I did a couple of MES (Marine Evacuation System) training courses at the old Harbour Station when it was in use by Stena during the nineties. This was when the MES systems in use employed slides. You climbed up a ladder onto a platform and then slid down the slide onto the liferaft embarkation platform. Then you hauled the encapsulated liferafts, which were mounted on wheels, around the side of the platform and secured them. There was a bit of theory beforehand, including survival aspects etc. Think that was held at the Golden Arrow building over by Southern House (Lord Warden).
On one occasion, we also staged a full scale deployment from the Stena Invicta over on the Admiralty Pier with all the authorities and media present.
The MES in use on most, if not all, of the P&O ships are the Marin Ark system which uses vertical chutes to descend to the liferafts. We use a similar vertical system manufactured by Viking on the three DFDS (ex Maersk) ships. In our case, the training is theoretical supplemented by a go at the real thing when one or more MES systems are deployed prior to going away to refit. The liferafts then have to go back to the manufacturer to be repacked and delivered back to the ship. It is not done in service as it would reduce the number of passengers the vessel would be permitted to carry. I expect that P&O do the same thing so a dedicated shore facility is not essential.
Below is a diagram of the Viking system. You launch yourself into a black hole and slide vertically down section by section, braking your descent by pressing your hands against the sides. White gloves are supplied to prevent friction burns. You drop out of the bottom onto the inboard inflated liferaft through a hole in the canopy then squelch across to the outboard liferaft. More liferafts can be dropped in their canisters into the sea where they inflate and are brought alongside by the ships' rescue boats (there is a Fast Rescue Craft on the starboard side and a nippy shepherd boat on the port side). We also have two conventional lifeboats.
These are the two embarkation liferafts and the shepherd boat after a deployment of one MES prior to a refit in Dunkerque.
This is the Pride of Kent after deploying one of her Marin Ark systems in Dover prior to going to refit last year.