Contributory negligence: knowledge by the plaintiff; "Volenti non fit injuria"
The plaintiff was employed by railway contractors to drill holes in a rock cutting near a crane worked by men in the employ of the contractors. The crane lifted stones and at times swung over the plaintiff's head without warning. The plaintiff was fully aware of the danger to which he was exposed by thus working near the crane without any warning being given, and had been thus employed for months. A stone having fallen from the crane and injured the plaintiff, he sued his employers in the County Court under the Employers Liability Act 1880.
It was held by the House of Lords, reversing the decision of the Court of Appeal (Lord Bramwell dissenting), that the mere fact that the plaintiff undertook and continued in the employment with full knowledge and understanding of the danger arising from the systematic neglect to give warning did not preclude him from recovering; that the evidence would justify a finding that the plaintiff did not voluntarily undertake the risk of injury; that the maxim "Volenti non fit injuria" did not apply; and that the action was maintainable.
The House of Lords decision in Smith v. Baker &
Sons  was the first case in which the defence of "Volenti non
fit injuria" was limited in employee situations.
It is a question of fact in each case whether the knowledge of the plaintiff in the particular circumstances made it so unreasonable for him to do what he did as to constitute contributory negligence.
When a workman engaged in an employment not in itself dangerous is exposed to danger arising from an operation in another department over which he has no control - the danger being created or enhanced by the negligence of the employer - the mere fact that he undertakes or continues in such employment with full knowledge and understanding of the danger is not conclusive to show that he has undertaken the risk so as to make the maxim "Volenti non fit injuria" applicable in case of injury. The question whether he has so undertaken the risk is one of fact and not of law. And this so both at common law and in cases arising under the Employers Liability Act 1880.