With respect Jay I stated “As there seams to be a desire and maybe even a trend towards larger subs”. When did I ever say that they were not the exception to the rule? They would not be so cool if they were common place. I stressed “desire” as has been demonstrated through postings like the recent Typhoon type drawings which generated so much response and to quote another member “I love big subs”. I also stressed ‘Trend’ because some of the subs on the drawing board and those being constructed are larger than a K350.
Just to correct some other comments before they fester into fact, UC3 is a little more than a concept these days. http://www.silenthunter.dk/link.asp?menu=Forum/forum_choice.htm&doc=http://www.silenthunter.dk/article/UC3/1/UC3_1_1.htm
And my understanding is that Spurdog at one stage was and still may be operational.
Big subs are never going to be the mainstream but if Carsten and the UC3 team had listened to opinions like ‘and the complication on the design all go against successfully completing a large PSUB’ then they would not have even attempted anything. How much have there efforts been appreciated by all but the tall poppy haters in this group.
I also know of 3 active subs that all require cranes to launch them but the owners still do it. If you’re passionate enough about anything then you do what it takes.
My understanding is that this forum is about enjoying the idea and throwing concepts around as much as it is about actually subing. I think one of the founders does exactly that! So what if some members have not spent large amounts of time underwater or in a Sub. I don’t remember that being a prerequisite to expressing an opinion or exploring an idea no matter how impractical.
On a finishing note Jay, thank you for sharing some of your knowledge because much of the information you provide is extremely useful.
There are two methods of acoustic triangulation, one from the sub and the other from a surface support ship. The one easiest from the sub would use 2 or more (preferably at least 3) long-leg acoustic transponders are placed around the area of interest from the surface; each transmits on a unique frequency or is keyed on a unique pulse from the sub. The simpler method of triangulation from the sub but more time consuming would have the acoustic receiver fix-mounted on the sub and the sub would rotate to find the strongest signal and thus the bearing to the transponder, the compass heading noted, and a bearing plotted. The intersection of a series of bearings would provide an accurate position. The other method from a submersible is to have the acoustic transducer able to be manually rotatable to find the bearings (similar to how the passive sonar transducer was mounted on early subs). There are automated sonar rigs that will automatically interrogate the transponders and display position on a screen but are expensive.
The surface ship method involves placing a transducer on the sub that can be tracked with a scanning sonar (bearing and angle) on the ship. The sub’s position is then transmitted to the sub over the UQC. Early work on this method was conducted by a fellow intern at Harbor Branch during the summer of 82. It used an Apple PC and Pascal for the position determination.
Despite what Steve says, large PSUBS are
the exception not the rule. The cost to build and maintain, draft
constraints both in launching and harbor operation, and the complication on the
design all go against successfully completing a large PSUB. As I stated Euronaut is the exception, UC3 is still a concept and in need of a
Jay K. Jeffries
[mailto:firstname.lastname@example.org] On Behalf Of Joseph Perkel
It seems to me the original question was for "precise" underwater navigation. So I suspect Jay is talking about pulse beacons on the seafloor of some type. I will defer to his expertise to elaborate but, I remember reading about an expedition to pacific thermal vents using this method.
I can tell you that as a diver, even with GPS to guide the boat, I have returned to many a same dive site only to have some trouble finding my target again, especially small ones.
My Octopus, as a self reliant vessel, would only leave periscope depth in sound phone contact with a surface escort to keep tabs on traffic, and will navigate in known waters, on compass and depth finder (an acoustic device). Someone with a research or salvage capable craft needs more capability.
It would be interesting to hear from Dan H, as to how he navigates his K350?