Milk may do a body good, but surprisingly it can be a contributing factor in truck accidents. When a commercial tanker truck carries a liquid such as milk, it can make the vehicle difficult to control for a number of reasons. The tanks on tanker trucks are elevated well above the roadway, making such trucks top heavy and leaving their centers of gravity much higher than those of vehicles with lower profiles. This makes tanker trucks more vulnerable to rollover accidents. Liquid in tanks (often thousands of gallons of it) can surge forward and back during acceleration or braking and side-to-side when the vehicle is cornering leaving the driver struggling to control the vehicle.
To help control the surging of liquid loads, tanks are equipped with baffles. Baffles are dividers inside the tanks with openings in their tops and bottoms that allow the liquid cargo in the tank to move, but without the surging that takes place in a wide-open or smooth bore tank. However, there are major problems with baffles: they control only the forward and back surging of liquid loads and do nothing to control the side-to-side surge that can accompany cornering in tanker trucks.
In addition, baffles are not allowed in tankers carrying food grade loads. Because they are too difficult to clean, baffles could lead to contamination of foods such as milk and are therefore illegal on trucks carrying such loads, leaving drivers of milk trucks and other liquid food grade loads at constant risk of dangerous surges.
In one recent example of a milk truck accident, on June 7, a semi-trailer carrying a load of milk flipped onto its side and skidded into the ditch while traveling on U.S. 68 in Greene County, Ohio. The Ohio State Highway Patrol is continuing its investigation into this truck accident and it is not known if surges played a part, but experience tells me it is likely. Luckily this accident occurred at an early morning hour on a nearly empty highway and no other vehicles were involved. The driver of the big rig received only minor injuries.
Unfortunately, as I’ve seen in the cases involving milk trucks that I’ve handled, such a lucky outcome is not always the case.
Drivers of trucks transporting milk and other food grade liquids need to be especially cautious when operating their vehicles. They must understand fully the safest way to negotiate turns; the challenges involved in starting and stopping a vehicle with a smooth bore tank; and the precautions necessary when driving such a vehicle into an intersection where a surge could carry the truck into the intersection despite the driver’s best efforts to stop.