Big Truck Extrication - Part 1: Anatamy 101
David Pease, Carolina Fire/Rescue/EMS Journal
This is the first of a three part article on big truck extrication. We are going to first take a look at basic truck anatomy. In article two we will discuss scene approach, hazards, and stabilization. In part three we will talk about extrication techniques. Trucks have been around since shortly after the coming of the motorized automobile.
They have become much bigger, more advanced, and travel much faster than ever before. In order to be able to execute a good extrication, a good basic knowledge of trucks and there anatomy would be essential. Trucks present us with quite a different challenge and we need to stay abreast to meet this challenge. So, “OK good buddy, let’s put the hammer down, and get this eighteen wheeler rolling.”
*We are going to approach this in a similar way I got my medic training some years ago. Before one can learn to treat a patient, we must first learn the basic human anatomy, which will give us a better understanding of how to stabilize and treat our patient.
I use the same philosophy when I teach extrication classes. By first learning about some basic truck anatomy, styles, and types, we will have a better understanding when it comes to stabilizing a light duty truck weighing 12,000 pounds verses a heavy truck weighing 140,000 pounds. You will also see that by knowing the construction of the cabs, you can better choose the tools needed to gain access to your victim.*
Trucks play a vital role in the economy of our nation and the lives of each and every one of us. Because of this, there are a large number of trucks traveling our highways all the time. Trucks make up over 3% of all vehicles on our roads. The one problem they present for us as extrication technicians, is they weigh up to thirty times more than the average automobile.
They also carry all types of cargo from the groceries we purchase from the store, to hazardous chemicals used in a variety of manufacturing processes. Trucks are involved in approximately one out of every eight motor vehicle crashes. When looking at truck crashes we will find that 60% of them occur on major interstates, 25% occur on major highways, and 10% occur on secondary roads. Most fire departments and rescue squads have one, if not all, of these types of roads running through their response district. So, hence the need for training in large truck extrication.
Trucks are put into two basic categories, medium and heavy. Medium trucks are put into a class 3, 4, or 5, and have a gross vehicle weight rating (GVWR) of between 10.000 pounds and 19,499 pounds. Heavy trucks are put into classes 6, 7 and 8. Class 6 is trucks that have a GVWR of 19,500 pounds to 29,000 pounds. Class 7 trucks have a GVWR of 29,100 pounds to 33,000 pounds, and class 8 are those 33,001 and greater. Trucks come in several types of designs.
The first and most common is the straight truck. These are built on a solid frame and not designed to pull a trailer. Most of these truck have two to three axles and have a GVWR of 10,000 pounds to 40,000 pounds. Next we have the specialty trucks which are designed for a specific purpose. Some examples of these types of trucks would be concrete trucks, dump trucks, wreckers, and fire apparatus.
The next type truck we have is the truck / semi-trailer combination. They are compiled of a truck, also called a tractor, and one or more trailers pulled by the truck. The tractors are either two or three axle and may weigh up to 18,000 pounds. The entire tractor trailer rig may weight up to 140,000 pounds. The trailers also come in a variety of types including a flatbed for hauling building materials, a closed box trailer for general cargo, tankers for hauling fuels, chemicals, and grain and vehicle transports.
Remember that some trucks will display placards for hazardous materials and some may not. Trucks can haul 440lbs of hazardous materials without a placard. Continue Reading: