266 Chapter 9Nuisance, trespass, defamation and vicarious liability
(ii) If an employee is authorised to do an act properly then the employer will be liable if the
employee performs the act negligently.
If all employees performed their work properly then vicarious liability would be
unlikely ever to arise. So if employers could escape liability on the grounds that the
employee had been acting negligently the concept of vicarious liability would all but
disappear.(iii) If an employee commits a tort while doing an act which is designed to help the
employer, then the employer will be liable.(iv) If an employee does something entirely for his own benefit, he is said to be ‘on a frolic
of his own’, and the employer will not be liable.Poland vJohn Parr & Sons (1927) (Court of Appeal)An employee wrongly believed that a boy was tampering with a bag of sugar on one of the
employer’s wagons. To protect the sugar, the employee slapped the boy, who fell under
the wagon. The boy suffered injuries which resulted in the amputation of his leg.
HeldThe employer was vicariously liable. The employee had implied authorisation to
protect the employer’s property.Century Insurance Co Ltd vNorthern Ireland Road Transport Board (1942)
(House of Lords)A petrol tanker driver, while emptying his tanker, lit a cigarette and threw away the match.
This caused a huge explosion.
HeldThe employer was liable. The driver was employed to empty his tanker and that was
what he was doing, albeit negligently, when he caused the explosion.Kay vITW (1967) (Court of Appeal)The assistant manager of a warehouse was employed to drive small vans and cars. In order
to make a space in the warehouse, he moved a large diesel truck belonging to another firm.
He did not notice that the truck was in reverse, and when he started it up he ran over the
claimant.
HeldThe employer was liable. The employee moved the truck so that he could get on with
his work. Moving the truck was within the scope of his contract of employment.Hilton vThomas Burton (Rhodes) Ltd (1961)In the middle of the afternoon employees of a demolition contractor drove from their place
of work to visit a café. The men were working 30 miles away from the employer’s main busi-
ness premises and the café was seven miles from the site at which they were working.