8 Dec 2025

Improved Prediction of Soil Thermal Properties Using Gated Recurrent Unit Neural Networks

Abstract: Frost actions, such as frost depth penetration and thaw weakening, are damaging to airfields and roadways in cold regions. Machine learning techniques, such as recurrent neural networks, have been applied to this problem, but with a large focus on long short term memory (LSTM) neurons. Gated recurrent units (GRUs) are similar to LSTM neurons in terms of accuracy, but are more computationally efficient, and have yet to be applied to predicting soil thermal properties. Using a hyperparameter search, an optimal architecture for a recurrent neural network based on gated recurrent units was identified. A general model using temperature, thermal conductivity, and volumetric moisture content was found to predict temperatures effectively, having an error of less than 0.25°F across all depths. For predicting thermal conductivity, a model including temperature but not moisture content was found to be effective. For moisture content, the results were inconclusive as both models were affected by similar errors. Overall, the GRU-base recurrent neural networks were found to work well for predicting soil thermal properties in high-plasticity clays, and it is recommended to further expand the training datasets to include other frost-affected soil types.

24 Nov 2025

Ice Demolition Techniques—Rapid Improved Ribbon Bridge Placement and Enemy Forces Denial: Using Traditional Military Explosives Under Ice

Abstract: As the United States military focuses on furthering their lethality across cold regions, developing new techniques for equipment usage is necessary. On 19 March 2025, the US Army Engineer Research and Development Center–Cold Regions Research and Engineering Laboratory (ERDC-CRREL) collaborated with the Army Engineers from the 50th Multi-Role Bridge Company (MRBC), 6th Brigade Engineer Battalion (BEB), and Sapper Leader Course (SLC) to determine whether explosives can be used for Improved Ribbon Bridge (IRB) placement in ice-laden environments. As the US Army adapts to meet the evolving threats from foreign adversaries, there is an increased tactical necessity for enhanced bridging capabilities in frozen terrain. Developing an expedient method of removing ice from these waterways and placing IRBs for easy crossing of heavy military equipment is essential. Through this experiment it was determined that the use of a 40 lb cratering charge primed with M152 boosters significantly fractures the ice cover expeditiously. However, the ice expulsion rate found in this experiment was insufficient for IRB deployment which requires 60% expulsion rate. Although the experiment fell short of IRB requirements, it proved to be an efficient and effective countermobility tool for units who use frozen water ways as avenues of approach.

4 Nov 2025

Preliminary Evaluation of Selected Expeditionary Shelter Systems in a Subarctic Environment: Phases I and II of Cold Weather Testing

Abstract: The warming of high latitude regions is causing geopolitical concerns and spurring increased human presence across the Arctic. Potentially, these situations require only a short-term occupation necessitating tested and developed expedient infrastructure. Operating requirements for high latitude conditions are vastly divergent from temperate locations. Shelters must be able to provide habitable conditions at temperature down to −60°F, withstand 100 mph wind speeds, and support 25 lb/ft2 of snow load. Although great advances have been made in providing efficient and comfortable Arctic infrastructure since the onset of the Cold War, significant work remains to further increase efficiencies and adapt to changing weather parameters. To address infrastructure technology gaps, the US Army Corps of Engineers–Engineering Research and Development Center (USACE-ERDC) established the Arctic Infrastructure Research Group (AIRG). Over two phases of investigation, the AIRG evaluated three selected expeditionary shelter systems at its Arctic Infrastructure Research Center (AIRC) in Fairbanks, Alaska during the winters of 2020–2021 (Phase I) and 2021–2022 (Phase II).

4 Nov 2025

Airfield Assessments to Identify Improvements in Support of Arctic Military Operations: Arctic Airfields Assessment

Abstract: This report examines current airfield capabilities in Alaska and Greenland as they pertain to the strategic priorities of the Northern Aerospace Defense Command (NORAD) and US Northern Command (NORTHCOM) in support of needs identified in the 2024 DoD’s Arctic Strategy. With increasing activity and competition in the circumpolar region, airfields in Alaska and Greenland play a vital role in enabling homeland defense, supporting domain awareness needs, and enabling rapid response operations. This report highlights key airfields across Alaska and Greenland, focusing on their current readiness to support NORAD-assigned airframes such as the C-17, C-130, F-15, F-16, F-22, F-35A, KC-10, KC-135 and KC-46A. It assesses currently available infrastructure, operational resilience, airfield suitability and current condition, weather considerations, and logistics sustainment. Gaps in infrastructure readiness and logistical necessities for different airframes are identified. Recommendations are provided to bolster airfield operational capabilities as they pertain to the NORAD mission, and to ensure Arctic basing remains a credible enabler of NORTHCOM’s mission to defend the US and deter threats across the circumpolar region.

10 Oct 2025

Standard Operating Procedures for the Site Selection, Design, and Maintenance of All-Season Roads Linear Infrastructure

Abstract: Planning, designing, constructing, and maintaining all-season roads in cold regions requires navigating complex environmental, hydrologic, and geomorphologic challenges. Harsh conditions, such as permafrost, frost-susceptible soils, muskeg, and extreme cold, are compounded by limited data availability, remote locations, and fragile ecosystems. Recent Arctic strategies across the DoD have identified changing weather patterns as significant threats to infrastructure, operations, and training land management in these regions. Key risks include degrading permafrost, changes in precipitation intensity and duration, and the loss of soil bearing capacity in saturated soils, all of which are examined in detail. As the Department of Defense expands Arctic training capabilities, infrastructure investments across Alaska must balance operational goals with sustainability and resilience. This report synthesizes the military’s typical methods for constructing roads in contingency environments, identifies practices used in the construction of the Alaska-Canada Highway, and draws from consultations with training land managers, a thorough literature review, and active engineering research. The report highlights the importance of holistic design that prioritizes longevity, environmental conservation, and safety by addressing cold-region challenges, mitigation strategies, and best practices. This resource is indispensable for military units and infrastructure planners tasked with navigating the complexities of cold-region infrastructure construction and operation.

10 Oct 2025

Standard Operating Procedures for the Site Selection, Design, and Maintenance of Low-Water Crossing Linear Infrastructure in Cold Regions

Abstract: Low-water crossings (LWCs) are critical components of DoD infrastructure in Alaska and other cold regions, yet their effective siting, design, construction, and maintenance are challenged by remote locations, limited environmental data, seasonal hydrology, and complex terrain. Harsh winter conditions, rapid spring melt, and freeze–thaw cycles introduce hazards such as ice-related scour, debris loading, and variable streambed stability. In cold-region operational areas, natural processes such as permafrost degradation, shifting hydrologic regimes, and sudden flood events from glacial or thermokarst activity further increase risk to infrastructure performance and longevity. This report addresses these challenges by consolidating best practices and mitigation strategies for LWC implementation in cold environments. Drawing on technical literature, input from land managers, and existing agency standards and SOPs, the report identifies key considerations for improving LWC resilience. These include accounting for ice forces, complex geotechnical challenges, sediment transport, and the use of appropriate materials to name a few. By framing LWCs within a systems-based approach to site selection and engineering design, the report provides guidance for supporting safe and sustainable operations across Arctic and Subarctic training environments. It serves as a technical resource for DoD planners and engineers tasked with managing infrastructure in cold regions.

24 Sep 2025

Assessing Heat Pump Technologies in Cold Regions for Army Installations

Abstract: Air-source heat pumps (ASHPs) can efficiently provide building heating and cooling. To assess the performance of ASHPs in cold regions for the Army Installation Technology Transition Program, we installed an air-to-air minisplit ASHP in Fairbanks, Alaska. This Interior Alaska location is exposed to extreme cold. The appropriate size of the unit was determined using building size and air temperatures from the location. Using monitoring equipment, the heating performance of the unit was analyzed using measurements collected over the winter months. Finally, the coefficient of performance (COP) was calculated, and a thermal camera was used to assess the heating performance qualitatively. The ASHP effectively heated the building during the project, and ASHPs are therefore recommended for use in cold regions.

18 Sep 2025

Standard Operating Procedures for the Design, Construction, and Maintenance of Summer Roads and Trails, Drop Zones, and Firebreaks in Cold Regions

Abstact: As DoD investments across Alaska increase in response to DoD Arctic strategies, expanded training opportunities are necessary to enable the military to enhance their Arctic capabilities. In addition, wildfire management is increasingly important in the area as the summer season has expanded and warmed in recent decades. This report addresses the siting, design, construction, and maintenance of summer roads and trails, drop zones, and firebreaks on DoD lands in Alaska and other cold regions. It considers the harsh weather conditions, extreme seasonality, and remoteness of these environments, in addition to the general requirements of understanding the local environment, relevant risks, permitting, and regulations. The three types of linear infrastructure are assessed together as each involves the clearing of land and maintaining it as cleared, and therefore share common risks. This report summarizes best practices throughout the project lifecycle and synthesizes risk mitigation strategies informed by a comprehensive literature review and conversations with local training land managers. Using Fort Wainwright in Interior Alaska as an example, it provides Standard Operating Procedures (SOPs) to aid land managers and military unit leadership as they navigate challenges and opportunities in their increased use of these critical linear infrastructure types in high latitude environments.

16 Sep 2025

Standard Operating Procedures for the Design, Maintenance, and Operation of Arctic and Subarctic Winter Roads

Abstract: Operations in cold regions require vehicular maneuvering across snowpacks or frozen surfaces. Winter roads and their route determination, construction, and monitoring are widely studied. This report analyzes historical and current literature on winter road construction and operations, reviews risk assessment techniques, examines the impact of uncertain weather on road reliability, and provides a standard operating procedure for design, maintenance, and use. Winter roads, snow roads, ice roads, and ice bridges enable seasonal access in Arctic and Subarctic regions. They allow cross-country maneuverability over terrain like wetlands and bogs, which are impassable in summer. These roads are critical for training, logistics, and construction in areas without all-season access. When combined with ice bridges they can provide near-unlimited travel. Effectiveness depends on proper planning, construction, and monitoring. Snow roads require controlled compaction for strength, while ice roads require sufficient ice thickness to support loads. Both rely on tools like visual inspections, ground-penetrating radar, and unmanned aerial systems to ensure safety. With extreme seasonal variability, adaptive strategies are essential. Shortened seasons and unpredictable freeze–thaw cycles demand modern technologies, predictive weather modeling, and improved reinforcement. This report integrates historical knowledge with engineering advancements to improve winter road durability, reduce risks, and support cold-region operations.

15 Sep 2025

Standard Operating Procedures for the Design, Construction, and Maintenance of Linear Infrastructure in Fens in Cold Regions

Abstract: In Alaska and across the Arctic and Subarctic, winter conditions can enable the expansion of linear infrastructure across the frozen landscape of fen wetlands. This expands military training opportunities into lowland wet, boggy, mostly impassable terrain. However, there are personnel, civilian, and environmental risks from using fens as travel corridors and drop zones. The effective design, construction, operation, and maintenance of such infrastructure on fens supports the dual mandate of troop training to fulfill the mission and protect the environment. This Technical Report (TR) addresses the risks of the establishment and use of linear infrastructure on the DoD lands in Alaska and in other austere cold environments where the DoD operates. This TR is founded on a review of methods used by US Army Installations, focusing primarily on Fort Wainwright in Interior Alaska. It establishes basic standard operating procedures (SOPs) by drawing on federal agency and international best practices and emerging research in circumpolar regions and beyond. This TR serves as a reference document for military land and infrastructure planners and unit leadership to create and maintain linear infrastructure on fens as environmental challenges evolve and opportunities develop to further the Army mission in high latitude environments.