On the picture thread,
Is it common for the Navy to send Carriers to respond to disasters? I would have expected the USNS Mercy or another hospital ship to go, but seeing that the Vinson was going kind of surprised me. Will it mostly be there to support helicopter operations on the island? Or perform some other function?
Well you're pretty close. The big deck amphibs are the ideal platform for this since they were designed around putting a
lot of people and gear on the beach. Remember that the Lincoln did good work after the tsunami five years ago. Any warship can be good R&R for relief workers so they don't burn out (serious consideration... and a clean shower and hot meal go a long way). Others already covered which ships are already heading down or heading soon.
You already "got it" how important logistics is and that the military has far more logistics muscle than anybody else. So in descending order from most important to not as important but still important, here are what the platforms can bring to this kind of mission, broken down "Barney style":
Amphib (the bigger the better here- LSD good, LPD better, assault ship best)
Landing craft <-- the old fashioned LCUs can move some
serious tonnage
Helicopters <-- can't move as much tons/hour but they can put it anywhere you need the stuff... if you use an LCU then sometimes once you get your stuff to the beach you need to unload some of it and then put it on trucks to get it to your distribution points (Port au Prince is crowded, pretty spread out, and has imposing elevation changes- for example, that collapsed hospital in Petionville that was in the news is around 1,000 feet elevation and while just a few miles straightline from the port that is normally an hour-plus drive through slums)
Water- potable water (means you can drink it) and the ability to produce lots of it
Space- lots of it
Carrier
Helicopters
Water
Space
Hospital ships
Hospital (duh...) that can do just about anything you can imagine
if it is staffed with the right kinds of people and enough of them
Amphibs and carriers can do command and control for a mission of this scale. That means a lot of radios, bandwidth, computers, and office space for staffs and liaison officers/reps to do their jobs. The hospital ships can be OK command and control platforms for smaller missions (BTDT). All three can do small boat transfer which can actually be very useful ("sticks" of a few dozen passengers, a lot like riding a bus, and also good for transferring most patients). The hospital ships being converted oil tankers happen to have a lot of internal volume and they also have a helicopter deck, but they weren't built with the intent of moving lots of people and gear ship-to-shore primarily in mind. By the way, the hospital on the amphibs is not particularly big. Some really great capability yes but just not to the magnitude of the hundreds of beds in the hospital ships.
Hope that makes sense, I think I covered the most significant points. @usmarinemike, I think you hit it right on, this time it's big.
For the full-on version think of it like putting the cammies on, going ashore, setting up radios/tents/generators and re-opening an airport. The scaled down version might be a makeshift location (for example, high school football field in Galveston a year and a half ago...). The Air Force has an equivalent capability too, they were talking about it on the radio around here yesterday. The Air Force also has their Redhorse expeditionary squadrons- think of them like Seabees but instead they build/fix runways (they can build a lot of other stuff too, just runways were the original purpose).