© 2016 Lichfield & Hatherton Canals Restoration Trust
The Lichfield Canal was formerly known as the Ogley Locks Section of the Wyrley and Essington Canal (the surviving 16 miles of the W & E main line being lock free). The locks are situated in groups which used to be referred to by the boaters as 1st Flight, 2nd Flight etc. as follows:-
1st Flight began immediately after the junction with the Anglesey Branch and comprised Locks 1 to 6 within the first 600 yards followed by 7 and 8 in a further 400 yards, therefore side ponds were used on this section.
A stretch of just over a mile follows before the 2nd Flight comprising Locks 9 to 12 which are spaced over a length of about 700 yards (located to the north east of Muckley Corner Island).
This is followed by another pound of a mile or so before the 3rd Flight comprising Locks 13 to 18 within a length of 500 yards with 4 side ponds (in the Wall Lane to Fosseway Lane Section).
The next mile of canal took it through the Sandfields area and contained Locks 19 to 23 before the final flight of Locks 24 to 28 which are contained within a length of about a mile running parallel to Tamworth Road.
After half a mile, the remaining 2 locks are spaced out over the next half mile, after which the final half mile is on the same level as the Coventry Canal.
The restoration of the Lichfield Canal is basically a 7 mile long civil engineering project. There are 2 alternative approaches to such a project:
- By Act of Parliament.
This requires massive effort both politically and financially up-front to convince the Government to pass the Act. Having achieved this, one then has compulsory purchase powers and is also able to engage contractors to construct the whole line concurrently. This is how the canal was built between 1794 and 1797.
- By mutual consent
This is how virtually every voluntary canal restoration project is being carried out at present. It involves looking along the route to identify sections where all the essential ingredients for that particular site can be acquired by negotiation. These include possession, planning permission, physical access and finance.
Can be freehold, leasehold or by licence. Our position is currently as follows:-
We have a freehold site at Darnford (from the road to the winding hole), a site licensed from Lichfield District Council at Darnford (from the winding hole to the far end) and another at Fosseway Lane, and 2 separate sites licensed from Lichfield City Council at Tamworth Road (Lock 25 and above and Lock 26 and below). The Trust has also purchased land between the canal and railway line at Sandfields for spoil disposal and small areas by the aqueduct and at Cappers Lane for embankment widening.
The whole line from Ogley to Huddlesford comes within the area of Lichfield District Council. Permission is generally required for each site but in practice tends to concentrate on the structures and particularly the new ones. Thus at Darnford we have one permission for the combined site and others for the new culvert and the new lift bridge, whereas at Tamworth Road one permission covers 2 sites (with existing locks). Planning authorities also have the power to vary their permissions and so having obtained permission at Fosseway Lane site, when circumstances changed it was possible for the Trust to obtain a variation to suit the new arrangement.
This cannot always be taken for granted. In one case part of our site was cut off by a stream and in another case the site was land-locked.
Proceeding site-by-site means that the only finance required initially is that for site purchase and the various fees involved. The major financial expenditure can be controlled by phasing the work. In our case grants are required to cover the employment of contractors and other big items but the pace of work carried out by Trust and WRG volunteers is such that the cost of the necessary materials can more or less be raised by our Marketing Group and donations received. (Please keep them coming in! Telephone the Treasurer on 01543 671427 for information.)
The wildflower meadow at Darnford, planted by the Trust's
Environmental Team (photo by Bobbie Battisson)
Traces of the puddle clay used in the original construction have been found on all our sites, not only in the main water channel but also around the locks behind the brickwork, probably obtained from clay pits at Brownhills. Current BW standards for puddle clay installation recommend thickness of at least 600mm. This corresponds to 10 or more tons of clay per metre length of canal or in those days half a dozen or so cartloads per yard of canal.
The basic subsoil all the way from Ogley to Huddlesford is sand over sandstone, so much so that the area around Locks 1-8 is known as 'Sandhills', that around 19-20 as 'Sandfields' and near Lock 24 as 'Quarry Hills'. Whether the original lining was put in at that thickness is unknown but certainly by the mid 20th century the canal had little water in the lower pounds. If left to dry out, clay develops cracks which will not seal when re-watered without re-puddling.
Laying the bentonite lining at Darnford Lane (photo by Jan Horton)
Both butyl and bentonite membranes require covering and protection: covering in order to hold the membrane in place preventing any chance of `lifting` due for instance to methane gas or to a rising water-table in the subsoil whilst the canal is de-watered; protection against perforation by boat hooks etc., and most importantly on the sloping (off-side), against the chines of boats. These requirements can be met by covering the membrane with an appropriate thickness of sandy soil, gravel ballast or concrete utilising suitable support on sloping surfaces.
Finally it should be remembered that metal piling is not waterproof because of the joints. In existing canals it usually relies on the original puddle remaining under the towpath but where this is not available a butyl or bentonite membrane can be installed behind the piling as an alternative.
The restoration scheme uses about six of the original seven miles. Replacement Locks 19 to 21 are required along the Southern Bypass section and numbers 27 and 28 are to be relocated because of the A38 diversion. The M6 Toll unfortunately prevents re-use of Lock 8, but a new deep lock is planned to replace it and part of the drop on Lock 7.
Additionally, alterations to various bridges to comply with modern highway standards will necessitate the re-siting of Lock 29 and possibly 9 and 24. Although reconstruction of this latter group is undoubtedly additional work which we could well do without, the existence of so many locks adjacent to road bridges which cannot now be reconstructed as `hump-backed` does provide an acceptable solution. However all the relocations will not change the basic arrangement of the original Flights well known to earlier boatmen.
The following notes are based on observations of locks 8 and 30 (which are the only ones not in-filled), Locks 18, 25 and 26 (which have been re-excavated) and Lock 29 (partly demolished).
All locks are of brick construction with single top and double bottom gates. Levels taken at the above locks and other intermediate points show that each lock has a similar drop averaging about 8ft 10 inches. They were originally constructed of orange coloured two and a half inch thick bricks. The invert was paved in brick and concave, and this paving extended out beyond the bottom gates to protect against scouring. Water entered via drop shafts on both sides with wooden paddles running in cast iron frames and ground paddle posts above. A substantial cast iron striker plate was located at the head of the lock with the water inlet immediately below it which was connected to the drop shafts by horizontal passages. Water left the chamber via paddles in both bottom gates. By-wash weirs led to underground brick culverts circular in section, except for Lock 26 where it is an open channel, probably as a result of being opened out following collapse.
Shortly after acquiring the Wyrley and Essington Canal in 1840 the Birmingham Canal Navigations Company carried out major re-construction work on most of the locks. This involved re-facing the walls in thicker and tougher blue engineering bricks including bull-nosed coping bricks and short rubbing stones or continuous stone copings. This re-facing did not extend below the bottom waterline but it did include the wing walls which were fitted with very heavy iron rubbing strakes incorporating horizontal lugs which were secured by vertical anchor bolts in pockets behind the facing bricks. The gate recesses were fitted with heavy cast iron quoins. The design and appearance is virtually identical to the Rushall Canal which was just being constructed at the same time by the company and appears very heavy duty and capable of withstanding continuous use by fully laden coal boats.
Our modern reconstruction uses solid red bricks below the water line and blue above gauged to suit the existing courses. We re-use old-style bricks to patch up original areas.
From 1990, when we began work at Fosseway, the Trust has always been aware of responsibilities to the environment. Whilst in general it seemed common sense that the re-creation of a waterway and associated hedgerows etc. in place of derelict land or farm land will increase both the range of species and their quantity, nevertheless care has to be exercised in the way that the work is carried out. At Darnford there is a badger sett and so plans were drawn up which avoided disturbing it and advantage was taken of adjacent surplus land for the Trust to plant a new copse.
To put environmental matters on a more formal basis, the Trust commissioned an Environmental Report. This summarises the history, route and restoration scheme proposals for the Lichfield Canal before dealing in detail with environmental issues, followed by a summary of probable Impacts, Environmental Benefits and Dis-benefits (some during the construction phase) and then Mitigation Measures required. The Mitigation Measures can be achieved by the adoption of an Environmental Action Plan and by following the British Waterways Environmental Code of Practice. The final section of the Report covers additional enhancement possibilities in the form of a Bio-diversity Action Plan and Habitat Creation.
In summary, it would seem that if the Trust continues to take appropriate advantage of opportunities where these can be fitted into the land available then we shall be able to demonstrate in accordance with the accepted criteria that the environmental benefits more than exceed the dis-benefits. Copies of the Report have been circulated to Lichfield District Council and Lichfield City Council and Staffordshire County Council, also the Environment Agency, British Waterways, English Nature and Staffordshire Wildlife Trust.
A modern alternative is the Butyl rubber/plastic types of membrane. These are very thin (2mm or so) and require specialist jointing. The joint is made by overlapping the sheets then "welding" them together using a machine which applies both heat and pressure to both edges of the seam. This system has been used by both BW and volunteer groups but found to require much care with the special machine which is very slow in operation.
A further alternative is to use sodium bentonite. This is a natural form of clay mined commercially only in Wyoming in the USA. It has very low permeability ratings combined with flexibility and self healing properties. It is crushed and processed to a plastic consistency, about half an inch thick and sandwiched between two synthetic materials and supplied in a rolls 2.2 metres wide and 40 metres long. The roll is laid from side to side of the canal and joined by overlapping the edges 6-8 inches, the joint then being sealed with bentonite granules. This material has been used by BW and contractors but not until now by volunteers.
Lichfield Canal - An Overview (page 2)