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!
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. |
| Missing brickwork on Stanway viaduct. |
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 |
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.
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| 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.
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| 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
