Mersey Docks & Labour Bd. v Coggins [1946]

Harbour authority owned crane and employed
driver.
Let crane and driver to respondent stevedores.
Contract stated driver shall be servant of
stevedores.
M injured at docks when crane-driver
carelessly drove into him.
House of Lords found harbour authority liable.
Lord Macmillan:
Always open to employer to show he has transferred
services of one of his general servants to another party, so as to constitute
him servant of that party.
Burden is on employer to show such
transference has occurred.
Did not occur here, despite wording of contract.
Stevedores could tell him where to go and
what to lift but had no authority to tell him how to drive crane.
[So most satisfactory test is: Who at particular time has authority to
tell person what to do and how to do it?]