Civil Engineering Blog: October 2022

CIVIL ENGINEERING - UPDATE SINCE 28.02.2022.

Lifting in a plate under bridge 8.

Bridge 8 Stanton Road bridge on completion.

The problem with doing repairs to Bridges is that they generally need the track to be lifted!! That means that any significant work can only be done in the shutdown period – January & February. This is the worst time for any construction activity with cold and damp conditions, and poor/short hours of daylight. The cold/damp weather can also prevent brick and concrete laying and painting of steelwork, so sticking to an already tight programme can be very difficult and sometimes means that items which we would like to do have to be abandoned until “next time”!! This happened on Bridges 08 & 10, but the omissions are not obvious!!

Bridge 10 tie rod replacement.

Fortunately, with the considerable help of a team from C & M we did manage to get a few small tasks done in the spring. They did the following works: - (1) Applying timber preservative to the ballast retention boards on 6 Bridges. (2) Fitting 11 Bridge Identification plates to the parapet walls of 4 Underline Bridges and 4 overline bridges. (3) Fitting galvanised steel tubular railings to provide edge protection of steep drops at all 4 end corners of the viaduct.

Painting timber ballast boards - before.

Timber ballast boards painted - after.


Galvanised railings fitted to Stanway viaduct.

Welding base plates on bridge 12.

Bridge identification plate fitted at Stanton.

We do have a programme of Bridge and Culvert examinations to carry out, every year, and are fortunate to have qualified Volunteers to undertake the Visual Examinations of all 52 of our structures and about 60 of our Culverts. In addition, to meet the 6-year maximum interval required to comply with the Network Rail Standards to which we work, as required by ORR, we have a rolling programme to undertake the Detailed Examination of about 8 Bridges and 6 Culverts, each year. Specialist Examination Consultants do these.

During September this year they examined Bridges – 13, 14, 21, 21A (River Isbourne), 22, 25, 26, & 27. Also Culverts 24C, 25A, 27B, 32A, 31B, 33B, 38A & 39A. These Consultants also carried out the Visual Examination of our 3 larger structures – the viaduct and both tunnels, as these are too large for a Volunteer to do. The reports are awaited. I attach photos of some of these Examinations in progress, including Br. 21 (where a full road closure was required), and 26 (a half-road closure was required).

Bridge examinations:

Bridge 21 over the B4632 at Winchcombe, with Foremarke Hall.

Bridge 25 over Working Lane and a culvert on the left, with Dinmore Manor overhead on its way to Cheltenham.

Bridge 25 at Gotherington, with a half road closure.

Culvert examinations:

Silted up culvert headwall

Inadequate drainage way from same headwall, causing the silting up.

Culvert examination

Examination of the inlet cover at Bishops Cleeve, where the culvert takes a stream under the track. This is next to a foot crossing with frequent use.

Grateful thanks go to our Lineside drainage team for clearing the vegetation and escorting the Engineers to the culvert locations. Similarly to our Lineside Clearance team for clearing around the bridges so that the examiners can see the Bridges better and more safely.

Fortunately, with the assistance of Funding from the GWR Trust, we have also been able to undertake extensive repairs to three more piers on the Viaduct. This work started in September and is expected to take about 8 to 10 weeks. The work requires very extensive/expensive scaffolding (see two photos) to reach the heights necessary. As was the case last year when Pier 8 was repaired, this field can get very waterlogged. Consequently, the contractor has built a temporary access road using interlocking, very heavy-duty plastic matting (see photo). Sadly, as reported in the recent GWSR Newsletter, the contractor had 20 panels of Heras fencing stolen in the third week. They even took those around the entrance (see photo before the theft!!).

Contractor entrance to the viaduct site.

Frost damage to brickwork on Stanway viaduct.

Scaffolding to repair brickwork on Stanway viaduct.

Scaffolding (update) with final lift added.

Overview of Stanway viaduct, with full scaffolding to work on the spandrels.

Much of the summer has been taken up with designing repair works to Bridges 28 (Stanley Pontlarge - photo) and 32 (Prescott Road - photo).

Prescott Road bridge.

Rust damage on the Prescott road bridge.

The design, drawings, specification, and tender documents work were all done by Volunteer Engineers. Tenders are due back by the end of October. Both bridges will require a track lift as the deck is leaking, leading to corrosion of the steelwork.

Bridge 28 - note missing or collapsed fences

Badly cracked padstones on Bridge 32 need replacement

During the replacement of the padstones the bridge will need propping.

Br. 32 will require a full 7 to 8 week road closure as half of the padstone holding up the steelwork are cracked or in a poor condition (Photos). We hope to be able blast clean and paint the steelwork during the closure, but painting is not possible below 5 C.

Further works are in the early planning stage for the 2023/24 Programme.

Thanks for some of the photos, go to colleagues – John Fancote (Structures) and Andrew Laycock & Jonathan Taylor (Drainage team).

Prepared by John Balderstone - Structures Engineer GWSR. 19^th October 2022.