Your guide to the terms, equipment & benefits associated with using wheel assemblies to assist with extrication procedures
Story & Photos by Les Baker
Many responders rarely consider using the wheel assembly to assist with extrication procedures. In fact, most only work with wheels if their department’s protocols involve deflating tires during stabilization. Further, many of these responders may believe that this procedure is simply too time-consuming with minimal strategic benefit. In reality, a good disentanglement group supervisor should remain attentive and flexible, always looking for solutions that may not be so obvious—solutions like using the wheels.
for a detailed flowchart of the process of sizing up the wheel based on points presented in this article.
Terms & Equipment
Photo 1: Specialized lug nuts (2) are designed to prevent wheel and rim theft. They have a unique design that works in combination with a special socket called a key. Decorative covers (3) feature an adjustable retention ring used to cover a plain steel rim.
Photo 2: This socket wrench power tool (4) is designed to deliver high torque output with minimal exertion by the user. The four-way lug wrench (5) is used to turn lug nuts on wheels. A two-way flip socket (6) is designed for the most common lug nut sizes.
Photo 3: Removing a wheel may create additional space for responders who need to extricate victims entrapped underneath a wheel-resting vehicle where space is fairly limited.
Photo 4: The driver’s side window is blocking the window opening. Removing the wheel would allow responders to assess the entrapped patient and administer medical care.
Photo 5: Responders can create several additional inches of space without rocking the vehicle by severing the door check with bolt cutters or another cutting tool and pulling the door forward using a ratchet strap anchored to the front tire rim.
Photo 6: The existing holes in the vehicle’s rims can be used as an anchor point for a ratchet strap that’s being used to marry vehicles together.
Photo 7: The existing holes in the vehicle’s rims can be used for tiebacks. A tieback provides an opposing force to allow struts to be placed on the same side of a side-resting vehicle.
Photo 8: During lift operations, the responder needs to consider the weight of the load and then select the appropriate lifting tools. Regardless of which tools are selected, strapping the tire assembly to the load prior to lifting can create a few additional inches of clearance by eliminating suspension travel.
Wheels can be divided into the tire and the rim. Tire shops may carry as many as 10 different tools to work on them; however, for the purpose of extrication, there are only a few terms and pieces of equipment that responders should be familiar with:
• Lug Nuts/Bolts: For these, you’ll need the fastener used to secure a wheel on a vehicle. The most common sizes are ¾" (19 mm) and 13/16" (21 mm) for passenger vehicles and light trucks. Four-way lug wrenches and some flip-socket sets also come with 7/8" (22 mm) and 11/16" (17 mm) sockets. Most vehicle manufacturers recommend that the torque be between 50 and 200 ft. lbs, but it’s possible that untrained individuals over-tightened them during the installation process. Some manufacturers use non-conventional lug nuts/bolt heads, but they’re easily recognizable, and most of the same rules (other than those related to the socket type) apply to them.
• Wheel Locks (Photo 1): These specialized lug nuts are designed to prevent wheel and rim theft. They have a unique design that works in combination with a special socket called a key. The simplest way to remove the wheel lock is to use the key. Although there are commercial devices to remove keys or damaged lug nuts, this is usually beyond the scope of emergency responders.
• Wheel Covers (Photo 1): These decorative covers feature an adjustable retention ring used to cover a plain steel rim. Most can be removed by using a flathead screwdriver or similar device to pry around the wheel between the cover and the rim; however, other wheel covers that cover the entire rim or the center portion may require more specialized tools.
• Impact Wrench (Photo 2): This socket wrench power tool is designed to deliver high torque output with minimal exertion by the user. Impact wrenches used for tires are typically ½" drive, electric, pneumatic or battery-powered, and deliver between 250 and 750 ft. lbs. of torque. For wheel operations, it’s more efficient to use a long anvil or at least a 3" extension.
• Four-Way Lug Wrench (Photo 2): This type of socket wrench is used to turn lug nuts on automobile wheels. An average person can loosen a lug nut tightened to more than 200 ft. lbs. of torque with a 20" four-way lug wrench. Notice that in the photo, the most common size is identified with tape. Because a simple lug wrench is vehicle-specific with one size socket, I don’t recommend it as a tool for extrication incidents.
• Flip Socket (Photo 2): These two-way sockets are designed for the most common lug nut sizes. If a department chooses to use regular impact sockets, mark the most common sizes for easy identification.
How It Helps
Responders can use wheel assemblies to assist with extrication operations in the following ways:
To assist patients trapped under vehicles (Photo 3): Patients struck by vehicles or ejected from rollovers may become entrapped underneath a wheel-resting vehicle where space is fairly limited for patient care and removal. Removing a wheel may create additional space for treatment and/or enlarge the path of egress. Even if it doesn’t assist with patient care, removal may allow for better visualization and/or placement of lift equipment. Additionally, for vehicle-on-vehicle situations where extremities are trapped between a wheel and the patient’s vehicle, removing the wheel may relieve the entrapment.
To support certain disentanglement tactics (Photo 4): There may be situations where the wheel of a secondary vehicle is blocking access points or areas where responders need to work. For example, in the scenario pictured at left, the driver’s side tire is blocking the window opening. If there was a patient sitting in the passenger seat of the bottom vehicle, removing the wheel would allow responders to assess the entrapped patient and administer medical care. It would also allow the passenger door to be opened for better access and/or passenger-side tactics.
With this in mind, consider the following points during the wheel-removal process:
• Before attempting wheel removal or proceeding with any other actions, survey the lugs for damage that would prevent the wheel from being removed.
• Do not jerk or jump on the removal device. This is unsafe and may move the vehicle.
• If the rim is equipped with a wheel lock, look for the key in the glove box or near the spare tire, and be prepared for alternative tactics.
• When relying on manual tools, initially loosen the lugs while there’s resistance against the tire.
• If the lugs can’t be removed because they’ve been over-tightened or damaged, prepare for alternative tactics.
• To alleviate pressure between the rim and lugs, responders may have to slightly deflate the tire or wait until the lift operation begins to remove the wheel.
• Once the tire and rim have been removed, treat the hub and exposed lugs as a thermal hazard and a sharp hazard, respectively.
• Place the removed tire in the debris pile to prevent a trip hazard in the hot zone.
• Secure the removed lug nuts/bolts to prevent a slip hazard in the hot zone.
To provide anchor points for strapping: Most victims in low-speed, motor-vehicle collisions are removed from the vehicle through the most applicable working door. Responders can create several additional inches of space without rocking the vehicle by severing the door check with bolt cutters or another cutting tool and pulling the door forward using a ratchet strap anchored to the front tire rim (Photo 5). Hyper-extending the door can enlarge the opening by as much as 12 inches and hold this position for responders to comfortably operate and remove the patient. This tactic can also be used when conducting a sideout and time doesn’t allow responders to completely sever the front door hinges.
The existing holes in the vehicle’s rims can be used as an anchor point for a ratchet strap that’s being used to marry vehicles together (Photo 6). Some responders have expressed concerns with connecting to the rim because it is linked to the suspension and may cause vehicle movement while tightening the strap down or conducting specific operations. In fact, the force of the ratchet strap can overcome the suspension movement, and no vehicle movement will result if the vehicles are properly stabilized.
Those same points can be used for tiebacks. A tieback provides an opposing force to allow struts to be placed on the same side of a side-resting vehicle (Photo 7). In some cases, both sides may not be accessible, making a tieback necessary. In other cases, it allows the struts to be placed away from the patient compartment side.
During lift operations, the responder needs to consider the weight of the load and then select the appropriate lifting tools. Regardless of which tools are selected, strapping the tire assembly to the load prior to lifting can create a few additional inches of clearance by eliminating suspension travel (Photo 8).
When utilizing the rim as an anchor for strap operations, consider the following points:
• Make sure the attachment points are substantial and not just a wheel cover.
• If a wheel cover is present, determine the ability to connect to the rim with the cover in place. During an attempted removal, the cover may bend, allowing responders to connect to the rim. If points are not accessible, attempt to remove the wheel cover.
• Consider the use of towing clusters in combination with ratchet straps to make connections easier and quicker.
• Lastly, attempt to use the closest point of the rim in relation to the direction of pull to decrease the potential of the wheel shifting once force is applied.
NASCAR pit crews can change four tires in 15 seconds. Even though emergency responders may not be as skilled at tire work, given the appropriate tools and knowledge, it’s reasonable to expect that a good crew could prepare to use or remove a tire in less than 1 minute. Responders should always remain open to ingenious ways to solve problems—which may involve working with the wheel.
Les Baker, a 12-year veteran of the fire service, is an assistant engineer with the City of Charleston (S.C.) Fire Department and a volunteer with the Darlington County (S.C.) Fire District. He has an associate’s degree in fire science from Pikes Peak Community College. Baker is an adjunct instructor with the South Carolina Fire Academy, a member of the Darlington County Extrication Team and a co-contributor to www.navra.net.
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