Barkway v South Wales Transport [1950] AC 185
TORT – NEGLIGENCE – BREACH OF DUTY – RES IPSA LOQUITUR
Facts
The claimant was injured when a bus drove off the road because of a latent, undetectable defect in the tyre that made it burst. There was evidence that the bus company ought to have made drivers report impacts which could cause this sort of defect, and had not done so. The claimant sued the defendant bus company in the tort of negligence.
Issue
To prove negligence, the claimant must show that the defendant breached their duty of care: that the defendant failed to act as a reasonable person would in their position.
Where it is not possible for the claimant to prove exactly what the accident’s cause was, the court will presume breach if the defendant was in control of the situation and the accident was not one which normally occurs without carelessness. This is the doctrine of res ipsa loquitur.
The issue in this case was what the doctrine means when it requires the cause of the accident to be unknown.
Decision/Outcome
The House of Lords held that this was not a case where the doctrine of res ipsa loquitur applied.
The House of Lords held that doctrine required the cause of the accident to be completely unknown. It was not applicable in a case where all the facts relating to the accident are known and the judge is merely being asked to decide between two or more competing interpretations of events.
In this case, all the relevant facts as to how the accident arose were known, and the judge was merely asked to decide whether the defendant’s reporting policies were negligent and could have prevented the harm. As such, the claimant retained the burden of proving negligence as usual.
Updated 19 March 2026
This case note accurately describes the facts, issue, and outcome of Barkway v South Wales Transport [1950] AC 185. The legal principles set out remain good law. The doctrine of res ipsa loquitur continues to be recognised in English tort law, and the House of Lords’ approach in Barkway — that the doctrine does not apply where the cause of the accident is known or ascertainable — remains authoritative. Subsequent cases, including Scott v London and St Katherine Docks Co (1865) and later Court of Appeal decisions, are consistent with this approach. Readers should note that res ipsa loquitur operates as an evidential principle rather than a separate rule of law, a point confirmed in Ng Chun Pui v Lee Chuen Tat [1988] RTR 298 (PC), which clarified that the doctrine merely shifts the evidential burden and does not reverse the legal burden of proof. This nuance is not addressed in the article but does not affect the accuracy of the specific points made about Barkway itself.
