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AER Little Current - Swing Bridge
Swing Bridge  
John Morgan  (1976)
North Channel and the Swing Bridge

The Swing Bridge between Goat Island and Manitoulin Island is one of the few remaining structures of the original AER.  Happily it will probably be with us for a long time as it is both the only land means of access to Manitoulin Island and has also been declared an Ontario Heritage Site giving it some measure of protection from those who would modernise access to the island.  The bridge was started in late1912 when the Foundation Co. was given the contract to build the piers and abutments.  The foundation work was completed by May 1, 1913 and in the words of R.S. McCormick, Chief Engineer of the AER, was "a very fine job of pier work.

The bridge itself consists of two 70 ft. deck plate girder approaches on the Goat Island (north) side and a single 60 ft deck plate girder approach on the Manitoulin Island side.  The swing bridge itself is a 368 foot through swing bridge span.  The swing bridge sits a clear 17.5 feet above mean water level and provides a 160 foot opening on either side of the central pier.  2,570 cubic yards of concrete went into the two wing abutments, three intermediate piers and the pivot pier.  The protection piers for the swing bridge are set at right angles to the centre line of the 
   
Swing Bridge
Canadian Railway and Marine News  (1913)
Swing Bridge Foundations
bridge tangent and are composed of timber cribs filled with stone.  The water is 24 feet deep at the centre pier which is set on solid limestone bedrock.  The accompanying photo is taken from the October 1913 edition of Canadian Railway and Marine World and shows the completed pivot and protection piers prior to the erection of the bridge. 

The following description of the bridge is taken from the October 1913 issue of Canadian Railway and Marine World.  "The draw span is 368 ft. long, c. to c. of end bearings, with trusses spaced 18 ft. 3 ins. c. to c., the length being divided into12 panels of 30 ft. 2 ins. each with a central panel of 6 ft. over the pivot pier.  The depth of the truss varies from 30 ft. at the end to 57 ft. c. to c. of chords at the centre over the pivot pier...  The end posts, top chords and main diagonal posts at the pivot pier are built of 21 in. web plates, 24 in. covers, 3½ by
 
Swing Bridge Construction  
Courtesy Little Current-Howland Museum
Sheguiandah, Ontario
Swing Bridge Construction Crew
3½ in. top Ls and 5 by 3½ in. bottom Ls.  The lower chords from end to end are built of 20 in. web plates with 4-3½ by 3½ in. Ls and with 13 in. side plates where necessary.  All intermediate diagonals, except where eyebars are used, are built of 18 or 20 in. web plates, with 4 Ls 3½ by 3½ in.; the verticals are built of a plate and 4-6 by 3½ in. Ls where they act as hangers and of 2-15" Ls where they act as post.

The floor system consists of stringers 53 ins. deep, riveted into the floor beams 68 ins. deep, which are in turn riveted into the verticals of the trusses.  Top and bottom bracing is of Ls, designed for tension only in the case of the top laterals, and for both tension and compression in the case of the bottom laterals.  Each portal consists of 4-7 by 3½ in. Ls latticed with 3½ by 3½ in. Ls, forming a frame 3 ft. 9½ ins. deep with two plate braces.  Transverse bracing at intermediate points consists of 4 Ls 5 by 3½ ins. laced with 3½ by 3½ in. Ls forming frames of varying depth according to the height of the trusses.  The transverse bracing at the centre posts is arranged to allow room for the operator's house and consists of frames similar to the intermediate transverse bracing, above the house, and in addition heavy kneebraces connecting the 24 in. box girder supporting the house.  The centre posts are braced longitudinally by 3½ by 3½ in. Ls, which stay the two adjacent posts against longitudinal flexure and at the same time allow the truss to adjust itself during erection to two bearing points over the pivot pier.

The span while swinging turns on a pivot provided with steel and phosphor bronze discs 25 in. in diameter, and is steadied by eight trailing wheels running on a cast steel track 25 ft. in diameter.  The main rack circle and the track are cast together in 13 sections.  The two main centre girders are 105 ins. deep out to out of Ls, with 8 by 8 in. flange Ls and 18 in. cover plate and carry the dead load of the span to the pivot girders 6.5 ins. deep resting on a steel casting which bears directly on the discs.
   
Swing Bridge
Courtesy Little Current-Howland Museum
Sheguiandah, Ontario
Swing Bridge Construction Nearing Completion
While closed the ends of the trusses are supported by cast steel wedges, which are driven by the operating machinery so as to bring a dead load reaction under each end of the truss of 60,000 lbs., thus preventing the end from rising from its support under certain conditions of loading.  Each truss is supported at the pivot pier by two wedges spaced 6 ft. apart, but which are so adjusted that they take the live load only, the dead load being carried by the pivot.  Both the end and the centre wedges are operated by worm gears driven by shafting from the operator's house, and protected by cast iron casing, which is so arranged that the gearing runs in a path of oil.  The main pinion for swinging the span is cast steel 15 ins. in diameter keyed to the 7 in. main turning shaft, and suitable gearing is provided between this shaft and the engine shaft to give the required speed.

The power for turning the draw and for operating the end and centre-wedges is supplied by a 25 hp. Fairbanks-Morse gasoline engine, located in the operators house above the tracks at the centre of the draw, the main shaft having a velocity of 220 r.p.m. and working the machinery through two friction clutches.  The turning shaft and the wedge driving shaft are each provided with a jaw clutch, so that power can be transmitted to each as desired by moving the necessary lever.  A safety device is provided for the wedge shaft, to prevent driving the wedges too far and injuring the latching machinery, consisting of a cross head connected by levers to the jaw clutch of the wedge shaft and so adjusted that when the wedges have been drawn far enough it will have moved sufficiently to disengage the jaw clutch and thus shut off power from this shaft.  The ends of the spans when closed are held in position by a latch located at the centre of the end floor beams and which is so connected with the wedge shafting that it is lifted from its socket when the wedges are withdrawn.  When the span swings, the latch strikes a projection on the socket casting and is lifted, thereby disengaging a trip, which allows it to drop to its original position, so that when the span is closing the latch rollers will mount the inclined sides of the latch casting on the pier and drop into the socket, thus firmly latching the span before the wedges are driven home.  All lengths of truss members are corrected to bring the lower cords in a horizontal line with the bridge closed, and the wedges driven to give a 60,000 lb. reaction at end of truss.  The computed drop in end of truss when the wedges are withdrawn is 1.4 ins. 
 
Aerial View  
Courtesy Little Current-Howland Museum
Sheguiandah, Ontario
Little Current Swing Bridge

The Canadian Bridge Co. was awarded the contract for this job, and this part of the bridge is now being erected.  Due to delays in delivery of material from the mill, the bridge company will not compete this erection until sometime in October."

The photo on the left was probably taken shortly after the bridge was completed.  The view is looking to the north.  The eastern end of the Turner yard can be seen at the top right of the photo with the spur to the coal loading dock just below it.  The causeway and small deck girder bridge used by the AER to go from LaCloche Island to Goat Island can be seen in the upper right of the photo.  This portion of the right-of-way is now use for the new Highway 6 realignment which was completed in 1998.
 
   
Channel Ferry
Courtesy Little Current-Howland Museum
Sheguiandah, Ontario
The Little Current Ferry
Although the highway from Espanola to Turner was completed in 1929, the Little Current swing bridge remained rail only until November 1946 when post war Ontario Government iniatives resulted in an improved Hwy 6 and the paving of the bridge surface to support vehicular traffic.  This change made access to the island much easier and resulted in the closing of the ferry, shown in the accompanying photo,  which had previously shuttled between Little Current and Turner.  

The first ferry to serve Little Current was named "Hiawatha" and had a capacity of twelve cars.  In 1929 fairs were set at 75 cents per car and 20 cents per passenger.  The Hiawatha was originally built in 1874 for ferry service between Dresden and Sarnia, Ontario.  She was retired in 1924, but was reactivated in 1929 and sent to Little Current. Hiawatha served as the Little Current Ferry until 1931 when she burned and sank off Low Island north east of Little Current

The bridge continued to serve both rail and vehicular traffic until the mid 80s when the tracks were removed from Little Current. With rail service terminating at Turner the bridge now carries vehicular traffic only.

More photos of the Little Current Swing Bridge


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