Throughout the summer, CTJV has continued to make steady progress with the advancement of the construction of the Parallel Thimble Shoal Tunnel Project.
The ventilation buildings continue to rise from the islands. These buildings will house critical infrastructure, including electrical switchgear, ventilation fans that will supply fresh air to the new tunnel’s egress corridor, fire pumps, portal pumps and a large emergency generator capable of providing backup power for the tunnel’s pump systems, lighting and jet fans.
All of the monitoring, operations and controls for the new tunnel will be managed through a SCADA (Supervisory Control and Data Acquisition) system from the facility’s existing Control Rooms. A phased approach to all the necessary renovations is now underway, allowing the necessary system upgrades to begin while the Electrical/Mechanical Department continues to maintain operational oversight of the existing tunnels throughout the project.
Beyond the construction of the ventilation buildings, work continues on the “cut-and-cover” sections of the tunnel. The cut-and-cover sections are being constructed at each end of the tunnel in the areas that were used as the launching and receiving pits for the tunnel boring machine (TBM). Construction will continue to rise above this area and tie into the new ventilation building, while the tunnel roadway will pass beneath the completed structure.
From the roadway level, this view below shows a portion of the cut-and-cover area as you look into the tunnel.
Inside the tunnel, CTJV continues to work on the installation of the walls that form the egress corridor as well as the passive fire protection boards which are designed to shield the precast concrete tunnel segments from the intense heat generated from a fire.
The protected egress corridor, shown below, provides an emergency egress for travelers in the event of a fire or other emergency within the tunnel. Designed to be ADA-compliant, the corridor will provide an exit to either of the portals on Islands #1 or #2. Emergency access doors, located approximately every 660 feet throughout the tunnel, will allow motorists to quickly enter the protected corridor and safely exit the tunnel.
CTJV has begun installing the brackets and conduit that will be mounted along the ceiling of the new tunnel. This infrastructure will support the future installation of the tunnel’s jet fans and roadway lighting systems.
Once complete, the new tunnel will be equipped with 15 jet fans. Six banks will each contain two fans, while one bank located near the tunnel portal will house three fans. Together, these fans will play a vital role in managing the ventilation of the new tunnel.
Located throughout the tunnel are recessed safety niches designed to house critical emergency equipment. These niches will contain fire extinguishers, emergency call boxes, fire alarm pull boxes and standpipes, which will provide connection points for fire suppression equipment.
The safety niches are spaced approximately every 275 feet throughout the tunnel, ensuring the emergency equipment is readily accessible to motorists whenever needed.
