The invention relates to a device for detecting a failure in a collection strip (2) of a device (1) for transmitting current between two elements that are mobile relative to one another, including a tube (4) made of a rigid material, which is designed such as to contain a fluid under pressure and which is to be attached between the collection strip and a means (5) for supporting said strip, such that the inside of said tube can be in fluid communication with means for detecting a pressure variation, characterised in that the tube has at least one discontinuity (11) producing a local thinning of the body of said tube.