For over 10 years there has been a concerted push within industry to move tanker loading operations to ground level. It removes the risk of the operator working at height. This is only possible if the receiving road or rail tanker is equipped to accept Bottom Loading; has some form of adequte venting or vapour return at ground level and hopefull, a high level alarm that lives with thne tanker. That is not always the case and logistics require as much flexibility in operations as possible. However, depending on the nature of the liquid, there may still be a need to vent from the top so safe tanker access systems will still be required in that case.
If you have overcome all these concerns, then you need to be considering a loading arm. A 3 stainless braided hose with a 3″ stainless steel ball valve and coupler will weight over 40kg at the tanker end. It creates stress on the connection and stress for the operator. A bottom loading arm is fully counterbalanced and can be easily handled by one person.