What is HRU and how does HRU work?

It is a unit fitted to secure the liferaft such that if the ship sinks it will automatically release the life raft at a depth of not more than 4m.



How does HRU work?
  1. Once ship starts to sink, and when it sinks upto 4 meter the water pressure will activate sharp knife in H.R.U.
  2. It will cut the securing rope around the canister or container of the raft, and now raft will float free.
  3. Now ship will further sink, the painter line will stretch and it will inflate the raft.
  4. Now due to increase in buoyancy, it will break the Red weak link at around 2.2 KN± 0.4 and life raft will be on surface of water now.