Concrete and clay will fix it

Monday 22 July 

Starting with the weather report for a change, cloudy and warm today with a bit of a breeze at Bridge 11 but no wind at Bridge 8. A lot of things going on on the work front, another major step forward with bricks going back on the end of the arch, this will be a slow process as they need to cure before we can move the former forward. Leak repair completed on the down cess extension and the grille fitted on the inlet to Culvert 7A. It sounds so easy, but there's a lot of activities going on to make it all happen. 

Steve had dug out the end extension pipe by the time we arrived on site, it was then just a matter of finding the leak, doing the fix and then getting it backfilled again. 

Digging out the old headwall 

Source for the leaking water 

The concrete joint has been taken out 

The water was leaking from two places, firstly the base of the join between the new twinwall pipe and the socket on the old SGW pipe and secondly there was flow from under the headwall foundation slab. There's probably some cracks in the SGW pipe that have been running into the scour hole for years, we couldn't see them before the new pipe was fitted. 

Under the old footings slab 

The water flow is visible in the swirls 

Roger was working on the new build of the walls for the up side cess outfall 

Last course on the inside wall
(Photo: Alastair) 

Meanwhile... 

Dave did some more brick cleaning
(Photo: Alastair) 

Nigel made up the former to go into the culvert to rebuild the arch on. it's based on a bit of 450 mm pipe with wood slats to expand it the required diameter 

Fixing the wood slats to the pipe
(Photo: Alastair) 

Thinking time 

Trial fit 

Alastair had a busy day on the mixer with mortar and concrete mixes 

Roger back up top for another load 

A new concrete seal backed up with puddled clay was positioned in the down side cess extension to cut down the leakage. 

First load of concrete in 

No sign of water with the concrete and clay in place 

A trickle starting to come out of the end of the pipe,
something must be working 

Last mix over the crown as the trench is backfilled 

A plywood skin was added to the former to close the last small gap 

Nigel takes the ends of the old broken bricks out so that
the replacements can be keyed in
(Photo: Alastair) 

The big moment, bricks going back in. These are all recycled bricks found around the site, plus some from the old headwall and the down side invert.  

The arch repair on the former
(Photo: Alastair) 

Then it was back to the outer side wall on the cess outfall. 

Headers going on
(Photo: Alastair) 

It must be hard work, sitting down on the job 😉
(Photo: Alastair) 

As no trains run on Monday's, it's good day to get things done that require crossing the line. After lunch, Dave, Nigel and Stuart went on a mission to fit the new grille that was made by Carriage & Wagon onto the down side (inlet) at Culvert 7A. First they had to find the turning spot and then cut the way into the culvert. The vegetation clearance may take some time this year. 

Up near Culvert 6A at Stanton, looking south 

Up near Culvert 6A looking for the turning spot 

Culvert 7A is a siphon, immediately north of Bridge 8. The grille is to protect any workers in the area when works eventually start on the bridge repair. 

Culvert 7A down side 

Nigel clears Culvert 7A up side

Dave clears the up side 

Yet another mystery, there's a large hexagonal object in the bottom of the inlet channel. It's too big to be a bolt or nut, there's what looks like a square hole in its centre. The only way to find out what it is will probably be to pump out the water, a job for another day perhaps. 

Hexagonal object - too big for a nut 😊

First part of the grille fitted 

Second part fitted, a slight bit of modification may be needed

Back at 11A, the brick arch now looks like this... 

First rings in place 

Side elevation 

A concrete skin will be added when the bricks have cured, the cracks that have been exposed to the right of the repair will be filled at the same time.  

Steve and Richard have finished today, after laying the scalpings to surface the farm track the last task was to install the third pipe on the down side cess extension and backfill the ditch.  

The resurfaced farm track completed this morning 

The end of the extended cess drain
A new headwall will go on here 

Steve finishes off the backfilling 

It's sometime good to look back at where we started, this was the up side in March when we were surveying the task. A pat on the back is in order 😊

Culvert 11A up side - March 2019