Tunnel Boring Machine

Assembly Timeline

Tunnel Boring Machine (TBM)

The Design-Build Team is building the twin tunnels, connecting Watson Island and Dodge Island in the City of Miami, using a Tunnel Boring Machine (TBM). The project broke ground in May 2010 and is scheduled to be completed in May 2014. The TBM was built by Herrenknecht in Germany and is the largest diameter soft ground tunnel boring machine in the United States.

TBM PRODUCTION: Production of the TBM parts ran from March through October 2010.Assembly commenced in October 2010 and was completed in April 2011. TESTING / COMMISSIONING: Fully assembled, the TBM's testing and commissioning was successfully completed on April 15, 2011.
SHIPMENT: Disassembly and packaging of the fully commissioned TBM pieces ran through April and May 2011. The packaged TBM was driven in special trucks from the Herrenkencht plant to the Port of Kehl, Germany. Cranes lifted the TBM pieces onto river barges bound for Port Rotterdam, Holland where is was loaded onto the Combi Dock I. The ocean carrier's self-contained cranes lifted the 19 TBM heavy haul pieces onboard and commenced its transatlantic voyage to Miami on June 8th.
TBM ARRIVAL IN THE U.S.A.: The Combi Dock I arrived at the Port of Miami on June 23, 2011. It arrived in pieces (75 regular, 20 containers and 19 heavy haul pieces). The regular cargo and container pieces were delivered via trucks from the Port of Miami to the work site at the center median of the MacArthur Causeway on Watson Island. The 19 heavy haul pieces were lifted by the ship's cranes off the ship and onto barges. The barges delivered the pieces to Watson Island. From the barges, each piece was loaded onto a special roll-on/roll-off vehicle that delivered the pieces one by one to work site on MacArthur Causeway center median during a very successful five-night rolling stop operation.
PRE-ASSEMBLY: Some of the TBM pieces (such as the cutterhead and tailskin), were pre-assembled after all of its pieces were on their staging site on the center median. This began the week of July 5th, 2011.
REASSEMBLING THE TBM IN ITS LAUNCHING PIT: The launching pit for the Port of Miami Tunnel's TBM is about 400 feet long, 100 feet wide and 40 feet deep. Assembly of the TBM began on August 10, 2011 when the first piece was lowered into the put from the staging area on the center median. that was one of the six pieces of the TBM shield. As one piece one day at a time, the head of the TBM began to take shape inside the launching pit, while the TBM's three gantries (tail) were also being assembled on the work zone. On September 1, 2011, the cutterhead of the TBM was lowered into the pit. This event drew much attention from the South Florida media as a never-before-seen construction activity!
TBM NAME: The Miami-Dade County Girls Scouts Troop named our TBM Harriet, after American History Icon Harriet Tubman. Born a slave, this African-American abolitionist and humanitarian escaped slavery and led several rescue missions through a network of secret passages and safe house known as The Underground Railroad. At its height during the 1950s-1860s, the Underground Railroad Movement freed more than 100,000 salved and became a staple of America's history. With out TBM going underground to make history for South Florida, Harriet is a fitting name for this Florida Mining Marvel.
LAUNCH: Harriet launched from her home in the Watson Island pit on November 11, 2011, boring the first tunnel and emerged on Dodge Island on July 31, 2012. Harriet was was partly disassembled, reassembled and to make a u-turn, and headed back towards Watson Island Boring the second tunnel on October 29, 2012.