Friday 31 January 2014

The History of Welsh Hill Lists


The History of Welsh Hill Lists – Part 1

The Early Years
1911-1940

1911 - John Rooke Corbett

No history of the hill lists of Wales would be complete without due reverence to Sir Hugh Munro, who in 1891 published his first Tables of the 3000 foot mountains of Scotland.  These consisted of 283 separate mountains with a further 255 subsidiary tops.  Except for the minimum height criterion the list was arbitrary in nature and blazed a trail for all hill lists that followed.  Sir Hugh never quite completed his 538 tops; he was working on a revision of his Tables when he died in 1919 with only three tops remaining to visit.

Subsequent years saw the Rev. Archibald Eneas Robertson become the first person to complete Sir Hugh’s 283 ‘Munros’, when on the 28th September 1901 he reached the top of Meall Dearg on the Aonach Eagach.  The Rev. A.R.A. Burn in 1923 not only repeated the Munros but also completed the subsidiary tops.  In 1929 J.A.Parker became the third person to complete the Munros.  Our Welsh story now properly starts with John Rooke Corbett, Munroist number four.

John Rooke Corbett was a district valuer based in Bristol.  He completed the Munros and tops in 1930, only the second person to do so.  As well as this, Corbett compiled a list of 219 Scottish mountains, between the heights of 2500 feet and 2999 feet, and subsequently climbed them all.  His listing of ‘Corbetts’ had no specific written criterion for defining a mountain, the Scottish Mountaineering Club (SMC) who the list was bequeathed to, analysed it and decided that each mountain had to have a minimum re-ascent of 500 feet on all sides.  However, subsequent detailed analysis of maps of the time by Robin N Campbell implies that Corbett was using ten separate ring contours to denote one hill from another.  The metric equivalent of the 500 feet criterion would form the basis of a much later and important list publication.  With Corbett’s listing and later publication the minimum height criterion used in a Scottish hill list had been reduced from one of 3000 feet to one of 2500 feet.  But Corbett had already used this minimum height criterion in a published list in the 1911 Rucksack Club Journal and thus the first published systematic listing of Welsh hills starts.

The Rucksack club was formed in October 1902 and its journal started in 1907.  Published on an annual basis, its 1911 edition had a five page article entitled ‘Twenty-Fives’.  These Twenty-Fives were the 131 mountains above 2500 feet that Corbett had noted in England and Wales.

After an introductory page the listing starts with a brief description of each group, followed by the mountain’s name, and in most, but not all cases, its height.  The last two pages relate to Wales with the Berwyn as the first group listed comprising Cader Fronwen and Moel Sych.  The next grouping, to the North of Ogwen Lake, consists of fourteen peaks.  Eleven mountains make up the third grouping, between the Ogwen and Llanberis passes.  Snowdon follows with four listed summits, whilst further West is the solitary peak of Moel Hebog.  The Moelwyn make up the next group with Moel Siabod and Moelwyn listed.  The following group ranges over an area that includes Arenig Fawr, Aran Mawddwy and Cader Idris; Cowarch is noted in this group as the only one that cannot be reached in an easy day from either Llanuwchllyn or Dolgelly.  Corbett’s last group is to the great ridge of old red sandstone that separates Brecknockshire from Glamorgan and comprises nine summits.  In all, 51 Welsh mountains are listed.  Corbett ends with a remark concerning Plynlimmon, which he states: “Has been described by writers who should know better as the third highest mountain in Wales, [this] only reaches 2,468 feet above sea level”.

With this article Corbett had set the precedent that many a subsequent list compiler would follow by incorporating the hills of England and Wales in one publication.  It also seems that the accepted spelling of hill names has altered in the years between this list’s publication and the writing of this article.  Corbett’s reasoning for producing the list was based upon the peak-bagging exploits of the then president of the Rucksack Club, Philip S. Minor.  Corbett goes on to explain that: “Minor was the first to take up the idea of ascending every mountaintop in England and Wales over 2500 feet”.  Because of this, members of the Rucksack Club scrutinised reputable maps of the time, such as Bartholomew’s or the one-inch Ordnance map, and if any point was above the 2500 foot contour line and was marked, it went on the list.  This of course was only done as Minor was approaching the completion of his task, so he could at least do it properly.  Although the exact date is unknown, Philip S. Minor became the first person to complete the Twenty-Fives when he finished Corbett’s list in 1911 or 1912.

An excerpt from the introduction to John Rooke Corbett's 'Twenty-Fives'

Although Corbett’s Twenty-Fives is accepted as the first systematic listing of Welsh hills to be published, it certainly wasn’t the first published listing.  During the Victorian age, hills with their respective heights were sometimes divided into groups and occasionally appeared in published format.  Harry Longuville Jones’s ‘Illustrations of the natural scenery of the Snowdonian mountains, accompanied by a description, topographical and historical of the county of Caernarvon’ is but one example.  Charles Tilt of London and Thomas Stevenson of Cambridge published this in 1829.  It included hills, with their heights, arranged in six divisions of mountains.  But detailed listings with a set criterion for defining a mountain only arrived in Wales with John Rooke Corbett’s 1911 publication.  It was only a year later when after thorough and exhaustive examination of the map of England and Wales, that an update to the ‘Twenty Fives’ appeared.



Next installment due on the 30th March 2014


For the Preface please click {here}


For Part 2 please click {here}

For Part 3 please click {here}

Monday 27 January 2014

Guest Contributor - Alan Dawson


Introduction

I have approached a number of people to write articles, but if readers would like to contribute an article please contact me. The only two stipulations I make are that the article has to be hill related and that I don't end up in court through its publication! Otherwise the choice of subject matter is down to the Guest Contributor.


Guest Contributor – Alan Dawson


Alan has compiled some of the most important of British hill listings, including the Marilyns, Murdos, Grahams, Corbett Tops, Graham Tops, Hewitts and Sims.  Many people justifiably consider him as Britain's pre-eminent published hill list author.  With the Sims list he unified the 600m hills of Britain, he's now considering doing this for another category of hill.


Surveying is a Doddle 


I was very pleased to hear that Myrddyn has splashed out and bought himself a new surveying gadget, a top-of-the-range Trimble. I see this as good news all round. Good for Myrddyn firstly, as I’m sure it will give him endless enjoyment and satisfaction and an even greater incentive to get out in the hills, not that he needed it. Good for me, because I’m hoping that Myrddyn will survey several hills that are on my own surveying to-do list, particularly marginal Sims (600m summits) in Wales. And good for the hill-bagging community in general, as he will be collecting a trove of accurate hill data and making it publicly available for anyone interested. He will be reclassifying some hills in his own lists, which I’m sure he will find particularly satisfying. It wouldn't surprise me if he set out to survey every Pedwar (Welsh 400-499m hill).

While I focus mainly on hills over 600m, with a few lower ones thrown in, and Myrddyn on 400-499m hills, with lots of lower ones too, this leaves a gap in between, the 500m hills. It has been suggested, by a few of the usual suspects that the British 500m hills could benefit from unification, along similar lines to the Sims. Currently the 500m hills (with a minimum 30m drop all round) fall into four categories: Welsh Deweys, English Deweys, Donald Deweys (in Southern Scotland) and Highland Fives. All these groups cover hills from 500-609.6m not 500-599.9m, so they are not metric lists but are based on one metric threshold (500m) and one imperial threshold (2000 feet). When considering Britain as a whole, this mixture of lists and units adds up to a dog’s dinner with breakfast, lunch, pudding and after-dinner mince thrown in. At least, it does for those tidy-minded and pedantic metric enthusiasts who like unified hill lists. Not a large percentage of the population admittedly, but enough to propose a single list of 500-599m hills for the whole of Britain. Dewey baggers south of the border would no doubt carry on as before, where the list of Deweys gives hill-starved baggers a challenging target, but in Scotland, where few people climb 500m hills that are not Marilyns or Humps, the unified list would effectively supersede the Highland Fives.

This raises the tricky but important issue of what to call such a unified set of hills. Several possibilities have been floated across the email waves, such as Clems, Dodds, Fives, Hifives, Quintos and Woodalls. While both Clem Clements and Rob Woodall played important parts in researching the hills now called Highland Fives, the consensus view is that it would not be appropriate for the unified list to have any single person’s name. Many others have also contributed, including Mark Jackson, Tony Payne, Michael Dewey of course, David Purchase (who compiled the Donald Deweys) and John Kirk, who produced an immense work listing all the hills over 500m with roughly 20m or more drop. The GJ Surveys team (John Barnard, Graham Jackson and Myrddyn Phillips) have also contributed by surveying several marginal Deweys and demoting quite a few. Various members of the team who look after the Database of British and Irish Hills (DOBIH), particularly Jim Bloomer and Chris Crocker, have also helped research and refine the list.

My personal view is that ‘Fours’ is an uninspired choice for the list of 400m hills in England, while ‘Pedwars’ or ‘Pedwarau’ is a better name for the Welsh 400m hills because it sounds more imaginative and distinctive for those of us who don’t speak Welsh. Similarly, I am not enthused by the term ‘Highland Fives’ or its potential successors ‘Fives’ or ‘Hifives’. The remaining two options, ‘Dodds’ and ‘Quintos’, need a little explanation. Dodds is derived from ‘Donald Deweys and Deweys and Scotland’, thereby acknowledging the major contributions of Michael Dewey and David Purchase. It is also a hilly-sounding name, although not many of the 500m hills are actually called something Dodd. One argument against is that it’s another D-word to add to the Donalds and New Donalds and Deweys and Donald Deweys. Quintos is based on the Latin prefix for five, as in quintet, a five-piece band, and quintessence, the classical but elusive fifth element, along with air, fire, earth and water. In a notorious case of bad planning, the London-based Asian-influenced rock band Quintessence had six members when they started in 1969, so they were a sextet not a quintet. I don’t suppose this nominative discrepancy bothered them much, as they were Hindus rather than pedantic hill baggers, though the two faiths are theoretically not incompatible.

Anyway, Dodds is currently the favoured choice, though further consultation is currently taking place amongst interested parties. So much for the name, what about the hills? According to version 13.3 of DOBIH, there are 1336 of them, comprising 941 in Scotland, 227 in Wales and 168 in England. There are also five in the Isle of Man and 186 in Ireland but, in line with the Sims, these would not be part of the unified list of British hills (the Irish 500-599m hills would presumably be called the Doddis).


Dodd, a 502m Dodd, with Skiddaw behind
Quite a bagging challenge then, but not an impossible one. There are 215 Marilyns and a further 189 Humps included, leaving only 932 to mop up for anyone who has done all the 500m-599m Humps. Only eight of these are 599m and only ten are 598m, so not many are likely to be promoted to Sims. Two of these have already been confirmed: last year I surveyed 599m Flasvein on Skye and found that it is 598.9m, and now Myrddyn has taken his Trimble up Whimble and found it to be 598.8m. Those OS surveyors were pretty accurate in most cases when they bothered to go walking in the hills, but now that they stick to planes or offices they’re not quite so good.
Apart from the name, another issue is that of overall responsibility for the unified list. Michael Dewey is still looking after his list, but the Scottish hills present a much bigger maintenance and editing task. To date the DOBIH team have taken responsibility for the Highland Fives, and may continue in that role for the Dodds, but there are some advantages in having a specific person as hill list editor, as there are inevitably cases, in any list, where subjective judgements are required about hill names and sometimes hill status. Precise surveys can remove almost all uncertainty about height and drop, but there will always be highly marginal cases where editorial judgement is required, and the vast majority of these hills will remain unsurveyed for the foreseeable future. Map-based research will continue to play a key role, and the inconsistencies and vagaries of OS mapping mean that subjective judgements will continue to play a small but important part in hill listings.
Myrddyn’s new Trimble will be a huge asset to him and to hill baggers in general, but it would take multiple Myrddyns (a vaguely uncomfortable image) with multiple Trimbles in multiple lifetimes before the full and final truth of British hills could be revealed. So there is really a need for another Trimble-wielder to focus on the British 500-599m hills, whatever they end up being called. A pedantic Hindu surveyor with lots of reincarnations could be particularly useful. In the meantime, there are a multitude of small truths out there waiting to be revealed, and I have no doubt that Myrddyn will have the time of his life uncovering new hill data, for the benefit of all who are suitably receptive.

The first Quintessence album, featuring unspecified peaks, possibly in the Hindu Kush

To access the RHB Marilyn News Centre website and Alan’s survey results using a Leica RX1250 GPS click {here}

Sunday 26 January 2014

Mapping Mountains – Trimble Surveys – Stiperstones


25.01.14  Black Rhadley Hill (SO 342 955)

Black Rhadley Hill (SO 342 955)

Black Rhadley Hill is positioned at the southern edge of the Stiperstones ridge, the outcrops of quartzite rock so evident on the latter are not to be found on this hill, but it portrays a quiet solitude as it looks out over the River West Onny and the hills of Heath Mynd, Cefn Gunthly and farther afield; Corndon.

The OS 1:25,000 map and the enlarged Geograph map have a summit spot height of 401m, whilst the OS 1:50,000 map has 402m.  The 1:50,000 map height matches the imperial height of 1,320ft given this hill on the old OS One-Inch maps.  As both heights are close to the height of 400m to qualify for the list of The Fours, I wanted to gather accurate data and see if the hill should retain its current status.

There are few parking opportunities when approaching the hill on the narrow lane that contours around its southern flank and then gains height on its eastern side.  But a car can just be squeezed off the road close to a gate that gives access on to a good path approaching the hill from the north-east.

The sky had brightened when compared to the greyness that pervaded the land earlier in the morning.  I assessed the col when I walked over it and decided to visit the summit and gather data first.  The path led up at an easy gradient toward the summit cairn. 

Land immediately at the base of the cairn seemed higher than any other, and no doubt the land under the cairn was even higher, but I wanted good clearance for satellite reception and did not want to put the Trimble immediately against the cairn and by doing so block off half the satellite reception.  Therefore I chose a spot about a metre away and set the Trimble on the ground and waited a couple of minutes until it had attained its required 0.1m accuracy and then pressed ‘Log’.

The Trimble set-up position in relation to the summit cairn

The summit area of Black Rhadley Hill with the Stiperstones in the distance

Over the last month I’d usually gathered data for five minutes at each summit or bwlch, today I’d been extravagant and gathered a minimum of ten minutes of data at each point I’d surveyed.  This gave me time to wander down to another cairn on the southern side of the hill’s summit.  Just below this vantage point is a mature monkey puzzle tree looking rather exotic and somewhat out of place. 

The grey murk of the early morning having disappeared it left a rich clarity of colour with Heath Mynd and Cefn Gunthly being highlighted to the south.  Towards the west Corndon stood out as an elongated, almost flat topped bulk of a hill, a very different profile to the conically shaped hill I am used to seeing.  Further west a mass of cloud was gathering heralding the next front of wet weather, this could be picked out as an almost straight line across the sky, it wouldn’t be long before the thunder and hail arrived, but just for the moment everything was tranquil atop Black Rhadley Hill.

Cefn Gunthly (SO 331 948) from the summit of Black Rhadley Hill
 
Corndon (SO 305 969) from the summit of Black Rhadley Hill

Once the Trimble had gathered ten minutes of data I headed down to the hill’s connecting col.  Ahead of me the first outcrop of the Stiperstones ridge rose out of the land, a welcome site amongst rounded hills of heather.  Once at the col I chose a spot and placed the Trimble beside a vehicle track for another ten minutes of data.  From here it was no longer than a minute back to the awaiting car.  All that was left was to investigate the critical col for Heath Mynd before the massed bulk of rain and hail arrived.

The col is positioned this side of the silver car with the rock outcrops of the Stiperstones ridge in the background

LIDAR image of Black Rhadley Hill (SO 342 955)


Postscript:

Since the survey of this hill full LIDAR coverage is now available.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height and positional data that is now freely available for England and Wales.  Consequently the numerical details for this hill has been analysed using this technique, resulting in the LIDAR height and position for the col of this hill being prioritised over that produced by the Trimble GeoXH 6000.


Survey Result:


Black Rhadley Hill

Summit Height:  402.2m  (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SO 34263 95594 (Trimble GeoXH 6000)

Col Height:  347.7m (LIDAR)

Col Grid Reference:  SO 34656 96003 (LIDAR)

Drop:  54.5m (Trimble GeoXH 6000 summit and LIDAR col)

Dominance:  13.55% (Trimble GeoXH 6000 summit and LIDAR col)




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

Saturday 25 January 2014

Mapping Mountains – Trimble Surveys – Stiperstones


25.01.14  Heath Mynd (SO 335 940) and Cefn Gunthly (SO 331 948)

Heath Mynd (SO 35 940)

There’s something very satisfying in the knowledge that hills have been visited before thunder, lightning and a deluge of heavy hail descends upon the land.  The weather forecast predicted a fine morning with the next westerly front bringing its customary winter greyness and rain arriving by early afternoon.  The forecast was spot on.

The intention was to visit three hills over two walks and survey each summit and at least two of the cols.  The third col was an option depending upon the weather front and the position of the col, as maps had the spot height on an A road outside a large house.  Not ideal, as the Trimble is still only young and I didn’t want it squished by passing traffic.

For many years my intended direction was heading west as that’s where the higher hills lie, occasionally trips south were planned to visit Bannau Brycheiniog, and since joining up with John and Graham our surveying trips have pushed us northward, but heading east is a rarity.  East is in to England and away from the high hills, but my priorities have changed over the years.  Now I get as much satisfaction from visiting a relatively low hill than a high one.  And more so if I haven’t visited the former as that will mean new territory being explored.

I’d visited Heath Mynd once before with Bob Kerr and Sarah on a late evening when the sun cast magical colour in the west, but Cefn Gunthly was missed that day, so my new hill could be visited and a circular route over the two hills seemed feasible from the south-west.

Bob and Sarah at the summit of Heath Mynd

The morning was still and grey when I set off up the southerly slopes of Heath Mynd, by 8.15am I was standing at the top looking over at Corndon as the cloud slowly lapped at its summit.  Grey predominated with only a hint of a sliver of brightness to the east as the sun struggled behind the cloud.

The summit area of Heath Mynd has a trig point and an ancient cairn on it.  The cairn is quite substantial in girth if not height.  The vegetation on the upper slopes is heather, at the periphery of the cairn the heather had overwhelmed the outer limits of the cairn and was now growing over the rock.

I considered setting the Trimble up at the base of the cairn’s periphery, but the vegetation that had now taken over the outer limits of rock has peat at its base, I considered this a sign that at least part of the ancient cairn was now a part of the hill and placed the Trimble on the ground and collected 11 minutes of data.

The summit area of Heath Mynd with its trig and ancient cairn

As I descended northward toward a track that contours the hill to the connecting col with Cefn Gunthly, the first sign of brighter skies started to show, below me a farmer was out on his quad bike laying out feed for the sheep.  Otherwise the land was all quiet with the summit breeze disappearing just below the upper part of the hill.  Soon the quad bike went on its way leaving me access to the green upper hillside of Cefn Gunthly.  Two gates were conveniently open and soon I was at the top, this consists of what looks like the remains of an ancient tumulus, rounded with rocks beneath the cultivated grass.  The Trimble gathered 10 minutes of data and I then retraced my way back to the col between the two hills, stepping ankle deep in liquid slurry on the way.

Corndon from the summit of Cefn Gunthly

The col has the marks of a vehicle track passing over it in the valley to valley direction, I placed the Trimble in the position I favoured for the critical col and gathered more data.  A few metres away the land at the base of a fence looked slightly better placed but it consisted of liquid mud and I didn’t want the same unfortunate thing happening to the Trimble as had happened to my boots!

The view of Cefn Gunthly from the descent back to the narrow lane after gathering data at the col

After another 10 minutes of data had been gathered I followed the vehicle track down to the narrow lane and walked back to the car, watching a farmer round up his flock of sheep in an adjacent field on the way. 

Rounding up the sheep

The walk had only taken two hours but it left a magical sense of peacefulness until I met the flock of sheep being driven by quad bike and dog down the road and encountered a convoy of vehicles heading in the opposite direction to me.  Tis a very narrow road hereabouts with few options for passing, after the sheep had been skilfully directed in to another field I headed toward the next survey; Black Rhadley Hill.

After visiting Black Rhadley Hill I decided to investigate the col position for Heath Mynd.  The hill is listed as a Marilyn, HuMP and Four and has a 292m spot height on the OS 1:50,000 map as well as the OS enlarged Geograph map at SO 32387 94521.  This spot height appears in the centre of the A488 as it makes its way towards Shrewsbury.

Once parked I headed toward where the 292m spot height appears on the ground, this is at the entrance to Pultheley Farm where an attentive dog gave my presence away with a lot of barking.  As the track headed in to the farm it seemed to gain height, as indeed did the track that headed in to Pultheley Bank which has an entrance just south of where the spot height appears.  This signified that the critical col wasn’t anywhere near the barking dog.  I contemplated putting the Trimble on the ground at this entrance and gathering data to compare the processed height with that of the spot height, but across the road on its western side the ground fell away to a large pond.  On the north side of this large pond was a boggy quagmire with horses grazing nearby.  The water in the quagmire seemed not to want to go anywhere, but the map indicates that this is an outflow and therefore the high land on the valley to valley traverse must be to the south of the pond.  Rather conveniently this was where I had parked my car, which was pulled in beside the entrance to Lower Bank Farm.

Gathering data on the southern side of the large pond at the col area of Heath Mynd.  The A488 is just to the right of the photo with the ground where the 262m spot height is positioned about 80 metres up the road.
    
I then left the barking dog and walked back to the car and the southern side of the large pond.  It was relatively easy to judge the land on the hill to hill traverse, but more difficult for the land on the valley to valley traverse, and as I was now positioning the Trimble on grass beside the track that led up to Lower Bank Farm I didn’t want to wander around in the adjacent field and spend a lot of time trying to distinguish where the absolute critical col was exactly positioned.  Beside the track looked good to me and so I started the Trimble gathering data and retired to the side of the car.  Ten minutes later I switched it off, packed it away and headed for a shop at Tesco’s in Welshpool and made it home just as the sky turned a thunderous grey and hail started to batter everything in its path.  And only an hour earlier I’d been standing in the sun, happy in the knowledge that all objectives had been surveyed and the hills had proved peaceful places. 

LIDAR image of Cefn Gunthly (SO 331 948) and Heath Mynd (SO 335 940)


Postscript:

Since the survey of these hills full LIDAR coverage is now available.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height and positional data that is now freely available for England and Wales.  Consequently the numerical details for these hills have been analysed using this technique, resulting in the LIDAR height and position for some of these hills being prioritised over that produced by the Trimble GeoXH 6000.


Survey Result:



Heath Mynd

Summit Height:  452.6m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SO 33559 94091 (Trimble GeoXH 6000)

Col Height:  261.9m (LIDAR)

Col Grid Reference:  SO 32354 94433 (LIDAR)

Drop:  190.7m (Trimble GeoXH 6000 summit and LIDAR col)

Dominance:  42.14% (Trimble GeoXH 6000 summit and LIDAR col)




Cefn Gunthly

Summit Height:  400.8m  (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference:  SO 33119 94831 (Trimble GeoXH 6000)

Col Height:  354.3m (LIDAR)

Col Grid Reference:  SO 33283 94544 (LIDAR)

Drop:  46.5m (Trimble GeoXH 6000 summit and LIDAR col)

Dominance:  11.61% (Trimble GeoXH 6000 summit and LIDAR col)




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

Thursday 23 January 2014

Mapping Mountains – Trimble Surveys – Mynydd Hiraethog


23.01.14  Cefn yr Ogof  (SH 916 773)

The upper slopes of Cefn yr Ogof (SH 916 773)

For a number of years Cefn yr Ogof languished as a Sub-HuMP with a listed drop of 97m, but with 5m contour intervals on the Ordnance Survey enlarged mapping on the Geograph website with bwlch contouring between c 100m – c 105m and with a map height of 204m the hill was a likely candidate for promotion to full HuMP status.  This was proposed to the hill bagging community in May 2012 and accepted as a fully-fledged HuMP in July 2012.  Cefn yr Ogof is currently listed as a HuMP with 101m of drop.

The hill is positioned in the north-west of the Mynydd Hiraethog range and overlooks the busy A55 and the north Wales coast.  It is part of limestone country with many outcrops on the hill’s upper slopes as well as on adjacent hills.

Today’s outing was the first with G&J Surveys that included the Trimble.  We met at John’s house in Mold and headed west toward the area of the bwlch which is near Abergele.

The bwlch is in a field, we sought access permission at a number of houses, this failed disastrously as the residents were either hiding from us or out, as no one answered.  However, we did speak with a farmer, who we flagged down as he steamed his way up the narrow country lane in his tractor.  It wasn’t his field but he didn’t express any objection to us wandering around with a multitude of flags and putting surveying equipment up.

An hour or so later and we had pinpointed the position of the critical bwlch.  This was done by setting out a grid of flags and taking readings to each one with a level and staff.  Once completed the readings give the relative height of the land as it ascends on the valley to valley traverse and descends on the hill to hill traverse.  It is an easy and effective way to pinpoint the position of a critical bwlch. 


The Leica GS15 set up position at the bwlch of Cefn yr Ogof

The Leica GS15 had been set up before doing this, once it had gathered over an hour’s worth of data we packed it away and took a reading from its set up position to the actual position of the critical bwlch.  The Trimble was then positioned on the latter and gathered 16 minutes of data.

Boys and their toys.  The critical bwlch of Cefn yr Ogof

We then drove to Rhyd- y-foel and headed up the hill.  As John and Graham are both quicker than me I normally try and get a head start and they normally catch me up and overtake me.  I opted for a barbed wired fence, brambly scrub land approach and they opted for a route through a hedge.  Once the obstacles were overcome we converged from different directions about two minutes below the summit.

The summit is a good vantage point and brought back memories of my previous visit when Des Taylor had celebrated his completion of the Welsh and English HuMps. 

By the time the three of us arrived at the summit the wind was blowing and it was bitingly cold.  We set about taking readings to the flush bracket on the trig pillar, to the trig’s base and its top.  The GS 15 was then set up over the highest embedded rock we could find amongst the summit cairn for an hour’s worth of data, whilst the Trimble was set up on the top of the trig for 30 minutes to compare its data set against the relative height we had just attained with the level and staff to the top of the trig and the highest rock.


The Leica GS15 set up over the high point of Cefn yr Ogof

By now the flashes of sunlight had disappeared and greyness had crept from the near sea and descended upon the land.   Away to the north-west the higher peaks of Eryri were swamped in deep cloud.  We all thought it was going to rain and took shelter in the near forest, more out of the wind than the impending shower.  The latter never materialised but the wind was unabating.

After the Leica GS15 was packed away the Trimble was aligned with the high point of the highest embedded rock, secured in place with small rocks and gathered ten minutes of data.  We then headed down out of the wind.  Another excellent day out on the hill and great to be out with G&J again.


The Trimble GeoXH 6000 wedged in place on the high point of Cefn yr Ogof



Survey Result:


Cefn yr Ogof

Summit Height:  204.5m (Trimble GeoXH 6000, converted to OSGM15)  204.5m (Leica GS15, converted to OSGM15)

Summit Grid Reference:  SH 91684 77301

Bwlch Height:  102.9m (Trimble GeoXH 6000, converted to OSGM15)  102.9m (Leica GS15, converted to OSGM15)

Bwlch Grid Reference:  SH 93547 75706

Drop:  101.6m (Trimble GeoXH 6000)  101.6m (Leica GS15)  (Hump status confirmed)

Dominance:  49.69%





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

Sunday 19 January 2014

Mapping Mountains – Trimble Surveys – Moel y Gamelin


19.01.14  Moel Morfudd (SJ 159 457), Pt. 497.7m (SJ 161 461), Moel y Gaer (SJ 166 463), Moel y Gamelin (SJ 176 465) and Moel y Faen (SJ 184 475)


Moel Morfudd (SJ 159 457)

With the weather set fair I met Aled at Bwlch Oernant (the Horseshoe Pass) above Llangollen where we parked one car and drove to the start of our walk at Bwlch y Groes (SJ 149 451).  The ridge that leads from this relatively high and narrow road heads north-eastward taking in the summits of four Deweys.  It was our plan to survey all of these and one or two other hills if time permitted.

The crest of the connecting ridge between all of these summits has a wide gravel track meandering across its spine, this somewhat spoils the aesthetic beauty but as all hills are immersed in copious amounts of heather it makes passage soooo much easier!

As we gained height the view below opened up with overnight winter cold having formed mist patches that crept around the lower hill sides as light cast radiant colour on the land.

Early morning mist in the Vale of Llangollen.

Our first summit was Moel Morfudd which has a trig pillar and a small rocky tor on its west side.  The Trimble was set up aligned to the highest part of this small tor and gathered ten minutes of data.

The high point of Moel Morfudd is above the base of the summit trig pillar.

We then surveyed a 497m map heighted hill for Sub-Pedwar status before continuing toward Moel y Gaer with its ancient hill fort on fine display when approaching from the south-west.  The sides of this hill are scarred with wide eroded tracks used by trail riders, somewhat of an infringement in such a beautiful place.

A hillside despoiled - Moel y Gaer.

By now we could see a cloud bank out to the west with darkened patches implying showery weather.  Thankfully the morning’s sunshine only disappeared for an hour or so as this cloud threatened to push eastward.  The sun prevailed and gave us blue skies for the remainder of the walk over the highest hill of the day; Moel y Gamelin which as well as being a Dewey is also a Marilyn.

At least waiting for things such as surveying equipment to do its stuff gives time to look and watch the play of light, and today down in the valley the sun cast its magic on fields of green with the limestone rocks of Mynydd Rhiwabon being highlighted against a dark foreground and milky blue sky.

Play of light on fields of green.


The limestone rocks of Mynydd Rhiwabon.

After five minute’s data collection to the top of a small embedded rock beside the summit cairn we were away heading toward our final objective; Moel y Faen.  During the walk we surveyed every bwlch we came to with good discussion on the placement of the Trimble and the margin of uncertainty associated with where we put it, when compared to where the critical bwlch may actually be.  I decided the whole process was a guess and smiled at what the G&J reaction may be if ever they read this sentence.

The Trimble GeoXH 6000 on the highest point we could find on Moel y Gamelin.

During the whole day the Trimble was in sluggish mood and decided to take its time achieving its required 0.1m accuracy, so much so that it added an approximate 90 minutes to the walks estimated time, and as it was now perched on grass beside a fence at the bwlch of Moel y Faen and seemingly very happy to still be in sluggish mode it meant that daylight was soon to be transformed to dusk and as the sun disappeared behind an adjacent hillside the temperature plummeted.  

Even though the distance of the walk was not great, taking on 11 survey points with a sluggish Trimble can mean a long day on the hill where surveying stamina is called for.  I’m now quite used to this unusual pursuit having practiced near hyperthermic conditions with the G&J team when marooned on a summit in horrid weather for two hours and more, but this novel experience was relatively new for Aled, he came through with flying colours, although if not for the varied topics of discussion I think our patience with our predicament could well have been tested! 

On our last summit of the day; Moel y Faen, we sat and looked out to the north onto agricultural land and far away hills full of heather and as yet unplanned days out with the Trimble.  Below us was Bwlch Oernant and Aled’s awaiting white van, by the time we packed the Trimble away and headed down we’d been out on the hill for over seven hours, with probably the same amount of time waiting for the Trimble as walking on the hill.  It’s funny the enjoyment one gains from the quirky aspects of life.


The summit of Moel y Faen.

It proved an excellent day on the hill even if our esteemed Europeaklist editor could not make the walk, and it was great to see Aled again and have the opportunity to discuss future plans.


Survey Result:


Moel Morfudd

Summit Height:  549.6m (converted to OSGM15)

Summit Grid Reference:  SJ 15965 45762

Bwlch Height:  434.7m (converted to OSGM15)

Bwlch Grid Reference:  SJ 17063 46541

Drop:  114.9m

Dominance:  20.90%





Pt. 497.7m

Summit Height:  497.7m (converted to OSGM15)

Summit Grid Reference:  SJ 16163 46144

Bwlch Height:  478.5m (converted to OSGM15)

Bwlch Grid Reference:  SJ 16080 46096

Drop:  19.2m

Dominance:  3.86%





Moel y Gaer

Summit Height:  503.5m (converted to OSGM15)

Summit Grid Reference:  SJ 16681 46360

Bwlch Height:  465.8m (converted to OSGM15)

Bwlch Grid Reference:  SJ 16515 46252

Drop:  37.7m

Dominance:  7.48%





Moel y Gamelin

Summit Height:  576.9m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SJ 17634 46515 (Trimble GeoXH 6000)

Bwlch Height: c 192m (interpolation)

Bwlch Grid Reference:  SJ 06920 47561 (interpolation)

Drop:  c 385m (Trimble GeoXH 6000 summit and interpolated bwlch)

Dominance:  66.72% (Trimble GeoXH 6000 summit and interpolated bwlch)





Moel y Faen

Summit Height:  547.1m (converted to OSGM15)

Summit Grid Reference:  SJ 18490 47530

Bwlch Height:  488.4m (converted to OSGM15)

Bwlch Grid Reference:  SJ 18034 47277

Drop:  58.7m

Dominance:  10.74%




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