Summer news roundup.

The latest edition of The Cornishman is again without a Civil Engineering article, mainly because nothing significant has been done since the viaduct ends were completed in February 19. The aqueduct was replaced last November/December, so I thought that it was time for a blog update on what is going on. You will have seen that colleagues from Lineside Clearance and Lineside Drainage have done articles in addition to their usual weekly blogs. As well as those two activities, Civil Engineering covers many linked fields, including embankment and cutting slippages, river embankment scour (current problem with River Isbourne near Winchcombe), lineside fencing to keep out livestock and graffiti/vandals, and bridges, of course, as well.

Much of the above is done by volunteers and some excellent work is being done every week; our drainage team have brought the condition of the lineside drains and about 60 underline culverts to a standard that Network Rail would be desperate to achieve. The vegetation clearance teams have also done a tremendous job, opening up vast areas of trackside views to our passengers and enabling any signs of embankment slippage to be spotted sooner. On the structures side, Alastair Watson continues doing the annual visual examination of all of our bridges and culverts, whenever he has time spare from his drainage team activities! These are now going straight into the new Office 365 system (see final paragraph below).

On the structures side, things have been difficult with the serious situation at Br. 08 – the B4632 road at Stanton. Plans to spend a lot of money on major repairs, this summer, were shelved when the result of detailed examinations received last November revealed that the condition of this bridge is much worse than we anticipated. An immediate follow up structural assessment was therefore carried out, resulting, in late December, in the need to impose a 3T weight limit, which is still in place. Work is in hand to obtain quotations for the design of a new bridge deck, and once that work has been done then tenders will be sought from contractors to do the replacement works. All of this takes several months but we hope that a start in late 2020 will be possible. Obviously, this will also depend on how much money we have available, and it will need a substantial amount!

Missing brickwork on Stanway viaduct.

Then we had the lesser problem of 30 courses of brickwork (about 60 bricks) falling off the corner of one of the piers to Stanway viaduct, in early May 19. This was spotted by the owners of the field where horses were kept – fortunately they were not hit. A detailed examination was carried out last November (a 224 - page report was received on 27.2.19), and this revealed many defects across the entire 15 arch structure, but did not indicate that any urgent repairs were required. Most of these defects are relatively minor but there are some that will need work, spread over the next two or 3 years. Following the incident, a scheme was hastily put together to get budget prices to repair 8 piers. The examination reports have since been examined in more detail and tender documents are now being prepared to repair two full and one-part pier and two arch barrels.

Most of the worst defects are linked to defects in the drainage system and so some drainage pit investigation and clearance work of that system will also be included. It is hoped that this work will start in October.

A435 Evesham Road bridge at CRC

Examination of the A435 bridge at Cheltenham

Whilst all of this has been going on in the background, we are pressing on with our detailed examination programme, which is always done by external consultants on a 6-yearly rolling programme basis. 



A you may recall we examined Br. 24 (Greet tunnel), Br. 43 (A435 Evesham Road) and Br. 44 (Hunting Butts tunnel) back in February, and fortunately there was nothing serious to worry us with those 3. These were reported in my blog report in February 19. 

We will have completed a total of 18 by the end of the year.


 

This year, as we continue to align ourselves with Network Rail standards, we have now included our two retaining walls in the Toddington North headshunt, and 6 culverts (over 450mm diam). The latter include requirements for working in confined spaces and one (C.45A, near our extreme southern boundary) requires CCTV cameras designed to travel in water between 300 and 400mm deep. The work will be done in two stages with the two walls, one bridge (Br. 45 – Swindon Lane), the south portal of Hunting Butts tunnel and 3 culverts, being done in early September. 

Hunting Butts tunnel mouth, south end.

 

Almost all of this work is south of Hunting Butts tunnel and despite massive vegetation and tree clearance done in the spring, our lineside and drainage teams have had to do further clearance to enable access to be obtained to these remote areas. Great cooperation between the departments. 

Stage 3 comprising 4 culverts (3B, 4A, 5C, and 6B), at the north end of the line and Br’s 28 (Stanley Pontlarge), 40 (Two Hedges Road), 41 (infilled accommodation bridge), & 42 (Southam Lane) will be done in November when no trains are running.

 

Greet tunnel inspection, north end.

As I have mentioned before, the examination reports are used to determine what repair works are needed. They then have to be considered against other needs, and finally a short list of priorities can be established. From this list budget costs for those selected then have to be obtained in time for the annual budgeting process in November/December.

2019 will go down as a year of few actual repair works, but hopefully we will make a good start on the viaduct and will identify the problems with the drainage system. A larger scheme to re-waterproof the deck and get the drains work properly will follow.

One final activity has been the transfer of virtually every one of the approximately 500 bridge and culvert report files onto the GWSR Office 365 system. This has involved many weeks of work for myself and my ex Network Rail colleague John Fancote. It now just needs a bit of tidying up, but it has been a major achievement. I can now stop printing out hundreds of pages every year!

24.8.2019 - JOHN BALDERSTONE