Barnes's Canal Cutting - Safety Issues & Loss of Amenity

The first part of this page describes the design and layout of the canal and tunnel, finished in 1805, and the second describes what has happened, or appears to have happened, to create a hazard for the Stoke Road.

The Grand Junction Canal, including the tunnel through Blisworth Hill to Stoke Bruerne, was completed in 1805.  The map below, from Grafton's survey in 1838, shows the south-western part of Blisworth including the mouth of the tunnel.  In the process of achieving alignments the chief engineer of the project, James Barnes, had set the level of the canal in Blisworth at about 90 metres above sea-level (there are no locks in Blisworth).  He also presumably positioned the canal a sufficient distance from the twin cottages (6 & 7), which once faced onto a green, so that the slope of the ground in the cutting for the canal would not exceed 20º.  As the road previously passed roughly over the position of the tunnel mouth, he must have rebuilt the road to be close to the cottages.  Indeed it appears that he was constrained in that the canal could not have been placed any further towards the east because of the cottages.  Modern Ordnance Survey bench-marking places the road at a height of 106 metres near location (A) and, by survey about 107 metres at location (B).  Simple calculation using the scale for the survey map reveals that the average slope angle for the cutting in both locations was about 17º and these results are shown on the map.  This calculation relates to the water surface, road surface and the edges.  Given a 6 foot towpath higher than the water and a grass margin of 8 foot to the roadside, the average soil slope would have been 0.2º larger.  Thus Barnes ensured that he abided by his own design rule.  It is noted in the company minutes, c. 1800, that Barnes energetically resisted increasing the rule to 30º in order to save digging out so much soil, rock and clay in the vicinity of the tunnel mouth.  There are archive pictures, taken 1890 to 1940, that appear to confirm a reasonably uniform slope.

The map also shows land ownership for 1838; the areas tinted pink were Duke of Grafton land, otherwise the area belonged to the original canal company, GJCCo.  At the sale of the majority of the Grafton Estate in 1919, for reasons of death-duty, there is no record of how much of the slopes area was acquired by the GJCCo.  

For example, did the Parish or County Council insist on acquiring a strip of land adjacent to the Stoke Road in order to fulfill the general requirements of maintaining the road, whatever requirements were thought appropriate for that purpose in 1919?  It is beyond the scope of this paper to comment on County Council land-holding in the period 1919 to 2000 but, regarding the Parish Council, there were requests sent to the GJCCo., to T.W.Millner in fact, from 1907 to 1919 to repair the fence by the Stoke Road, with the implication that the GJCCo. "owned" the land and trees up to the road well before the estate sale.  This correspondence warrants a detailed examination from the "GJCCo. side" and attempts are being made to do this.  In the N.R.O. there is an assortment of letters both to and from Millner and it is clear that the County Surveyor also wrote to him about the state of the fence.  In the earliest Parish Council letter of 1905 it was pointed out that "the bank was giving way as well".  In 1915 Millner received a reply to his letter from his boss instructing him to continue patching the fence and when the war is over "we will consider some ferro-concrete fencing".  Ownership of land and fence seems implicit.  Incidently, the boat stable shown may also be visible in an early picture of sailing on the canal.

Today's Canal Cutting

Our Safety Campaign

Concern has been expressed over the fact that the Stoke Road is threatened by soil slip and in c. 1996 and 2000 contractors were called in to rebuilt the road (see link re. the 2000 work).  A steep fall in the land adjacent to the road verge is of concern in case a vehicle should leave the road.  A strong 'Armco' type barrier seems appropriate and it would be a good idea for road engineers to apply safety measures to this sometimes busy road just as they do in other places.

The Start of the Campaign.
On January 25, 2008 contact was made with the "Street Doctor" at the Northamptonshire County Council and a full report was lodged with them under reference number 317667.

Late-February 2008  The enquiry has been forwarded to NCC experts in highway safety who are considering whether the costs of a fence will be the responsibility of the landowners (ie. British Waterways).  The point has been made to the NCC experts that a strong fence of steel is appropriate to the apparent risk to traffic and not a mere wooden fence that would protect only pedestrians.  Late-March is the deadline for inclusion of this, as a project, in the County road improvements for 2008/9.  Post deadline additions are always possible in theory, I'm told.  A separate written complaint by a villager to the NCC has received a letter response to the effect that the Stoke Road risk area has a "zero casualty record" associated with it and that it would not receive attention - so someone seems to have made his/her mind up! 

March to June 2008  An iron or steel fence has not been included in the 2008/9 budget.  Members of the village have requested a formal Safety Report from the NCC.  This will be done sometime in 2008, we are told, as the new contractors 'responsible' for safety adjust to their work load.  The previous incumbents had made no mention of any hazard associated with the embankment.

August 7th 2008  Letters recently written to the NCC, SNC and BW may be having some effect; the hazard aspects of the Stoke Road have at last been recognised.  The NCC 'Transport and Highways' Dept. have written to me* to say that a safety barrier (..of a specialist nature..) is to be installed late in August 2008, seemingly as a matter of moderate urgency.  This came as a complete surprise since the more junior members of the highway team, that we know of, had not hinted at this action in any recent communication with other villagers.

* link to an OCR generated copy
This is an excellent outcome which heralds the end of the Campaign.
The installation project is covered elsewhere

Comments on the Embankment profile

Result of a Mini-Survey   Today there is a variably wide plateau in the soil of the slopes to the east of the canal and this is noticeable for 100s of feet running north/south in the vicinity of both locations (A) and (B).  The possession of an elementary optical level gauge has allowed assembly of a representative profile for the slope and this is shown in the diagram to the left, being very much an estimate.  At both ends of the soil profile the slope exceeds 45º and it is obvious that the road could be being destabilised by such a profile. 
On entering the area by path from the south end, the first impression is that the land has slumped down maybe 3 metres  near the road.  Could it also have slumped towards the canal (and be washed towards it by the weather) and be lost from the site in the form of dredged out mud?  Could it have been excavated and used elsewhere?  Perhaps no-one has been watching this area over the years so a precise answer cannot be given.  However, there is gained a very definite impression, particularly from the roadside, that much soil or clay has been lost over the years.  At one location there is a pile of moss-covered blue clay (marked 'C' in the map, 5 to 10 tonnes), evidently pushed together by a vehicle, which suggests that one reason for alteration to the slopes profile might have been in moving and/or in removing clay.  At another there are old tracks, marked in red, left by some sort of tractor vehicle but for what reason cannot be stated for certain.  Whatever has been going on, the plateau in the profile gives the impression of being man-made and features like some crevices suggest being probably a result of that disturbance.  The lower 'bulge' near the towpath is simply not there in archival photographs taken early in the 20th century with a vague suggestion that some movement was seem by 1960 - see links immediately below.  No similar profile changes have been noticed on the other side of the cutting.

The moss-covered clay heap referred to above.

 

 

 

There are relevant archive pictures on the website, for instance:

Near towpath profile, 1925   
Near towpath profile, 1930  
General, c. 1925    also in 1944
Opposite slope c. 1930   
Access from Road, 1950   
Near towpath profiles, 1960
It has been 200 years since the gently sloped sides of the cutting were formed.  After 100 years a councillor notes in 1905 that the bank has given away (somewhat?) and this can be taken as the result of clay movement due to its weight and its water content.  An old-timer recalls as a boy in the 1930s that the lower slopes were grassed and joined the towpath without a step as shown in archival pictures.  He remarks that there was some "drop" at the top that was too inconvenient to walk down by.  But at the ironstone railway and at the bend in Stoke Road there was a well worn path straight down to the towpath from the road.  He said that on some summer days there were dozens and dozens of people just messing about or relaxing "under the trees" - an idyllic scene that will never return.  Since the cutting was dug in blue lias clay, which tends to support briars, ivy and moss &c., the grassed area must have been encouraged originally by applying a layer of more loamy soil.  Such fertility has gone - further evidence that a simple 'slump' movement alone is not a sufficient explanation of what has happened.

On the assumption that the physical condition of the clay slope and the effects of nature in the last 50 years were the same as in the first 150, we would expect some worsening of the subsidence at the top of the profile, after the 50 years, but little change at the bottom near the towpath where a grassy area of uniform slope should still be seen.  

Fortunately there have been more photographs which have come to light and an approximate account of the modification of the  profile of the embankment over the last 200 years is given in a separate document that concentrates on the future welfare of the road.  It has been pointed out to me by John Mallard that many of the trees in the recent photos above are leaning towards the canal.  As trees tend to grow vertically, this indicates that the surface profile has changed during the lifetime of the trees.  This detail is consistent with the account.

Tony Marsh     28 January 2008