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Satellite)
A view of the anchorage.
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Gary Merrick posted
Aerial view looking west over the approach to the Angus L. Macdonald Bridge.In foreground is the Dartmouth Shopping Centre,Wyse Road,Victoria Park. CFB Stadacona and Halifax Dockyards in background..1970's.
Greg Hartt: Most likely the ‘60’s. The car lots are still at the top of Lyle and Lyle still runs all the way up to Wyse. You can’t see our house on Lyle St due to all the Poplar trees in the neighbours yards. Porter’s Dredging is still at the foot of Lyle. Eric J.M. Salem shared |
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versilis
It was built with two lanes. A reversible land was added in 1999. |
Note that the design of the fence makes it difficult to climb and commit suicide. And the design has a minimum impact on the view. In particular, you can place your camera lens between the bars. The pedestrian and bike lanes were added in 1999 when the reversible land was added. (I tried digging into how much the new fence design reduced the suicide rate, but the only thing I learned is that the bridge authority won't release any data concerning suicides even though they were ordered to do so a few years ago.)
During a workday, the bridge sees 48,000 crossings per day. The reversible lane carries traffic to Halifax in the morning and to Dartmouth in the afternoon. [
MacdonaldHistory]
These statistics are from
MacdonaldHistory.
| Angus L. Macdonald Bridge Statistics | |
| Total Length: | 1.3 km (0.84 mi.) |
| Suspension Bridge Suspended Spans: | 762.1 m (2,500.4 ft.) |
| Length of Halifax Approach: | 148.3 m (486.5 ft.) |
| Length of Dartmouth Approach: | 436.9 m (1,433.5 ft.) |
| Width of Deck: | 11.5 m (34.8 ft.) |
| Width of Bicycle Lane/Sidewalk: | 2.6 m (8.5 ft.) |
| Height of Towers: | 102.9 m (337.69 ft.) |
| Elevation of Road Deck (above water at centre span): | 54 m (177.25 ft.) |
| Clearance Under Bridge (at centre span, high water level): | 46.9 m (153.87 ft.) |
| Number of Traffic Lanes: | 3 |
| Restrictions: | No trucks weighing over 3,200 kg (7,055 lbs)
Buses permitted
Vehicle clearance of 4 meters |
Starting in 2014, American Bridge replaced the suspended deck. "The superstructure replacement work was completed in 10m (32′) and 20m (65′) orthotropic deck truss segments. The old thru-truss deck segments were cut away, lowered to a waiting barge, and the new segment raised and installed [using] a custom lifting gantry fitted with strand jacks, temporary deck connection (to maintain continuity of the stiffening truss), and custom cantilevering falsework mounted on delivery barges that enabled positioning of the segments over the tower islands. American Bridge developed a 57 step procedure for replacing each segment, with individual durations ranging from 10 minutes to 3 hours. Constantly changing loads were accurately calibrated and distributed through retensioning of suspender extensions after each lower and lift. Other work included the replacement of 148 hanger assemblies, installation of new handstrands, replacement of six cable bands and 192 cable band waisted rods, and the addition of a dehumidification system for main cables." The work was completed in 2017. "This was only the second time that the suspended spans of a suspension bridge was replaced while keeping the bridge open to traffic. The first was completed by American Bridge on the
Lions Gate Bridge in 2002." [
AmericanBridge].
The following five photos are from the American Bridge
webpage.
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the-big-lift, this webpage has a gallery of photos
The Lion's Gate Bridge, which had its deck replaced 15 years earlier, is a sister bridge. That means it had the same design. I wonder if American Bridge kept its custom gantry so that they could reuse it. |
A newspaper article about the Big LiftI noticed in the above photo that the old truss was a pony truss, and the new one was a much shallower deck truss. So I looked for a street view before the deck was replaced.
The next available view is Sep 2017. The deck appears to be done, but they are still working on one of the towers. At least traffic is no longer obstructed.
I caught a frame in a timelapse video that shows the cutting torches in action.
A little after 2:07 in the above video I noticed the suspension cable go up and then come back down as they removed the old truss and then added the new truss to the gantry load. At 6:04, you can see the deck go up and down as the load on the gantry is changed.
During a workday, the replacement of a panel is supposed to be done overnight. So this one must have been done on a weekend.
They had been turning the panels 90-degrees. I could not figure out why until I saw this sequence. They are over land so that can't use barges. So they are moving the panels on a carriage on rails over the roadway to the end of the bridge. Thus they turn the panels 90-degrees so that they fit in the roadway. In addition to the turning, we see the old truss go down the road and the new truss arrive.
I skimmed this video. It explains the history of the bridge and the 1999 work.
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