A concrete mix with a low water-cement ratio, fly ash, and moderate amounts of an active pozzolan was specified to allow the jackets to be constructed using a 2.5" minimum concrete cover with uncoated reinforcement. The concrete in the splash and tidal zone received a polyurea coating, which impedes micro cracking and reduces the weight of the jackets. The concrete jackets were matchcast horizontally in approximately 10ft tall segments and placed around the existing shafts, spandrel beam and diaphragm wall in two halves, connected by transverse HS rods. These rods also connected the precast segments vertically.

Two-thirds of the precast concrete jackets were submerged under water when placed in their final position. The precast jacket concept allowed for a high degree of off-site prefabrication followed by in-the-wet erection with minimal use of divers. The existing shafts were cleaned as necessary by high-pressure jets before placing the pre-cast jackets. An erection frame was placed on top of the existing shafts that allowed two pre-cast segments to be placed on each side of the concrete substructure above water. HS rods were used to connect the segments on the outside of the shafts. Prior to joining the segments an epoxy coating was placed on top of the matchcast surfaces. Vertical HS rods were placed in ducts and connected to the first segments through couplers and were then prestressed.