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15 multiple assets. For example, the use of a sunken vessel to air, or monitoring of traffic may be made unusable for an damage the tunnel shell will cause a great amount of first extended period. Replacement of the sabotaged system may responder resources to be devoted to mitigating the water- incur great costs and lengthy installation times. Significant borne disaster. An aggressor may take advantage of the con- loss of MEC systems may cause tunnel operations to be sus- centration of resources at that site and strike another area pended. The related assets are as follows: deemed to be the higher-value target. In this example, the sunken vessel only serves as a delivery mode for an explosive Tunnel structures. A disrupted utility may cause the sus- to reach the tunnel shell. A quantity of explosives detonating pension of tunnel system operations due to unsafe condi- outside the shell would damage the shell. The extent of dam- tions. Power loss in a tunnel system will likely trigger a age will be determined by the exact placement of the explo- closure of the underground area and evacuation of stand- sive and the quantity deployed. All explosions occurring from ing populations. Water or sewer inflow will trigger an the outside on the tunnel shell will cause the closure of the immediate suspension of tunnel operations or severe tunnel to users for a period of time while the damage is restrictions on travel through the system. inspected and mitigated. Efforts will also be expended to Vent shafts. Exhaust and air intake machinery may suffer evacuate any tunnel users in harm's way. a loss of function due to a loss of power or a sudden water The related asset is as follows: inflow. Stations (passenger tunnels only). Sabotage of MEC Tunnel structures. Subaqueous tunnels may suffer dam- systems may adversely impact a passenger station due to age or collapse if struck by a ship of sufficient size. The power loss, which cripples lighting, ventilation, and damage or collapse may allow sufficient water inflow to safety systems. Disrupted sewer, steam, and water lines flood the tunnel, thereby endangering lives, property, and allowing material to enter the station could create an the use of the tunnel. unsanitary condition, thereby precipitating injury and evacuation. Substation. Facilities containing connections for pumps Fire (Arson) and feeder machinery may suffer a loss of function due to Arson is the criminal act of enacting a conflagration on a loss of power. property. The act is intended to inflict injury to persons and Control Centers. Monitoring capabilities of a control cen- damage to property. Arson that is intended to damage or ter are diminished or negated by a loss of power. Staffed destroy property may also recklessly endanger the safety of control centers are also subject to evacuation because of tunnel users and first responders. An occurrence of arson unsafe or unsanitary conditions that may be found with a could inhibit the ability of the tunnel operator to open the disrupted water, steam, or sewer pipe. tunnel for a period of time. A 341 million British thermal Distribution channels. Piping, wiring, conduit, and units (MBTU) per hour (100 MW) fire is the maximum shafts to control fire control, ventilation, smoke detec- design fire currently used globally for most road tunnels and tion, carbon sensor, and video monitoring equipment is the maximum size fire that can be controlled by the may suffer a function loss due to a power loss or inten- majority of road tunnel ventilation systems. In typical tran- tional damage. sit and rail tunnels, the maximum design fire size is much Utility terminus building. This facility may be the direct lower, in the neighborhood of 68.2 to 170.5 MBTU per hour target of an aggressor determined to damage or interrupt (20 to 50 MW). Any fire larger than 341 MBTU per hour MEC systems within a tunnel system. Loss of the utility ter- (100 MW) will not be controllable in any tunnel and, there- minus building would require intensive repair efforts. fore, could be a major catastrophic event. Therefore, this project considered only fires larger than 341 MBTU per hour (100 MW). 2.4 Conclusions To varying degrees, the hazards and threats presented in Sabotage of MEC Systems this chapter have occurred in the United States. They will A premeditated, intentional disruption of tunnel MEC likely present themselves again. Their capacity to close a tun- systems presents a threat to all nearby below-grade tunnel nel system, however briefly, is proven. Although their detri- structures. Loss of system function may alter the effective- mental effects on the tunnel system, equipment, and users ness of safety and operational systems, thereby presenting a may be mitigated, the more consequential security threats tunnel condition unfit for general use. Systems designed for may have unprecedented consequences in terms of major the evacuation of water, delivery of power, provision of fresh tunnel damage and indeterminate service impacts.