Mapping Mountains – Trimble Surveys – Drumochter Hills

30.07.15  Mullach Coire nan Cisteachan (NN 663 806)    

Mullach Coire nan Cisteachan (NN 663 806)

Mullach Coire nan Cisteachan rises to the east of the A9 as it speeds its way past Dalwhinnie.  The hill has recently been surveyed by Alan Dawson with his Leica RX1250 with the result being that the hill was measured as 914.56m high, as this height is over 914.4m / 3,000ft the hill is a candidate for the Scottish Mountaineering Club (SMC) to consider for Munro Top status.

As the Heighting Project instigated by Iain Robertson on behalf of The Munro Society (TMS) has now finished we thought it appropriate to finalise those lose ends of hills that have not had two hours of data gathered from their high points.  Mullach Coire nan Cisteachan is one of these hills, and our aim was to survey its summit in conjunction with the SMC and TMS.

We met in a large lay-by beside the A9 close to where a track accesses this hill’s north-western slopes.  By the time we arrived David Batty was brewing up and passed a hot mug of tea to Alan Brook who was parked in front of David’s camper van.  Soon afterward Iain Robertson closely followed by Eleanore Hunter, Ian Collie and John Rogerson arrived.  As Bill Wheeler pulled up I had my boots laced up and was walking toward the gate and the track.  I needed a start on these fitter and quicker people, as although all are older than me they seem to speed up the hills.  As I walked over the road I noticed that Rab Anderson was turning into the lay-by, he and Andy Nisbet were representing the SMC and would liaise with Derek Bearhop who instigates any reclassification to Munros Tables.

The track made steady progress up toward the grassed slopes of the hill and wound its way directly up one of the broad north-westerly whaleback ridges that descend from the hill’s western slopes.  The gradient proved sufficiently steep not to tax and within 25 minutes of setting off I looked behind and noticed the first of a number of small figures on the lower part of the track, I thought I stood a chance of gaining the upper slopes before being overtaken.

As height was gained the views opened up and a slight breeze dampened the warmth of the sun, this proved ideal for the ascent.  The track splits higher up near to a small quarry which is indicated on the map, when I arrived at this point I could hear John and Rab’s voices approaching and as I swung left to walk along the track toward the summit of the hill they quickly caught up with me and we proceeded to the summit together.  The others soon appeared with Alan taking over tripod carrying duties which I was thankful for.

On the upper part of the track

Once at the summit we set up the level on the tripod and proceeded to take a number of readings close to the obvious high point which is positioned just to the left of the track when approaching the hill’s summit from the south-west.  These readings were taken from the north, west, south and east at increments of 5 metres out to 25 metres from the level, this gave us the lay of land around the summit.  A near rock proved slightly higher than our favoured natural high point, but consensus of opinion was that this was put there by man and so it was discounted from the summit measurement.

Shortly afterward the Leica GS15 was set up on the tripod and just before starting to gather data we had enough time to take a number of summit photos with the team of surveyors and SMC and TMS members gathered round.

Summit photo:  (L-R) Bill Wheeler (TMS), John Rogerson (TMS), Eleanore Hunter (TMS), Alan Brook (TMS), Rab Anderson (SMC), Andy Nisbet (SMC), Ian Collie (TMS), Graham Jackson (surveyor), David Batty (TMS), John Barnard (surveyor) and Iain Robertson (TMS)

When Alan surveyed this hill he also surveyed its connecting bealach to the adjoining Munro of Carn na Caim, the drop value from these two surveys came to 30.3m which may form a part of the deciding factor in the possible reclassification of this hill by the SMC to Munro Top status, if Alan’s measurements were confirmed with the Leica GS15, which we were sure that they would.  Therefore after the GS15 started collecting data John, Graham and me walked down to the hill’s connecting bealach to inspect the lay of its land.  In close pursuit were a number of people all heading off to bag the summit of the Munro; Carn na Caim, with Iain along with David volunteering to remain with the equipment at the summit of the south Top.

When we arrived at the bealach we were met by an unsavoury expanse of peat laden, mud splattered bog.  This we spent a number of minutes squashing around in and assessing the land and its direction from a number of positions.  The conclusion being that the critical point of the bealach probably lay in one of a number of peat runnels that crossed the bealach in a valley to valley direction.  Although I took two data sets with the Trimble, one near to where Alan had set up his Leica and one a few metres away in one of the peat runnels we decided that we should level and staff the bog once the two hours of summit data had been collected.

The first data set with the Trimble at the bealach was very close to where Alan took data from with his Leica RX1250

As the Trimble gathered its second data set John and Graham headed back to the summit and as I followed them after packing the Trimble away I met Iain as he walked down the path heading toward the summit of Carn na Caim.  I arrived back at the summit with about 30 minutes remaining of the two hour vigil and spent much of the time flat out on the ground nestled out of the breeze munching on a sandwich and chatting with Eleanore and listening to the varied conversation of the others.  All too soon it was ready to pack the equipment away and head back down to the connecting bealach.  As we did so Andy and John headed south to bag more hills, whilst David had already descended and Eleanore, Bill and Ian decided to wait for Iain to come back from the summit of Carn na Caim before heading down toward the cars.  This left John, Graham, me, Alan Brook and Rab to venture down to the delights of the bog invested bealach.

The second data set with the Trimble at the bealach was where the Leica GS15 would eventually be positioned

Alan, Graham and John heading from the summit down to the delights of the bealach

Meeting Iain on his way back from the Munro summit of Carn na Caim, which is in the background

Over the next hour we had fun in the bog laying two rows of flags, one from the hill to hill direction and the other from the valley to valley direction, we then followed one of the peaty runnels on the valley to valley direction and by doing so we pinpointed where the critical point of the bealach lay, this was where I had taken the second data set with the Trimble.

As Graham was the lightest we decided that he should venture out into the bog and operate the staff and lay the lines of flags

The next hour was spent in brightening conditions as the Leica GS15 gathered an hours’ worth of data, I then repeated the previous Trimble survey and gathered another five minutes of data.

Graham, John, Alan and Rab beside the Leica GS15 at its set-up position at the critical bealach of Mullach Coire nan Cisteachan

The third data set with the Trimble at the bealach repeated its second data set

After all the equipment had been packed away we walked back up to the summit where I gathered another five minute data set with the Trimble, and proceeded down the track in warming late afternoon sunshine to the awaiting cars below.

Gathering data with the Trimble from the summit of Mullach Coire nan Cisteachan

Descending the track after another good day on the hill

It had been a good three full days in Scotland with Tuesday’s filming by ARD with TMS members, and the unexpected bonus of surveying Creag na Caillich on Wednesday and now a two hour summit and one hour bealach data set from Mullach Coire nan Cisteachan. 

The results of these surveys will be sent to Ordnance Survey for their verification and the results forwarded to the SMC for their assessment.

Survey Result:

Mullach Coire nan Cisteachan

Summit Height:  914.6m (converted to OSGM15, Trimble GeoXH 6000) 

914.6m (converted to OSGM15, Leica RX1250) 914.6m (converted to OSGM15, 

Leica GS15) (prospective new Munro Top, now confirmed)

Summit Grid Reference:  NN 66386 80690

Bealach Height:  884.3m (converted to OSGM15 and average of two surveys, 

Trimble GeoXH 6000) 884.3 (converted to OSGM15, Leica RX1250, with 

0.07m height compensation for position) 884.2m (converted to OSGM15, Leica 

GS15)

Bealach Grid Reference:  NN 66970 81301

Drop:  30.3m (Trimble GeoXH 6000, using average of two bealach surveys) 

30.3m (Leica RX1250) 30.4m (Leica GS15)

Dominance:  3.32% (based on Leica GS15 result)

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

Mapping Mountains – Trimble Surveys – Cairngorms

27.05.15  Meall Gaineimh (NJ 166 051)    

Meall Gaineimh (NJ 166 051)

The Cairngorns are renowned as being some of the most committing hills in Britain with a high plateaued area comprising many of the highest mountains in the land.  Although I had seen these hills before, albeit from afar, this would be my first visit to their inner depths.

Our main purpose for visiting was to survey Meall Gaineimh which is positioned at the end of the north-easterly ridge that continues from Ben Avon down toward the Builg Burn and River Avon.

This survey had been arranged for Iain Robertson who is the instigator behind the heightings programme undertaken by The Munro Society (TMS).  It was this programme that initiated independent absolute height surveys in Britain using Differential GPS equipment; it was also this programme that initiated the surveys of Sgurr nan Ceannaichean and Beinn a’Chlaidheimh, resulting in the Scottish Mountaineering Club (SMC) reclassifying each from Munro to Corbett status.  This heightings programme has now ended, but as a sign of our appreciation toward Iain and TMS we offered a survey of their choice, the hill decided upon was Meall Gaineimh.

The reason for choosing Meall Gaineimh is that it has a 912m spot height beside the cairn on its summit area, however Jim Bloomer had previously assessed this area with an Abney Level and concluded that the granite tor which is positioned approximately 100 metres from the cairn, is at least 2m higher than the ground beside the cairn, meaning that if the spot height is accurate the hill is close to the 914.4m / 3,000ft benchmark height for it to be considered by the SMC for Munro Top status.

We met at the parking area below Corgarff Castle to the east of the hill, having overnighted at the Smugglers Hostel in Tomintoul, which is highly recommended for a base to investigate the eastern part of the Cairngorms.  John had been given permission for us to drive as far as Inchmore by the Balmoral Estate which reduced our walk from 18 to 12 miles.  This was important as we carried all necessary surveying gear with us and the weather forecast from mid-afternoon on was not conducive for surveying, with a low pressure system predicted to hit this part of Scotland with 30-40mph winds and heavy rain. 

There were eleven of us setting off up the hill; John, Graham and me as surveyors, with TMS members being Iain Robertson, Alan Brook, David Batty, Anne Butler, Bill Wheeler, Peter Willimott and John Rogerson, with Rab Anderson also present representing the SMC.  With a further four people; Laurence Rudkin, Ian Rudkin, Katy Thompson and Harry Lowe cycling in from the north and planning on joining us on the summit after visiting Ben Avon.

The team, (L-R) Iain Robertson, Alan Brook, Graham Jackson, Rab Anderson, Anne Butler, Bill Wheeler, David Batty, Peter Willimott, John Barnard and John Rogerson

The Balmoral Estate had also given us permission to drive as far as their boundary fence with the next estate which is owned by the Sultan of Brunei, therefore Anne dropped five of us off a further mile up the track before driving back to Inchmore, this gave John, Graham and Alan an opportunity to set off ahead with the surveying gear, and for Iain and me to plod up at a steady pace behind.

Walking up the track to collect our gear

Having never visited the Cairngorms before I was surprised to find them clad in heather, their rolling ridges reminiscent of my local hills; Y Berwyn in mid-Wales, but their scale is vast and seemingly unending. 

Once we collected the gear that Anne had kindly dropped off as far up the track as she could safely drive, we continued by foot on the track as it contoured around the northerly expanse of Cairn Culchavie toward the boundary fence between the two estates.

All around were heather clad hills rising from elongated glens with larger dominating hills in the distance, these still had large amounts of snow sticking firmly to their corried eastern edges.  Sometimes on these surveys time is of the essence, and with the predicted weather worsening in the afternoon we could not linger, but I had a sense of vast openness in these hills, especially so the higher I got, as the landscape then truly opened up showing a land stretching out to a cloudy western horizon, with lower glens bisecting the hills, it seemed a landscape of solitude, but one that had to be respected as the distances were relatively vast when compared to the ones I was used to in Wales.

Looking west with large amounts of snow still on the hills

Our first view of Meall Gaineimh from the descent to Inchrory

The track led down to Inchrory which sat beside the River Avon looking rather grand and somewhat misplaced; however a metalled private road leads to this estate house from the north.  As we approached the estate house Laurence, Katy, Ian and Harry appeared around the corner having cycled in from the north.  They soon continued over the bridge that spans the Builg Burn, I followed with the knowledge that one by one the quicker members of our party would overtake me as we started up the track and continuing path that weaves its way up the northern flank of Meall Gaineimh.

Inchrory, looking rather grand

Laurence, Katy, Ian and Harry crossing the Builg Burn

Knowing what the forecast was I had set off in full waterproofs, but as the ascent of the hill started I felt as if I was walking in a sauna, I stopped and packed my Goretex coat and over trousers in my rucksack and continued up the hill.  One by one people passed me, this is not uncommon and as long as I steadily make progress at my own pace I’m happy enough.

Rab, John and Alan starting the ascent of Meall Gaineimh

John Rogerson on the upper section of Meall Gaineimh

The views were now opening up with cloud skimming some of the higher tops out to the west and banks of snow still in evidence on their sides.  As I approached the summit the granite tor rose up from the rounded summit area and John and Graham were already busy at work positioning the tripod.

Another view west onto a land of remote hills

Setting the Leica GS15 up on the summit tor of Meall Gaineimh

The highest part of the granite tor was on the lip of a four metre vertical drop to its base on its eastern side, because of this the tripod could not be positioned over the high point, therefore a measurement offset was taken between the set-up position and that of the high point.  A staff reading was also taken from the high point to the ground at the base of the cairn which was positioned approximately 100 metres away, the height difference is 2.7m.  This meant that if the height and positioning of the 912m spot height was accurate the summit of Meall Gaineimh was 914.8m high and would surpass the 914.4m / 3,000ft benchmark height by 0.4m.  However, photogrammetry has a margin of uncertainty of +/- 3m and the height may have been spotted to the top of the cairn, this would be relatively easy to do as a photogrammetist is viewing a 3D image from above and the construction of a cairn has similarities to that of a small rock outcrop.

Once the Leica GS15 had been put in place we positioned a number of rocks at the base of the tripod legs to secure it, pressed the button and started collecting data.

Graham beside the Leica GS15 on the summit tor

The tor was ideal for shelter as it proved chilly on the summit with a keen westerly wind, and as we left the equipment gathering data we descended the tor to join everyone on its eastern side, well sheltered from the brisk wind.

Sheltering on the eastern side of the summit tor

A number of people had either headed further west toward the continuing ridge to bag more hills before joining us on the summit, or they now did so.  Now began the long wait, as the Ordnance Survey require a minimum two hour data set to verify the result and this wait can prove a chilly affair on high hills in Scotland.  Thankfully, the predicted rain had not yet arrived and at times even the brisk wind lessened to a slight breeze.

Curve of snow

During this wait we checked the position of the ten figure grid reference for the 912m spot height and confirmed that it is beside the large cairn, I also took a five minute data set with the Trimble at the summit.  This would give us two data sets for the summit and a ten figure grid reference for the highest point of the hill.

Gathering summit data with the Trimble

I spent a number of minutes wandering around the tor taking photos and stood on its lower southerly part admiring the hills to my south and west, the land looked welcoming but a teense wild as the distances were large in comparison to the ones I am used to.

The southern part of the summit tor with Peter heading off to investigate the land beyond the connecting bealach

Once the first hour of data collection had passed we prepared to descend to the connecting bealach and gather data with the Trimble to give the hill an accurate drop value.  On our way down we met Peter who was on his way back up, he’d been out investigating the land beyond the bealach, and we stopped and chatted for a few minutes before continuing downhill.

Meeting Peter on our way down to the bealach

Graham nearing the bealach

The bealach has a small dried up puddle on it and is relatively tight on the hill to hill traverse, as we assessed the ground Alan Brook appeared like a wild man coming out of the wilderness, he was full of smiles and stayed with us as we chose the spot for the Trimble placement.  Once five minutes of data were gathered John, Graham and Alan headed back up the hill and I headed down as I expected those on the summit to catch me up and overtake me on the descent.

Alan Brook emerging out of the wilderness

The set-up position for the Trimble at the bealach

The path that we had followed up the hill does not continue to the summit of Meall Gaineimh, as it continues to its bealach, it was this path that I now followed as it swept around the northern flank of the hill before heading straight down it.  After sorting my gear out and packing the Trimble away I headed down on the path and looked back toward the bealach and the opposing granite tor as the sky turned a foreboding murky grey colour which heralded the incoming rain.

One last look back toward the bealach as the sky turns an ominous grey

I wanted to pace myself on the downhill as we had commented that the inward descent to Inchrory would be a slow uphill grind at the end of the day on our outward journey.  It was good not to think that I had to try and keep up with faster hill walkers on my descent, it was also good to be in such landscape on my own where the hills can take over in preference to conversation.

As I approached the lower section of the hill a party of horse riders were on the track heading for the bridge across the Builg Burn.  Once on the track I slowly made my way over the bridge toward the deciduous wood and the grounds next to Inchrory, and looked back toward Meall Gaineimh as it climbed into the sky heather bound and rounded. 

Horse riders approaching the bridge across the Builg Burn

I stopped for a while to admire the scene of river and hill and watched as five birds flirted across the sky as they flew up stream.  Slowly I plodded up the track beyond Inchrory and was buzzed by a Lapwing as it darted across the landscape.  We had earlier spotted Black Grouse when starting our walk and I now encountered a Red Grouse and her young chicks nestled on the path, as I approached the mother ran off with her chicks in close pursuit, I contentedly watched as the young scampered off down the track and eventually into the surrounding heather.

Taking flight

Meall Gaineimh and the River Avon

Trying to catch my dinner!

By now the sky had turned a silken grey and I noticed that I had instinctively quickened my pace.  As I approached the boundary fence between the two estates a few rain drops were cast down in the breeze, these were on my back and almost unnoticed except for their touch upon puddles that I passed.  I hoped that I may be able to out-pace the incoming rain and set a brisk pace down the continuing track, but the rain increased and when larger drops started to fall and the land infront as well as behind had turned grey I decided it was time to stop and put on my waterproofs.

It seemed a longer journey out of the hill than into it, but slowly the metres disappeared behind me and at last the welcome sight of the cars parked beside Inchmore came into view.  I hoped that I could find shelter either inside this house or beside it, not unexpectedly the front door was locked, but around its eastern side were breeze blocks stacked up to make a relatively comfortable seat which was a welcome surprise.  I spent 30 minutes happily seated here out of the rain as it blew in from the west, waiting for the others to arrive.

It had been an excellent walk, my first into Cairngorn country, which proved an impressive land of rock tor, glen and wild hill.

Survey Result:

Meall Gaineimh

Summit Height:  913.6m (converted to OSGM15, Trimble GeoXH 6000) 913.6m (converted to OSGM15, Leica GS15) (Corbett Top status confirmed)

Summit Grid Reference:  NJ 16683 05113

Bealach Height:  843.9m (converted to OSGM15)

Bealach Grid Reference:  NJ 16431 05220

Drop:  69.7m (Leica GS15 summit and Trimble GeoXH 6000 bealach)

Dominance:  7.63%

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