Archaeological digging

Our team’s work is primarily to maintain and improve the railway’s drainage system. The earliest structures date from the construction of the line starting in 1902. Not often do we come across items that pre-date this time. However, our work at Stanton on the up side diversion of the outlet of culvert 11B has found two such items – one considerably older.

Thursday 13th April

Two groups working at two sites. At Stanton aqueduct one group installed the rebar and shuttering ready for the concrete pour on the up side abutment. The rebar sits on top of the first layer of grout which was poured the previous week. The concrete layer then surrounds the rebar.

 

Rebar high mileage side of trough. (Photo by Roger)

Rebar low mileage side of trough. (Photo by Roger)

Shuttering around the new collar. (Photo by Roger)

The other team attempted clearance of the up side outlet of culvert 31B at Prescott Road. Using the minidigger in the JJ Farms leased field beside the road, some silt and debris was removed from the ditch upstream of the roadside pipe. However, as the Evolution petrol powered pump would only work intermittently, the water level never became low enough to expose the entrance of the pipe. A rather frustrating day, so another visit is needed with a working pump.

Thursday 20^th April

Two groups again, but both working at Stanton, almost within sight of each other.

At the aqueduct, the ‘aqueduct repair’ group mixed and poured the concrete. The mix of this used the special high strength 40N cement. There were no leaks from the shuttering.

 

The concrete pour on the high mileage side of the trough.

The shuttering on the high mileage side of the trough - expanding foam to seal the joints.

Just down the line at culvert 11B, we were able to get the minidigger on site. Excavating of the trench for the new pipe resumed, it was dug to the correct level almost as far as the first intermediate chamber site. That is approximately one quarter of the trench dug. The reason for the slower than anticipated progress is two fold. First the very wet weather earlier in the year making it impossible to get the digger on site. Secondly, the heavy clay soil which even the minidigger complains about. Frequently one of us has to remove solid clay from the digger’s bucket with a spade. How the old canal and railway navvies managed with hand digging in such conditions is amazing.

Jonathan concentrates on keeping the ditch in a straight line and at the correct depth.

Thursday 27^th April

A slightly reduced team size of five today. However, we still progressed work at both of the Stanton sites.

At culvert 11B, a group of two with the minidigger continued extending the ditch northwards and excavating the first intermediate chamber.

 

Looking back (towards Toddington) from the first intermediate chamber site.

The other three attended Stanton aqueduct. The grout was poured (two separate pours, one each from each side of the abutment) around the through; thus completing the additional anchorage for the new retaining collar. The shuttering will be left in position until next week - although the grout goes off quickly; a weeks curing time will mean it is very solid. The three then joined the diggers at 11B.

Shuttering on the outlet end of the aqueduct trough. Stuart makes final checks on the high mileage side after the grout pour.

 

The grout is self levelling. This is the low mileage side complete.

High mileage side, just before final top up. The length of plastic guttering on the right is the pouring funnel.

The ditch digging is slow going as below 6 inches the soil is the infamous Stanton clay. We came across remains of clay field drains; the depth and alignment of these suggest they were in the field when the embankment was built. Also close examination of a whole section of pipe indicates that is hand-made; it has a one slightly flat face. This suggests these land drains date from the early 19^th century, our first pre-railway find. The second find is even older – a small ammonite fossil. This will be at least 66 million years old.

The very old land drain at the first intermediate chamber site. Even though it is clogged with silt, water still dribbles out of it.

 

The Stanton ammonite.

The ditch now extends to approximately 12m north of the first intermediate chamber. Some hand digging ensured that chamber is ready for the concrete to go in, a wood post marking the correct level. One advantage (perhaps the only advantage) of thick clay is that there is no need to construct wooden shuttering for these bases.

Back at Winchcombe we fitted some replacement parts to the Evoultion petrol powered pump - adding some underwater grease to the inlet pipe threads. This will be tested next week at Prescot Road (culvert 31B).

Thursday 4^th May

Just like on the 13^th April, two groups of three headed to two sites in opposite directions.

The first group took the minidigger and the repaired Evolution petrol powered pump to Culvert 31B at Prescott Road. The pump now runs well. After pumping the outlet out; they rodded the pipe in the roadside ditch outside of the railway land. This indicated a blockage just a couple of feet in. They then excavated this length; revealing a couple of lengths of broken and misaligned SGP pipe. After removing this, the roadside exit is flowing well. This should prevent the build up of water in the bore which runs under bridge 32. There is a large amount of silt which has built up in the catch pit and back up the bore under the bridge – this will require removing at some point. Finally the group installed some red plastic barriers to fence off the excavation from the road and the field.

 

Exposed - where the roadside pipe of the 31B outlet was broken.

The second group headed to Stanton, first to culvert 11B. They cast the concrete base of the first intermediate chamber of the up side diversion of culvert 11B to 11. Added interest was that the young grass snake (Natrix natrix) visited the ditch. It quickly slithered away before we had time to take a photograph.

Snakes eye view of Foremarke Hall from the new 11B ditch at Stanton.

 

Concrete base of the first intermediate chamber.

After lunch the group moved on to Stanton aqueduct to remove all the shuttering from the up side abutment now the grouting and concrete around the new retaining collar is complete. The new retaining collar is now firmly held in place. The repair is complete, apart from filling a small void in the lower grout level caused by some of the sealing foam.

Nice clean edge to the grout and concrete around the trough and new collar. Low mileage (Broadway) side.

With all the shuttering removed, the new collar looks like it has always been part of the structure.

 

Signs of spring at Stanton included observations of increased insect activity, we noted a hornet and a red tailed bumble bee (Bombus lapidarius). Also the magnificent pear tree on the down side just on the low mileage end of bridge 11 was in full blossom.

Stanton pear in full blossom. (Photo by Roger)

Forty days and forty nights

I suspect most of us remember the legend of Saint Swithun, that of forty days and nights of rain following rain on his saint’s day. Recalling the date of that is not so easy. This spring it seemed that every day in March was St. Swithun’s. For the record, St. Swithun’s feast day is 15^th July.

Thursday 30^th March

Yet another wet day but we did manage to make some small amount of progress amongst the mud at Stanton 11B. Not helped either by three flat tyres - one of the LWB Transits, a wheel barrow and the sack truck!

Seven of the team attending. Four headed to Stanton 11B. To avoid churning up our neighbour's field we took the minidigger to site through Stanton Yard and then over the accommodation level crossing. A long slow route. A length of bypass pipe was inserted into the existing outlet pipe and the outlet ditch dammed enabling the petrol pump to bring the level down sufficient for the digger to complete the excavation for new chamber 1. The inlet to the pump was fitted with filter made by Nigel which prevented most of the silt, clay and other muck entering.

Dave attempts to stem the leaks from the bypass pipe. Nigel's filter on the end of the pump inlet - not sure who was on inlet pipe holding duty, hand just visible.

Water and mud - the temporary bypass pipe with dams at both ends was not 100% effective. Good job we had the rapid setting cement.

Two of the team headed to Travis Perkins at Cheltenham to collect the materials ordered to complete the repair to the up side abutment of Stanton aqueduct. This comprised 40N concrete, Five Star grout and some expanding foam to fill the gaps in the shuttering.

The final member stayed at Winchcombe to complete the assembly of heads for mileposts 8¼ and 10¼. When the Cheltenham two returned, the aqueduct materials were unloaded into the shed (as the grout is in paper bags) and a supply of concrete blocks loaded and the three headed to Stanton 11B.

With all seven working at 11B we did mange to mix and pour the concrete foundation for the first new chamber. This used all our remaining quick setting cement, needed since as soon as the pump was turned off the water level rose considerably. Even with the down (Cotswold) side inlet dammed there was a considerable amount of water passing through the bore and seeping out of the ground of the excavation. A start was made on excavating the ditch for the bypass pipe, another slow job as the clay kept clogging the bucket.

Deepening the hole for the first new chamber at 11B. All that water and the clay soil plus a steep embankment makes for a difficult work site. Not surprisingly two members of the team needed a change of overalls before entering the Churchward House mess for afternoon tea. [Photo by Dave]

Finally we did manage to complete one task the new head for milepost 8¼ was fitted, so that post goes from the worst on the line to one of the best.

Milepost 8¼ with one of the Stanton Pear trees in the background. That should be in blossom just after Easter. [Photo by Roger]

Thursday 6th April

Once again we decided to abandon any further excavation on the 11B to 11A up side diversion at Stanton. The water level had dropped a bit since last week, but the approach over the neighbour's field with the digger on the trailer would have made deep ruts.

With all eight of the team attending we divided into two groups of four.

The first four formed the aqueduct repair team. The shuttering was sealed with spray foam and the first pour of grout made. This pour came up to just above the bottom of the trough. The group then joined the others for lunch at Toddington before heading back to Winchcombe to continue milepost manufacture.

Grout pour, low mileage end. [Photo by Roger]

Grout pour, high mileage end. [Photo by Roger]

The second team of four headed up the line. First stop was at the River Isbourne Bridge (21) to see how Walsh are progressing with the river improvement/flood alleviation work. They have built an impressive stairway from the down side to the headwall. We will need to keep that clear of vegetation in the autumn.

Jonathan tests the new steps the River Isbourne Bridge. Walsh's big digger can just ford the water, it is digging by where the stream that flows at the back of Churchward House enters the Isbourne.

Then on to culvert 20C at Chicken Curve. The new balance pond on the down side is now at 'normal' level, there is a trickle of water leaving via the exit pipe into the 20C inlet.

The down side balancing pond at Chicken Curve with landscaping complete and filled to normal level.

Just a dribble flowing out of the balancing pond into 20C.

Next stop was Hayles Abbey to replace broken covers on an up side cess manhole. Obviously damaged during the recent track replacement.

Replacement cess manhole covers are now the blue mesh, weighted down with a concrete slab. Hopefully the marker posts at the front will make the chamber more obvious.

We also noticed another manhole which need a replacement concrete ring – so one job removed from the master task list and another added! The next job was fitting the new head for milepost 10¼ by Didbrook No2 bridge.

Milepost 10¼, on the high mileage (Cheltenham) end of Didbrook No2 bridge.

Whilst there we cleared some debris from the up side hedge and removed silt from where the down side high mileage drain meets the road gully. 

Next was inspection of the recent slip at Toddington North up side. We also checked the slip markers on the down side, no apparent movement there but we noted a couple of small bear earth faces. On the up side we noted the top row of slip markers were still all upright and in line. The recent slip appears to be confined to the middle section of the old slip affecting only one slip marker post – but that is now 2m or so downhill. There are also quite a few holes on the crest. We walked back to Toddington along the crest of the cutting, rediscovering the old crest drain (SGP pipe). This is quite a distance from the boundary fence and is probably broken at the site of the old slips. We formulated plans for a new crest ditch closer to the boundary fence and running further south to almost where the new houses are.

Using the spade to show the depth and location of new hole near the top of the cutting.

Top row of slip markers still upright and in place.

Lower row of markers with one now well out of place.

The slip face, the shiny smooth surface illustrates the extent of the recent slip. Fortunately it did not cover the up side cess at the bottom of the cutting.

As this was Maundy Thursday we had no trains to wave too; so the RAF obliged with a low altitude training flight.

Then lunch at Toddington under the platform canopy whilst very heavy hail storm passed. Finally on to Stanton 11B/11A with the laser level to check the depth of the first part of the new ditch dug last week. It is deep enough, actually 3cm deeper than required. This was a task we had to abandon last week when it too wet. We noted the concrete base of the first new chamber we poured last week had set, but it will need a bit of levelling before installing the concrete rings. We also checked the extent of the standing water on the down side to determine where we need to take the new ditch or pipes. Answer: approximately in line with milepost 8½.

There is a solid concrete base in there! Existing 11B outlet pipe on right - at least this week the top of it was above water!

With all the wet weather we are now at least 3 weeks behind on our estimate for the 11B to 11A up side diversion. This time last year we had to postpone some work as the ground was too dry and hard. The only predictable aspect of the English weather is it’s unpredictability!

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 16^th 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 23^rd 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).

Spring(?) Cleaning

For meteorologists spring starts on the 1^st of March; astronomers prefer the date of the vernal equinox (20^th 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 2^nd 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 9^th 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.