By Christina Short, Fort Meade, Md.August 8, 2016
FORT RUCKER, Ala. (August 8, 2016) - It was the Saturday of the first battle assembly weekend in the new fiscal year, and a staff sergeant and a few of his Soldiers were conducting a recon. The plan was to take a HMMWV into the hills to find the perfect location for training. This plan would have worked out great had it not rained the past two days.
On this day, however, the weather was clear with the temperature hovering about 68 F. Everything was going well on the recon until the Soldiers got to a bridge. The structure wasn't exactly what comes to mind when picturing a bridge; it was more of a low water crossing. If not for the previous days' rain, crossing this bridge would have been a piece of cake. Now it was flooded.
"No problem," the sergeant thought. "We're in a HMMWV. A little water won't hurt us." Before attempting to cross, the sergeant talked to some locals who lived nearby about the width of the bridge. They assured him the HMMWV could make it. He also watched a pickup truck cross the bridge successfully. Two Soldiers then walked across the bridge so the sergeant could roughly measure the width. Neither Soldier fell in the stream, so the sergeant figured the bridge was wide enough for the HMMWV.
The Soldiers entered the HMMWV and started across the flooded bridge. Just before reaching the middle, the HMMWV's left-front tire slid off the left edge. At this point, the sergeant realized attempting to cross was a bad idea; but before anyone could move, the left-rear tire also slid off the bridge. The sergeant instructed the Soldiers to slowly exit the HMMWV. After everyone was safely out the vehicle and back on land, all they could do was watch as the HMMWV rolled off the bridge and into the stream.
Since it was Saturday, the nearest Army Reserve maintenance shop was closed, so the proper wrecker wasn't available to retrieve the HMMWV. This forced the Soldiers to call a local towing company. The first tow truck arrived on the scene but couldn't move the HMMWV, so another truck was called. Fortunately, the second truck was able to pull the HMMWV from the stream. Unfortunately, the HMMWV wasn't properly hooked up to the tow truck and sustained nearly $20,000 in damage.
The sergeant and his Soldiers learned an important lesson that day: Floodwaters can hide damaged roadways and low water crossings, so if you can't see it, don't cross it. They also learned to conduct training recons during the week -- when the maintenance shop is open -- and have a retrieval plan for vehicle breakdowns and accidents. Luckily, no one had to pay for these lessons with their life.
Crossing the Gap Safely
CHIEF WARRANT OFFICER 5 MARC ASSUMPCAO
Fort Rucker, Alabama
Vehicle water crossings are an inevitable, yet necessary, task for leaders, Soldiers and personnel to accomplish their mission. Because of the inherent danger in water crossings, it is imperative units conduct proper terrain analysis, personnel training in fording operations, equipment preparation, and apply risk management during the planning process and well before the execution phase.
There are many important factors to consider before conducting water-crossing operations. I would like to highlight a few best practices and lessons learned in an effort to shed light on how to mitigate risks associated with water crossings.
Soldiers and leaders may not realize the buoyant force on an object is equal to the weight of the fluid displaced by that object. A cubic foot of water weighs about 62.4 pounds. Vehicles displace a lot of water when they enter a river or creek bed, and the pressure exerted by moving water increases with the square of its velocity.
The depth and width of the area to be crossed, the bank conditions and the river's current velocity are major factors to consider before attempting a water crossing. These factors will determine if equipment and personnel can cross by fording or swimming, if use of expedient materials is practical, or if specific bridging assets are required.
Some common risks of trying to cross water include vehicles stalling or becoming stuck. Most times, when a vehicle stalls, personnel try to get out of the vehicle. Once outside, they are exposed to swift currents that may result in them falling into the water and being swept away or jammed into debris downstream.
Drivers and their vehicle commanders also must be aware of environmental conditions and other issues associated with water crossings. Water clarity and lighting circumstances could conceal the condition of the roadway beneath them. Floodwaters can also hide a damaged roadway.
Other factors to consider before conducting water-crossing operations include:
• Follow all vehicle fording and swimming instructions in accordance with the vehicle's technical manual.
• During training exercises, ensure drivers and crewmembers wear personal flotation devices if the water is more than 4 feet deep.
Factors to consider during water-crossing operations include:
• Ensure the water depth at the fording site is below the vehicle's fording limits and the site is clear of submerged obstacles.
• Do not exceed 4 mph when entering and traveling through the water.
• Consider not wearing load-bearing equipment during fording operations. The equipment could snag on vehicle components and prevent crewmembers from escaping through the top hatches during emergencies.
• Consider leaving combat locks unlocked during fording and when operating near bodies of water.
• Store sensitive items and small arms inside the vehicle. If the vehicle sinks, these items can be easily retrieved during recovery operations.
• Attach dismounted troops to a safety line when crossing.
• Do not cross more than one vehicle at a time, and do not cross a vehicle beside dismounted troops.
• Ensure the fording site has adequate entrance and exit points and a firm bottom.
Analyzing wet gaps and using the necessary resources available should allow for safe crossings and minimize unnecessary risks. Just remember to always act safely, trust your training and don't cut corners.
Field Manual 3-90.12, Combined Arms Gap-Crossing Operations, focuses on the elements necessary for the forces to cross an obstacle, wet or dry. To view this publication and others related to equipment safety operations, check out our Driver's Training Toolbox at https://safety.army.mil/driverstrainingtoolbox/. Having a strong, solid foundation on the aspects necessary for the conduct of water crossings enables the personnel and equipment to be safely postured.
Think your tactical vehicle is heavy enough to protect you from fast-moving water? Think again. If a 97,000-ton aircraft carrier can float, so can your 3-ton HMMWV. The reason is buoyancy. According to the National Weather Service, most cars can be swept away in 18-24 inches of moving water. Trucks and SUVs -- even with their higher clearance -- do not fare much better. Whether driving or walking, any time you encounter a flooded road, the NWS encourages you to "Turn Around, Don't Drown."
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