Tide gates save Midtown Tunnel from floods Nov 2012
Peter Kenyon, TunnelTalk
Motorists using the Downtown and Midtown Tunnels under the Elizabeth River in Virginia were spared serious disruption as protective measures and the successful operation of the tide gates ensured no repeat of the 2003 inundation caused by Hurricane Isabel.

Tide gates on the Norfolk approach of Midtown tunnel successfully held back a 13ft storm surge

This despite record storm surges of 13ft that were similar to those that devastated New York's tunnel infrastructure.
Elizabeth River Tunnels (ERT), which manages the tunnels for Virginia Department of Transportation (VDOT) began moving protective equipment and pumps into place on Friday (October 26) in advance of a three-hour closure of the Midtown Tunnel between 5-8am to allow a full test of the tide gate system that failed so spectacularly in 2003 despite the heroic and near-fatal efforts of workers at the time.
On Sunday (October 28) rising tide levels threatened the first closures, which are triggered by surges above 6ft, and the Midtown was restricted in both directions with a pilot vehicle ferrying drivers at lower speeds through the tunnel.
Deteriorating conditions, tidal surge and high water finally forced the first closure of the Midtown Tunnel at 8.50pm, but the main approach from the Martin Luther King Expressway was reopened just two hours later, though access ramps from Raleigh Avenue, Claremont Avenue and Cleveland Street remained closed.
Workers raise the tide gate on Monday afternoon

Workers raise the tide gate on Monday afternoon

The Downtown tunnels remained unaffected throughout the superstorm.
At 8am on Monday (October 29), as the height of the storm and flood surge approached, a decision was made to close the flood gates of the Midtown Tunnel and by 12.30pm ERC reported that crews were actively pumping water away from the tunnel approach on the Norfolk side using mobile pumps. ERC officials reported the water level on the Norfolk side of the tide gate reaching as high as 13ft.
But within just four hours all standing water at the Norfolk approach had been pumped away, the gates were reopened and a normal service resumed, with no serious damage suffered.
In 2003 the Midtown tunnel was completely inundated after a stuck plate meant the tide gates remained open during the storm surge. The tunnel filled with 44 million gallons of water - almost exactly the same amount that is currently sitting inside the Brooklyn-Battery tunnel in New York City - and the tunnel remained shut for four weeks for pumping out and repair work.
On that occasion VDOT employees risked their lives in a desperate struggle to release the plate, which should have been removeable with a few blows from a small hammer. Four bolts were removed as the storm waters surged, but frantic efforts to break what should have been temporary welds ended in failure.
As workers grappled with the plate, now under the rising water, the flood began to engulf them. Other VDOT employees began rushing to the scene as they heard of the struggle.
One, Darrell Southerland, drove a truck through 3ft of water from the Portsmouth side, and Facility Manager Bruce Wilkerson tried to do the same in his car, but his vehicle stalled by the rising flood. Another employee, Robert Hewitt, was also forced to leave his stalled pickup in the tunnel and scurried along a handrail on top of the catwalk to get to the Norfolk side.
Aerial view of Norfolk side entrance to Midtown tunnel

Aerial view of Norfolk side entrance to Midtown tunnel

Meanwhile, Robert Huffman drove a tow truck from the Norfolk side to the tunnel entrance to haul the men out if necessary. After jumping out of the truck and trying to help with the plate, Huffman was swept into the tunnel. He was rescued only after a human chain of workers was formed to pull him back.
Finally Wilkerson took the decision to abandon the effort and evacuate and the men scrambled onto two trucks and drove out of the deepening storm surge.
Within the next week, the men's heroic stand had been praised not only by Commissioner Shucet, who called them gallant; but also by Governor Mark Warner, who said they had gone above and beyond the call of duty; and by President George Bush, who recognized them in a stop in Richmond for reports on storm recovery efforts.
The flooding initiated plans for a second Midtown crossing, to run parallel to the existing tunnel. Early construction in advance of a 1.7km long two-lane submerged road tunnel is currently under way, and is expected to be complete by 2018.
An ERC spokeswoman confirmed to TunnelTalk that the new submerged crossing does have a tide gate system designed into it. She also confirmed that "no direct damage" had been caused to either the Midtown or Downtown tunnels as a result of Sandy.
ERC Chief Executive Officer, Greg Woodsmall said: "Our men and women mobilized quickly and were ready to do whatever it took to keep the tunnel open as long as safely possible. We continued to evaluate conditions, monitoring the storm and tides and were ready to execute our closing plan when the time came."
ERC Chief Operating Officer, Bruce Wilkerson, added: "Our team executed the response plan extremely well. We began our planning well in advance of the storm and we had equipment, mobile pumps and crews positioned to mobilize as soon as was needed."
Superstorm devastates New York region - TunnelTalk, November 2012
New York tunneling projects brace for Irene - TunnelTalk, August 2011
New York tunneling projects weather Irene - TunnelTalk, August 2011
Financial close seals Midtown Tunnel start - TunnelTalk, April 2012
Midtown P3 contract awarded in Virginia - TunnelTalk, December 2011
Bangkok examines flood prevention plans - TunnelTalk, December 2011
In search of resilient cities - TunnelTalk, December 2011

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