Harlaw wall repair

Firstly, apologies for my tardiness in posting this, almost two weeks after the event. This is what happens if I don't post stuff straight away ... 

So, on the second of this month we went to Harlaw in the Pentllands to repair a section of wall which had come down, and had resulted in the cattle in the field escaping. And for once, I have 'before' pictures - not because I remembered on the day, but because I'd been to the site a couple of days before hand to check out how much work there was, and to deliver some extra stone. It was a glorious day (I'd've happily stayed up there and climbed a few hills, if I'd had the time) but the wall had almost totally collapsed, and the park rangers had had to pile up the stones as a temporary repair to fill the gap below the barbed wire to keep the cattle in.

Sadly, it wasn't nearly such a nice day when we came to do the work, but at least it was dry and there was a breeze which kept the insects at bay.
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The first thing we needed to do was move the barbed wire - fortunately an easy enough job as the fence posts weren't in very deep - and then strip the wall back to the foundations. This wasn't too difficult as the wall, unsurprising, came down very easily: in fact, a bit too easily, and what had started as a three metre gap soon became more like five or six metres as the defects in the initial build and subsequent repairs made their inadequacies felt.

In fact, this was almost a master class in how not to build and maintain a dry stone wall. The stones had been 'traced' (that is, they had been placed with their length running along the wall, rather than in to it), plus the section we were working on had no throughs (stones reaching right through the thickness of the wall, binding the two sides together) - and where there was a through a bit further along, there were running joints up both sides of it, greatly limiting its effectiveness. Add to this the fact that when we got down to the foundation stones we found some of them to be sloping out of the wall and it wasn't surprising that the wall had started to 'spread', i.e. the sides had started to move apart at the bottom. This still might not have caused a collapse if the wall had been left dry (and therefore flexible, with gravity holding everything together despite the movement), but an earlier attempt at repair had seen the copes mortared into place. And while this might have been very effective at the time, a few years down the line the spreading had caused the stones below the cope to move down so that they were no longer held in place, and so had started to fall out: from there, it was just a matter of time before it all came down.

​Our section was by no means the only place this problem had evinced itself: just a couple of metres past the running-joint-through a large hole has appeared on one side of the wall, and this section will come down soon as well unless it's fixed - and indeed, there were plenty of other places where the same problems are starting to show.

All the above, obviously, is why we were here, and so we set about putting it back up correctly. This is where we'd got to by lunch time - note the big stones set with their length running in to the wall (so not traced!).

 And by mid-afternoon we were up to 'through' level (you can just see a through on the wall just behind Alan - fortunately we had a few long stones which would do the job).

As the afternoon wore on, it became clear that we wouldn't have quite enough stone to finish the job: this was my bad, as the duty ranger had dropped by earlier and asked if we needed more stone, and I'd reckoned we'd be all right (to be fair to myself, we weren't far short). We did as much as we could, and managed to get most of the gap up to cope height.

We then coped the whole wall, including the unfinished bit - this last just temporarily (it doesn't look too bad from this side). Note also the running joint still evident next to the through in the bit of the wall just to the left of where we were working - we would really have liked to fix this as well, but there's a limit to what we can do in one day.

After that it was just a matter of re-instating the barbed wire, and the finished wall looks a lot better than it did.

Though maybe best not to mention the 'unfinished' bit (this is how it looks from the other side).

Hopefully it will stay up until we can get back up there to finish it off properly (and fix that other big hole while we're up there, before that bit comes down too).