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Saturday, 20 November 2021

Climate change October

With the UN COP26 Climate Change Conference in Glasgow commencing at the end of October, the subject of climate change is very topical.

For us on the drainage team the warmer autumns have two main effects. Firstly, the higher daytime temperatures mean that we soon warm up when working. Not quite the tee shirt and shorts (plus PPE) of the summer, but certainly no need for the several layers of woolies to keep the cold out. Mind you, when pausing for a breather or a coffee break, you soon cool down, particularly if there is a bit of a breeze blowing.

The second effect is delay to the start of the main leaf fall season. Consequently we do not have to commence the regular checking of the drain grills and covers which we know are prone to leaf blockage until later in the year. The downside is when the first frosts do come, or we get a heavy gale, then the quantity of leaves and twigs can be greater.

Tuesday 5th October

First job today for the five team members present was to extract our mains powered kit in order for it to be PAT tested. Not helped by the fact that some of the kit was required for use at Royal Oak - so had to be brought back for testing.

The main items we needed at Royal Oak were the pump and extension cable. The hole we had excavated last week for the concrete base of the culvert 24B haul road inlet headwall was full of water from the previous night's heavy rain. After pumping and bailing out the water, and stopping most leaks from the temporary bypass pipe, three of the team poured the concrete for the base. Concrete goes up to 25mm below the base of the pipe under the road. This took 5 bags of cement and around 1 cubic metre of aggregate - plus quite a bit of labour!

Dave bailing out the culvert 24B concrete base excavation whilst waiting for the pump to arrive after being PAT tested.
End of day, concrete base poured and temporary pipes back in place. Read now for brick and block laying.

The other two team members undertook checks of the culverts at Gotherington loop; 35A 35B 35C and 35D. No evidence of culvert failure or blockages reported; all 'high tide' marks from the recent heavy rain were under half way up observed pipes. The reason for this check was to rule out culvert problems as the root cause of a minor track defect on the main line through the loop. However we did note that access to culverts 35A and 35B does need clearing - so these are at the top of the list for this activity.

What we like to see when inspecting a culvert, water flowing well, no very high tide marks and no sign of blockages. This is up side (or Malvern side or outflow side) of culvert 35C at Gotherington.

Tuesday 12th October

All six of the team working this Tuesday, so we split into two groups. Added a bit of changing around at lunchtime for variety.

One group progressed the construction of culvert 24B haul road inlet headwall. All the concrete blocks and the first course of bricks were laid. No use of bailing today, the pumps were in place right from the beginning and ran all day.

Brushing away the last drop of water to the pump before building work commences.

The first two layers of concrete blocks in place. Water seepage evident, but not a wellie job yet!

The second group undertook vegetation Cutting and structure inspecting. They cleared vegetation from the track down to culvert 24C down side, all around the headwall and back to boundary fence. On up side they cleared the area around the outlet. This enabled the internal visual examination to take place, the report of which goes the the railway's bridge engineer and structures manager.

Culvert 24C down side (inlet) headwall. Requires some repointing work.

Looking inside culvert 24C from the down side. This is a long culvert as it runs diagonally under the Gretton embankment.

A second visual examination of culvert 25A, the one which runs under Working Lane bridge was completed. For a change this did not involve any clearance! After lunch the rearranged group started clearing the culvert 25B exit ditch on the up side, working back from the new headwall on the 25A/25B junction. There was a lot of growth in the two plus years since this was last undertaken, but the heavy weight brush cutters coped with it. The group reached as far back as where the ditch comes under the boundary fence. Further on the ditch is back on the railway land, clearance of this will be a task for a future week.

Clearance team almost lost in the growth of the up side ditch from 25B back to 25A.
 
Vegetation fights back! Photo by Dave.

Same spot as photo above, an hour later. We can now see where the ditch is. Photo by Dave.

Also in the afternoon we met with a prospective new team member. More on that next month.

Thursday 14th October

The first working day for the joint Estates Management (Drainage) and Permanent Way milepost replacement project team. One member from each department today.

Photographic surveying of the existing mileposts progressed by checking all between Didbrook (mp 10) and Greet Tunnel north portal (mp 12 & quarter). Mile post 12 and half does not exist, it would be half way through Greet tunnel, so there is just a white mark on the tunnel wall.

Mp 10 at Didbrook requires major restoration. Half the head is missing and the post leans at a funny angle.
 
In contrast most of the posts between Didbrook and Winchcombe are in good condition, these were refurbished a few years ago. This one will only need the post, former GW broad gauge bridge rail, painted.

One that the public can closely inspect, it is on platform two at Winchcombe. In good condition, apart from missing a metal cap to the head. Without this the wooden head will rot quicker.

The first post the project will replace is 7 and quarter near the foot crossing at Stanton Fields. The numbers and marks for this received a first coat of primer.

For mp 7 & quarter we have original GWR cast iron numbers and quarter marks, and one horizontal divider. The other divider is a replica lead casting of the same thickness.

Traditionally, the GWR used lengths of former broad gauge bridge rail as posts for mileposts. These had 4 feet above ground and about 2 feet below ground. The GWR also used bridge rail for fence posts, and we have several lengths of this in various locations around the railway. Today three lengths were extracted from Winchcombe yard. Using the PW rail saw these were cut to six foot lengths, the short corroded bits which had been below ground went to the scrap bin. Four more lengths require extracting, but that will be more than a two man lift.

Three six foot lengths of bridge rail ready for de-rusting and painting.

Tuesday 19th October

Attendance reduced as one team member away on holiday and one on Jury service. So only 4 of us in today.

The morning was spent at culvert 24B up side new inlet headwall under the haul road. Six courses of brick were added to the brick face and in-filled with concrete in the hollows in the blocks and behind the blocks. Using two cement mixers, one for mortar and one for concrete was a big benefit.

Polly progressing the brick laying - water level on the base only just below boot level!

Dave was in charge of mixed number 2 for concrete production.

When rain stopped work at lunchtime this was the state of the construction. Cover sheeting about to go on.

As the weather looked like it would get very wet in the afternoon, plans to brush cut more of the culvert 25B outlet ditch were abandoned. Instead the milepost replacement project was advanced, by fettling the steel bars for the horizontal dividers and quarter marks, painting the numbers and marks for 7 & quarter and cleaning up the cut lengths of bridge rail.

Tuesday 26th October

Again a reduced number of the team were available today. The main task was progressing the build of the culvert 24B up side haul road inlet headwall at Working Lane/Royal Oak. Fortunately with the lack of rain, continually pumping out the base was not needed. Six brick courses laid today, including a lintel formed from an old concrete fence post. Plus the concrete back fill behind the blocks was completed.

Nigel mixing mortar and Polly laying the bricks.
24B up side haul road inlet at the end of day, just the coping layers to go.

Access on the down (Cotswold) side to culverts 24A and 24B was brush cut. This enabled the visual exams for these two to be completed.

Nigel (l) and Dave clearing around the down side of culvert 24A, Royal Oak pub in background.

Finally the monthly clearance of the grill on the outlet pipe of culvert 24C up side where it exits under the fence to our neighbours property. This has a grill which often collects twigs and other debris. Again lack of rain in the past week meant the level here was minimal.

Today was the last day the team will see passenger trains south of Winchcombe until the spring. 4270 passes with an up service.

Wednesday 27th October

An interesting day for the blog writer acting as PTS cover for the Brunel University team who were monitoring the vibrations of Stanway viaduct. Readings were taken with all the passing trains (4 steam with 4270, and 6 DMU) on the centre span, with sensors by the sleeper end and by the parapet wall. Also between trains readings of the background vibrations were taken on all 15 spans of the viaduct. It will be interesting to see the results. 

Dr Tomor of Brunel University setting up the vibration monitoring equipment on the up side of Stanway viaduct. The blue box is the sensor for the parapet wall, a second unit was placed by the sleeper end. Readings were taken for all trains of the day - first 10:23 DMU to Broadway, last 17:06 DMU arrival from Broadway. Good job it was a dry day!

 
The instruments are very sensitive, here is a plot from the test where we jumped up and down on the middle span.

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