The state should have done more to warn Seattle Tunnel Partners about the location of a steel pipe the tunnel machine struck in 2013, a dispute panel says.

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The state should have done more to warn Seattle Tunnel Partners about a steel pipe that tunnel machine Bertha struck Dec. 3, 2013, three days before the giant drill overheated and stalled, a dispute review board has ruled.

The decision isn’t binding, but it shows that the state is in for a long struggle over who pays for which problems during the $2 billion tunnel project, whose final price may not be settled for years.

The board did not address whether the pipe hit caused Bertha’s continuing shutdown. Members did find that a crucial, primary document the state provided to Seattle Tunnel Partners (STP) — the geotechnical baseline report to describe soil conditions — is “silent” regarding the steel pipe. It does appear in secondary, reference documents.

The tunnel drill hit a 119-foot-long well casing Dec. 3, 2013, causing a 55-foot segment to break and poke through the surface. Other fragments were removed weeks later. (Mark Nowlin / The Seattle Times)
The tunnel drill hit a 119-foot-long well casing Dec. 3, 2013, causing a 55-foot segment to break and poke through the surface. Other fragments were removed weeks later. (Mark Nowlin / The Seattle Times)

The ruling doesn’t resolve whether the Washington State Department of Transportation (WSDOT) owes money to Seattle Tunnel Partners or how much. STP tentatively sought $125 million last year in a change-order request. Negotiations and lawsuits are likely.

The opinion, released Friday, “did not deal with how the tunneling machine was damaged or the costs associated with repairs,” Todd Trepanier, WSDOT’s Highway 99 program administrator, emphasized in a statement Friday. The state disagrees with the board’s opinion, he said, and will study options to protect taxpayers.

When troubles began

STP argued the pipe strike set off a succession of problems, leading to a breakdown that continues to this day. Project director Chris Dixon said steel pieces damaged the bits on the rotary cutting face, leading Bertha to need more thrust than usual, sustain more friction and eventually overheat.

WSDOT managers replied that the pipe’s location was shown in reports given to tunnel bidders, and in any case, that Bertha’s problems go far beyond the effects of hitting an 8-inch-diameter pipe, and maybe stretch back to Japan, where the $80 million machine was built by Hitachi-Zosen.

The world’s largest boring machine has advanced only a few dozen feet since the stall, mainly to reach a repair-access vault along Seattle’s central waterfront. Bertha has traveled 1,083 feet of its 9,270-foot route since mid-2013.

Repairs are under way to replace the main bearing and install tougher seals before resuming the dig to South Lake Union. Bertha is scheduled to restart in August, though Dixon admits that timeline is aggressive.

This is the biggest dispute to date in the four-lane tunnel project, which is the costliest piece of a $3.1 billion replacement for the old Alaskan Way Viaduct.

The tunnel is forecast to open in January 2017.

Earlier, the board, created to deal with the Highway 99 tunnel project, ruled the state is responsible for unexpected groundwater flows in the Sodo launch pit, for which STP asks $20 million. Another ruling said contractors should pay for extra strengthening of the viaduct at Yesler Way, at a cost of around $5.5 million, where Bertha is supposed to pass below the viaduct foundations this winter.

The $125 million pipe dispute is being watched closely by the international tunnel industry.

A report last month, by the governor’s expert review panel formed to oversee the project’s financial health, said the dispute-review board system “has not been effective” in leading STP and WSDOT to settle differences, “due to both parties’ reluctance to acknowledge the decisions made in the process.” The panel suggested trying other remedies, without saying what those might be.

Test well from 2002

The 8-inch-diameter pipe in dispute, known as Test Well 2 (TW-2), was installed by state contractors in 2002 to investigate a much different, shallow cut-and-cover tunnel option, then reused in 2010, for groundwater-pumping tests.

As it turns out, intensive groundwater pumping was needed last fall so that STP could dig a deep access vault to repair the stuck Bertha; the pumping is suspected of sinking a section of the viaduct and Pioneer Square water pipes 1¼ inches last fall.

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Dixon blamed the stoppage on the pipe in a March 14, 2014, “potential change order” letter.

The tunnel-boring machine (TBM) was cruising along fine at the start of December 2013. When the cutter head hit the steel pipe, it pushed the pipe 6 feet above the surface, Dixon wrote.

“Just before encountering WSDOT’s steel well casing, the TBM had its best day ever,” Dixon wrote. Bertha advanced by 52 feet on Dec. 3, allowing eight of the 6½-foot concrete tunnel rings to be installed behind the machine.

“The TBM continued to perform well on December 4 and 5, 2013, leading WSDOT and STP to believe that the steel pipe had been simply pushed out of the way of the TBM, without causing any damage,” he wrote.

The dispute-board report noted that maps showed the pipe location, but STP understandably assumed it was made of plastic, as were nearly all of the 589 groundwater-monitoring sites downtown. The pipe Bertha hit included a steel cap at street level, and the state had that cap lifted for a groundwater test in 2010, just before the bidding, the report said.

“WSDOT and its consultants were in an excellent position to identify the existence and depth of the steel casing in TW-2,” the opinion said.

But the findings, signed by board members Joseph Keating, Russell Clough and Pete Douglass, all industry veterans, stressed they were not providing information about actual costs.

As for that issue, the contractors’ initial $125 million estimate for repairs and delays could increase. Dixon’s letter predicted a 269-day delay until Sept. 1, 2014, but if Bertha restarts Aug. 31, the delay would be 622 days.

Bertha already faulty?

State officials, all the way up to Transportation Secretary Lynn Peterson, have dismissed the notion that a thin pipe crippled Bertha, which can push with 31 million pounds of thrust and spin with 15 million foot-pounds of torque.

“As to the cause of the current tunneling stoppage, we have all agreed that it is highly unlikely that the well casing is the only issue facing the machine,” Peterson said in a letter last year.

Her view is bolstered by the extensive strengthening plan that Hitachi, the tunnel drill’s manufacturer, has planned this summer.

Not only will new teeth be installed, but Bertha will have wider openings for muck to pass through, longer mixing arms to improve the flow of muck into the internal conveyor belt, stiffer rubber seals around the bearing to block or trap any grit, and reinforcing steel throughout the front end.

Could state funds run out?

In what the governor’s panel has called a worst-case situation, change orders and administrative costs could reach $318 million, while WSDOT holds $124 million in contingencies.

Still, panel members say the state can avoid cost overruns.

In their scenario, the project could recoup $85 million from Bertha’s insurance plan, the contractors could pay $50 million penalties for finishing the job late, and the state would spend $70 million less than the $290 million it estimated to rebuild waterfront Alaskan Way.