User:AntiCompositeNumber/Lowell Canal System/notes


 * Proprietors of Locks and Canals on the Merrimack River incorporated in 1792
 * PL&C began work on Pawtucket Canal in 1792
 * Pawtucket Canal completed in 1796
 * Pawtucket Canal used for transportation to bypass Pawtucket Falls
 * ~1803 Pawtucket Canal traffic decreased with decrease in Newburyport timber demand
 * Competed with Middlesex Canal, which connected Merrimack R. to Boston
 * 1821 Boston Associates purchase controlling stock in PL&C
 * 1822 Merrimack Manufacturing Company opens
 * 1822 Pawtucket Canal begins to feed power canal system
 * 1826 Two new canals built with plans for 4 more
 * 1836 Planned system complete
 * Two levels of power
 * 1837 James B. Francis becomes chief engineer
 * First Pawtucket Dam was "crude wooden structure"
 * c. 1830 "Masonry dam seated on heavy wooden cribbing"
 * 1833 "Two more courses of granite headers" and wooden flashboards added to dam
 * 1840s water shortages, excess flows common (not at same time)
 * Excess flow decreases efficiency of mills
 * Increased current in canals decreases head
 * JBF proposes Northern Canal
 * Would require more control over river flow
 * Would require lower flow through canals at night to store water
 * Essex Company of Lawrence and PL&C partner to gain control over NH lakes
 * 1847 Northern canal finished
 * Northern canal "reversed the current in the Western Canal from the junction to the Swamp Locks Basin".
 * 1848 Francis completes Moody Street Feeder
 * Underground Boott Penstock transfers flow from Merriack Canal to end of Eastern Canal
 * Northern canal cost $551,585
 * Moody Street Feeder cost $86,132
 * Boott Penstock and Western Canal work cost $15,000
 * Previous system had capacity of 91 "mill power"
 * Northern canal increased system to 139 mill power in all seasons
 * Additional power was available when conditions permitted
 * Accounted for almost 12,000 HP
 * Francis would close gates during lunch break in summer to save water
 * 1846 turbine experiments showed turbines more efficient than breast wheels in common use at time
 * Turbine conversion happened during and after Northern Canal construction
 * Pawtucket Gatehouse used by Francis to study turbine operation and weir flow
 * Gatehouse contained testing chambers, other scientific equipment
 * Gatehouse one of first industrial research labs in US
 * Francis published research in 1855 Lowell Hydraulic Experiments
 * 1847 Pawtucket Gatehouse contained first practical Francis Turbine
 * 9ft diameter, positioned vertically in cylindrical granite wheel pit
 * Francis turbine is inward-flow turbine
 * Francis turbine improvement on 1838 design by Samuel Howd
 * 1849 Improved turbine installed in Boott Mills
 * Francis was in charge of landscaping along Northern Canal (Note: Records apparently exist in PL&C papers of plantings. Inquire with UMLL CLS?)
 * Canals became part of Lowell NHP in 1978
 * Northern canal is 4,373 ft long, 100 ft wide (avg), 15 to 21 ft deep
 * Single bend designed to reduce friction head loss
 * First 130 feet of wall downstream from dam is concrete and rubble
 * Next ~1000 ft built on island of rubble in cement, backfilled with cleay and earth and rubble retaining wall
 * Last section is Great River Wall, with walkway
 * (continue at Pawtucket Gatehouse)
 * (continue at Pawtucket Gatehouse)