Reasons for Designation
Romano-British canals were used for inland transport and/or the control
and diversion of water. Current understanding suggests that some may have
been only partly navigable, their function as water control systems being
at least as important as their transport role. Generally some canals
appear to have been dug in straight sections, with angular bends at the
junctions, while others were created by straightening and deepening
existing natural watercourses. The upcast from digging was piled up to
form banks on one or both sides of the channel. Causeways are known to
have crossed the canals, some built as an integral part of the
construction, others created by later filling-in of the channel.
There is some uncertainty about the precise dates of Romano-British
canals, but present evidence suggests that their construction and use
mainly spanned the 2nd to 4th centuries. Some appear to have been filled
or silted up at the end of this period, although there is evidence that
some continued in use for transport during the medieval period.
All known examples of Romano-British canals in England are located in
similar topographic positions within the low-lying Fenland areas of
eastern England. The canals vary greatly in length, from small examples
around 6km in length, to the most famous system, known as the Car Dyke,
which stretches some 92km between Lincoln and Peterborough. Although these
canals can be traced over distances of many kilometres, few sections
retain the full range of original construction features. They are
recognizable as earthworks or as cropmarks on aerial photographs, or as a
combination of both. All known lengths, where significant archaeological
deposits are likely to survive, are considered worthy of protection.
The Car Dyke is the largest of the known Romano-British canals, stretching
from the River Witham in the north to the River Nene in the south. First
recognised by antiquaries in the early 18th century, it forms an important
feature of the Roman landscape in the Fens. Although some sections are no
longer visible and much of its length has been incorporated in modern
drainage systems, sufficient evidence does exist for its route to be fairly
accurately identified from Washingborough, 4km east of Lincoln, to 1.5km
east of Peterborough, a distance of approximately 92km. It was originally
thought to continue south of Peterborough to the Waterbeach canal, north
east of Cambridge, but no link has been proven. The Car Dyke survives in a
variety of conditions, at its most complete taking the form of a wide
channel flanked by parallel banks. It is more often visible as low
earthworks or as cropmarks, identified from aerial photographs. It is
clearly influenced by the local topography, taking a sinuous route in the
northern portion, at the boundary between the fens and the upland. The
central portion, south of Billinghay to Market Deeping, takes a more
direct route across relatively flat land, at about the 4m to 5m contour.
The southern part of the route generally follows the 5m contour, again
skirting the upland, with the exception of a short section near Eye where
it cuts through a ridge, rather than following the more circuitous
contour line. It has been suggested that the angular bends along the route
are evidence that it was excavated in sections, the bends occuring where
separate lengths met.
Traditionally, the Car Dyke has been regarded as a means of transportation,
created in the 2nd century AD, and more recently as a catchwater drain,
although firm archaeological evidence for the construction date and use of
the canal in its original form is sparse. It has been suggested that the
presence of unexcavated causeways along its route make it impractical as a
navigable waterway. However, the undug causeways may have served to maintain
differing water levels in the separate channels and long stretches of the
route would still have been navigable. As a catchwater drain, the channel
would have collected and diverted water from the uplands to limit flooding
of the Fenland, although no evidence of a wider drainage scheme has been
identified. It has also been suggested that the Car Dyke formed a boundary
delimiting an imperial estate centred on the Fens, although it is not clear
how such a boundary would have functioned. One or more of the suggested
functions may have been in use at any one time. The size and extent of the
monument implies considerable expenditure of labour and resources, whether
military or civilian in origin. In places the canal appears to have silted
up and fallen into disuse by the end of the Roman period, although its route,
at the Fen edge, may have been subsequently utilised as a boundary. The Car
Dyke is first mentioned in early medieval documents, when parts of it served
as a boundary and there is evidence that at least one section of the Car
Dyke was being used for transport in the 14th century.
The section of the Car Dyke between Whitepost Road and Fen Bridge survives
well as a series of earthwork and buried remains. Despite being maintained as
part of the modern drainage system, deposits in the original, partly
infilled, water channel will contain information on the construction and use
of the waterway. Organic material, including both artefacts and evidence
for the local environment during the Roman period, will be preserved in the
waterlogged deposits. The bank is unusual in its state of preservation,
and evidence of landuse prior to its construction will be contained in soils
buried beneath the bank. As part of an extensive canal system, it will
contribute to our understanding of its impact and influence on the development
of the Roman and later landscape.
Details
The monument, which is in three separate areas of protection, includes the
remains of a section of the Roman artificial watercourse or canal known as the
Car Dyke, part of a linear, north-south canal system which stretches from
Lincoln to Peterborough. Located at the northern edge of modern day
Peterborough, this section of the Car Dyke follows a south east-north west
route from Whitepost Road to Fen Bridge, an overall distance of approximately
4.4km, most of which now forms the civil boundary between Newborough parish
and Peterborough. The route follows the southern edge of the fen at about the
5m contour above sea level.
Between Whitepost Road and Fen Bridge, the Car Dyke is visible as a water-
filled channel, with a parallel earthen bank on its northern side. Its
course is interrupted by two roads, Guntons Road and Gunthorpe Road, which
cross the route, bridging the channel; the roads and bridges are not included
in the scheduling. The three areas of protection, from east to west, measure
respectively 1.56km, 1.23km and 1.54km in length.
The course of the canal comprises a series of fairly straight sections with a
number of oblique and sharp bends. From Whitepost Road the canal initially
follows a line to the north west and then turns to the south west. Between
Guntons Road and Gunthorpe Road two straight east-west sections are linked
by a short north-south stretch turning through two sharp, almost right
angled bends. From Gunthorpe Road the canal turns to the north west following
a slightly curving line to Fen Bridge, a Listed Building Grade II.
The steep sided channel, which now serves as part of the modern drainage
system, measures between 6m and 8m in width at the top, narrowing to
between 3m and 4m at the present water level. A flat berm, measuring 4m to 5m
in width, lies between the channel and the foot of the northern bank. The
bank is flat-topped with a steep slope down to the berm and a gently sloping
outer, north face. The bank measures between 20m and 30m in width at the base
and 6m to 10m at the top. It stands between 1.5m and 2.5m in height along
most of its length except for one section, west of Guntons Road. It stands
0.5m above the general ground level. A fairly steep scarp rises between
1m and 3m above the channel to the ground level to the south. In places a
sloping berm, up to 3m in width, lies between the channel edge and the
southern scarp.
The overall width of the channel, berms, and visible remains of the banks and
scarps is between 40m and 70m.
All fence posts, stiles, water troughs, manholes and access chambers, drain
outlets, sluices, modern surfaces, bridge abutments and revetments, as
well as pipeline stanchions, are excluded from the scheduling, although
the ground beneath them is included.
MAP EXTRACT
The site of the monument is shown on the attached map extract.
