Tech Rescue

Fixed & Mechanical/Hydraulic Wheel Dollies

Issue 4 and Volume 9.

In January’s In-Depth Extrication article, we discussed the use of floor jacks at motor vehicle collisions (MVCs) and customer service opportunities. As you know, there are multiple scenarios in which movement of the patient vehicle or secondary vehicles will help first responders gain access to the patient(s) and/or create a sufficient path of egress. Depending on the vehicle damage and the operating system’s status, portions of the vehicle may need to be raised and moved. Responders can use floor jacks to help remove vehicles from a roadway or highway lane (or multiple lanes), which can reduce traffic congestion.

Another tool that can be used to assist with vehicle movement: wheel dollies. Floor jacks and wheel dollies are very similar in that they both help provide vehicle stability during movement, and when used together, they provide more stability than the floor jack alone. But because many departments view wheel dollies as a one-dimensional tool, it may be difficult to justify their cost. What some departments may not realize is that there are many other, not-so-obvious uses for wheel dollies that make them a great asset to fire departments.

Wheel Dolly Uses

Depending on their configuration and/or attachments, wheel dollies may provide an easy means of moving trailers, especially those without a stand and/or those that stand without a wheel. Rather than a responder holding the tongue of the trailer, the tongue can be placed on a wheel dolly and easily moved.

Every department has a welder or carpenter who can fabricate a plate to easily attach to the top of a wheel dolly; doing this transforms it into an equipment hauler that can move a wide variety of tools and supplies. It can also be used to assist with the loading of large-diameter hose. And because it’s relatively flat, it can be stored in many compartments for quick deployment.

There are two main types of wheel dollies, each with their own advantages and disadvantages. It’s up to each department to decide which type they need, and which specific brand best suits their needs and intended use. For the purposes of this article, we’re going to refer to the two main types as “fixed” and “mechanical/hydraulic” wheel dollies.

Fixed

Fixed wheel dollies are simply pieces of metal (angled tubing, plate) welded together to create a platform that’s affixed to casters. They require the use of a lifting device so they can be placed under the wheel assembly; however one huge advantage to using these types of wheel dollies is their flexibility. They will work no matter the condition of the wheel assembly. It doesn’t matter if the tire is flat, the tire/rim is missing, etc. In some cases, the chassis itself can be set onto these wheel dollies. These dollies are also the easiest to fabricate for other uses.

Mechanical/Hydraulic

These heavy-duty wheel dollies feature a telescoping main frame with casters mounted on each end that “sandwich” the tire. The quick-action hydraulic or manual foot pedal lifts most vehicles in seconds while providing instant mobility in any direction. And they’re entirely self-contained; there’s no need for a floor jack or other lifting device to raise the vehicle initially.

Yet, despite these advantages, there are several disadvantages to using this type of wheel dolly. First, they require an intact wheel assembly and an inflated tire. The lifting assembly doesn’t work well on flat tires, because as the ends come closer together, the rubber forms in between prevent the wheel assembly from clearing the ground. Typically, if the tire is missing or significantly damaged, the ends can’t close far enough to raise the assembly.

Another disadvantage that must be considered during the evaluation and purchase phase is the associated cost. Because there are obviously more moving parts and engineering involved, the associated cost can be as much at two to three times more than fixed models, and they may require more preventative maintenance. Lastly, it’s harder to retrofit these wheel dollies to serve other functions.

A Note about Recovery Vehicles

One often-overlooked resource at MVCs are the recovery vehicles, and in many cases, these vehicles carry wheel dollies. There’s no guarantee you’ll get one specific type, but because they all have fairly consistent features, there should be a small learning curve, especially with the assistance of the operator.

Summary

Wheel dollies have a variety of uses at MVCs and other emergency situations. They’re a great supplement to floor jacks when moving patients and/or secondary vehicles, and they can provide much assistance during other common emergency incident tasks. Remember: Do your homework prior to purchasing a wheel dolly so you select the most appropriate one for its anticipated use, and always follow safe working procedures.

A special thanks to Steck Manufacturing Company and Merrick Machine Company.