Alternatives Lock (water navigation)

1 alternatives

1.1 inclined plane

1.1.1 marine railway


1.2 boat lift
1.3 caisson lock
1.4 hydro-pneumatic canal lift
1.5 shaft lock
1.6 diagonal lock
1.7 combined system – 3 gorges dam

alternatives

as static approaches mentioned earlier (various types of contouring, excavating, , spanning), there many ingenious dynamic solutions, variations on boat lift or inclined plane. these tend more expensive install , operate, offer faster transit , waste less water.

inclined plane


boat in cradle, @ top of inclined plane on morris canal.

an inclined plane consists of cradle (to hold barge) or caisson (a box full of water in barge can float) moves on rails sideways slope 1 waterway other. since box wet (filled water), archimedes principle ensures caisson weighs same, regardless of size of boat being carried (or if contains water). makes easy counterbalancing fixed weight or second caisson. motive power may steam or hydraulic, or may come overbalancing top caisson water upper waterway.

there no working waterway inclined planes in uk @ moment, remains of famous 1 can seen @ foxton in leicestershire on leicester arm of grand union canal. plane enabled wide-beam boats bypass flight of ten narrow locks, failure make improvements @ other end of arm , high running costs led demise. there plans restore it, , funding has been obtained.

marine railway

big chute marine railway in trent-severn waterway, ontario, canada

a marine railway similar canal inclined plane in moves boats or down slope on rails. however, vessel carried dry (in carrying frame, or cradle) rather in water-filled caisson. principle based on patent slip, used hauling vessels out of water maintenance.

in operation, boat navigated carrying frame, has been lowered water. boat secured cradle, possibly raising slings under hull using hydraulics, , cradle hauled out of water , hill cable. @ top of slope, cradle lowered upper waterway, , boat released. boat not floating, archimedes principle not apply, weight lifted or lowered device varies – making counterbalancing (by dead weights or second boat carriage) more difficult.

in locations, notably big chute marine railway on trent-severn waterway, in ontario, canada, marine railway installed temporary measure @ planned site of flight of conventional locks. in , several other cases, locks never built, , marine railway continued serve on permanent basis.

boat lift

the falkirk wheel, world s first rotating boat lift, acts centrepiece of restoration of forth , clyde , union canals. spectacular wheel presents 21st century s solution replacing flight of locks formerly connected canals , filled-in in 1930. falkirk wheel winning design in competition design new lock. visitors can take boat trip on wheel , lifted on 100 feet (30 m) in few minutes compared time took when original lock staircase operated.

the victorian anderton boat lift, world s first vertical boat lift, linking trent , mersey canal , river weaver in cheshire, has been restored. world s highest boat lift of strépy-thieu in belgium raises or lowers 1,350 tonnes boats 73.15 metres.

another famous derivative peterborough lift lock boat lift located on trent canal in city of peterborough, ontario, canada , lock 21 on trent-severn waterway.

the dual lifts highest hydraulic boat lifts in world, rising 19.8 m (65 ft). considerable accomplishment when conventional locks had 2 m (6.6 ft) rise. each lift has capacity of 1,300 tonnes.

the basins 140 feet (43 m) long, 33 feet (10 m) wide , 9 feet 10 inches (3.00 m) deep. vertical distance lifted 65 feet (20 m). trent-severn has similar lift lock @ kirkfield, basins of same dimension, lifts on smaller vertical distance.

caisson lock

operation of caisson lock

around 1800 use of caisson locks proposed robert weldon somerset coal canal in england. in underwater lift, chamber 80 ft long , 60 ft (18 m) deep , contained enclosed wooden box big enough take barge. box moved , down in 60 ft (18 m) deep pool of water. apart inevitable leakage, water never left chamber, , using lock wasted no water. instead, boat entered box , sealed in door closing behind it, , box moved or down through water. when box @ bottom of chamber, under 60 feet (18 m) of water – @ pressure of 3 atmospheres, in total. 1 of these locks built , demonstrated prince regent (later george iv), had various engineering problems , design not put use on coal canal.

hydro-pneumatic canal lift

possibly inspired weldon s caisson lock, william congreve in 1813 patented hydro-pneumatic double balance lock in 2 adjacent locks containing pneumatic caissons raised , lowered in counterbalance movement of compressed air 1 caisson other. in 1817 regents canal company built 1 of these locks @ site of present-day camden lock, north london. here motivation was, again, water supply problems. company insisted on various modifications congreve s design; resulting installation proved unsatisfactory, , replaced conventional locks.

shaft lock

entrance minden shaft lock

looking superficially similar caisson lock shaft lock. shaft locks consist of deep shaft conventional upper gates. lower gates reached through short tunnel. gates close off approach tunnel not have reach full height of lock. notable examples have been built @ saint denis (paris, france), horin (near melnik, czech republic) , anderten (hannover germany). shaft lock @ minden 52°18′23″n 8°55′11″e / 52.30639°n 8.91972°e / 52.30639; 8.91972 has fall of 12.7 metres (42 ft) , has 8 tanks linked in pairs lock chamber. lock emptied water run each chamber in turn, filling water released chambers saving waste of complete lockfull of water. earlier attempt @ shaft lock had been made @ trollhättan in sweden on line of present göta canal. fall have been 16 metres (52 ft), astonishing in 1749. approach tunnel proved unusable in times of flood , shaft lock replaced 2-rise staircase in 1768.

diagonal lock

this new concept in lock design has yet installed on waterway. shaft lock diagonal shaft. proposal long tube of reinforced concrete, of size accommodate boats being lifted, built on slope between upper , lower levels. bottom of tube sealed strong watertight door, there single pair of conventional lock gates @ top, installed boat s length far wall of tube. change in level achieved filling tube water top pound, or draining. vessel floats on surface of water, guide float or pontoon, shaped fit tube, floating alongside keep clear of walls. side ponds, piped main tube, incorporated save water. in replacing traditional flight or staircase of locks, considerable time saving anticipated. differs similar caisson lock design in boat not have carried in submerged chamber.

the diagonal lock advisory group has identified several sites in britain new design installed, either on new waterways or canals under restoration. projects under consideration include restoration of lancaster canal kendal , proposed new branch of grand union canal between bedford , milton keynes.

three gorges dam model view. pair of 5 locking steps @ center ship lift left


a combined system – 3 gorges dam

at 3 gorges dam on yangtze river (chang jiang) in china there 2 stairsteps of 5 large ship locks (each 300 m long , 35 m wide) ten-thousand-tonne ships. in addition there boat lift (a large elevator) capable of moving three-thousand-ton ship vertically in 1 motion. locks , boat lift provide total lift of 113 metres.