dry conditions during the walk was a thankful probability. 

Bryn y Tail (SN 916 874) with Llyn Clywedog below

The broad green path continued toward the upper part of the hill which consists of heath and moor, it diverted from the area of the summit a few minutes’ walk below the highest point, and we followed a narrow sheep track heading off the main path aiming toward the summit.

Nearing the summit

The high point of Bryn y Fan is a small rocky knoll a few metres from its trig pillar, as I walked toward it the majority of people were gathered around the trig with a few forming an arch with their walking poles for the ceremonial last few metres to the summit.  This was the first time I’d walked through a ceremonial arch of walking poles toward any summit, I quite enjoyed it!

Beside the trig

Gathering near the summit

The ceremonial arch of walking poles.  Photograph © Charlie Leventon

Reaching the top was fun, and was more so when shared with good hill walking friends.  As photographs and videos were taken I called Alex over as he had achieved his 1,000th Welsh P30 about an hour before me, we stood beside the summit, posed for a few photographs and quickly dashed down on the leeward side of the hill out of the wind to de-camp for bubbly and lots of cake.

At the summit of Bryn y Fan with Alex

On occasions such as this it is hard to catch up with everyone as usually the ascent is taken at your own pace and the after-reaching-the-summit cake eating and alcohol swigging can all be a bit of a blur.  During our sheltered cake and Cava fest I set the Trimble up aligned with the highest part of the small embedded summit rock and gathered what proved to be 11 minutes of data.  It felt good to be here surveying with the Trimble as friends chatted below. 

As the multitude of cake on offer was quickly devoured Mark and I sneaked off to find a sheltered spot for an interview on Welsh P30s, as ever Mark proved a whizz behind the digi-camcorder and my thanks to him for this suggestion as it will form a lasting document of my day on the hill.

Gathering data with the Trimble GeoXH 6000 at the summit of Bryn y Fan

Enjoying the cake and bubbly

The Trimble set-up position at the summit of Bryn y Fan

After about 40 minutes on the summit it was time to make a move and the descent proved fun as the hills all around sparkled in intermittent sunshine.  We retraced our inward route downward toward the awaiting cars and said our goodbye’s as various people headed off to do a myriad of things, with Jeff and Enid Dewey bagging, Mark taking Alex back to Mold for an onward train toward Conwy, David driving back to Bristol, Ed heading toward Montgomery, Charlie picking off a few more P30s on his way home to Shrewsbury and Carole and Alan heading to the end of the Llŷn peninsula to celebrate Carole’s completion of the Welsh Marilyns on Mynydd Anelog.  This left me and Lou, and Huw and Debs to follow Darrin to his and Lisa’s still relatively new house in Trefeglwys for coffee and chat.  It was good to be with friends, old and new, relaxing over coffee and good conversation.

Heading down

Down toward the awaiting cars

After leaving Darrin and Lisa our day continued toward the midnight hour with a road trip hunting out never visited pubs and forgotten pubs that are now boutique hotels, followed by an excellent meal in the Sun Inn at Clun and last orders in the Oak in Welshpool.  It had been an excellent day and my thanks to everyone who attended as it was good to share my 1,000th Welsh P30 with such good friends, old and new.

Myrddyn Phillips (April 2017)


Survey Result:

Bryn y Fan

Summit Height:  482.0m (converted to OSGM15)

Summit Grid Reference:  SN 93123 88494

Bwlch Height:  307.2m (LIDAR)

Bwlch Grid Reference:  SN 92775 89173 (LIDAR)

Drop:  174.8m (Trimble summit and LIDAR bwlch)

Dominance:  36.26% (Trimble summit and LIDAR bwlch)

1911 John Rooke Corbett ‘Twenty-Fives’ published by the Rucksack Club Journal (1)

1933 Edward (Ted) Moss ‘Some New Twenty-Fives’ published by the Rucksack Club Journal (2)

1940 Edward (Ted) Moss ‘The Two-Thousands of Wales’ published by the Rucksack Club Journal

1925 Herbert R C Carr and George A Lister ‘The Mountains of Snowdonia’ published by John Lane The Bodley Head Limited of London (3)

1984 Terry Marsh ‘The Summits of Snowdonia’ published by Robert Hale (4) 

1985 Terry Marsh ‘The Mountains of Wales’ Hodder and Stoughton

1995 Michael Dewey ‘Mountain tables’ published by Constable (5)

1995 Alan Dawson ‘The Murdos’ published by TACit Tables (6)

1997 Alan Dawson ‘The Hewitts and Marilyns of Wales’ published by TACit Tables

1997 Alan Dawson ‘The Hewitts and Marilyns of England’ published by TACit Tables

1999 Alan Dawson ‘Corbett Tops and Corbetteers’ published by TACit Tables

2004 Alan Dawson ‘Graham Tops and Grahamists’ published by TACit Tables

2002 Myrddyn Phillips ‘400m hills of England, Isle of Man and Wales’ published on the RHB Yahoo Group file database, with subsequent publications in 2004 ‘The Welsh 400 Metre Peaks’ on v-g.me website and 5everdene website, following co-authored with Aled Williams 2013 ‘Y Pedwarau’ by Europeaklist, 2014 ‘Y Pedwarau’ by Haroldstreet and 2017 ‘Y Pedwarau’ by Mapping Mountains (7)

2004 Myrddyn Phillips ‘The Welsh 300 Metre Peaks’, ‘The Welsh 200 Metre Peaks’, ‘The Welsh 100 Metre Peaks’ and ‘The Welsh 30m – 99m Peaks’ published by v-g.me website and 5everdene website

Dates of publication unknown (to me) Clem Clements produced P30 listings to the 300m – 500m hills of Scotland, England and Wales with a variety of other prominence based listings also compiled (8)

2009 Mark Jackson ‘Tumps’ published on the RHB Yahoo Group file database (9)

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