SEPTEMBER 2018

We recently received the following email :-

 

It was with great interest that I discovered your ‘ before’ and ‘after’ fact sheet about the construction of the A467 through Brynmawr between 1986 – 1988.

I was the Construction Project Manager employed by for Monk Construction Ltd and responsible for overseeing the whole project from Abertillery through to the Heads of the Valleys Roundabout at Brynmawr.

Your article brought back some vivid memories of the challenges facing my construction team at the time.

My recollection of the challenges my team resolved includes the following:-

Before earthworks could commence it was necessary to arrange for deposition locations for the earthworks surplus materials to be permanently placed. That required negotiation with landowners, discussion with local authorities and securing planning permission for the solutions. These locations included the rear of Dunlop Semtex (Now an Asda or housing); An area at Coalbrookvale discussed with Councillor Law for public amenity; An Area to the West of the new road at Blaina.

The project required a main office and section offices to house up to 50 staff and engineers for 3 years. We established our main offices at the Dunlop Semtex office building by converting the ground floor for the Resident Engineer for Gwent County Council and the top floor for Monk the contractor. We established a section office for the Southern end at Roseheyworth.

Before earthmoving could commence we needed to treat disused mineworkings and addits to make the ground stable below the new road. This was required: Between Barleyfield Way and Blaenavon Road (Here there had been older pit type workings) ; Between Nantyglo and Coalbrookvale. This involved drilling a boundary curtain wall and filling the seams with pea gravel and then drilling and cement grouting the contained footprint to fill seam voids. A number of disused shafts were also capped.

The new road was aligned right through the middle of the coal spoil tip from Roseheyworth Collliery. We investigated washing this colliery waste material to recover useable coal but in the end we set about moving the ¾ million cubic metres of spoil to the adjacent fill area which now supports an industrial estate. The project cut/fill earthworks were generally undertaken by teams of 30T excavators and articulated dump trucks. However, the Roseheyworth tip movement was short haul and large quantity so a team of 5No  twin engine motor scrapers was used to achieve the high output necessary.

It was necessary to import a significant quantity of granular fill material for the works. This was recovered from Silent Valley, Ebbw Vale and transported by road with a fleet of 30 road haulage trucks.

New structures included a number of overbridges; pedestrian underpasses; steel pedestrian overbridges; and numerous reinforced concrete retaining walls. I recall the retaining walls between Blaenavon Road and the HOV Roundabout to be particularly difficult due to constrained working; difficulties in keeping rock excavations dry for base construction; detailed sequencing and temporary works. We encountered a previously uncharted geological fault in this area when excavating our temporary works requiring a redesign of our plans and the geological records revised.

I recall that when we undertook the drainage and earthworks in the Nantyglo area, we discovered the various layers of previous generations of industrial history (copper; coal; rail etc).

It was necessary to carry out a range of temporary road diversions to enable new road cuttings and new overbridges.  These included Blaenavon Road (as shown in your photographs); Barleyfield Way; Nantyglo near the old comprehensive school; Coalbrookvale.

We renovated an existing brick arched culvert under the new junction at Blaina which still remains.

The repaving works to Brynmawr Town Centre involved a time-consuming detailed sequences of works to keep the town centre live while we undertook the significant area of new block paving.

Demolition works included the old cinema at Abertllery and the main old railway bridge over the existing road at Abertillery. A detailed sequence of traffic management was necessary for this and to construct the new road alignment.

 

Two of the new subways we constructed were lined with bespoke tiled murals. These depicted local history and the artist was pre-commissioned by Gwent County Council. The murals were produced in his studio away from site and then transported for insitu installation when the subways had been constructed.

 

I hope the above points assist in filling in a bit of recent local history.

 

Regards

Don Thomas    BSc CEng MICE