PROJECT BACKGROUND

Objective: Complete removal and replacement of 6ea concrete diffusers at the Eisenhower lock.

Project Scope:

For this Design-Build project, Kubricky Construction Company worked directly with a 3rd party designer to create the final design of replacement 3ea diffusers, dependent on how they would be installed and anchored. Due to severe deterioration, existing diffusers were to be removed and replaced.

Through this process, it was decided to utilize a post-tensioned precast product in lieu of cast-in-place concrete. Once that decision was made, the team worked with the materials division to finalize plans for fabrication.

However, the location of these diffusers, in the St. Lawrence Seaway, required that all work be completed during winter shutdown periods over two construction seasons. Each phase of the project had a hard end date of March 8th so as not to delay the seasonal opening of the international seaway.

Heavy planning efforts were performed by the project team to determine how to remove the existing diffusers as well as erect and complete the installation of the new ones, all while dealing with temperature-sensitive products under extreme weather conditions.

Temperatures were consistently down to -20 degrees Fahrenheit or more at night and didn’t get above 32 degrees during the day. Operations were being performed 20 out of 24 hours a day and therefore exposed crews and equipment to these extreme elements. Not only was it cold for the employees, but with such low temperatures, equipment had difficulties remaining operational due to fuel and other fluids gelling up.

KCC utilized several fuel-powered heaters and tented in the work area to maintain temperatures above freezing so that all products installed could be done in accordance with their respective requirements.

The other difficulty related to this project was the schedule. Due to the heavy load of work required to remove and replace these units in a short period of time, KCC elected to run two 10-hr shifts per day to maintain the intended schedule.

KCC has worked with the Seaway on several projects over the years and has developed a vast amount of experience with the nature of work, the weather challenges, as well as the owner and their expectations. They also had the right people, equipment, and support to perform such a challenging project under extreme conditions.

Hauling, handling, and erecting the precast pieces was a significant challenge. Due to their size, it required special hauling permits to get the pieces on site. This mixed with the winter weather made it challenging to get all pieces on-site and backed under the crane for erection.

The crane itself also had to be large enough to handle the pieces at a large radius due to the limited access. Bay Crane was contacted to supply their 450TN hydraulic truck crane in order to safely handle the 92,000-pound pieces.

This project tested KCC’s planning and scheduling capabilities. It was highly technical work that could easily have been derailed with the slightest error or broken piece of equipment. With proper planning, acquisition of backup parts/materials, and on-call mechanics/suppliers, KCC was able to complete the project not only on time but earlier than the intended completion date.

This was a great learning experience that helped both senior-level staff and younger field engineers and craft employees to understand what is required to execute a job like this and to gain the confidence in being able to do so.

This was a great project that had some extreme challenges. The project team did a great job setting the project up as well as executing it in the field. The project was completed safely, on time, and under budget.