An Overview of Marple Locks
Click the buttons below and images will be displayed. Each lock has two images; one is the bridge over the tail of the lock, while the other is the lock itself. Buttons displaying the tail bridge have the suffix 't'. All photographs are dated 1978.
The rise of a lock is taken to be the vertical height of its bypass (or overflow) weir above that of the bypass weir of the lock below it. In the the case of the Peak Forest Canal the Deposited Plan of the Marple flight recorded the overall vertical rise to be 212 feet but at this stage the number of locks to be built had not been agreed upon. The Committee of the Peak Forest Canal Company recognised that the flight was to be extraordinarily steep and they requested their engineer, Benjamin Outram, on two occasions to reconsider the number of locks in the flight. In the event, Outram settled on their being 16 locks in the flight, with an average rise of 13 feet 1 inch, which meant that the overall rise was to be 209 feet 4 inches.
Nevertheless, as built, the flight rose by 209 feet 5 inches with the rise of individual locks varying between 12 feet 7 inches and 13 feet 6 inches. The two deepest locks at Marple are Nos. 8 and 14, each with a rise of 13 feet 6 inches.
Statistics of Marple Locks based on an Ordnance Survey of April 1894
Above Ordnance Datum at the summit of the locks: 517.98 feet (517 feet
11.76 inches)
Above Ordnance Datum at the foot of the locks: 308.38 feet
(308 feet 7.08 inches)
Vertical rise between the foot and the summit: 209.39 feet (209 feet
4.68 inches, say, 209 feet 5 inches)
Distance between the foot and summit of
the locks: 1 mile 3 chains
Gradient or slope of the locks: 1 in 26.16
(3.825%)
Maximum rise: Locks 8 and 14 at 13 feet 6 inches
Minimum rise: Lock
10 at 12 feet 7 inches
Maximum length: Locks 5, 9 and 14 at 77 feet 6 inches
Minimum
length: Lock 10 at 76 feet
Maximum width: Lock 9 at 8 feet 3 inches
Minimum width: Lock 13 at
7 feet 7 inches
Maximum capacity: Lock 14 at 52,135.35 UK gallons
Minimum capacity:
Lock 13 at 45,970.43 UK gallons
Maximum weight of water: Lock 14 at 232.75 tons
Minimum weight of
water: Lock 13 at 205.23 tons
Total capacity of all 16 locks: 791,217.61 UK gallons
Total weight
of water in all 16 locks: 3,532.22 tons
Average capacity of each lock: 49,451.10 UK gallons
Average weight
of water in each lock: 220.76 tons
Average rise of each lock: 13 feet 1 1/16 inches
These locks are among the deepest narrow locks in the country and the Upper Peak Forest Canal is the second highest canal pound, the highest being the summit pound of the Huddersfield Narrow Canal.
Due to severe financial constraints on the Peak Forest Canal Company, the construction of Marple Locks took many years to complete and to overcome the delay the temporary Marple Tramway was built to bypass the unfinished locks.
Key Dates
October 1795: The Committee instruct Benjamin Outram to stake out the line
of Marple Locks but groundwork only commenced on locks 1, 2, 3 and 4.July 1796: The Committee considered that it was not entirely obligated to
building locks and it examined a range of options. In contradiction to this,
the site of lock 16 (Top Lock) was agreed upon and this determined the location
for the construction of Samuel Oldknow's lime kilns.February 1797: The Committee resolved that locks shall be built at Marple and
groundwork started on locks 6, 7, 8 and 9.March to October 1797: Groundwork started on locks 13, 14 and 15. There was no
mention of lock 16 and it can be deduced that this was in an advanced stage of
construction.October 1797: All work on the locks was suspended and it was decided to
build the temporary Marple Tramway.January 1798: Work commenced on construction of the tramway to bypass the
unfinished locks.May 1798: The tramway opened with a single track having passing
places.August 1801 to October 1801: It is likely that there was limited construction work on the
locks.November 1802: It is believed that some groundwork for the locks was
underway.November 1803: Groundwork was complete and work started on building the
locks.August 1804: The locks were in an advanced state of completion.13 October 1804: Locks 13, 14, 15 and 16 opened. These four locks gave Samuel
Oldknow canal access to both the top and bottom of his newly built lime
kilns.October/November 1804: It is understood that construction of lock 6 was completed
during this period. This was the last one to be completed but the locks were
still not open throughout for navigation.12 November 1805: Marple locks were open throughout on, or shortly before, this
date. The most likely date lies somewhere between the first and twelfth day of
November 1805. Although the locks were then open for trade, their construction
was by no means complete.February 1807: Marple Tramway closed.June 1811: The Committee of the Peak Forest Canal Company, Thomas Brown
(now the Consulting Engineer) and the Agent of Richard Arkwright Junior agreed
that all construction work on Marple Locks was complete and that no further
work was needed other than routine maintenance. Richard Arkwright Junior was
the major financier for the construction of the locks.
