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.

17 Sep 2025

Spring House, 666 Front Street, Lahaina, Hawaiʻi: Historic American Buildings Surveys HI-676

Abstract: The US Congress codified the National Historic Preservation Act of 1966 (NHPA), the nation’s most effective cultural resources legislation to date, mostly through establishing the National Register of Historic Places (NRHP). The NHPA requires federal agencies to address their cultural resources, which are defined as any prehistoric or historic district, site, building, structure, or object. Section 110 of the NHPA requires federal agencies to inventory and evaluate their cultural resources, and Section 106 requires them to determine the effect of federal undertakings on those potentially eligible for the NRHP. Lahaina is located in the western part of Maui County, in Hawaiʻi. The Spring House, erected circa 1823, is currently scheduled for demolition due to its major fire damages. This report documents the building to the standards of the Historic American Buildings Survey and includes a historic context, architectural descriptions, photographs, and measured drawings. This report satisfies Sections 106 and 110 of the National Historic Preservation Act of 1966 as amended and will be used by FEMA to document the building before its demolition.