Mapping Mountains – Trimble Surveys – Pumlumon

 

04.03.22  Pen y Banc (SN 939 845)

Pen y Banc (SN 939 845)

Prior to visiting this hill I had analysed its numerical and positioning data via LIDAR.  I had also examined approaching the hill from the comfort of sitting in front of my laptop screen, by driving a Google car up the paved road leading to Pen y Banc farm.  Online logs give the summit of the hill positioned behind the farm house beside a small water tank.  The ten figure grid reference for the summit produced by LIDAR analysis matched those from hand-held GPS units given online. 

LIDAR image of Pen y Banc (SN 939 845)

This hill was one of the few that I had not visited close to Llanidloes, this was probably due to the summit being so close to the farm house.  However, I also wanted to make place name enquiries as although the farm is named Pen y Banc, contemporary Ordnance Survey maps imply this is also the name of the hill.

Earlier in the day I had visited Drum Ddu (SN 971 604) and Pen Llys (SN 998 584) and although the weather forecast was for intermittent sunshine, with generally dry conditions and an occasion rogue shower materialising, the sky was now looking ominous with heavy showers cropping up across the land.

I drove toward Llanidloes and turned left off the A470 road on to the B4518 road as it heads in to the town.  Across the valley Pen y Banc stared back as a bulk of a hill partly forested on its southern side.  I drove through the town and turned left over the river and continued on the minor road now heading north-westward, only leaving this road when the wide entrance to the paved road leading up to Pen y Banc farm came in to view.

I pulled up in the farmyard near to where another vehicle was parked close to the front door of the farm; this implied that someone was in.  Gathering all necessary equipment I locked my car and walked down the steps leading toward the door and gave it a good knock.  With the vehicle outside I expected the local farmer to emerge at any minute, but there was no reply.  I gave the door another good knock and then shouted ‘hello’ just in case the farmer was in the near barn, again there was no reply.

Leaving the house I walked past my car toward the outbuildings, on my way shouting out ‘hello’, again there was no reply.  As the summit was only a minute or so walk from the farm house I followed a track up toward a conifer plantation and a bricked water tank which has a larger green structure close to it.  As I was now at the summit I decided to see if I could gather data with the Trimble.

The positioning of the Trimble beside the water tank and conifer plantation meant that in all likelihood data would be compromised, this was evidenced when the Trimble was activated and then screeched a number of times, an indicator that either satellites were dropping out or that the 0.1m accuracy level was not being attained.  However, I persisted and gathered the minimum two minutes of data advised by Trimble.  This would at least give comparison between Trimble data and that produced by LIDAR. 

The Trimble set-up position at the summit of Pen y Banc

As I took photographs of the Trimble set-up position at the summit I heard the distinctive sound of an approaching tractor.  I packed the equipment away and headed back down the track as it emerged in to the farm yard.  I waved across to it and spent the next five minutes or so chatting with Jonathan Grewe; the son-in-law of the local farmer.  Having explained my interest in the hill and its name he asked me to wait for him to park the tractor and for me to follow him back down the road to where their cabins were situated, this was where his father-in-law was and he should be able to help me.  Jonathan disappeared around the corner to park the tractor and get in to his car, at this moment a quad bike and trailer appeared and drove in to the near barn, I waved across toward it.  By the time I had got my key out of my rucksack and turned to unlock my car, the person driving the quad bike was beside me asking who I was and what I wanted.  I asked if he was the local farmer, he said ‘no’, Jonathan and his wife; Kate later told me he was.  I mentioned that I had talked with one of his colleagues who had just driven around the back of the outbuildings in a tractor; he said ‘no he hadn’t’.  By now I realised that whatever I said would not be sufficient for him to engage in polite conversation.  He then asked quite sternly ‘what do you want’, I explained that I was interested in the name of the hill, he said ‘now you’re mouthering me’ and disappeared in to the house, as he did so I thanked him for his time and got in my car to wait for Jonathan who soon appeared and I followed him down to the cabins where his wife; Kate joined us.  I explained who I had just met and they both apologised for his rudeness, I said it was no bother as Kate’s father was confronted by someone who he did not know and who was standing in his farm yard. 

Jonathan and Katie Grew

We chatted for a number of minutes with Kate taking my telephone number and email address promising she would ask her father what name he knew the hill by.  As I thanked them for their time rain started to fall, this was the start of what proved to be a heavy downpour that lasted for an hour or so, it seemed the forecast for rogue occasion showers was optimistic.  I still had one more hill I wanted to visit, so waving my goodbyes to Jonathan and Kate I headed down the paved access road and on to the minor road back in to Llanidloes. 

 

Survey Result: 

 

Pen y Banc

Summit Height:  312.8m (LIDAR)

Summit Grid Reference:  SN 93927 84591 (LIDAR)

Bwlch Height:  273.1m (LIDAR)

Bwlch Grid Reference:  SN 93683 85143 (LIDAR)

Drop:  39.7m (LIDAR)

Dominance:  12.69% (LIDAR)

 

 

For further details please consult the Trimble Survey Spreadsheet