Under what circumstances is an additional survey required for a chemical tanker with the BCH Code?

An additional survey for a chemical tanker under the BCH Code is required when modifications or repairs are made to the vessel. This is essential because any significant alterations or repairs can impact the ship's structural integrity, safety systems, or the operational capabilities concerning the transport of hazardous materials. The BCH Code sets rigorous standards for the safe carriage of chemicals, and these standards must be reaffirmed after any significant changes to ensure compliance and safety.

Modifications may include alterations to cargo tanks, piping systems, or safety equipment, which would necessitate a thorough inspection to verify that all aspects of the vessel still meet the stringent requirements for carrying chemicals. The additional survey ensures that the vessel remains fit for service and poses no risk to the environment or crew while it is in operation.

In contrast, hiring new crew members, changing cargo types, or operating in different waters does not inherently require an additional survey, although each of those circumstances might still necessitate other forms of training or compliance checks.