Baffled vs. Unbaffled Tank Construction
Baffles are internal partitions inside a tank that have holes or openings in them, allowing liquid to flow between sections while slowing that flow significantly. Bulkheads are completely solid dividers that fully separate one section of the tank from another, creating independent compartments. The distinction matters enormously for both the type of product that can be carried and the driving dynamics the operator will experience.
Unbaffled tanks — those with no internal dividers at all — are typically used for food-grade products such as milk, edible oils, and juices. The reason for using no baffles in food tankers is sanitation: baffles with holes or welds create crevices where bacteria can grow and are extremely difficult to clean. An unbaffled tank with a smooth, polished interior can be thoroughly washed and sanitized between loads. Milk tankers are the classic example — a single stainless steel chamber that allows the entire interior to be reached by cleaning solution.
Baffled tanks slow the front-to-back movement (surge) of liquid without fully stopping it. The baffles act as a series of partial barriers, absorbing some of the kinetic energy of the liquid as it moves during acceleration or braking. The tradeoff is that baffled tanks are more difficult to clean because the baffles create obstruction to cleaning hoses and solutions. Petroleum tankers address this by using multiple compartments separated by full bulkheads, which completely stops surge between compartments but requires the driver to manage each compartment's fill level independently.
Chemical compatibility is another driver of tank design. A petroleum tanker with four compartments can carry regular, premium, diesel, and kerosene simultaneously with no cross-contamination risk because the bulkheads are solid. An edible oil tanker carrying two different oils must have full bulkheads if the oils cannot be mixed. Understanding which products require segregation by bulkhead versus which can be separated by baffles requires reading the product's technical specifications and applicable regulations.