IIRC, this tradition stems from the RN's involvement in the relief of the seige of Ladysmith, during the Second Boer War (1899-1902).
The RN stopped at the 100 year mark (i.e., in 1999), but the Royal Canadian Navy carried on for several more years; see video, below. To the best of my knowledge (could be wrong) they also stopped (due to budget cuts) in the mid-2000's. I can confirm that injuries (severed fingers, broken arms, etc.) did occur.
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