Sir, The two feature articles on the Aberfan disaster in Geoscientist 26.9 October 2016 have rekindled strong memories of a defining period in my early career as a geologist.
By mid-1967, I was in post with the South Wales Geological Services, a unit formerly concerned with coal production but now rapidly expanding, taking on staff to cover tip site survey - the upgrades to the Mines and Quarries Acts were looming. Before this there had been no geological input at all into tip site selection and management. The expanded unit included four “old hands” to continue the coal production work, three new boys such as myself and a geologist acquired from the Opencast Executive to work on the tip site surveys. Only the latter had any experience of the shallow geology of the coalfield. We were fully supported by clerical and drafting staff.
The NCB has quite rightly been pilloried many times over because of the Aberfan disaster, but the purpose of this letter is to try and show that at least at grassroots level its specialist staff made great efforts to redress this shocking situation. The upcoming Acts meant that tens if not hundreds of sites both large and small needed a careful survey and report. We did our best, our efforts often not being appreciated by senior management who for one thing did not accept that geologists should express an opinion. We were firstly directed to inspect those tips threatening lives and property, and those whose collapse might interfere with the NCB’s prime activity. Other sites, future, current and disused came later. We were learners at this stage and we made use of all available methods, some of which must seem very basic today:
- Surface mapping of solid outcrop and superficial deposits.
- Feature mapping (absolutely vital).
- Basic hydrogeology based on understanding lithology and structures, augmented by borehole data and piezometer readings.
- Core logging (and the liaison with drillers and consultants).
- Detailed desk studies of old surface maps and underground plans
- Air photo interpretation.
- Liaison with colliery survey and tip site staff.
- Logging of any nearby shallow drifts of roadways.
After field work and data collection we were then required to prepare a site map and report, identifying any features of significance or concern. However, we were not permitted to refer to any of these as “problems” or “threats” as we were not senior engineering staff and thus were not in a position to come to valid conclusions!
Working with colliery staff in the office or up on the mountain top was always a pleasure. Information was given freely, usually with a cup of tea, and no end of useful tips picked up. These people did more to help clear up the mess (on all scales) than is given credit for.
Field work on the tip sites led to many a long and physical day, often in all weathers, and not without its hazards in terms of deep bogs and exposure. In many ways it was the ultimate in fieldwork-based geology, and one that shaped me for the future (but perhaps it would not suit everybody today).
The NCB workforce, and the lower echelons of management I believe can in no way be blamed for the disaster. There was no background training for any event of this type or scale, even though the warning signs were there, and today would be obvious. Everybody I met was keen to learn and make sure nothing similar ever happened again. Of the higher management, I don’t feel so kind, having experienced pomposity, narrow mindedness and jealousy of status. I suppose this was compounded by an alarming amount of ignorance. It is good to think that management practice is in a different world today.
In the Geoscientist’s two features there is no mention of the effect of superficial deposits on the hydrogeology, particularly the cloak of impermeable boulder clay that covered the flanks of most valleys to varying heights. This boulder clay we found to be of concern as it could displace a spring line up the hill from its position suggested by the solid geology. I believe this was a factor in the Aberfan slip.
Also worthy of mention there was an even closer template for the Aberfan slide than that of Tip 4 in 1944, occurring a year or two earlier across Mynydd Merthyr close to Penrhiwceiber in the Cynon Valley. This tip was a large linear tip that was built up across the slope to the south. In 1941 or 1942, it gave way and ran as a slurry slide down the hillside, crossing the A4059 Abercynon road near the valley floor, continuing westwards to block the railway and fill the old canal. But like Tip 4, no one was hurt, and in the darkest days of World War 2, it must have seemed an inconvenient but largely insignificant event. People’s minds were focused elsewhere.
Dr Andy Lane