FIRE AND SAFETY PRECAUTIONS
When a tank vessel has docked, responsible persons must make sure there are no fires, open flames, or open lights on deck or anywhere near the part of the deck at which the cargo hose is to be connected. Although it is sometimes necessary to keep fires in the boiler room when cargo is being loaded or unloaded, the potential hazard should be weighed. Extreme care should be taken when tugs or other vessels that may have open flames come alongside. Smokestacks of coal burning tugboats, dredges, or pile-driving equipment should have spark arresters. These precautions are very important during the transfer operation when large amounts of explosive vapors may form. Smoking or flame-spark-producing devices should not be allowed on the vessel or at the terminal, except in special places. Fire fighters must not be allowed to clean out stacks while vessels are docked. No garbage or waste of any kind should be thrown overboard while the vessel is docked. Additional measures are described below.
Caution signs must be posted. They include NO SMOKING and NO LOITERING signs and traffic direction markers. A warning sign stating DANGER: THIS VESSEL HANDLING PETROLEUM must be posted. A sign stating NO FIRES, NO SMOKING, NO VISITORS should be posted in clear view on the gangway while product is being loaded or unloaded. The sign must be lettered in red on a white background. When a petroleum cargo is transferred at a mooring or dock, the vessel must display a red flag by day and an all-round red light by night.
A grounding cable must be connected between the dock grounding system and the hull of the vessel before the cargo hose is connected. This cable must not be removed until after the cargo hose is removed.
Cleanup of Spills
All spills must be cleaned up as soon as possible. Sources of vapor ignition must be eliminated.
No vessel should be allowed to dock or moor within 50 feet of a vessel that is unloading bulk cargo, unless the depot officer or supervisor and the master of the vessel transferring cargo agree.
At the end of each mooring line, at the bollard or belay pile, there should be a manila or synthetic fiber line that can be cut in an emergency. It is used if there is no other emergency release.
Relief Valves on Suction Lines
A shutdown of the booster pumps, either through error or power failure, will stop the flow and cause the full delivery head from the vessel's pumps to back up at the dock. There may also be a surge of pressure that could burst the hose. Precautions should be taken against these hazards. A battery of relief valves may be connected to the pump station suction line. The valves will relieve pressure until vessel personnel can be told to shut down the vessel's pumps.
To ensure safe operating procedures, the depot supervisor must inspect conditions both on shore and on the vessel before loading or unloading operations are started. There will usually be at least one deck officer and one engineer officer on duty aboard a tanker during such operations. This rule may be changed to suit transfer operations to and from small vessels.
Deck Watch and Hose Watch
During the entire loading or unloading operation, the vessel personnel usually provide a deck watch and the shore organization provides a hose watch. The hose watch observes ship/dock operations, looks for straining or chafing of the cargo hose, stands by at all times to close the dock valves, and coordinates with the deck watch to start and stop the operations.