To be honest, somewhat pointless, as the SBS showed on an exercise once.
If they were put on for pirates, same story. Any good pirate worth his salt could throw a grappling hook that high.
Far too many posts from people who know nothing about Ship Security. As the saying goes, if you know nothing, don't open your mouth and confirm to the world that you know nothing! Let them still think you do know something!
These grids are on ALL ships and ARE a very good deterrent believe me.
The ship is not going to be stationary waiting for pirates to attack, she's gonig to be underway and i challenge ANYONE to board QE2 via the aft mooring deck, where the grills are, while she is underway and making 20/23 knots. The wake she creates at that type of speed would be
enough to turn any boat over and throw the crew into a very dangerous vortex of swirling water, created by the propellers.
When QM2 was running her 3 'Crew/Cunard families & friends' cruises prior to naming week, we had a planned 'assault' by 'UK Special Forces' and, even with the ship 'co-operating' by travelling in a straight line at a fairly low speed, they still found it very difficult boarding, and that was without the grill in position and using their high tech kit!
I challenge anyone to throw a 5lb grappling hook 35 ft into the air and forward about 100ft from a rubber boat chasing a 60,000 ton liner at 20 knots, if you can do that then you're wasted in being a pirate and would be the Olympic & World record holder at shot & hammer!