Addressing the Bertha bearing seal issues - TunnelCast

13 Feb 2014: Damage to the vital seals of the 10m diameter main bearing on which the 17.5m diameter x +100 ton cutterhead of the giant Hitachi EPBM rotates has brought the machine to a halt and must be replaced before the machine can move again. Chris Dixon of the construction JV, Seattle Tunnel Partners (left), and Todd Trepanier, Program Administrator for the client, WSDOT (right), speak of the possible causes and the consequences of the situation, describing in detail the Bearing Seal Damage; the Contract Risk Allocation; availability of the Contingency Fund; and consequences of the delay to the Project Schedule.


Addressing Bertha's bearing seal issues

Sterling Noren reporting for TunnelCast in Seattle
AWV, Alaskan Way viaduct, replacement
tunnel, Seattle
Construction JV:
Seattle Tunnel Partners - Dragados/Tutor-Perini
Washington State Department of Transportation
Project scope:
World's largest single-tube, double-deck highway tunnel to replace earthquake damaged Alaskan Way viaduct across the Seattle waterfront
Tunnel design:
17.48m o.d. Hitachi EPBM drive for a 2.7km highway tunnel under downtown Seattle
Segmental lining:
Nine segments and a key in each 600mm
thick x 2m wide ring
Start of TBM drive - June 2013
Breakthrough planned for July 21, 2014