Tuesday 28 March 2023

Wet, Wet, Wet

You can always rely on the English weather! That is relying on the exact opposite of your wants. After one of the driest February’s, March has gone the other way, very wet. This has played havoc with our plan to progress the 11B to 11A upside outlet diversion at Stanton. We do not want to churn up our neighbour’s field by bringing in the digger on a trailer. Plus of course, it is very hard to work in excavations that are filled with water! At least work on the aqueduct repair is generally out of the water.

Thursday 16th March

Six of the team in action today. Two of the team attended to Stanton Aqueduct. Main activity was to plan the construction of the shuttering for the grout on the up side to restrain the new collar. The area under the trough cleaned out as much as possible including removal of the second old roller. The hole outside of the railway fence on the outlet was covered with a blue mesh cover; anchored into the ground. On the down (Cotswold) side we checked that all the slip marker posts were still upright and in line. We did notice several spots where water is seeping out of the cutting side. The likely source of this water is the land drains in the adjoining field; at one time these may have emptied into the cutting crest ditch. We checked both the up and down side cess drains. The up side is flowing south which eventually takes the water to culvert 11A. The down side cess is a deep concrete U channel which has got some ballast/gravel washed into it. This will need further investigation. The Senior Bridge Inspector met with us on site to discuss the method of filling the up side anchor space with grout and concrete.

Stuart clears out the narrow gap between the aqueduct trough and the concrete foundation. The anchor points for the new collar fit in this gap. [Photo by Dave.]

The other four members of the team attempted to progress the 11B to 11A up side diversion. However the existing outlet ditch was backing up from the boundary exit and its level only went down an inch after a couple of hours pumping with small electric pump. (The larger electric pump was with the C&W electrician for cable repairs, but subsequently was deemed to be beyond repair). Consequently squaring off the hole for the first new chamber and concreting it's base was abandoned, the water was still more than one wellie depth. So instead we moved bricks, blocks, gravel and one concrete ring to site in readiness for when the weather dries out. We also moved sufficient lengths of 225mm twinwall pipe to the line of the new bypass to confirm our marked location for the second new chamber.

This illustrates the reason for this work at Stanton. This is the down (Cotswold) side, standing water at the foot of the embankment and puddles in the adjoining field between bridge 11 and the farm accommodation crossing.

The existing 11B outlet ditch running to the small field drain by the hedge. In the foreground is the hole for the first of the new chambers. The bottleneck caused by this field drain is the root cause of the pooling water here.

Moving the lengths of pipe on the LWB Transit. Polly watches the load as Nigel backs the transit towards bridge 11. Lack of trains helps with this sort of operation.  

However, we did manage to complete one task from our ‘to do’ list; another spot of repointing/mortar fill on the inlet (down side) of 11A. This was one of the few items noted in last summer’s detailed external inspection report for this culvert.

Back at base, Polly, Martin and Nigel dug out the petrol pump and tested it on the yard puddles. Once suitably primed this works well. Should have taken it to site, rather than the small electric one.

Thursday 23rd March

Wet again!

Following a very heavy rain storm in the Winchcombe area on Wednesday evening / early Thursday morning we re-planned work for the day; once again avoiding use of the minidigger as taking it across the neighbours field at Stanton on the trailer could have made sone deep ruts. There were very deep puddles at the field gate.

With seven of the team in attendance, one group of three headed for Stanton Aqueduct to further progress the design and build of the shuttering for the up side foundation repair. Following a call with the Infrastructure Manager, the method was finally agreed. This is to use both Five Star grout and 40N concrete. Measurements were taken and the quantities estimated so the materials can be ordered. Using a mix of grout and concrete saves quite a few pounds - the grout is relatively expensive.

Following this the team of three installed the replacement bridge rail post for milepost 8¼ (near bottom of the high mileage slope from Stanton Yard). The old milepost was a battered BR style yellow metal head mounted on a round post – the worst example on the line, as noted by a recent post in the Heritage Herald blog.

The refurbished length of bridge rail for milepost 8¼. The blue marks on the ground either side were to ensure it is correctly half way between 8 and 8½. In the background is one of fine pear trees at Stanton. [Photo by Roger]
 

Our plant operative took the telehandler to Toddington Yard. The other three members followed along the railway, stopping at culvert 20C at the high mileage end of Chicken Curve. Following the heavy rain this had been reported as backing up on the inlet side. There was some evidence of this – so we cleared the concrete apron of silt and grass. The bore was just coping with the flow from the stream. The new balancing pond in Chicken Curve down side orchard was inspected; about one third full of water so nothing flowing out of the overflow into 20C. This is going to be a signifiant help in controlling the flow through 20C. Then on to Toddington Yard to met the telehandler. The first of the two remaining stacks of concrete chamber rings was loaded and taken to Stanton Yard. Then a swap of vehicles to take the second LWB Transit back to Toddington to collect the second stack; and then move the telehandler to Stanton. This means that after 3½ years there are now no stacks of drainage chamber rings residing at Toddington.

The new balancing pond on the down (Cotswold) side at Chicken Curve. Not quite finished, but already regulating flow of water into 20C. This is the orchard, newly planted fruit trees on the left. Next spring this will probably be one of the most attractive sites on the line.

 
Culvert 20C inlet (down side) after clearing. In wet periods this always has some standing water, as the outlet on the up (Malvern) side outside of the railway property is a small diameter pipe. That pipe runs along the boundary of the old orchard, when the GWR built the line it went through the middle of the orchard. Environment vandalism in Edwardian times!

After lunch the combined team worked as much as the wet conditions would allow on the 11B up side diversion. All the required 225mm pipes and collars were laid out and the exact positions of the intermediate chambers marked out. The petrol pump was used to pump out the existing outfall ditch allowing the two team members with wellies to dig out the hole for the new chamber. A bit more digging is still needed - hopefully we will get the minidigger on site next week.

With the telehandler on site at Stanton, this was the mode of choice for moving the 225mm twinwall pipes. Requires careful positioning to get the balance right, and of course checking with the Operations Manger that no trains on the move.

 
Stuart tends the pump, Nigel in the hole digs out, whilst Roger, Martin and Dave assist from the bank. Pumped out existing outlet ditch of 11B in the foreground.

Close up of the entrance to the existing land drain under the boundary hedge. Depth of water removed by the pump obvious. Last time we saw this pipe was back in the hot weather last summer when it was completely dry. This land drain will remain; just that it will not be taking any of the flow from the down side that comes trough 11B.

Pipe lengths laid out along the line of the new bypass. All we need now is the ditch in which to bury them (and the chambers at 30m intervals).



Monday 13 March 2023

Spring(?) Cleaning

For meteorologists spring starts on the 1st of March; astronomers prefer the date of the vernal equinox (20th March this year). Whenever it starts, Spring is the customary time for annual cleaning. Paradoxically the return of wintery weather in early March enabled our cleaning activities.

Thursday 2nd March

With the full complement of 8 team members working we split into groups of 2 and 6.

The group of 6 started the excavation of the up side diversion of the outlet of 11B at Stanton. Using the mini-excavator access from our neighbour's field, the first job was to excavate a hole to locate the previously installed stub pipe under the farm access track at bridge 11. Once located the depth and position of this was noted and the master drawing adjusted. This excavation will form the 5th new chamber on the diversion. The digger then moved to the current 11B exit and the hole for the first new chamber excavated. The line of the diversion pipe and the approximate locations of the other 3 new chambers were marked. All in all a good start to this long delayed construction. As the ground here is the notorious Stanton clay; it was soon evident that the mini-excavator was vital.

Locating the existing stub pipe, Jonathan digs carefully watched by Martin, Nigel and Dave. Polly in the background checks the flow in culvert 11A.

End of pipe located, so out comes the old dumpy bag which was stopping soil from entering.

Whilst at bridge 11/culvert 11A/cross drain 11B the group attended to some other odd tasks. Repointing of the arch of the inlet bore of culvert 11A was completed and then the surplus mortar used on an extra curricular task, repointing part of the up side wing walls of bridge 11. Various items of concrete/brick/slag rubble which had been left near the down side inlet of 11B were collected and used as scour protection on the outlet of 11A at our boundary. (One activity completing two tasks on our task list!)

Polly uses up surplus mortar by repointing the up side high mileage wing wall of bridge 11.

 

Scour protection added to the outlet of 11A; the exit pipe is that which will become the outflow of 11B.

From the up side of bridge 11 showing the excavated hole for the final new chamber; the pipe under the farm access track was laid back in 2019 (remember that pre-COVID era?) [Photo by Jonathan]

(For the record; the stub pipe was installed on 8th July 2019 - take a look at this previous blog entry).

It was good to be interrupted by the passage of a train once again. The green EE Type 3 (class 37 for younger readers) ran an ECS move/test run of the main set Winchcombe-Broadway-Toddington.

When the sun shines, Stanton is a photogenic spot; enhanced with a train!

Plastic mesh fence erected at the end of the day around the hole for the chamber at the current 11B exit.
 

The team of two first went to Travis Perkins at Cheltenham to collect materials ordered for the repair/alterations to the up side outlet of Stanton Aqueduct (bridge 9). This included some reinforcing bar; which was taken to the Steam Loco folk at Toddington to be cut and bent into shape. In the afternoon they went to the aqueduct to start construction of the shuttering as specified in the repair drawing. However they discovered that the new retaining collar which has been manufactured and fitted by outside contractors did not exactly match the drawing. Decided that on-site discussions with the bridge engineers would be best way to proceed. They also found time to repair the electric pump which had stopped working last week whilst at Prescott Road Bridge. The problem was the impeller was jammed with bits of bone and remains of a plastic bag.

Thursday 9th March

Unsurprisingly the return of the cold wet sleet/snow winter weather affected our planned activities for today. However, all 8 of the team attended, so credit to all for getting in.

We cancelled all work on the cross drain 11B to culvert 11A discharge (up side) diversion at Stanton. Taking a trailer with the minidigger on it across our neighbour’s field would have made a mess; plus it was too wet and cold to mix concrete for the new chamber bases. Two team members did check on the sit, the existing outlet was running and there was some discharge into the stub pipe at 11A from the new chamber pit. (And the anti scouring material added last week to 11A outflow was being tested).

Spot the difference from last week - a lot more water flowing in 11A. Even some discharge from the 'new' 11B outlet.

Five of the team spent most of the morning at Stanton Aqueduct (bridge 9). The main activity was to remove a small amount of concrete from the up side foundation block; thus ensuring the trough ribs were not fouling the block. Also checked the fitting of the lengths of rebar which had been cut and bent to shape by the Steam Loco department. They met the Bridge Inspector to discuss and agree the way forward with the repairs/modifications to accommodate the recently fitted new collar. This will involve use of self levelling grout. They also tried, without much success, to jack the trough across to make the gaps at either side of the foundation block equal. The inlet channel was checked, no leaks from the new 300m id pipes, only water in the inlet channel was from the rain/snow. On the up outlet side the grill on the outlet was cleared, the outlet pipe is only just over the 300mm internal diameter. Also checked the slip marker posts on the down side cutting again, pleased that there is no sign of movement.

Drilling out the aqueduct foundation block around the trough rib.

Completed slot.

The concrete/brick inlet channel is almost dry; all the flow from the stream enters the aqueduct in the new lengths of pipe.

Two of the team stayed in the relative warm of the old C&M workshop at Winchcombe resuming milepost work. Heads for 10 & quarter and 14 & half were completed, plus the rebuilding of two old damaged heads into one serviceable one. Other refurbished heads were given a second coat of gloss white paint.

Our final team member worked on the replacement of the trailer electrics of the Isuzu truck. Although in the dry of the new Churchward House workshop, this did involve lying on the cold concrete floor. A second wiring defect was also attended to, so all lights on the trailer board now work correctly.

After lunch it was a spot of spring(!) cleaning. The main item was removing everything from the cab of our prime LWB Transit; vacuuming it out and tidily replacing the essential items. The result is that five people can now use the cab comfortably! Some odd items of drainage equipment were moved from the old workshop and gas compound to the EMD shipping container. This had the added bonus of finding some of the acrow props which will be used for the aqueduct shuttering.

Vehicle cleaning. At least the cab of the Transit truck was in the dry.

We are now wishing for proper spring weather to progress the works at Stanton – or at the very least some dry weather.