Tuesday, 27 October 2020

Tell me about ditches

Week Ending 24 October 

This week started off with a report from Permanent Way to say that there has been water running down the embankment slope south of Bishops Cleeve for about 2 years. This hadn't been been picked up because it wasn't adjacent to a culvert and the current inspection regime doesn't include ditches and areas away from culverts. On Monday Dave and Nigel headed south to investigate, they took some fencing materials to repair the fence next to the Pecked Lane foot crossing as they went past. It's called multi-tasking 😉 

Report from Dave... 

New rails on the crossing approach fence 



Pecked Lane foot crossing 

The water run off down the slope was to the south of Two Hedges Road bridge, the slope is covered in thick vegetation so the only evidence of the water is in the cess. There's a cess drain along here, but the crest ditch is supposed to intercept any flow. It's likely now that the cess drain permeable layer has been blocked with fines. 

Water running down the down side slope 

Silt washed out into the ballast shoulder 

Next job was to find out where the water was coming from, that meant scouting out the crest, where they found a 90⁰ bend that picks up the flow from a pipe and sends it along the crest ditch. The ditch at the end of the pipe had silted up and caused the flow to run back along under the pipe until it found a way to escape down the slope. 

Stream divert into the crest ditch 

Piped flow from the stream 

Mystery cavity under the piped flow 

More investigation is needed here to see what the mystery cavity is. The gang dug the end of the pipe out and cleared the ditch to reduce the flow down the slope. This is a historical problem, there's no record of how long the plastic pipe has been in the crest, but there was some work carried out here in January 2016. This was to remove a blocked 6" plastic pipe that had been buried in the base of the slope and run to a cess drain.  

Pipe still in the crest ditch in 2016 

Andy P surveying the blocked plastic pipe removed in 2016 

Alastair and Kieth opening the cess
to clear the flow from the crest in 2016 

After the pipe and crest ditch had been partially cleared,the flow diminished into the cess 

A bit dryer in the cess (back to the present)
A bit of digging required in the cess next 

Before setting off back, the turnaround area down towards Kayte Lane was cleared, this saves anyone getting stuck or having a long reverse back to the entry point. 

Cleeve south up side tuning point 



On Thursday, Andrew and Martin had a pallet collection run for the Steam Loco Department, this should be the last of these jaunts for a good while. After dropping the load at Toddington they headed up to Broadway to call in at the station cafe for a break, the cafe is open on Thursdays even though there aren't any trains running. 

Report from Andrew... 

Culvert 2A down side concrete headwall 

Broadway footbridge across the end of Culvert 2A 

The next adventure was to head north under Springfield Lane and up to the culvert at Smallbrook Farm. This is the old trackbed that doesn't belong to the GWSR, but the station drains run along to empty at the culvert, hence the need to check it each year. 

Smallbrook Farm Culvert down side 

Smallbrook Farm Culvert up side 
Nasty crack in the headwall 
Good flow in the cess drain north of the A44 

A couple of the chambers need to be sorted out 
dropped ring and lids here 

Lids need retrieving in this one 

Martin in the search for a chamber 

Something (or somebody) is creeping in under the
palisade gate at the end of track at Broadway 

While out and about candidates for the milepost replacement programme get noted and added to the list...

Milepost 4¾ in need of attention 


The numerals used on the extension markers
aren't GWR pattern, they don't look right - Milepost 5¼ 



Sadly the Friday gang were overtaken by other events, not railway related, and were unable to attend. The saga of Bridge 29 down side coping recreation will have to wait for another week. 




2 comments:

  1. Hi Stuart. The 90 degree plastic bend has history. One of the first jobs to be tackled by the fledgling drainage gang. The 'bend' was ordered by the late Ron Brislin as a special, but what he hadn't specified was that one end needed to fit a 24" concrete pipe and the other a 600mm plastic pipe. What we received was a bend to fit 600mm at both ends so it is not a watertight fit around the concrete pipe. It was on the works schedule for summer 2018 when the stream had run dry.....it does occasionally! A new bend was to be ordered along with 5 x 6mt lengths of twinwall pipe. The ditch was to be excavated for 40 mt along the crest, lined with a waterproof membrane and the twinwall inserted.
    The cavity was thought to have been a result of the force of water that escapes the bend during heavy periods of rainfall.
    Hope this helps. Andy P.

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    1. Thanks Andy, I wasn't sure how long it had been in, it looks like we're going to have to do something with it, but with cash and effort in short supply just now it's going to be a temporary fix
      Thanks, Stu

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