Shipbucket

i missed this

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Supreme Commander of the Astrofleets

note that well decks are also vulnerable in all weathers were you cannot operate helicopters anymore. maybe even earlier. the fact that you have to open an large door in the back of your ship, in which, if your ship turns a bit, the waves can slam in........
and of course, you want to recover boats while not moving too fast, thus you have little forward speed is little steering in weather that is trying to push the bow to the side, which results in the back (with the dock) being exposed.
no, I think I would go for an LPD, maybe even without or with an small dock, with an small helicopter hangar (like, space for 2 chinooks folded) and enlarged crew spaces and hospital space, of course.
such a ship could be relatively low tech, relatively fast (if you would do away the dock, you might even go for an container ship hull instead of the blocky hull an dock requires) build to civilian damage control status.

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Drawings are credited with J.Scholtens
I ask of you to prove me wrong. Not say I am wrong, but prove it, because then I will have learned something new.
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Another thing to consider with a well deck ship on the plus side is that any ship can enter and leave a well deck and basically have dock side facilities. In other words any number of local government or impressed small civilian boats and ships can get easy access to unload as long as their draft doesn't prohibit it. LHDs and LPDs, for instance, have been known to take in captured dhows in the HOA for transport to an impound location.

As for winch and davit small boats launching these is pretty much out of the question for nearly any seas that would put a well deck out of action and since a ship like this is about MASS casualties boating highly vulnerable stetcher bound paitients in an 8 or 11 meter rib one at a time and them winching them up to a high freeboard LHD/LPD is not really idle. Hell, its a PITA when just doing this for normal operations and non injured sailors as it is and I have moved quite a few injured personel between ships or shore via RHIBs before and it is a very dicy affair. I think they should have one or two for utility purposes (force protection when transiting through ports, non medical personnel transfers, etc.), but not as a patient mover.

Honestly now that I think about it a couple of LST type ships that could beach themselves and be an on the ground emergency medical clinic would have been highly useful in say Haiti or the two recent tsunami responses. Leveling the decks for treatment purposes while on the beach is the only thing that makes them less than ideal. One of the most important things WASP did when in New Orleans was provide power into the local grid while pierside.

well, if well decks and davids had the same use circumstances, then ships damaged in storms would be in big trouble, because all the lifeboats are in davids. no, it is not perfect, nor comfortable under those circumstances, but you can safely use them a lot more then well decks or bays.

launching them is possible under almost any circumstance, recovering is a bit harder. but, you don't go into seas from the coast to the hospital ship under those circumstances with patients, you might want to leave the ship (for rescue or anything like that) but you won't tackle the boats on board.

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Drawings are credited with J.Scholtens
I ask of you to prove me wrong. Not say I am wrong, but prove it, because then I will have learned something new.
Shipbucket Wiki admin

Ships damaged in storms "launch" ie toss over the side cannister inflated lift rafts and board them from the water once they themselves heave over the sides. It's an uncomfortable truth but ships in a storm back when winch and davits the sole means of having life boats more often than not went down without using them for this reason. "All hands lost" was a common headline.
I suppose modern hard hulled life boats on some merchants operate on this concept, they are pretty much capsules designed to survive all seas and are also pretty much dropped over the side which must be one hell of a ride.

But like you said hospital ships are most concerned with getting patients on, not off. By their nature they arrive after a disaster not during unless they are acting as a military hospital. In all likelihood patients would be helicoptered on by any modern nation fielding such a ship and the well deck would probably be mostly involved with moving medical vehicles and stores ashore. Unless the place is completely screwed up where you can't just find a place to dock or land helos the well deck is probably not going to be the first choice in patient loading. That's actually one of the biggest critisisms of the Mercy class, their inadequate aviation facilities.

So I was thinking about this yesterday an actually started toying around with an LPD 17 to flesh some things out but quickly ran into a few conceptual questions that really need to be answered before make design decisions.

1.) For one I think the well deck is unnecessary for a hospital ship. If all it is supposed to do is take on the most seriously injured for full hospital treatment then air as already mentioned is the way to go. The weakness of the Mercy in this regard is its aviation facilities, namely that they are tacked on amidships which is bad news for heavy weather landing and crash management and they don't have hangers.

2. ) If a hospital ship is all its supposed to be then I don't think a well deck makes sense. Yes you could boat mass casualties in and yes you could deliver supplies and medical personel in bulk to any place along the coastline. The thing is this can largely be accomplished by helicopter too (though not as fast) and which is cheaper to build and operate; a well deck with LCU/LCAC with access to only the coast or a hanger and a couple helos with access near anywhere in range? I think civilian hospitals have already answered this for us regarding helos and access to critical or remote patients.

3.) Regarding bulk delivery of materials via well deck craft again it comes down to mission. Is that a hospital ship's role?

4.) So via mission if you want to go an LPD/well deck route a hospital ship is not the mission you are satisfying, but rather a disaster response ship. For that sort of vessel the well deck is not there primarily to help patients, but rather more general activities. Fill the vehicle decks with excavators, bulldozers and other heavy equipment to clear roads and search for survivors. Have well deck craft to deliver containers of disaster relief supplies and the prime movers to get them around. As the tsunami and haiti incidents showed proper docking facilites ARE NOT available so here the vehicle moving capabilitiy is needed.

5.) Besides the savings in damage control standards, engineering redundancy and weapons emplacements is there anything in #4 that a modern LPD is not perfectly suited for right now? Would you save anything by having dedicated civilian LPD vessels instead of just using one at military specs that is useful when not responding to disasters?

well, for an purpose build hospital ship, looking at this thread, I would build the following:

- an ship between 150 and 180 meters in length, with an relatively large draft for high stability under all circumstances.
- with 2 deck spots at 3 quarter aft, with an hangar for max 2 stallions. (or more smaller heli's, but never more then 4 would be needed) the deck aft of this position has nothing that is higher then the flight deck level.
- build to civilian standards, accepting lower stresses but being in this case similar in price
- with at least one cargo door in the side or stern that opens as an small platform, that can thus load or unload from landing craft or ships.
- with lifeboats which can serve as sloops for patient transfer. this means an relatively low position and some different model of sloops (note, an modified one from cruise ships might just do the bill) helicopter transfer is expensive so you don't want to do that for every patient.

all in all, an LPD seems to be a much more potent in the above respects then an LHA or LHD, especially considering that while the mercy has too few aviation facilities, an LHD will have way too much.

note also, that it is impossible to move hospital beds trough any kind of watertight door. you want your patients on the higher levels, anyways, as those are the easiest to reach, so why not move them above the actual hull? again an LPD or passenger ship even as base would be better.

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Drawings are credited with J.Scholtens
I ask of you to prove me wrong. Not say I am wrong, but prove it, because then I will have learned something new.
Shipbucket Wiki admin

On this point, on the Mercy the issue isn't water tight doors but rather that the original separated tanks that were vital to the sturcture and integrity of the ship were not penetrated. Most of the hospital beds are actually in spaces built inside these tanks, so to move a patient you have to move them up so many decks out of one tank and then back down into another.

There really isn't an issue with watertight doors. They can be made to to be many feet wide and all you need is a stopping mechanism on each side of the rolling bed that lets you temporaraily support it while you lift over one set of wheels. If it was built to military standards it would be more difficult, but there are far fewer such doors on a civilian ship.

I don't have a problem with facilities on top of the hull, but what do you intend to fill the hull with?

fill the hull with storage.
btw, the problems with the watertight door is not the width, but the height of the bottom. a human can step over them, but watertight doors are per definition not level with the floor.

that said, an purpose build ship would have the watertight levels lower then that of the mercy, of course. if you have 10 decks above the waterline, only the lower 2-3 would be integrated with the watertight compartments.

below that level you put machinery, stores, and if you want to make the ship real compact, accommodation (this is not normally done, accommodation is almost per definition above the waterline on civilian ships) it is also good to add some additional ballast tanks, so you can let the ship lay deeper when static to let her roll less.

_________________
Drawings are credited with J.Scholtens
I ask of you to prove me wrong. Not say I am wrong, but prove it, because then I will have learned something new.
Shipbucket Wiki admin

I didn't realize accomodations were never below the waterline on civilian shios. Is this true for cruise ships too? I always figured the crew was somewhere down there to maximize guest space!