confined spaces

Jess Bryan (MOLA): Back to the Walbrook, sewer or later!

Today is a special Day of Archaeology version of our Walbrook blog; welcome to all those new Day of Archaeology faces and old Walbrook friends!

So we have fearlessly returned to the site! Like newborn foals, our pasty feeble arms and legs are coaxed into life after a few months of checking paperwork in the office. As we walk down onto site we realised a lot has changed… mainly the access. How the hell do we get down to the area now?

We had two main things to do today: look at the section underneath the retaining wall in what was our main area of excavation, and say hello to the crew who are going to be digging the sewer heading.

We headed down to our old area first. This took a lot longer than we think, not only because of the access issue noted before, but also because we couldn’t walk 10 meters without one of the McGee’s guys saying hello and asking how it is going. It’s nice to be loved! Although not everyone loves us, I am sure their were some steely eyes watching us from the contractors office, ready to pounce and mitigate in case we uttered the words ‘can I just take a look at that?’

Hi Mike!

McGee’s love our friendly Canadian (c) MOLA 2013

So for those of you that follow our blog about the excavation, you may remember we had two large open areas and a number of trenches, and in the largest area (20 sq m) we excavated a depth of about 8 m of archaeology. This ranged from Post-Medieval through to the earliest Roman inhabitants. Well after we had finished they cleared the area to a flat level (after all archaeologists never dig flat sites) and then built a large piling mat on top to enable the piling. For those of you who have ever wondered what one of those really tall machines are (that is not a crane) sticking out the top of site with what looks like a big screw attached, that’s a piling rig. And as we never do things by half on this site, we had the biggest one in Europe! It had to driven all the way over from Germany with its own German crew – this thing can drill some big holes!

Anyway I digress… so today was the day they had finished removing the piling mat, and had dug the ground level down below the natural clay at which we stopped digging. Basically we are here to check the ground to make sure that it was only London clay that could be seen, and no earlier archaeology had appeared, or we had left any timbers in the ground (not that we don’t have enough timber anyway). So, as all archaeologists do when they walk up to a big hole that has been dug by a machine, we all held our breath whilst we went round the corner… and were greeted by a wall of London Clay. Nothing had appeared below the level we had excavated. Occasionally it is possible that very early layers of alluvial material may cover evidence of prehistoric activity, but in this case there was none.

Putting the super in supervisor

Sadie checking out the work (c) MOLA 2013


This is how deep the site is now! See the abandoned orange mains breaker box on the 2nd row of steel? I remember just before Easter standing on the ground and plugging cables into that! (c) MOLA 2013

So with the main area checked out, and more re-acquaintances made, we navigated our way across site to the sewer heading that would be our home for the next two weeks. By this time the heat has really caught up with us (I tell you we are out of shape) and the water in coolers that had been placed around site by the principle contractor are much appreciated.

So the sewer heading: you never see TV archaeologists doing this (oh wait, Sadie you are a TV star…). Mike and myself had never encountered a sewer heading before and, after asking a few old hats in the office, had worked out that it is probably one of the more restricted environments you will find yourself in, not just for space but also for scope of recording any archaeology that comes up. Sadie did point out that they are fun, and that you get to crawl around in a new tunnel underground, which piqued our interests a bit more. Although within a few minutes of meeting the guys who were excavating the sewer heading I am not sure how much access we are going to get to it… they really were not convinced we had the correct confined spaces tickets to enter. It is good of them to challenge us, as after all the hole is their responsibility, but this really isn’t the kind of thing you try to blag your way into for a bit of a laugh. When we go down there we need a harness, breathing apparatus and a rescue plan, so although the idea of crawling underground may be fun, the reality is fairly dangerous should something happen. So we have got over the introductions and they realise we are serious; they let us have a look at what they had done… not a lot! It was going to take a while to break through the basement wall.

Who doesn't like a good sewer heading?

Start of the sewer heading (c) MOLA 2013

So maybe next week they may hit soil, and then we will be in the tunnel about 4m underneath one of London’s busiest roads, looking for more of the Pompeii of the north

But for the rest of the day it looks like it’s back to the office and more paperwork.