The cause of a mechanical loss can be as simple as a piece of equipment or a more complex system. In other cases, a mechanical loss could be due to an entire assembly line. For example, we often encounter complex mechanical claims if an item has moving parts. In such cases, the object would have different components that could be utilized to move those parts smoothly and without friction. Instead, however, those parts can fail.
Mechanical systems are sometimes intertwined with electrical systems, which would make these systems electrically energized. Mechanical claims are not only based on cars, but vehicle claims are amongst the most common. Vehicles have intricate and detailed designs, making their claims more complex.
The first step of every fire investigation is determining the area of origin. Without this step, it is impossible to investigate the cause of a fire. When determining the area of origin, we consider fuel loads, wind speed, and wind direction (if the loss occurred outside).
It is also essential to collect background information, discovery, and service history. Technological advancements have made the information-gathering process much more manageable. We now have computer systems that provide some of this information. For example, we can find wiring and routing diagrams of different vehicle wiring harnesses without going to the dealer.
In-vehicle fires, a flammable liquid that has escaped from its position can form a vapor cloud, which a hot surface can ignite. In addition, there are hot surfaces in the engine compartment that run from the front to the rear of the vehicle, meaning there are several opportunities for ignition.
A complex mechanical claim always starts with a preliminary investigation. This involves a site visit to determine the extent of the damage, the level of complexity, parties involved, and specialists you may need to retain. A preliminary examination allows one to examine and preserve the physical evidence and determine if it needs to be moved. However, it is highly unethical to conduct an on-site examination without all the involved parties present.
Gathering background information
Mechanical systems are often three-dimensional, making it challenging to document all physical evidence at the beginning of the investigation. Therefore, one of the first analysis steps is to request information from the client and gather witness statements. This makes it easier to collect discovery information at the earlier stages. In addition, fire department and police reports are often precious sources of information.
It’s also crucial to request documentation for recent service work on the vehicle or equipment. For example, determining if the car was stationary or moving at the time of failure could indicate potential failure modes. It is equally crucial to get information on the vehicle’s performance before the fire. A recent service report involving the electrical system further allows investigators to identify parties to examine the scene or evidence.
Always ask for the Vehicle Identification Number (VIN) to access recalls and published recalls through Transport Canada or NHTSA. You can also use Mitchell1 and AllData to access technical service or technical support bulletins. Additionally, an investigator must request a CarFax to access the vehicle’s accident history and servicing information. This could help determine the area of origin of the fire.
Potential ignition sources
- Electrical failures
- Leaking fluid ignited by sparks or hot surfaces
- Mechanical failure
- Open flame
Case study 1: Personal vehicle
A Dodge Ram EcoDiesel was recalled after discovering that the Exhaust Gas Recirculation (EGR) cooler suffered leaks from thermal fatigue. The cooler expands when heated and contracts as it cools down. At times, the thermal expansion of EGR coolers creates tiny cracks. However, EGR cooler fires only occur when the vehicle is in operation.
Figure 1: The vehicle that caught fire
The owner was driving the vehicle at approximately 100km/h when he heard a loud pop from the engine. When he pulled over, he saw nothing wrong. However, when the vehicle owner continued driving, he experienced a loss of power. Shortly after, he was alerted to the fire by someone in a nearby vehicle. It is impossible to see where fire ignites when looking at the engine because it occurs inside the intake manifold.
The engine compartment and the hood sustained minimal fire damage, and the hood was flipped up onto the windshield. The engine compartment had a distinct fire pattern underneath the intake manifold, which indicated that the fire originated inside this intake manifold.
Figure 2: The inside of the engine compartment (left) and the underside of the hood (right).
During a preliminary examination of such vehicles, one must document the systems to determine the cause of the fire. Then, the vehicle manufacturer and the dealer must be invited for the examination. Removing the EGR system, followed by a pressure test, is the only way to determine whether there is a failure or leak in the EGR cooler. In such cases, a destructive examination is necessary. This refers to the altering of evidence for an extensive investigation. During the joint destructive examination, we removed the entire EGR system.
Figure 3: The car’s EGR system.
The car exhaust flows through the EGR cooler with two downward-facing side ports. These ports are the inlet and outlet of the coolant. The EGR cooler takes coolant from the engine coolant system and routes it through the heat exchanger. So, the exhaust and coolant run through the EGR cooler, but separately.
During the failure of an EGR cooler, thermal fatigue causes the coolant to leak out of its controlled system into the exhaust flow, which then goes directly into the intake manifold. Usually, an EGR system blends some exhaust gas into the intake with fresh air to keep it within the target emission level.
Figure 4: A schematic of the EGR system.
Thermal fatigue cracks can occur in the heat exchanger, allowing coolant to enter the intake manifold. The EGR Transport Canada Recall states that “thermal fatigue may cause the cooler to crack internally over time. An EGR cooler with an internal crack will introduce pre-heated vaporized coolant to the EGR system while the engine is running. In certain circumstances, this mixture interacts with other hydrocarbons and air in the system, potentially resulting in combustion within the intake manifold. It can lead to a vehicle fire.”
Figure 5: Two hoses connected to pressurize the coolant running through the EGR cooler.
As indicated in figure 5, there is a pressure gauge at the end of one hose. Under the testing conditions determined by the manufacturers, we used a bicycle pump to get the pressure in the system to 20 psi. We then submerged the cooler into a pail of water. Submerging the cooler in water results in a stream of tiny bubbles if there is a leak. A more significant leak will result in much larger bubbles. Tiny bubbles were observed.
The manufacturer had a long delay in engineering and manufacturing the replacement parts for this EGR recall. You can acquire an EGR delete kit online and through parts suppliers. However, it is not an OEM option, so the vehicle manufacturer does not support an EGR delete kit. It removes the car system, increases the power in the vehicle, and increases emissions. If improperly installed or completed, it could even be a possible failure mode.
We discovered that an EGR delete was partially completed, and the exhaust was not completely connected. The vehicle owner drove with the exhaust coming out of the manifolds. He essentially had no exhaust system from that point towards the rear.
Critical takeaways for auto adjusters
- Do not quickly payout vehicle fires without investigating the cause. Uninvestigated fires can leave future investigators with unanswered questions.
- Retain an expert before you payout because the insured may not be motivated to answer subsequent questions when they’ve been paid. It could lead to incomplete information, which would make it impossible to investigate the claim any further and even affect future subrogation.
Case study 2: Wheel-end fire
Figure 6: The truck that experienced a wheel end fire.
Wheel-end fires are common in mechanical claims. There are three different scenarios when a wheel-end catches fire. First, a truck typically has two wheels on one side on the same axle and two wheels on the other side. If one of those tires loses pressure while the trailer is being pulled down the road, it can create friction and result in a tire fire with nothing wrong with the brakes or the wheel bearing. In such cases, the tire itself can burst into flames.
Figure 7: A functioning wheel bearing (left) and a bearing indicating failure (right).
Wheel-end fires could also be caused by a failure in the brakes and bearings. However, if the cause of a wheel end fire is not the brakes or bearings, we can hypothesize it is a tire fire. In this case, the truck was pulling the trailer at the time of the fire. The driver saw smoke coming from the trailer. When he pulled over and got to the rear of the trailer, one wheel-end was burning.
Preliminary examinations of wheel-end fires often have limitations. You cannot remove the wheel-ends without the other involved parties present. During an initial examination, we can do things to help eliminate the brakes or bearings. However, a complete investigation is only possible after removing the wheel ends and in the presence of all involved parties.
In the functioning wheel bearing in figure 7, all the roller bearings are spaced perfectly around the perimeter. The other bearing shows two different sets of rollers. On the right-hand side, the roller bearings look damaged. They have essentially been smeared due to elevated temperatures. The cracking and gouge marks on the right-hand side in figure 8 indicate a brake drag resulting in excess heat.
Figure 8: Fire-damaged brake pads with no cracking or excess heat damage (left) and brake pads with visible cracking and gouge marks (right).
The brakes automatically engage if you lose air pressure to a vehicle system such as a tractor-trailer system. The air pressure pulls the brake pads away from the inside of the drum. It is a noticeable change to the vehicle driver because a brake system failure results in a significant drag. The scoring and cracking inside the brake drum in figure 9 indicates a brake drag that resulted in extremely high temperatures. The friction from the brake drag subsequently causes fire.
Figure 9: Fire-damaged brake drum with no cracking or excess heat (left) and the inside of the brake drum with visible scoring and cracking (right).
Even in a wheel-end fire, a service record is necessary before an investigation can be concluded. Investigators also need to know when a wheel bearing was last changed, previous problems with tire pressures, and the mileage on the trailer.
Figure 10: A diagram showing a brake pad system.
As indicated in figure 10, the slack adjuster and push rod normally form a 90-degree angle. A typical preliminary examination includes measuring this angle to ensure that it is correctly oriented. This angle is measured at all the wheel-ends and in every axle. The measurement shows us if one wheel-end is significantly different from the others.
The slack adjuster will automatically adjust to keep even brake applications as pads wear, but they need to be appropriately set when they’re installed or when the wheels are removed. A brake system failure could also result from a manufacturing defect or improper servicing.
Figure 11: Images showing the measurement of the slack adjuster angle and the pushrod length.
We discovered that during the manufacturing process, there was a bracket. We determined that the bracket was installed upside down to secure the slack adjuster in position. Since it did not retain the slack adjuster, it did not operate properly. In this case, all the brackets in the trailer were installed incorrectly.
Figure 12: Images showing the improperly installed bracket.
Case study 3: Agricultural
A combine suffered a fire while it was operating. Smoke and then a fire was observed by the operator on the right-hand side of the combine. The operator shut the combine down but was unable to extinguish the fire. There was a tremendous amount of fire damage on one side of the combine (figure 13), and there were no reported operating issues leading up to the loss.
Figure 13: The fire-damaged combine.
Multiple ignition sources surrounded the combine. The fire was first spotted on the damaged side of the combine, near the elevator.
Figure 14: A close-up of the combine elevator.
The bearing for the straw chopper was identified as having a failure. A bearing failure can never result from the fire because the temperatures reached during a fire are not high enough to smear hardened steel. When we noticed that the alignment of the bearing was off, we requested a service history of the equipment.
In the absence of a service record, we would have to look at the recommended maintenance by the manufacturer to see if and how it was supposed to be serviced. We discovered that no servicing was required for the equipment.
Figure 15: A disassembled bearing for further analysis.
To get a clearer view of the areas of interest, we removed any obstructing items from the equipment. It allowed us to see that what remained of the bearing was smeared metal.
Some bearings are self-lubricated, while others need to be greased every 30 hours. Some equipment has an onboard fire suppression system, including a tank of suppressing agents piped to nozzles throughout the machine. Most often, this would be the engine compartment. Sometimes it will be where the hydraulics are, but that is rare.
The nozzles are always open so that if the suppression system is activated, the agent will be forced out of every nozzle. There are two methods of activation – manual and automated. Sometimes, there are temperature sensors in the engine compartment, and a manual activation sometimes is required. The switch for manual activation is usually in the cab.
Due to its several systems and parts, a combine loss can become an extremely complex fire investigation.
Figure 16: An example of the parts and systems of the combine.
Figure 17: A close-up of figure 16 indicates the part that failed with a red oval.
Figure 17 shows the bearing components for one beater bar. Part of the combine has a separator, and the separator hours are tracked on a combine. The total hours these components would be running are then documented. As such, we needed to examine the hours and greasing procedure compared to the manufacturer’s recommendations. We also had to consider the grease amount and the type of grease used.
Using the wrong grease might impact whether a bearing can withstand its expected lifespan and load conditions or if it would fail prematurely. Sometimes we must analyze the bearing side versus the load.
Case study 4: Mechanical damage
Figure 18: The safe
Nine years ago, we were retained to investigate and assess an alarm system after an alleged break-and-enter at home in Toronto. During an alarm system assessment, we discovered that the safe had been broken into. Over $100,000 worth of items were stolen from the safe. As such, the safe was examined.
Figure 19: The locking mechanism on the safe.
The safe was in the locked position while the family was gone, and no one that remained in Canada had the combination to the safe. However, no deformation was observed on the throw of the safe. The secure door was removed, and the safe body remained intact within the wall. The safe installation was between two wall joists. The safe was therefore removed for further examination.
Figure 20: The safe after removal from the wall.
As shown in figure 20, the upper holes on the safe body indicate that the split pin from the hinge assembly on the door sustained minimal damage. The bracket in the bottom image is where the throw from the locking mechanism would have come against, and it had minimal scraping damage, but there was no total deformation. The flange was located approximately an inch from the edge of the safe, and the door rested against it when closed. The door was recessed about an inch inside the safe body.
Figure 21: The front of the safe door.
Figure 21 shows the deformation on the hinge assembly, which indicated that it was pried away from the door at the top and bottom. The limited deformation on the body of the safe did not match the extensive deformation on the hinge assembly. Therefore, it made no sense for the safe to have been pried with the door closed.
Figure 22: A close-up of the hinge assembly showing scratches.
There was significant deformation to the edge and surface of the hinge assembly. This indicated that a pry bar was placed between those two parts to open the safe. However, the damage only lined up with the doors in an open position.
We concluded that this was an attempt by a colleague of the insured to pry the safe door. They tried to pry it open when it was closed, but they could not break into the safe. So, they opened the safe door using the combination and then pried the door off while in the open position to make it look like the safe had been broken into.
Key Takeaway:
- We must go through the entire investigation before concluding; we cannot skip straight to the end.
Partner Up with Origin and Cause to Uncover Mechanical Loss Claims
Claims involving mechanical losses might be difficult to decipher and grasp. Origin and Cause’s team is well-equipped and knowledgeable in the field of complex claims, as well as how to perform an investigation to determine the root cause of a failure. We provide concrete responses based on facts, and all conclusions are reached only after the facts have been verified. To assist you with your claim, call Origin and Cause at 1-888-624-3473 today.