The photos below were taken in late May from the Portsmouth west tower. Three of the cantilevered vehicular deck sections are complete, and several segments await installation. The last remaining piers from the old bridge can be seen to the left. The lift span is also visible in the second photo.
The first three piers connecting to the abutment near the Albacore carry only the vehicular deck, and the cantilevered spans rest on bridge bearings. However, the shared piers have only the rail deck on bearings, and the vehicular deck segment cast into the pier itself. This is called a knuckle. The photo below shows one of these knuckles, and in the background, the three piers with bearings (note the shadow between the pier and the deck).
Since the first photo below was taken, work has progressed on this span. The second photo shows the same pier with several of the segments installed, two weeks after the first photo. These segments are being installed at a rate of four every 24 hours - 2 during the day shift and 2 overnight.
The view below is from the same pier, looking toward the towers, with the completed rail deck below, and the knuckle that will support the final span on the Portsmouth side.
In the photo below, the span on the right will receive one more segment, leaving a small gap between the two spans. This will be filled with concrete that is poured into forms that are built on-site. This is know as a "closure pour", and occurs at the ends of each cantilevered span.
When the vehicular spans reach the towers, they will be supported by concrete beams that span from one tower to the other. Below are photos of the rebar cage, the concrete placement, and the completed beams 2 weeks later.
Meanwhile, in the base of the towers, the machinery has been installed.
All of the tendons that hold the tower segments together have been tensioned and grouted on the two Portsmouth towers, and they are now able to handle the counterweights.
The four counterweights (one in each tower) consist of metal cages into which concrete blocks are stacked. Each will weigh a million pounds, so the cages are lifted empty to the tops of the towers, and temporarily held in place by steel fixtures, one of which (in beige) can be seen below (the cage is not yet in place). The weights, shown in the second photo below, are then added.
The black tubes that are visible along the inside walls of the tower were used to inject the grout around the tendons.
On top of the towers, small sheaves have been installed. These sheaves are for the control cables that raise and lower the bridge. In the coming weeks, the large sheaves that will carry the lift cables will be installed.
On the Kittery side, the rail deck is about halfway complete, and the knuckle has been constructed atop the single shared pier. Below are photos looking back from the vicinity of the railroad abutment toward the tower, and from the shared pier back toward shore. The railroad curves to the east, and has a separate abutment, as it does on the Portsmouth side. The third photo is of the construction of the rail abutment.
Below the abutment from the original 1820 bridge.
Work is well underway on the lift span. This 4-million-pound span is constructed of 6 main girders, 3 along each side, cross-braced in the center. The first photo below is of the entire span. The second photo shows one of the points where the girders are joined, and the cross bracing is visible in the center.
Polycarbonate wind fairings line the up- and down-river sides of the span. Here we see one being lifted for installation. These are visible in the overview photo above. A few have not yet been installed. The photo immediately above (lifting girder) shows the exposed mounting points for the fairings.
I'll close this post with an historical perspective on the project. Below is a photo taken around 1920 by prolific Kittery photographer, J. Frank Walker. Walker was standing atop the lift span of the 1820 bridge (this bridge survived until 1939 - more on that in a future post). The photo below it was taken from a similar perspective.