Progress Wendover Arm

Wendover Canal Trust are making progress on shifting the ash infill that’s been an obstacle to restoration from the current limit of navigation

Grand Union Wendover Arm

Wendover Canal Trust’s recent activities have centred around three important tasks.

Firstly, building a ‘narrows’ – a vertical sided narrow section of canal channel – immediately beyond the limit of navigation on the restored and reopened section at Tringford, which will form a limit for widebeam craft as well as a location for stop-planks when the canal needs to be drained for maintenance.

Secondly, removing a large amount of household waste from 100 years ago consisting mainly of ash, which was used to fill in the length of canal from the site of the narrows onwards – and which needs disposal at a specialist tip, at considerable expense (funded thanks to recent grants from local authorities).

And finally continuing with the next section (continuing from Bridge 4) of the regular longrunning job of profiling and lining the channel with Bentomat (bentonite clay matting) for two miles from Tringford to Aston Clinton so that it will hold water (this section suffered from chronic leakage problems throughout its working life, leading eventually to it being drained, with the canal’s water supply function carried out by a pipeline instead).

August working party: The two-week August work party started on 5th August with the first week prioritising preparation work for ash removal from the tip area in the second week. The WCT work party followed on directly after the two weeks of Waterway Recovery Group Canal Camps (see Navvies 314 for camp reports).

Bridge 4: Surplus materials were moved from Bridge 4 and the shelter dismantled and moved to where the canal lining would be continuing.

At the end of the current lined section some of the spoil was moved and the end of the bed of Bentomat was uncovered. There were two areas of damaged Bentomat which were repaired by patching-in squares of Bentomat cut from the end of a roll. The joints were sealed with Bentonite granules. The next 40m roll of Bentomat was joined at the bed and sides and rolled out.

‘Sleeping policemen’ (concrete upstands to protect the Bentomat joint and to provide support across the canal channel) were cast at 10m intervals and backfill placed on the Bentomat. This work completed a further 40m of canal channel. The end of the Bentomat was covered with protective boards and surplus spoil was heaped over the back ready for the next connection.

Tip Area: The boundary fence at Henry Grace’s boundary was taken down and the materials stored. The stock fencing and barbed wire could possibly be reused. A survey of the fence lines to both sides of the canal channel was undertaken. The surplus spoil over the ash was scraped up and used as backfill in the canal channel at Bridge 4. A hard-core access track was laid to allow the muck-away lorries taking the ash away to the tip to be loaded direct at the excavation face. The 20 tonne excavator was delivered to site and the low loader was able to drive onto the site so there was no disruption to the traffic on Little Tring Road.

The second week of the work party concentrated on removing the ash from the tip area. There was an average of five volunteers each day due to the criteria of not having facial hair in order to effect a seal when wearing a face mask, a requirement of the control measures identified in the risk assessment.

The 20T excavator dug out the bulk of the ash, which was made much easier because it had a tilt rotator bucket which could be turned sideways or to any angle. The 5T excavator trimmed the sides down to the coal tar layer (a remnant of one of the many unsuccessful attempts to make the canal hold water – it was lined with tar) and moved ash to the 20T excavator.

By the end of the week 70 lorry loads of ash had been removed: 1400 Tonnes of material. The coal tar had been exposed over the full length on the towpath side but only part way on the offside. Discussions about boundaries of the canal cannot start until the full extent of the coal tar has been exposed and the channel surveyed. Well done to the team that spent the week excavating the tip.

Tidy Friday was spent continuing strimming and cutting the grass on the path, around the benches and at Whitehouses. The new powered wheeled strimmer donated in memory of David Page was used. This will save strimming time by 75% and will reduce the risks of vibration, noise and manual handling from using hand-held strimmers.

September Working Party: At Bridge 4 the orange plastic fencing was taken down and moved to the storage area while there was still access for plant along the bed of the canal. The vegetation along the towpath was cut back and a new post and rail fence erected to replace the orange fencing. Measurements were taken to allow more fencing to be ordered to make the area look tidy and finished.

Joints to the offside brickwork foundations were inspected and cut back where there was obvious damage or weak areas.

Canal Channel: Final profiling of the offside bank was carried out over the 40m ready to lay the Bentomat. Solid concrete blocks and coil roll was placed over the Bentomat to complete the lower section of bank lining. The banks are ready for backfilling when the spoil has reached the right moisture content (if the spoil is too dry it slides down the Bentomat).

The next roll of Bentomat was joined at the bed and sides and rolled out over a 20m length. ‘Sleeping policeman’ were cast at 10m intervals and backfill placed on the Bentomat. The rolled-up end of Bentomat was protected with timber boards.

Tip Area: More ash was excavated and stored at the end of the access track ready for disposal off site. Bottle collectors have been on site making the tip unsafe. Heras fencing has been erected across the site, but they are still getting in. in addition they have been throwing bottles onto the farmer’s land and he is worried that broken glass could injure his livestock.

Narrows: Progress has been made laying the coping to the top of the Narrows walls. Two concrete corner ‘stones’ have been cast. The excavation for 12m of the towpath strengthening wall has been carried out and a length of concrete blinding placed. Solid concrete blocks and bulk materials were moved to the area of the Narrows to allow WRG BITM to hold a work party on the weekend of 16-18 September.

Mikk Bradley