Duhaime's Law Dictionary

Collision Definition:

An accidental contact between two or more vehicles or ships which causes damage.

In insurance law, collision has two general areas of application: in maritime law and in regards to automobile insurance.

In the context of maritime law, the term holds great significance and fills the pages of law books dedicated to that topic alone, such as Kenneth McGuffie's 1,313 page tome The Law of Collisions at Sea.

In his 1839 American Law Dictionary, John Bouvier described a collision as a term of maritime law and as follows:

"... the act of ships or vessels striking together, or of one vessel running against or foul of another."

He goes on to describe several varieties of collision, each with their own consequences as to liability:

  • collision without fault;
  • by inevitable accident;
  • by mutual fault;
  • by inscrutable fault; or
  • by the fault of one of the colliding ships.

The wording of the insurance policy is telling as to the scope of possible collisions covered.

"Risk of collision" or "collision" may be limited to collisions with other ships whereas "collision with any object" is far more extensive.

In Chandler v Blogg, Justice Bigham held that accidental contact with a sunken barge, was a collision. He wrote:

"... 'collision', when used alone, without other words, means two navigeable things coming into contact."

In other cases, contact with a submerged anchor was a collision as it is "necessary for its navigation and without which, she could not prudently put to sea (Bennett Steamship, cited below, page 377)

At the other end of the spectrum, in Bennett Steamship, Justice Pickford (in a 1913 case), had to determine whether damages ensuing from accidental contact with a drifting fish net that extended a mile behind the ship, was a collision. The Court decided that it did not, impressed with the fact that from time to time, the mother ship Burma detached from the drift net.

In automobile insurance, collision is a typical insured risk. In London Guarantee, the issue before the Court was whether in capsizing,  a vehicle was insured or not under "collision". Justice Idington of Canada's Supreme Court thought not, although the judgment rode on the wording of the policy before the Court:

"Even granting that in the clause insuring the automobile against damage 'by being in accidental collision ... with any other automobile, vehicle or object,' the words 'or object' are not to be construed according to the rule noscitur a sociis, still I cannot bring myself to believe that what the parties meant was to treat as a collision the overturning of the car. The car was necessarily in contact with the highway all the time and if it overturned or upset, bringing its side, instead of its wheels, in contact with the roadway, that certainly was not a collision within the meaning of the policy."


  • Bennett Steamship Company Limited v Hull Mutual Steamship Protecting Society Ltd. 1913 3 KB 372.
  • Chandler v Blogg 1898 1 QB 32
  • Duhaime.org wishes to thank Mr. Darren Williams, maritime law lawyer of Victoria, British Columbia, for his assistance in suggesting this definition.
  • London Guarantee and Accident Co. v Sowards 1923 SCR 365 or (1923) 2 DLR 495.
  • McGuffie, K., British Shipping Laws - The Law of Collisions at Sea (London: Stevens & Sons, 1961).
  • Reischer v Borwick (1894) 2 QB 548

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