R brokered a deal whereby A chartered a ship from C and R was to receive 3 per cent of the amount paid.
R was trying to claim from the C (owners of the boat) their commission and the A joined R as plaintiffs.
It was held by HL that a charterer can contract on behalf of the brokerer.
Hence the charterer can sue as the trustee of the brokerer.
This is for commercial convenience.