Issue link: https://geospatial.trimble.com/en/resources/i/1415420
august 2019 csengineermag.com 45 it would require 400 drivers compared to the two engineers that could run one train. MOTSU's ability to continue mission, although compromised, dem- onstrated the resiliency of its multi-modal infrastructure. Additionally, only a relatively short period of time, two months, was necessary to conduct critical repairs and bring the installation back to full opera- tional capability (FOC). This further demonstrated resiliency and high- lights the role a strategic asset management program has in improving infrastructure resiliency. Background: Mid-September 2018, Hurricane Florence made landfall on the coast of North Carolina causing widespread flooding. In Hurricane Flor- ence's impact zone rests Southport, NC. Neighboring this coastal town is one of the Nation's most critical military ports, MOTSU. The port is the U.S. Department of Defense's primary east coast deep-water port which serves as a multi-modal facility for rail, trucks, and ships. The success of the port's mission depends upon the installation's transportation infrastructure which allows for the seamless transfer of munitions and equipment from shore to ship. Hurricane Florence dev- astated MOTSU's infrastructure causing over $25 million in damage to railroads, wharfs, and interior roadways. MOTSU's rail network exceeds 100 miles of track which consists of 300 individual tracks, switches, bridges, and highway crossings. Of the 100 miles of track, the external rail is approximately 18.25 miles long. The remainder of the rail is a series of internal rails (dip yards, class yards, holding yards) which support the movement, storage and sorting of train cars. The railways were constructed in the 1950s and have been added to and renovated many times since originally built. MOTSU's railways are the installation's primary means to move, orga- nize, and store large amounts of inventory for global distribution. The railways were inundated by floodwaters during the hurricane. Under the pressure of rapidly rising flood waters, Sanford Dam gave way. Waters coursed over MOTSU's network of railways, washed out tons of ballast, destabilized hundreds of feet of culvert, undermined the integrity of miles of track, and left multiple areas of track rails exposed with railroad ties dangling. MOTSU's railway network supports a mixture of military and com- mercial traffic. After the storm, external military and commercial railway operations completely halted due to the washouts. Internally, however, railway operations still continued due to redundancies built into the rail network. Scope of Work Development: The U.S. Army Corps of Engineers (USACE) was assigned the mission to assess all damage caused by Hurricane Florence to MOTSU and contract the repairs. USACE brought the entire enterprise of expertise and assets to bear on this national security problem in order to return MOTSU to FOC by November 26, 2018. With more than 100 miles of railways to assess in addition to other infrastructure damage, the Sa- vannah District USACE leveraged the expertise of its railway subject matter experts (SME) from USACE's Engineer Research and Devel- opment Center (ERDC) and a Rail Assessment Team (RAT) provided by the 757th Expeditionary Rail Center (ERC). They supplemented MOTSU's Department of Public Works (DPW) Railway Maintenance Department's inspection capability of rail infrastructure and rail equip- ment. Together, the USACE teams rapidly evaluated and prioritized repairs. With the exception of extensive wash outs, the overall condition of the MOTSU rail system rated as good. The entire MOTSU rail system had undergone a complete upgrade within the past 10 years. As a result of these upgrades, a majority of MOTSU tracks could absorb Hurricane Florence's impact. The assessment team provided a framework upon which to evaluate, prioritize, and estimate repairs. The team formed recommendations to align with codes and standards. A risk matrix identified areas of deficiencies and recommendations for mitigation which they used to prioritize repairs and provided the template to develop a cost es- timate. Repairs fell into two categories: (1) minimal spot repairs that MOTSU's DPW Railway Maintenance Department could correct and (2) extensive repairs requiring USACE contracts. Focus on Repairs: Up against the clock, the USACE teams and MOTSU DPW collabo- rated to more finely delineate the project's scope of work and priorities. The institutional knowledge of the USACE railway SMEs and MOT- SU's own railway maintenance team, formed through their training and years of service proved invaluable. Together, the teams delineated the critical components of the railway necessary to safely support a fully loaded train. The railway consists of rails which are supported by ties and held in place with plates, spikes and anchors. The entire railway rests upon ballast which supports, stabilizes and distributes the load of the train. In addition, this bal- last serves to shed water away from the timber crossties to prevent premature deterioration. Furthermore, rails must be level and aligned Washed out section of railway – structural fill and ballast absent leaving rail and ties suspended. Photo: Meg Vermillion