Lock 1, Flight, Grand Union Line

Top and bottom lock gate replacement, change of balance beam (material) and minor repair works: Winter 2018/19.

S. Pointer (Graduate Heritage Advisor for and South-East)

Canal and River Trust

M: 07484 901301 E: [email protected] 24/05/2018 Introduction / Role of document: This Design, Access and Heritage Statement has been written to support a listed building consent application to District Council. A stoppage is planned for Winter 2018 at Lock 1, Leicester Line to carry out essential repair work to the structure. This work includes; the top and bottom gates, the replacement of metal balance beams with timber examples, the extension

The Applicant: Previously known as British Waterways, Canal and River Trust is a charitable organisation that was set up in 2012 to look after the majority of inland waterways.

Currently. the Trust is the guardian of approximately 2000 miles of navigable and rivers, over 2000 listed buildings and over 50 scheduled monuments. Altogether these represent one of the finest collections of industrial heritage in the world.

A major function of the Trust is to provide and maintain navigable waterways, whilst conserving waterway heritage and environment. It also has a duty to provide a safe environment for the increasing number of boaters and visitors to the canal network.

With ever increasing rates of obesity, stress and declining mental health in the UK, the Trust is also uniquely placed to make a significant contribution to improving the wellbeing of millions of people. Canals and rivers run through some of the most heavily populated communities in and Wales, providing accessible

Site location and access:

Figure 1 Location Plan. Lock 1 has been circled in red.

Located on the Grand Union Canal Leicester Line, the historic Watford Locks are situated approximately five miles north-east of Daventry and close to the picturesque village of Watford. The lock flight is bordered on its eastern boundary by the and Service area, and by the Roman (A5) to the west. The Railway also passes renowned Watford Gap, which creates present and historic infrastructures.

Approximate postcode: NN6 7UJ

OS Co-ordinates: 459317, 268591

National Grid Reference: SP 59285 68805

Brief Historical Context: Watford locks and side ponds lie in a section of what is now referred to as the Grand Union Canal Leicester Line.

Originally referred to as the (old) Grand Union Canal and built between 1810 and 1814 by engineer Benjamin Bevan, the original navigation sought to provide a link between the (at Norton Junction to the south) and the & Northamptonshire Union Canal also known as the Old Union Canal (above Foxton to the north).

Revenue for the old Grand Union Canal Company was enabled through trade between London and the , mainly in coal. Unfortunately, this trade declined by the mid-19th century, and the old Grand Union Canal Company was amalgamated with the Old Union Canal.

This canal was subsequently purchased by the Grand Junction Canal Company in 1894 and in 1929, when navigation merged with the Regent s Canal in London it became the Grand Union Canal (as it is referred to today). One of the main limitations of the Grand Union Canal Leicester Line was that it could only facilitate narrow beam vessels. Passing boats though the ten locks at Foxton took a considerable amount of time 75 minutes which slowed traffic and profits along the canal.

Consequently, the canal company decided to construct a steam-powered inclined plane lift at Foxton (now a Scheduled Ancient Monument) which enabled two boats to navigate the flight in 12 minutes. A similar scheme was proposed for Watford Locks, funding however, was not forthcoming. Ultimately, this hindered the success of Foxton innovations. Traffic was not as high as predicted and there was a costly and constant backlog of boats at Watford still. The inclined plane was abandoned in 1910.

Description of Heritage asset and its setting: Watford flight of locks is located on the Leicester line of the Grand Union Canal. The Grand Union Canal runs from London to the Midlands; one of its branches is the Leicester line which runs from Norton Junction, north- east of Daventry to Leicester where it meets the . The flight consists of 7 locks, 4 of which form a staircase (where there is no passing pond between the locks). The locks are narrow beam (single boats) and have a pair of timber (green oak) mitre gates at the bottom end of the lock and single gates at the top end.

Designation & significance: List entry number: 1342732

- II

Staircase of 4 locks; as part of flight of 7 locks. Early C19, refurbished 1902 (datestones). Retaining walls blue brick with stone coping. Wing walls at top of flight blue brick. Wooden gates, balance beams in steel to some locks. C20 footbridges. The paddle gear is probably 1902 but may incorporate some earlier work. The gear is notable as being still connected to the paddle by wooden rods, mostly replaced elsewhere by metal rods (note from A.T. Conder, Curator, Waterways Museum, Stoke Bruerne). West of the locks is a group of side ponds for conservation of water. The Grand Union Canal was authorised by Act of Parliament in 1810, the Watford section was opened in 1814. (A.H. Faulkner, The Grand Junction Canal, 1972, p.187 -

The site is also located within the Grand Union Canal Conservation Area (Daventry District Council).

Proposed work: The various aspects of the proposed work package for Lock 1 has been divided into two broad categories; alterations and minor repairs / maintenance. The former, which includes swapping the existing steel balance beam with an oak replacement and an extension to the lock ladder are the main reason for a listed building consent application. The latter group is represented by minor like for like repairs and general maintenance tasks.

ALTERATIONS: 1. Lock ladder extension:

Upon its last principal inspection, Lock 1 was found to be non- avigation Standards . These state that invert level where this This is to provide a secure foothold beneath the water, should a member of the public fall in the lock when it is empty. To make this structure compliant with these standards, the existing lock ladder will be extended (see technical drawing uploaded).

Typically, ladders are mounted in a recess cut into the lock wall. This is usually achieved by carefully breaking out the extant brickwork over-sized. This can then be repairing using matching materials which are bonded and tied into adjacent courses. In some instances, this is not always practically possible. For instance, it is not always possible to remove bricks from areas where a cementitious mortar has been used without damaging adjacent masonry. In this instance, a disc-cutter may be judiciously used to produce sound and straight outer edges, with the recess cut out to the required depth. Loose bricks on the sides of the newly created recess may need to be replaced and the rear elevation repaired or rendered (to prevent leaks behind the chamber wall).

As the recess for the Lock ladder extension will be

impact on the asset. Similarly, whilst there will be some minor disruption of historic fabric, the structural integrity of the lock will not be compromised.

2. Replacement of extant steel balance beams with green oak examples:

Balance beams are vital constituents of lock gates. Figure 2 1970s photograph demonstrating a historical Whilst these primarily provide leverage to allow users precedence for timber balance beams at Watford of the canal to open and close the heavy lock gates, locks. (Source: Waterways Archive) the beams also balance the weight of the gates in their sockets. This allows the gate to swing more

freely. Traditionally, balance beams were constructed using heavy dense timber, such as oak (see Figure 2). However, over the last 200 years various alternative materials have been utilised. Some of the locks on the Bridgwater and Taunton canal in Somerset for instance, have concrete balance beams.

Presently, the top gate of Lock 1 is fitted with an oak balance beam, whilst the bottom set of gates have steel examples. Steel balance beams were often incorporated into locks during the 1970s, consisting of a steel leaf with timber mitre and heel posts were routinely installed. This innovation in design was advocated as a cheaper and supposedly more su interface between the two materials.

Consequently, these composite gates are being slowly replaced with traditional oak gates. Indeed, since 2014 (when the bottom gates of Lock 6 were changed), every lock on the Watford flight has timber gates in situ. Therefore, to further enhance the special character of the Watford locks site, it is proposed to replace the extant steel balance beams of Lock 1 with traditional timber examples. These will match the design of those elsewhere on the site and no historic fabric will be lost.

1. Replacement of bottom and top lock gates:

Although Lock 1 is in good condition, following an inspection by our engineering team last year it was recommended that the top and the bottom set of gates should be replaced (see photographs below).

This type of work is a standard procedure for the Trust. Timber gates are replaced approximately every 25 years and are relined in between that time to ensure a tight joint at either the mitre (for double gates) or against the clapper post (for single gates). This helps to reduce water loss and maintain the level of individual pounds.

The replacement lock gates for Lock 1 workshop in Stanley Ferry. Both the top and bottom gates will match the existing design and timber material of those currently installed (see. If practically possible, metalwork from the existing gates will be salvaged and re-used. It is anticipated that this work will have a positive visual impact on this heritage asset.

Figure 4 Picture illustrating the current condition of the Figure 3 Photograph showing the current condition of bottom mitre gates of Lock 1. Lock 1's single top gate.

2. Replacement of damaged cill fender.

Presently, the fender which prevents boats from hitting and damaging the cill of the lock is defective. The fender itself is suffering from rot and an impact from a boat has snapped it in the middle. As such, pieces of metalwork (nails) which would have originally fixed the fender to the cill are now exposed.

To address this defect, it is proposed that the

basis using green oak. This will be sustainably sourced from FSC certified suppliers.

Figure 5 Picture showing the defective timber cill of Lock 1

Access statement: The above work has been designed to ensure that members of the public (boat users) can safely use Lock 1. Access to and egress from the Lock will vastly be improved by addressing the condition and current design of the ladders installed within the chamber.