By 1LT Alan J. Morris
Submitted to Army Engineer Magazine
On February 12th 2010, Alpha Battery (A BTRY) 3-17th Field Artillery Battalion (FA BN) came to the 60th Engineer Company and discussed the possibility of constructing an underground bunker adjacent to their gun line. The purpose of this bunker was to house Soldiers who were on duty for fire missions, protect them in the event of an indirect fire attack and give them a short distance to traverse in order to fire counter-battery missions. This project was requested directly by the 3-17th FA BN Commander and was designated as a project that needed to be completed immediately. An underground bunker was the ideal solution for this project because a low profile structure was needed to allow the gun to traverse low angles based on the fire mission. Although there was no construction directive cut initially for this project, 2nd platoon was between construction projects, and 3-17th FA BN was supplying their own building materials, they were designated to complete this construction mission.
SSG Eric Placencio, 1st squad leader for 2nd platoon, was assigned as the project manager for this project while 1LT Alan Morris, 2nd platoon leader, was responsible for the design of the structure and ensuring its structural integrity. SSG Placencio, SPC Gary Johnson, and SPC Lucas Ellenberger were integral to the design process by adding input during the design process. The most critical step of the design process was determining the required strength to support the roof of the structure, estimated to weigh nearly 50 tons under the worst weather conditions. Based on several calculations from 1LT Morris and input from both of 60th EN CO’s warrant officers, WO1 Papa Kone and WO1 Cipriano Trujillo, they determined that using steel pipe as girders would work as the support system for the roof structure.
Due to the extremely close proximity of the 155 mm guns with the bunker, special reinforcement was required in order to withstand the constant overpressure of artillery fire. These modifications included using screws instead of nails in key locations as well as constructing the entire bunker using 2”x12” lumber and ¾” plywood. HESCO bastions were used to retain the soil on the perimeter of the excavation as well as retain the overhead cover. This load was suspended by 2”x12” girders and 10 ¾” diameter steel pipe. Steel pipe was selected because it was not needed for any other projects on the FOB and because it was the strongest material that was readily available. Ideally steel I-beams would have been preferred, but due to the urgency of the project there wasn’t time to wait for the materials to arrive in theater.
The finished bunker includes climate control, interior lighting, and electrical outlets. The drainage for the structure includes a sloped gravel base, gravel drainage barriers between the HESCOs and bunker walls, a sheet metal base, and silicone epoxy as a sealant. These drainage structures lead to a French drain beneath the steps with the potential for a sump to be added later once one is procured.
1LT Alan "AJ" Morris graduated from Marquette University College of Engineering and was commissioned in May 2008. 1LT Morris is currently assigned to Fort Benning, Georgia.