Tag: Caisson

Lowering the Caisson into the Pier Casing

Lowering the Caisson into the Casing.
Lowering the Caisson into the Casing.

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This HDR image shows the 60 foot long caisson as it is being guided, by the Ironworkers and Carpenters, into place inside the pier casing. After placing the caisson the next step will be to fill the pier with concrete. The steel casing sits on the river bottom and then the caisson fits into a rock socket has been bored 30 feet below the casing into the bedrock of the river bottom. This makes the total length on the pier nearly 60 feet from the surface to the base. The iron cylinder is there to both guide the drill during drilling and to form a protective shell for the pier once the bridge is built.

This image is from a three frame bracket set using -2, 0 and +2 EV settings. I merged the bracket set in NIK HDR Efex Pro 2 and because the workers were moving quite a bit I had to apply 80% anti-ghosting to isolate them and remove the ghosts of their arm movement. After merging and some mild tone-mapping in NIK HDR Efex Pro 2 I returned the merged file to Aperture 3 where I completed my processing by adjusting contrast, alignment, sharpening and the individual color channels to achieve the look I wanted for the final image.

Rigging for the Caisson Pick

Rigging the Caisson For Lifting #1
Rigging the Caisson For the Pick #1

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These Ironworkers are setting the rigging to pick this caisson and right it so that it can be lowered into the casing for final placement. To lift it two cranes must coordinate their actions so that the main crane can upright the assembly and transfer it from the barge to the pier casing. Photo Tip: Having the men in the photo helps give scale to the size of the structure.

Once more this is a three bracket set of exposures using -2, 0 and +2 EV to capture the broad dynamic range between the sky and the foreground I encountered. This is one of the most important reasons to learn and use HDR techniques so that in a situation like this there is a reasonable chance that there will be enough data to create a good image after merging the exposures.

I used NIK HDR Efex Pro 2 and Aperture 3 to merge and process the image.

Rigging the Caisson For Lifting #2
Rigging the Caisson For the Pick #2

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This second image is not an HDR image. There was too much movement of the cables and hooks, between frames in the bracket set; for the anti ghosting to handle in NIK HDR Efex Pro 2. I decided to take the normal (0 EV) exposure into Topaz Clarity to see how well it would do with the wide dynamic range. All in all I am fairly pleased with the way that I was able to bring out some shadow detail and still hold the sky detail using a single exposure. I know some folks like to take the normal exposure and change the exposure value in subsequent copies for a faux HDR look but I don’t go that route since there isn’t any additional data captured as there is when a bracket set is used.

 

Caisson Pick

Lifting the Caisson Into Place
Moving the Caisson Into Place

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Yesterday morning the caisson for the bridge pier, 6R2, was moved into place inside the 12 foot diameter steel casing that will protect the bridge piers from damage once the bridge is finished and the river channel is reopened. The rebar caisson is over 60 feet long and moving it requires excellent coordination between the crane operator and the crew on the ground. The caisson must be precisely placed so that the connections to the next components of the tower can be completed. Not only are there Ironworkers involved but additionally there are Carpenters, Pile Drivers and Surveyors that have specific roles to play when these caissons are positioned. The men in the foreground are surveyors whose role is to make sure that the attachment points are properly aligned by accurately measuring exactly where the caisson is situated in the bore. Once all that is completed the cylinder will be poured full of concrete and the pier will be ready for the next piece to be attached.

This is a three frame bracket set of images shot at -2, 0 and +2 EV. The three images were merged in NIK HDR Efex Pro 2 to create the HDR image. After merging and tonemapping the image was returned to Aperture 3 for final processing.

Be Back Soon

Caisson at Sunup
Caisson at Sunup

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I’ve had to add another 3TB hard drive  to handle my library again. It arrived on Friday and I was able to start the copying process yesterday afternoon. 1,715,000 photos = 1.73 TB  of data that has to be copied before I can get back to work. Looks like it will be finished in another 7 hours if all goes well.