Mapping Mountains – Trimble Surveys – Pumlumon

04.03.22  Pen Rallt (SN 951 859)

LIDAR image of Pen Rallt (SN 951 859)

I had visited this hill once before in January 2004 when it formed one of five walks during the day, then I approached from the minor road to its west and scampered up and down in 14 minutes.  Today was a more leisurely affair, it also proved much wetter!  Prior to visiting the hill I had conducted LIDAR analysis for its summit and connecting bwlch, and had come prepared with the necessary ten figure grid references for both.

On my previous visit I considered the pastured grass of a grazing field on the northern section of the upper ridge, to be slightly higher than an artificially raised green on the opposite side of the ridge fence and which makes up a part of Llanidloes Golf Club.  As there is a large parking area at the Golf Club I thought this would give easy access to the high point and as this was the third walk and fourth hill of the day it would also hopefully give me a leisurely saunter to its summit, before visiting friends in town followed by a dinner party later in the evening.

As I drove toward the Golf Club the heavens opened, I hoped this would be no more than a passing shower, but as I drew up and parked the rain battered my car for the next 45 minutes.  Peering out of the rain splattered window the sky to my north had taken on a slate grey and foreboding look.  It continued like this for quite some time.  All I wanted was a 30 minute gap to scamper up, survey the summit and plod back down, and ideally followed by a few minutes of dry weather to visit Penrallt; the local farm just below the Club House to make place- name enquiries about the hill and then a few more minutes without any rain to change and get dry and clean clothes on for my impending evening’s entertainment.

Slowly the downpour lessened and as what I then thought to be the last rain drops fell, I decided to go for it and gathered all necessary equipment, locked my car and started up a very soggy driving range toward the upper part of the golf course.  As I did so it started to rain again!

Reaching the high point of the golf course I looked out across the valley toward a greyed scene where Bryn y Fan was silhouetted in rain, it swept across the land.  Even though I had not got my wet proofs on I would usually have just bagged the high point and very quickly descended back to the car.  However, surveying requires a little more methodology!  I decided the best course of action was to wait out the rain and therefore I stood behind a hawthorn tree for 20 minutes or so with my back to the rain watching it sweeping across the land to my south.  Great drops of wet stuff fell on me from the tree, I tried shielding the Trimble which was already switched on and logged in to a number of satellites, whilst also shielding my camera which was dangling around my neck.  I should have been more patient and remained in my car for another 30 minutes until the grey rain cloud had definitely passed.  But here I was, getting soggy and cold standing behind a hawthorn tree.  I related this story to a friend later in the evening; they replied that it was a wonder I wasn’t arrested, which brought a smile to face.

The rain eventually stopped and brought glimmers of sunshine, with the late afternoon colour to be savoured after such wet conditions which consisted of silvered grey dullness.  I quickly left the confines of my hawthorn tree as the last few drops of rain skirted the upper part of the hill. 

Bryn y Fan

The high point of the golf course was just behind me and I was soon on top of it looking out toward the high point of the grazing field on the opposite side of the intervening barb wired fence.  This part of the golf course was artificially raised and my eye agreed with what LIDAR also gives; that the natural ground in the grazing field is higher.  I was soon over the fence taking photographs as the low light gave wonderful colour.

Soon the Trimble was placed on what I judged the highest part of this hill and as it quietly beeped away collecting its individual datum points I looked out toward Bryn y Fan, which was now bathed in delicate colour. 

Gathering data at the summit of Pen Rallt

Once the allotted five minutes of summit data were gathered and stored, I closed the equipment down, packed it away and sauntered back over the fence and wandered down the golf course to my awaiting car.  I now wanted to call at the farm which is just below the Club House.

I met Janet Breeze at the farm, her husband; Graham was out lambing.  Janet told me that the whole hill including the golf course and the high grazing field where I had just gathered data from was a part of Pen Rallt land and it is known by that name. 

Janet Breeze of Penrallt farm

I thanked Janet for her time and drove the short distance down the access road to the Golf Club and back in to Llanidloes to find a quiet spot to change before visiting Eryl and Rita, followed by another excellent dinner party with much merriment and raucous laughter at Suzanne’s.  I was home by just before midnight; it had proved a wonderful day with three walks and four hills visited, with one marginal hill confirmed as a P30, local farmers met, names of hills confirmed, friends visited and excellent food, conversation and company had. 

 

Survey Result: 

 

Pen Rallt (significant name change)

Summit Height:  301.9m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SN 95168 85960 (Trimble GeoXH 6000)

Bwlch Height:  223.9m (LIDAR)

Bwlch Grid Reference:  SN 94689 85959 (LIDAR)

Drop:  78.0m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Dominance:  25.84% (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

 

For further details please consult the Trimble Survey Spreadsheet