Berwyn Viaduct Progress - part five (16/03/2002)

Civil Engineer, Steve Jones writes ...

trackwork   trackwork

Above: Trackwork being reinstated at the West end of the viaduct on Monday 11th March.

By last weekend the track had been reinstated across the full length of the structure, the line was connected back up at the West end by Monday night, and a ballast drop was made on Wednesday. All works within the trackbed are now complete, apart from final alignment and tamping of the track.

overview

Above: Track reinstated over the viaduct using bullhead rail on timber sleepers.

Conventional scaffolding has been erected under arches 3, 4, and 5, with support over the stream being afforded by the use of long span trussed girder scaffold beams carried by scaffold towers.

scaffolding   Scaffolding Contractors

Above: Scaffolding in place over arches 3 to 5

The platform support steelwork columns are all installed, and the cantilever brackets will be installed this week. Precast concrete planks for the platform are being made this week, and will start arriving on site next week. The South side parapet has been trimmed to a slope to form the West end of the new platform.

platform   platform

Above: The ramp at the end of the extended platform. The platform reaches almost right across the viaduct.

Stitching and pointing works on the arches is progressing well. Anchor installation is now virtually complete on the South elevation, with work progressing on the North elevation. Rebuilding of damaged arch brickwork is also progressing. On the South elevation this is chiefly restricted to areas at the arch springing points, where past frost damage has been worst. On the North elevation the entire faces of arches 1 and 2, and most of arch 6, have had to be completely stripped away and reconstructed for a transverse width of up to two feet due to the combined past effects of frost damage and severe tree root growth.

Radial ties are now being installed in similar locations, and localised pointing of arch barrels, especially at the arch edges, is taking place as soon as stitching is completed. Most of the South elevation arch faces have now been repaired, and all areas of arch brickwork rebuilding have been completed. Work is now therefore moving to the North elevation.

The whole of the South elevation is having to be repointed, whilst localised patch repairs have only been necessary on the North (river) side so far. This side has apparently been fully repointed in hard mortar at some time in its life.

Work has also commenced on repairing the soffits (undersides) of the arches, and external repointing has reached an advanced stage on the South elevation.

arch 2   arch 3

Above: Repairs to the North faces of arches 2 and 3.

As regards parapet stonework, thankfully it has not been necessary so far to have to rebuild any bulged or tilted areas; however there are some locations at the west end of the South elevation where the rubble filled core of the parapet wall has now had to be pressure grouted and stitched to prevent its outer skin from peeling away and eventually falling out onto the road beneath. It is anticipated that there may be other similar areas to these on the North elevation on arches 3, 4, and 5.

The S&T location cabinet at the West end of Berwyn Station platform has now been moved to a new location on the rear face of the Gents toilet. This will now enable the west end of the existing platform and railing panel to be demolished to facilitate construction of the new platform extension decking, and the interface of levels between the existing and new platforms.

Finally, the Contractor is set to clear the Gents toilet of his remaining stored materials and equipment so that Berwyn Station will be available for public use again when train running commences on Saturday 23rd March.

platform supports

Above: The reinstated track levelled but awaiting final tamping.

Once trains recommence, they will operate over the viaduct under a temporary speed restriction (TSR) of 10mph, and lookout protection will be present at all times when the Contractor is at work on the structure, especially adjacent to the track.

Photos by John Joyce and Eric Keen

Copied over from JJ Website 12th October 2007 by John Rutter webmaster@llangollen-railway.co.uk

Berwyn Viaduct Progress - part six (07/05/2002)

Apologies for the lack of updates recently. Much of the work has been a continuation of that already documented here; for example, rebuilding arch faces, re-pointing, and tie installation. However the platform extension is now progressing well.

train

Above: A significantly changed scene at Berwyn as 7754 heads away with the 13:00 train on 23rd April 2002. The platform structure is installed, but requires surfacing and fitting out with items such as railings. The hardwood handrails are also fitted. (Eric Keen)

ballast train   ballasting

Above: 25313 and 13265 provided the power for ballast trains over the viaduct. (Pete Sheridan)

The platform is largely composed of pre-cast concrete beams which were transported to site by road. They were then offloaded onto one of the Railway's flat deck wagons for the short journey to the viaduct itself, where a rail-mounted crane lifted them into position.

unloading   craning into
place

Above: Assembling the platform from the precast concrete beams. (Eric Keen)

lowering into
position   Scaffolding Contractors

Above: A beam is lowered into position, it being lifted using inserts cast into it during manufacture. Any final adjustments can then be made. (Eric Keen)

 Copied over from JJ Website 12th October 2007 by John Rutter - webmaster@llangollen-railway.co.uk