Chesterfield Canal Structures - Thorpe Salvin, UK - UK Historical Markers on Waymarking.com

The Chesterfield Canal
Canal Structures

Staircase Locks
Locks allow boats to change level as the canal climbs or descends a hill. When the change of level is steep, locks are grouped together as 'flights', with each lock separated by a short stretch of level canal known as a 'pound'. Sometimes if the canalhas to climb a very steep hill two or three locks are built together with no intervening pound. These are known as 'staircase' locks. They are rare in England, but the Thorpe flight of the Chesterfield has two sets of treble staircases and two doubles.

Turnerwood
The basin was an addition to the canal, probably created in the 19th century. The wider area of water allowed boats to stop to load stone quarried nearby.

Why are the locks so narrow?
The cost of building a canal was minimised by making it as narro as possible. When early canals, such as the Chesterfield, were built it was judged that to make a profit each boat had to be able to carry a cargo of about 20 tons. Experiments found that the minimum width for such a boat was near 7 feet, any less and it would not be stable. With the width set, it was found that a length of near 70 fett was needed to carry the cargo required. The locks were made just wide and long enough for one such boat to pass through at a time. These dimensions later became a standard for many other canals.

Near navigable rivers the locks were often built at double width, to allow larger river craft to pass through. That is why the canal's locks between Retford and the river Trent were built to a wider pattern.

Findings of the Archaeological Survey
The restoration of this section of the canal, which was completed in 2003, offered a rare opportunity to study the engineering methods of the pioneering phase of canal construction in Britain. Archaeologists recorded a great deal of important evidence about the original construction of the locks in the 18th century, as well as the repair and rebuilding works that kept the canal in use throughout the 19th and early 20th centuries.

The lock chambers are built either of brick or stone, or a combination of both. It is not known why the materials vary, but the brick kilns could not always produce enough bricks of the right size and quality, whereas suitable stone was readily available in the area. Another reason may be because the locks were constructed by different contractors.

The lock walls contain a massive timber framework, which strengthens the walls and prevents them from collapsing inwards as the pressure of the water rises and falls. This framework ends about 2 metres into the surrounding earth.

On the approaches to the gates the walls were originally built of roughly shaped stonework, perhaps intended to give the locks a rustic character to blend in with the countryside.

However on the flight of locks below Turnerwood the lower approach walls have massive stone end-blocks.

Each lock has a weir that carries excess water past the lock into the pound below. Many have survived in their original state, often simple channels through the natural clay of the area with brick and stone lined inlets and outfalls.

More elaborate by-weirs were also built, such as the cascaded one at Turnerwood Bottom lock.

The staircase locks also had overflows from the lock chambers to the by-weir channels. This is because it is easy to flood such locks if they are not correctly operated.

Masons' Marks
Stone is readily available locally and was widely used in the construction of the locks and bridges. The masons who cut and dressed the blocks often marked them by carving their own individual symbols, to show who had done the work. Many examples have been found and recorded.

The 46 miles of the canal link Chesterfield to the River Trent at West Stockwith, in Nottinghamshire. There a large lock allows boats to pass between the canal and the tidal river, thereby giving craft access to the rest of the national inland waterways network, and the North Sea via the Humber Estuary.

The Chesterfield Canal is of great historical importance. It was one of the first canals to be built in this country and is the work of the pioneering engineer James Brindley. Construction began in 1771 at Norwood tunnel at Kiveton Park, and continued towards Worksop. Therefore the locks here were the first to be built and their configuration was planned under Brindley's direct supervision. The canal was completed in 1777.

Early in the 20th Century the twenty miles of canal between Chesterfield and Worksop became derelict. Restoration is well underway, with the work on the stretch in Rotherham (completed in 2003) funded by Yorkshire Forward, the Heritage Lottery Fund, British Waterways and Rotherham Metropolitan Borough Council.

The major obstacle on the canal's route is a hilly limestone ridge in South Yorkshire. the 22 locks between Kiveton Park and Cinderhill make it possible for boats to climb the eastern flank of the ridge up to the level of Norwood tunnel. On the other side of the tunnel the 13 Norwood locks descend the western flank of the ridge.

The towpath of the canal is a popular walking route called the Cuckoo Way.

The Chesterfield Canal Partnership is the grouping of local authorities, statuary and non statuary bodies, the voluntary sector and private enterprise working toward ensuring that the historical, ecological and recreational value of the canal is retained and supported.

You are invited to explore and use the Chesterfield Canal for boating, walking, fishing and other leisure activities. Always remember that the canal is a special environment and has a high ecological and heritage value. Help to protect it for future generations to appreciate.