Marple Locks

Overview of Marple Locks on the Peak Forest Canal
The images shown below are of all 16 of the Marple flight of locks. There are two images of each lock, one of the tail bridge and one of the lock chamber. All are dated 1978.

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The Rise of a Lock
This 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 locks517.98 feet (517 feet 11.76 inches)
Above Ordnance Datum at the foot of the locks308.38 feet (308 feet 7.08 inches)
Vertical rise between the foot and the summit209.39 feet (209 feet 4.68 inches, say, 209 feet 5 inches)
Distance between the foot and summit of the locks1 mile 3 chains
Gradient or slope of the locks1 in 26.16 (3.825%)
Maximum riseLocks 8 and 14 at 13 feet 6 inches
Minimum riseLock 10 at 12 feet 7 inches
Maximum lengthLocks 5, 9 and 14 at 77 feet 6 inches
Minimum lengthLock 10 at 76 feet
Maximum widthLock 9 at 8 feet 3 inches
Minimum widthLock 13 at 7 feet 7 inches
Maximum capacityLock 14 at 52,135.35 UK gallons
Minimum capacityLock 13 at 45,970.43 UK gallons
Maximum weight of waterLock 14 at 232.75 tons
Minimum weight of waterLock 13 at 205.23 tons
Total capacity of all 16 locks791,217.61 UK gallons
Total weight of water in all 16 locks3,532.22 tons
Average capacity of each lock49,451.10 UK gallons
Average weight of water in each lock220.76 tons
Average rise of each lock13 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 1795The Committee instruct Benjamin Outram to stake out the line of Marple Locks but groundwork only commenced on locks 1, 2, 3 and 4.
July 1796The 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 1797The Committee resolved that locks shall be built at Marple and groundwork started on locks 6, 7, 8 and 9.
March to October 1797Groundwork 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 1797All work on the locks was suspended and it was decided to build the temporary Marple Tramway.
January 1798Work commenced on construction of the tramway to bypass the unfinished locks.
May 1798The tramway opened with a single track having passing places.
August 1801 to October 1801It is likely that there was limited construction work on the locks.
November 1802It is believed that some groundwork for the locks was underway.
November 1803Groundwork was complete and work started on building the locks.
August 1804The locks were in an advanced state of completion.
13 October 1804Locks 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 1804It 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 1805Marple 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 1807Marple Tramway closed.
June 1811The 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.