Baffles, Bulkheads, Compartments, and Smooth-Bore Tanks
What this domain tests
This section covers baffles, bulkheads, compartments, and smooth-bore tanks. The exam tests tank internal structures: what each part does and how it changes handling and loading.
Core rules
- A smooth-bore tank has no internal walls; liquid can move the full length of the tank, producing the strongest surge.
- Baffles are partitions with openings that let liquid pass slowly. They break up surge but do not seal the tank into separate product spaces.
- Bulkheads are solid walls that divide a tank into compartments. Each compartment can carry a different product and is loaded and unloaded separately.
- Compartments reduce the free surface in each section, but a partly filled compartment can still surge.
- Never assume a baffled tank can carry incompatible products in the same space; only compartments with separate plumbing allow that.
Worked example
A shipper offers a tanker with two compartments for two grades of fuel. The driver sees openings in the internal walls and thinks the walls are bulkheads, so the products will mix. Reasoning: openings mean baffles, not bulkheads. A true bulkhead is solid and separates compartments. If the tank has separate compartments with separate valves and domes, the two grades can be carried; if the openings connect the spaces, they cannot. The driver must verify the tank design before loading.
Traps
- Confusing baffles with bulkheads.
- Believing baffles stop all liquid movement.
- Loading incompatible products into a baffled but not compartmented tank.
- Forgetting that each compartment has its own valves and limits.