Corps Of Engineers Research Articles

Storm Surge Barrier Protection in an Era of Accelerating Sea-Level Rise: Quantifying Closure Frequency, Duration and Trapped River Flooding

Gated storm surge barriers are being studied by the United States Army Corps of Engineers (USACE) for coastal storm risk management for the New York City metropolitan area. Surge barrier gates are only closed when storm tides exceeding a specific “trigger” water level might occur in a storm. Gate closure frequency and duration both strongly influence the physical and environmental effects on enclosed estuaries. In this paper, we use historical observations to represent future storm tide hazard, and we superimpose local relative sea-level rise (SLR) to study the potential future changes to closure frequency and duration. We account for the effects of forecast uncertainty on closures, using a relationship between past storm surge and forecast uncertainty from an operational ensemble forecast system. A concern during a storm surge is that closed gates will trap river streamflow and could cause a new problem with trapped river water flooding. Similarly, we evaluate this possibility using historical data to represent river flood hazard, complemented by hydrodynamic model simulations to capture how waters rise when a hypothetical barrier is closed. The results show that SLR causes an exponential increase of the gate closure frequency, a lengthening of the closure duration, and a rising probability of trapped river water flooding. The USACE has proposed to prevent these SLR-driven increases by periodically raising the trigger water level (e.g., to match a prescribed storm return period). However, this alternative management approach for dealing with SLR requires waterfront seawalls to be raised at a high, and ongoing, additional future expense. For seawalls, costs and benefits will likely need to be weighed on a neighborhood-by-neighborhood basis, and in some cases retreat or other non-structural options may be preferable.

Forecast Informed Reservoir Operations Using Ensemble Streamflow Predictions for a Multipurpose Reservoir in Northern California

AbstractEnsemble Forecast Operations (EFO) is a risk‐based approach of reservoir flood control operations that incorporates ensemble streamflow predictions (ESPs) made by the California‐Nevada River Forecast Center. Reservoir operations for each member of an ESP are individually modeled to forecast system conditions and calculate risk of reaching critical operational thresholds. Reservoir release decisions are simulated to manage forecasted risk with respect to established risk tolerance levels. EFO was developed for Lake Mendocino, a 111,000 acre‐foot reservoir near Ukiah, California, to evaluate its viability to improve reservoir storage reliability without increasing downstream flood risk. Lake Mendocino is a dual use reservoir, owned and operated for flood control by the United States Army Corps of Engineers and operated for water supply by Sonoma Water. EFO was simulated using a 26‐year (1985–2010) ESP hindcast generated by the California‐Nevada River Forecast Center, which provides 61‐member ensembles of 15‐day flow forecasts. EFO simulations yield generally higher storage levels during the flood management season while maintaining needed flood storage capacity by strategically prereleasing water in advance of forecasted storms. Model results demonstrate a 33% increase in median storage at the end of the flood management season (10 May) over existing operations without marked changes in flood frequency for locations downstream from Lake Mendocino. EFO may be a viable alternative for managing flood control operations at Lake Mendocino that provides multiple benefits (water supply, flood mitigation, and ecosystems) and provides a management framework that could be adapted and applied to other flood control reservoirs.

Performances of the New HEC-RAS Version 5 for 2-D Hydrodynamic-Based Rainfall-Runoff Simulations at Basin Scale: Comparison with a State-of-the Art Model

The Hydrologic Engineering Centre-River Analysis System (HEC-RAS), developed by the US Army Corps of Engineers, is one of the most known, analyzed and used model for flood mapping both in the scientific literature and in practice. In the recently released version (release 5.0.7), the HEC-RAS model has been enriched with novel modules, performing fully 2-D computations based on the 2-D fully dynamic equations as well as the 2-D diffusion wave equations; moreover the application of rainfall to each cell of the two-dimensional domain is now possible. Contrarily to the common applications for flood propagation in river reach, this specific module has never been analyzed in the literature. Therefore, the main purpose of this work is to assess the potential and the capabilities of the 2-D HEC-RAS model in rainfall-runoff simulations at the basin scale, comparing the results obtained using both the options (fully dynamic equations and diffusion wave equations) to the simulations obtained by using a 2-D fully dynamic model developed by the authors for research purposes. Both models have been tested in a small basin in Northern Italy to analyze the differences in terms of discharge hydrographs and flooded areas. The application of a criterion for hazard class mapping has shown significant variations between the two models. These results provide practical indications for the water engineering community in the innovative research field related to the use of 2-D SWEs at the basin scale.

Integrating Reservoir Operations and Flood Modeling with HEC-RAS 2D

Current free to use models developed by the United States Army Corps of Engineers (USACE) perform unique functions (e.g., hydrology, hydraulics, reservoir operations, and flood impact analysis) that are widely used in numerous studies and applications. These models are commonly set up in a framework that is limited to point source connections, which is problematic in regions with flat topography and complex hydrodynamics. The separate models need to be integrally linked and jointly considered for accurate risk communication and decision-making, especially during major storm events. Recently, Hurricane Harvey (2017) exposed the shortcomings of the existing framework in West Harris County, TX, where an insufficient understanding of potential flood risk and impacts contributed to the extensive flood damages sustained in the region. This work illustrates the possibility of using a single hydraulic model, HEC-RAS 2D, to perform all hydrologic, hydraulic, and reservoir operations modeling necessary for accurate flood impact assessments. Implications of this study include a simplification of the entire flood impact analysis, which could help future flood risk communication and emergency planning.

Alternative Mitigation to Counter Resource Losses from the Lake Cumberland Drawdown, Kentucky

ABSTRACTThis article presents a case study of the process of developing and implementing mitigation as the result of adverse effects to cultural resources from the drawdown of Lake Cumberland, Kentucky. Signs of a dam failure in early 2007 triggered the U.S. Army Corps of Engineers (Corps) to implement the emergency drawdown. While the drawdown prevented a life safety catastrophe, it created a new erosion zone and exposed archaeological sites to looters. When it became clear that conventional Section 106 procedures to identify and evaluate these endangered archaeological resources were not an option, alternative and creative mitigation became a necessary approach for the Corps to meet its obligations under the National Historic Preservation Act. This article discusses the creative brainstorming among the Corps, Kentucky state historic preservation officer, and tribes that led to three alternative mitigation measures aimed at educational outreach, raising public awareness, and staff training. Furthermore, the article identifies challenges encountered during the implementation of the mitigation measures. Through the presentation of our mitigation journey, we share some of our lessons learned to improve awareness of the challenges and successes one may encounter during the execution of such alternative measures.

Modeling Future Streamflow for Adaptive Water Allocation under Climate Change for the Tanjung Karang Rice Irrigation Scheme Malaysia

Spatial and temporal climatic variability influence on the productivity of agricultural watershed and irrigation systems. In a large irrigation system, the quantification and regulation of the flow at different locations of the channel is quite difficult manually, leading to a poor delivery of supply and demand. Water shortage is a crucial issue due to mismatch between available water and demand at intake point of Tanjung-Karang Irrigation Scheme. This study assessed the potential impacts of climate change on basin outflow for 2010–2039, 2040–2069, and 2070–2099 to the baseline period (1976–2005) and used it as input hydrograph to simulate river discharge. A Hydrologic Engineering Corps Hydrologic Modeling System (HEC-HMS) model driven by projections from ten global climate models (GCMs) with three scenarios (Representative Concentration Pathways (RCPs) 4.5, 6.0, and 8.5) used to simulate the outflow and the Hydrologic Engineering Centers River Analysis System (HEC-RAS) model applied for hydraulic modeling. The projected seasonal streamflow showed a decreasing trend for future periods. The average available irrigation supply for historical period is 15.97 m3/s, which would decrease by 12%, 18%, and 21% under RCPs 4.5, 6.0, and 8.5, respectively. Projected irrigation supply showed oversupply and undersupply to the required supply during the growing season. Simulated discharge could therefore be incorporated into cropping practices to boost the sustainable distribution of water under the new realities of climate change in the future.

Vulnerability of Florida residential structures to hurricane induced coastal flood

This paper presents a methodology to develop hurricane induced coastal flood vulnerability functions for residential construction based on empirical tsunami fragility functions. A force equivalency mapping procedure first transforms the tsunami fragility functions into coastal flood fragility functions. Following the quantification of the damage states and the incorporation of repair costs, the coastal flood fragility functions translate into coastal flood vulnerability functions. Insurance claims data from the National Flood Insurance Program and vulnerability functions independently derived by the US Army Corps of Engineers are employed to validate single-story on-grade timber and reinforced masonry structure model outputs. The limitations of the model and future developments are discussed.

Vegetation Sampling Concepts for Compensatory Mitigation Sites

I n 2018, the Norfolk District of the U.S. Army Corps of Engineers (USACE) and the Virginia Department of Environmental Quality (DEQ), in their roles as co-chairs of Virginia’s Interagency Review Team (IRT), proposed modifications to the Virginia Mitigation Banking Instrument (MBI) Template (Template). The Template is a document used to establish compensatory wetland and stream mitigation banks in the state, serving as a planning-level tool with minimum standards and design criteria for that purpose. Prospective mitigation banks are approved via IRT ratification of an acceptable MBI, which provides the necessary documentation for the “…establishment, use, operation, and management…” of mitigation banks in Virginia.

Uncertainty and Legal Foreseeability in Flood Risk Management

AbstractThe legal concept of foreseeability is an important element of proof in flood loss litigation against the US Army Corps of Engineers. Although hydrologic forecasting and engineering uncerta...

Modeling the slope of embankment dam during static and dynamic stability analysis: a case study of Koga dam, Ethiopia

Quantitative assessment of the stability of slopes is very important for the evaluation of an earth fill dam in order to perform the intended function throughout the service life. This study presents the slope stability and analysis of the Koga earth fill dam. The analyses were carried out using finite element-based PLAXIS 2D software. The behavior of both the body and the foundation of the dam was described using the Mohr–Coulomb criterion. Based on the result of this study, the resulting factor of safety values during end of construction for both static and dynamic stability analysis was 1.6221 and 1.3592, respectively. For steady-state condition, the water level was fixed at normal pool level (2015.25 m). The factor of safety obtained for static stability analysis was 1.6136 and the dynamic analysis 1.3157. The rapid drawdown condition is analyzed with normal pool level of 2015.25 m lowered to 2008.5 m. The analysis results showed that the factor of safety for the static and dynamic analysis was 1.2199 and 1.0353, respectively. Using recommended design standards: United States Army Corps of Engineers, British Dam Society and the Canadian Dam Association the slope stability analysis of the Koga earth dam at all critical loading conditions are safe. The displacement result shows the maximum total displacements for static and dynamic analysis were 1.033% and 1.628% of the dam height, respectively. The displacement result coincides with Fell et al. (J Geotech Geoenviron Eng 129(4):307–314, 2003) standards.

Growth Machine Up-links and the Manufacture of Flood Risk in Mid-twentieth Century New Orleans

Environmentally destructive megaprojects, which substantially shift the topography and hydrology of the ecosystems in which they are embedded in ways that potentially exacerbate preexisting disaster risks, are created through a combination of lobbying by municipal growth machines and applications of higher level state authority, resources, and control. New Orleans’ manufactured hurricane storm surge risk provides a crucial case study of this dynamic. After Hurricane Katrina, forensic engineers found that the proximate cause of the New Orleans flood was the levee and floodwall failures along the city’s shipping and drainage canals, but this disaster cannot be fully understood without an examination of the city’s mid-twentieth century political economy, particular regarding the power of the local shipping industry and its up-links to entities in the federal government. During this time period, local New Orleans elites were able to take advantage of the two world wars and postwar economic expansion to dramatically enlarge the city’s shipping canal system with massive funding and expertise from the Maritime Commission and the Corps of Engineers, massively amplifying the city’s flood risk in ways that ultimately led to the Katrina catastrophe.

Comparison of generalized non-data-driven lake and reservoir routing models for global-scale hydrologic forecasting of reservoir outflow at diurnal time steps

Abstract. Large-scale hydrologic forecasts should account for attenuation through lakes and reservoirs when flow regulation is present. Globally generalized methods for approximating outflow are required but must contend with operational complexity and a dearth of information on dam characteristics at global spatial scales. There is currently no consensus on the best approach for approximating reservoir release rates in large spatial scale hydrologic forecasting, particularly at diurnal time steps. This research compares two parsimonious reservoir routing methods at daily steps: Döll et al. (2003) and Hanasaki et al. (2006). These reservoir routing methods have been previously implemented in large-scale hydrologic modeling applications and have been typically evaluated seasonally. These routing methods are compared across 60 reservoirs operated by the U.S. Army Corps of Engineers. The authors vary empirical coefficients for both reservoir routing methods as part of a sensitivity analysis. The method proposed by Döll et al. (2003) outperformed that presented by Hanasaki et al. (2006) at a daily time step and improved model skill over most run-of-the-river conditions. The temporal resolution of the model influences model performances. The optimal model coefficients varied across the reservoirs in this study and model performance fluctuates between wet years and dry years, and for different configurations such as dams in series. Overall, the method proposed by Döll et al. (2003) could enhance large-scale hydrologic forecasting, but can be subject to instability under certain conditions.

Soil fatigue hazard screening analyses framework for spacio-temporally clustered induced seismicity with examples of damage potential due to liquefaction

Current studies that focus solely on the cause of the increase in seismicity neglect to include considerations for effects of small magnitude cluster events on federal infrastructure. These effects can be almost undetectable at first, but if left unchecked can evolve into a larger issue. The need to reassess and potentially modify the established risk assessment practices for evaluations of federal infrastructure needs to be reviewed to ensure the continued ability of the structure to function as intended. The U.S. Army Corps of Engineers (USACE) is responsible for hydroelectric power, flood protection, recreational areas, navigational channels and water supply along the waterways that were either constructed prior to seismic design requirements or designed to a lower seismic level than current seismic activity. The need to establish revised evaluation methods of critical infrastructure has become very apparent to ensure that risk assessments include the stability of these systems and the safety of those that depend on them.

GIS preprocessing for rapid initialization of HEC-HMS hydrological basin models using web-based data services

Hydrological GIS preprocessing tools are used to spatially relate different datasets for producing topologically connected watersheds and deriving attributes for model parameterization. Obtaining such information requires disparate data-sources from various websites with lengthy processing requirements. This research describes the development of HMS-PrePro, an open-source GIS preprocessing tool that was developed for the U.S. Army Corps of Engineers' (USACE) Hydrologic Engineering Center's Hydraulic Modeling System (HEC-HMS) software. HMS-PrePro provides data as a service by connecting to Esri's Living Atlas web service and extracting authoritative hydrological datasets for any watershed of interest in the contiguous United States. The datasets are saved to a local geodatabase, and spatial operations are executed to automatically delineate the watershed, derive topological connections, and estimate several common hydrologic parameters. An output basin text file is produced in HEC-HMS format for rapid model initialization.

Design guidelines and optimization of ultra-high-performance fibre-reinforced concrete blast protection wall panels

Ultra-high-performance fibre-reinforced concrete is the latest generation of structural concrete, having outstanding fresh and hardened properties; this includes the ease of placement and consolidation with ultra-high mechanical properties, as well as toughness, volume stability, durability, higher flexural and tensile strength, and ductility. As more research is being focused on it, the material behaviour and characteristics are getting more understood, and the research demand for the special applications of the ultra-high-performance fibre-reinforced concrete is growing higher. One special application that ultra-high-performance fibre-reinforced concrete is thought to have an outstanding performance at is in the field of protective structures, specifically against blast loads. This article presents part of a study that is concerned with the behaviour and response of ultra-high-performance fibre-reinforced concrete wall panels under blast load. Size and shape optimization techniques were combined in this study to optimize the design of a 200-MPa ultra-high-performance fibre-reinforced concrete under blast loads using finite element modelling. This design optimization aims to maximize stiffness and minimize the cost while satisfying both design stresses and construction requirements. The design variable to be optimized for are the thickness ranging from 100 to 300 mm at 25 mm increments, in addition to the reinforcement ratio of 0%, 0.2%, 1% and 3%, and aspect ratio of 1, 1.5 and 2; the boundary condition is four edges fixed and restrained. The numerical simulation has been performed using an explicate finite element software package. The complete behaviour of an ultra-high-performance fibre-reinforced concrete is defined using the concrete damaged plasticity model. The concrete constitutive model has been developed considering the contribution of tensile hardening response, fracture energy and crack-band width approaches to accurately represent the tensile behaviour and guarantee mesh independence of results. The blast load is applied using the Conventional Weapons method of the US Army Corps of Engineers that is readily available in the finite element software. The validity of the numerical model used is verified by comparing numerical results to experimental data.

Military policy and infrastructure: the role of the Engineer Corps in nineteenth-century Greece

This article describes the role of the military, particularly the Engineer Corps, in the building of the Greek state in the nineteenth century through the construction of the necessary infrastructure. after the assassination of the first leader of the country in September 1831 and the ensuing civil war, the European Powers selected the Bavarian Prince Othon as the country’s first king. The priority of the new royal authority was the imposition of order and the consolidation of political power in his hands. Moreover, it was also necessary to carry out basic infrastructure projects to enable the state to function properly. This role was taken up by the Engineer Corps, which accomplished remarkable work in the construction of public buildings, roads, ports, etc. The first officers of the corps were Bavarians, who had accompanied Othon to Greece. With their experience, they laid down the operational basis of the Greek state. Othon’s government (1833–1862) faced numerous difficulties, the economic hardship of a small state being the major one. furthermore, the need to counteract the bandit gangs that dominated the countryside and undermined the central authority was paramount. large infrastructure projects were implemented in the last quarter of the century, inspired by Prime Minister Harilaos Trikoupis’ agenda to improve the country’s unity. however, major national problems, such as the Macedonian and Cretan questions, as well as the growing competition with and surges of nationalism in the other Balkan states, forced Greece’s leaders to undertake costly military mobilisations, thus restricting the modernisation project. however, the engineer corps achieved its mission. staffed with skilled and well-trained officers, as well as engineers and professors from the Military Academy (Evelpidon), the remarkable work of the corps is still visible.

Use Surplus Federal Real Property to Expand Medical and Quarantine Capacity for COVID-19

Last week, the Trump administration announced plans to partner with states to increase hospital capacity to address a potential surge in patients needing emergency care owing to the COVID-19 pandemic. Vice President Mike Pence stated that the government was committed to answering requests from governors for additional capacity by “creating field hospitals” or “retrofitting existing buildings,” with support from the Army Corps of Engineers. In addition to constructing field hospitals and expanding existing hospital capacity, the US government should identify potential surplus federal real property for immediate conversion to increase hospital bed capacity and to fulfill other needs, such as extensive quarantines or isolation needs related to COVID-19. The federal government has thousands of surplus facilities, including hospital buildings and dormitories, that are eligible to be repurposed for public health needs under current federal law.

Where's the Science? Recent Changes to Clean Water Act Threaten Wetlands and Thousands of Miles of Our Nation's Rivers and Streams

The vision of the U.S. government when they passed the Clean Water Act (CWA) in 1972 was to restore and maintain the chemical, physical, and biological integrity of the nation's waters to support fishing and recreation. The U.S. Environmental Protection Agency and Army Corps of Engineers have recently made major and controversial changes to the CWA in a 2020 regulation referred to as the Navigable Waters Protection Rule. This article reviews the bipartisan history of the CWA and the historic trajectory of how “waters of the United States” are defined to provide legal jurisdiction. It then discusses the science that supported changes to the CWA made in 2015 and lack of science that supported recent changes. The 2015 Clean Water Rule was intended to be a science-based clarification of what “waters of the United States” mean to CWA regulation. That rule was based on synthesis and review of >1,200 peer-reviewed articles that served as the basis for a 408-page scientific Connectivity Report. For the recently released regulation, U.S. Environmental Protection Agency's (EPA's) Science Advisory Board wrote that EPA did not incorporate the best-available science into the rule making process and provided no “comparable body of peer-reviewed evidence” to support the proposed changes to the CWA. Furthermore, the EPA ignored science by even stating that “science cannot dictate where to draw the line between Federal and State waters.” EPA's mission is to protect human and environmental health, the Corps has a vision of “engineering solutions for our Nation's toughest challenges.” Ultimately, the EPA and the Corps have ignored their responsibilities, mission, and vision by ignoring well-established science in their mandates to protect our nation's water for current and future generations.

Stakeholder Involvement in Natural Resource Decisions: The Missouri River

The Water Resources Development Act of 2007 authorized creation of the Missouri River Recovery Implementation Committee (MRRIC) to provide recommendations to the U.S. Army Corps of Engineers (USACE) on a recovery and mitigation plan to avoid jeopardy of three endangered species (Pallid Sturgeon Scaphirhynchus albus, interior least tern Sterna antillarum athalassos, and piping plover Charadrius melodus). Formation of the MRRIC in 2007 ushered in a new era of federal, state, tribal, and nongovernmental stakeholder collaboration in the river basin following nearly 20 years of litigation and legislative actions in Congress related to management of and operations on the river. Over a decade, through its deliberations, MRRIC has been instrumental in influencing the USACE endangered species recovery and mitigation efforts. The diversity of MRRIC membership proved beneficial when examining the socioeconomic impacts of river operations. However, this diversity also presented challenges to the communication of technical issues facing recovery of imperiled species, especially the Pallid Sturgeon. By instituting an independent science panel trusted by MRRIC members, the committee advanced key recommendations to the USACE in the development of an adaptive management plan. Unfortunately, at two key points in the past decade, members of MRRIC opted to work outside of the committee construct, engaging in legislative strategies to limit potential recovery actions. This paper describes actions by MRRIC that have benefited the USACE recovery effort and limitations within the committee that in turn have constrained the recovery effort.

A Crucial Leavening of Expertise: Engineer Soldiers and the Transmission of Military Proficiency in the American Civil War

A Crucial Leavening of ExpertiseEngineer Soldiers and the Transmission of Military Proficiency in the American Civil War Mark A. Smith (bio) Current scholarship on Union military engineering in the Civil War legitimately emphasizes its improvisational nature. In Northern armies of both theaters, volunteer soldiers with experience in mechanical or skilled trades improvised solutions to engineering problems. They built roads, bridges, and field works as needed to support military operations. Historian Thomas F. Army Jr. has even argued that the ability of Northern armies to concoct these solutions on the fly was a key reason for ultimate Union victory and a reflection of the North’s particular industrial and educational culture. There is, however, an important qualification to the improvisational nature of Union engineering that nearly all historians of the subject acknowledge: experience. It took time for the volunteers to develop the necessary expertise, especially in the peculiarly military aspects of the problems they faced. Road building, general bridge construction, and railroad management were all components of military engineering that had direct civilian analogs; skills in these endeavors found immediate application in military operations. Other facets, however, such as the construction of field works, siege works, and pontoon bridges, had no comparable component in the civilian world, and federal volunteers needed time to master or improvise these new skills.1 [End Page 9] In the western armies, as both Edward Hagerman and, more recently, Justin S. Solonick have noted, there were considerably fewer trained engineers to accelerate this process of converting volunteers into military engineers, but by late 1861 the eastern Army of the Potomac included an engineering component that could provide expertise until the improvisational ability of Union volunteers developed and could also accelerate the improvement of volunteer engineering proficiency. The soldiers of this component, distinct from their officers, went by many names: engineer troops, engineer soldiers, and sometimes, based on their special skills, sappers, miners, pontoniers, or some combination thereof; often, the simple, single term sapper was used generically for all engineer soldiers.2 Whatever they were called, their numbers were infinitesimal compared to the line troops of the three combat arms. Even in the Army of the Potomac and early in the war, before Northern volunteers had developed their improvised capability for field engineering, the sappers simply did not have the numbers to erect all the works the engineer officers planned. Their primary contribution came in another form. Despite one historian’s assertion that there was little distinction between engineer troops and the volunteers in the line, the sappers were the purveyors of special, inherently military skills that they had honed in the antebellum era and that they deployed using processes first developed in the war with Mexico.3 During the Civil War, these skills and processes were shared by one prewar engineer unit, Company A Corps of Engineers, with new regular army engineer companies and with improvised volunteer units. All these organizations subsequently deployed their knowledge to maximize its effects by supervising work parties drawn from line units to build bridges and field works. The sappers and their oversight provided a crucial leavening of military engineering expertise early in the war that directly supported military objectives and simultaneously accelerated the development of an improvised [End Page 10] engineering capacity by delivering practical albeit incidental instruction to line volunteers who served in fatigue parties. Moreover, the sappers’ experience, from their beginnings in 1846 through the end of the siegelike operations around Yorktown, illustrates the mechanisms by which military expertise was preserved and spread in the mid-nineteenth-century army. While their skills were unique and uniquely military, the ways the engineers maintained them in peace and shared them in war demonstrate how the capabilities and experience of long-term regular soldiers could be transmitted to a much larger volunteer force. Though the Union government opted to keep the regular army intact rather than dispersing its skills throughout the state-raised volunteer forces, the activities of the engineer soldiers reveal the importance of the regular army as a core of competent professionals who could provide critical skills while volunteers trained and that could assist in that training. ________ Congress created the antebellum engineer company just days after the...