GARY E. KILPATRICK AND ASSOCIATES, PA
FORENSIC ENGINEERS
Accident Reconstruction and Product Liability Analysis
TRAFFIC ACCIDENT RECONSTRUCTION FOR ARTICULATED VEHICLES
Articulated Vehicles are made up of at least two separate units. One unit is powered for propulsion, steering and control and the other unit is the towed vehicle or trailer. For heavy trucks, this powered unit is called a road tractor. These two units are joined together at a hitch point. For passenger vehicles and light to medium trucks, this hitch point is usually located either on the rear bumper or on a structure attached to the rear end of the vehicle's chassis. This hitch point can also be located in the bed of larger pickup trucks. For heavy trucks, this hitch point is called a fifth wheel and is located behind the cab and is attached to the chassis of the truck. Passenger vehicles or light trucks towing a utility trailer or a road tractor towing a semitrailer or full trailer are examples of articulated vehicles.
A semitrailer is a unit that does not have a front axle. The frontal portion of a semitrailer has a king pin mounted underneith the trailer and engages and locks into the fifth wheel of a road tractor where the trailer rests and pivots on the road tractor's fifth wheel plate. A full trailer is a unit that has both front and rear axles. The front axle will pivot for the purpose of steering the trailer. A draw bar is attached to the front axle and is utilized to pull the full trailer. The free end of the draw bar is attached to the rear of a road tractor or another trailer.
When an articulated vehicle is involved in a collision with another vehicle, it may behave differently than a vehicle with no trailer attached to it. The powered vehicle, particularly a road tractor, has a tendency to rotate about its fifth wheel instead of its center of mass. The more weight a trailer applies to the fifth wheel, the more of a tendency the road tractor will yaw about its fifth wheel. However, if a pickup truck is towing a light trailer, the trailer may have little effect on the yaw of the pickup truck during a collision. Every accident however is unique, and each accident must be analyzed to determine its own particular events.
The employer and an employer's driver must be familiar with and understand the Federal Motor Carrier Safety Regulations Handbook that is prescribed by the U.S. Department of Transportation Federal Motor Carrier Safety Administration Parts 40, 325, 350-399. The rig must be inspected per the regulations under part 393. A driver must complete a Record of Duty each day to record his or her on-duty and off-duty activities.
We provide the following forensic engineering accident reconstruction services:
• Preimpact and Postimpact Velocities
• Engineering Dynamics Corporation HVE Vehicle Accident Reconstruction Dynamics and Simulation.
• Vehicle Vector Trajectory
• Cause Analysis
• Lamp Analysis
• Tire Examination
• Steering and Braking System Analysis
• Human Factors
• Driver Visibility Analysis
• Download and Analysis of a vehicle's Crash Data Report from a vehicle's Event Data Recorder (EDR)
• Airbag Deployment Analysis
• Seat Belt Function Analysis
• Accident Scene Photogrammetry with iwitness
• 3-D Laser Scanning of the Accident Scene
• Vehicle Inspections For Defects and Non-Conformance
• Defective Vehicle Component Determination
• Vehicle Diagnostic Trouble Code (DTC) Download and Interpretation
• Catastrophic Component Failure Determination
• Vehilcle Standard of Care and Maintenance Evaluation
• Metallurgical and Failure Mode Analysis
• Manufacturing Process Defects and Failures