Help for Novel

[Rich Keller]

Right, but if one did so, would that mean they could get back to he surface without the cord, just with their tanks? Can we imagine they have no tanks at all or would that seem suspiscious?

You could leave the part about the tanks out of the story if you needed to, non-divers would have no idea it should have been there and 99% of sport divers would not know either. Two posts after I explained to you what a bail out bottle was the sport divers were telling you such a thing did not exist when in fact it is standard equipment for deep surface supplied dives. You could have the system set up in a way that there was enough air in the bailout system to get them back to the habitat but not enough to get them to the surface. Even though the one atmosphere suits can handle very high constant pressure they also must come up slow. The joints in the arms and legs only work because pressure sensors adjust the hydraulic pressure in the joints so they match the outside pressure. If a one atmosphere suit comes up too quickly that system can not adjust fast enough and if a joint fails as a result the suit will implode killing the diver.

 

[Grenouille]

Awesome info guys, as always... need time to chew, swallow, and digest. Will be back.

 

[Rich Keller]

James Cameron dived at 7 miles, if I'm not mistaken, in that little sub of his, breaking a record, how is that different from my situation? James Cameron's sub is like our shelter, why would they need years of decompression if he didn't, and he dived much deeper? Sorry if I misunderstand some basic things, it's still all pretty new to me
Oh and also, what kind of time would they have outside with an umbilical cord? A few hours? Unlimited?

You understood it correctly, the person inside the bell would always be at one atmosphere and would not need to decompress. For deep saturation dives as a rule of thumb a diver would need to decompress about one day per every hundred feet they were down. This could take about a week or so on average, no where near months. As for the amount of time a diver could spend outside that would be unlimited as long as the air supply kept going. Other factors would come into play that would limit the dive before the air ran out.

---------- Post added May 13th, 2013 at 04:11 PM ----------

Right right, but I thought I'd been told here that with the kind of suits we were talking about (the name escapes me now, but that's the ones looking like astronauts suits), it was like a mini-sub wrapped all around you, so you're not subject to pressure either.
So if I want my divers to be able to get out whenever they want to explore and get stuff, I'd need to pretend they can recreate the gasses that they need as much as they want... which sounds scifiish, from what you're saying.

The one atmosphere suits currently in use are the JIM and WASP suits and can scrub the air of CO2 and some other gases just like a sub. This technology has existed for decades and is not scifish by any means.

---------- Post added May 13th, 2013 at 04:21 PM ----------

Hahahaha! Well there's a really smart inventor in this story, borderline genius, without going scifi I think he's able to build such a suit with a buoyancy bladder smaller than a small zeppelin . But so I don't know why we were discussing the reason they were stuck down there, even with oxygen tanks, they'd be just way too heavy to go back up anyway. Might have to take this story to the Moon instead, should be easier

First these suits are too buoyant to start with and weights need to be added to either keep them on the bottom or make them neutral. Second technology already exists to make a lighter/smaller suit but there is just no need for one.

---------- Post added May 13th, 2013 at 04:34 PM ----------

Shallower it'll be, then. Anyone knows where I can find a map of how deep different parts of the ocean are? Especially the area around Miami.

This is an on line NOAA chart for the area that is interactive to a point. You will see it gets deep close to shore in that area.

Chart 11465

---------- Post added May 13th, 2013 at 05:15 PM ----------

Well, for the plot, I need them to not be able to go back up just with their suit, but to be okay going back on a submarine and take 3 days to decompress in there before emerging, if that makes sense at all (forcing the crew to stay together in there for 3 days). I'd like them to build a probe that they send to the surface to get some data, and I'd like them to try and build a capsule big enough for 2 people, with material from mostly plane wrecks, for someone to go back up (at a time when they don't have a submarine yet), but that plan fails and leaves one of them paralyzed after a decompression accident, and another dead. I really would like to use the umbilical cord, I find that awesome. The only thing is the guy who designed it didn't want them to go back up for a long time, and I feel like 100 or 200 meters wouldn't be a good guarantee for that, it doesn't feel "that deep" for such a project.

If they are going from the habitat, into a suit and getting into a sub and all at one atmosphere there would be no need for decompression so that part makes no sense. If they are using aircraft parts to make an open bottom bell the pressure would be the same inside as outside so it would not have to be too strong, just strong enough to contain the force of the air inside and it would need to be leak proof or nearly leak proof at the very least. If they are going from a one atmosphere habitat into an open bottom bell they would not have been down long enough to be saturated so it would not take one day per 100ft to decompress either. They would now have to use a different gas blend for the initial transfer form the habitat to the bell but the decompression stops would take place closer to the surface so they would need to adjust the blend to the depth they were currently at. If their air is being supplied to the bell from the habitat by an umbilical that does not reach all the way to the surface they would have to leave the bell in shallower water and finish the last stops on scuba. Lots of grey area here for decompression errors to take place especially if this needs to be put together in a hurry. As for your paralyzed and dead diver a CNS hit would be a very reasonable explanation for both outcomes.

 

[Grenouille]

First these suits are too buoyant to start with and weights need to be added to either keep them on the bottom or make them neutral. Second technology already exists to make a lighter/smaller suit but there is just no need for one.

I don't understand what you're telling me. Are you saying it makes sense that they use those suits or it doesn't? If they're so heavy, why would you need anything to keep them on the bottom?

If they are going from the habitat, into a suit and getting into a sub and all at one atmosphere there would be no need for decompression so that part makes no sense.

Could there be any reason why a sub would need to wait a little before emerging? Maybe not 3 days but at least half a day?

If they are using aircraft parts to make an open bottom bell the pressure would be the same inside as outside so it would not have to be too strong, just strong enough to contain the force of the air inside and it would need to be leak proof or nearly leak proof at the very least.

I was picturing a closed capsule, like a mini sub but in the form of a cocoon, something that slowly goes back up. I have no idea how the bell works and if they could build one and make it work from the bottom of the ocean. If it's that easy that's a problem for me, they'd have managed to go back up a long time ago. When they use a real submarine, they have what they need to connect it to the structure, so that one will be a breeze, but when they build a capsule, it's trickier. I don't want the capsule to go that far up, I want it to fail miserably for some reason. I didn't picture an umbilical cord for the capsule, but some reserve of oxygen inside. Basically I saw it working like a sub and with the same atmosphere as in the habitat, so there would be no need for adaptation. I'm really lost right now, I need to do more research because you're speaking Chinese to me and I don't understand half of the things you're talking about

 

[Rich Keller]

I don't understand what you're telling me. Are you saying it makes sense that they use those suits or it doesn't? If they're so heavy, why would you need anything to keep them on the bottom?

Could there be any reason why a sub would need to wait a little before emerging? Maybe not 3 days but at least half a day?

I was picturing a closed capsule, like a mini sub but in the form of a cocoon, something that slowly goes back up. I have no idea how the bell works and if they could build one and make it work from the bottom of the ocean. If it's that easy that's a problem for me, they'd have managed to go back up a long time ago. When they use a real submarine, they have what they need to connect it to the structure, so that one will be a breeze, but when they build a capsule, it's trickier. I don't want the capsule to go that far up, I want it to fail miserably for some reason. I didn't picture an umbilical cord for the capsule, but some reserve of oxygen inside. Basically I saw it working like a sub and with the same atmosphere as in the habitat, so there would be no need for adaptation. I'm really lost right now, I need to do more research because you're speaking Chinese to me and I don't understand half of the things you're talking about

It makes sense to use these suits but it does not make sense to build a more scifi type. There is no technical reason why the sub would need to wait to come up. You could have the sub get caught up in some wreckage that would have to be cleared before it could proceed. It would be far easier for them to make an open bottom bell out of wreckage then a capsule. The bell is just like an upside down bucket with an air pocket inside, all they would need to find is one piece of wreckage that is big enough for them to fit into and can hold air. The bell would need to be tethered to the habitat so it would not just shoot to the surface and air would need to be pumped to the bell from the habitat with an umbilical. Making a working one atmosphere mini sub out of aircraft wreckage would impossible.

---------- Post added May 14th, 2013 at 07:02 PM ----------

If you move the habitat into shallower water, say 200' to 300', lose the idea of it being at one atmosphere and go with ambient pressure instead you would solve a lot of your problems. Anyone living in it would have to decompress for 2-3 days in order to get to the surface, you could lose the one atmosphere suits and just use regular commercial diving gear. This would mean they would have to breath something like trimix which would not complicate you story beyond giving a simple explanation of what it is for the non divers. Something like: They live deep enough that they must breath a special mix of helium, oxygen and nitrogen blended for that depth. You never need to get into what percentage of oxygen they are using or why the nitrogen needs to be in the mix. That explanation would be enough for the non divers and many divers have at least heard of trimix. Anyone looking up what trimix is would find your explanation to be 100% correct as far as it goes. As for your research, if you get a copy of the book I recommended earlier, Commercial Oil-Field Diving by Nicholas B. Zinkowski, I could use my copy to direct you to just the areas that you would need to look at. I still have my copy from when I went to commercial diving school, mine is the second edition printed in 1978. If you get a newer edition I can direct you to the right areas, if you get the same edition I can direct you to the right page and paragraph you need.

 

[Grenouille]

Thanks, I just ordered the book, I'll let you know when it's there. Gotcha on the trimix, sounds like a good explanation and easy enough to write organically in the story.
So if we go back to a shallower depth, then I can go back to having my character having to train to become a diver, meaning all the techniques for buoyancy, breathing etc? Which I didn't need with a crazy suit like we talked about before, because it didn't apply. Thing is, having them be regular divers isn't nearly as fun as them being really deep, because the regular diving is known by lots of people, but having them really deep in the darkness with suits that look so weird, it makes for a much more special environment.
I'm worried about the bell, it sounds much better because like you said, the capsule seemed unrealistic and I knew that, but the bell seems so easy, how can such an idea exist and they're still stuck for 19 years? The guy who put them there has a very elaborate project, there's no way he could put them in a situation where they actually have a big chance of leaving, best case scenario their way of leaving needs to be very risky and with a very high chance of failure. That was the reason we put them so deep in the first place. In terms of making the bell work, even if they build it outside, in the water, you're saying they could inject air from the habitat and kick some of the water out of it? If they're wearing equipment to be in the water, what's the point of the bell, is it just for the pressure?

 

[Rich Keller]

Commercial diving is far from regular diving, the equipment is very different, lots of people know what scuba is not commercial diving, even most scuba divers know little or nothing about it. Also being saturated at 200' to 300' is deep. The bell would not work for people saturated on trimix because it would take 2-3 days to decompress and the bell could not be heated so they would freeze to death long before the reached the surface. Trimix is made up mostly of helium and this gas sucks the heat right out of your body, using aircraft wreckage would work for a bell, you could easily get air to it but heating it for days would not work.

---------- Post added May 15th, 2013 at 04:58 PM ----------

Even though they would be using normal commercial diving equipment saturation diving is far from the norm. Even among commercial divers this type of diving is rare.

 

[Grenouille]

I got the book today. Not sure if the appropriate smiley should be or

Edit: Oh man that is GOLD!!!

---------- Post added May 16th, 2013 at 03:30 PM ----------

Question: Would someone wearing one of those heavy suits for the deeper dives not experience nitrogen narcosis? Does it only apply if you're wearing regular scuba-diving equipment, a wet suit with tanks etc? (Since it seems to be coming from the partial pressure of nitrogen, I understand in such a suit you're not pressurized, and so you shouldn't feel it?)

 

[Rich Keller]

Question: Would someone wearing one of those heavy suits for the deeper dives not experience nitrogen narcosis? Does it only apply if you're wearing regular scuba-diving equipment, a wet suit with tanks etc? (Since it seems to be coming from the partial pressure of nitrogen, I understand in such a suit you're not pressurized, and so you shouldn't feel it?)

If you were breathing normal air you would feel the effects of nitrogen narcosis regardless of what equipment you were using. In you scenario they are breathing a special blend of trimix so this would not happen. Trimix is mainly helium with enough oxygen to sustain you at that depth and the nitrogen is there in a very small amount for the narcosis effect it causes. This will take the edge off the shock to you system that the helium causes at extreme depths. The trimix used by scuba divers has a much higher percent of nitrogen that is there to reduce the cost of using a straight mix of helium and oxygen.

Edit: As I said earlier you should not need to get into this much detail for your book. Just a simple explanation of what trimix is and the divers will think they know and the non divers will not question this.

 

[gekodivebali]

Would you really feel narcosis in a 1 atmosphere suit? Sounds counter intuitive!