To clarify my earlier post regarding a fast moving war-boat type submersible...
We have visited the issue of surface radar for psubs before, however in Krakas case and my initial war-boat replica there is an advantage if you could have a functional system.
Line of sight range for an antennae at 5.5' height is 3.1 statute miles or 5,456 yards (1,663 m)
This can be usable in the following example
http://www.frappr.com/?a=viewphoto&id=269116&pid=5719043&myphotos=1
Joe
From: "Joseph Perkel" <joeperkel@hotmail.com>
Reply-To: personal_submersibles@psubs.org
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] Collision with surface vessel
Date: Thu, 10 May 2007 10:44:29 +0000
>Peter,
>
>This is purely speculation on my part but, I suspect that since a
>surface vessel has no reasonable means of detecting a submerged and
>or surfacing submersible. That the burden to remain clear and yield
>to traffic is on the submersible.
>
>You are of course correct in the assessment that in all
>practicality, it does not much matter. But, should I survive and
>have holed a substantial pleasure yacht, I think that their
>underwriter will not wish to pay the claim.
>
>If I were a fast moving diver like Kraka, U-boat-like in
>performance. In addition to passive sound gear for surfacing, I
>would be very tempted for the addition of surface radar ala the
>Kokes Marine boats. http://www.researchsubmarine.com/
>
>In this manner, you could both visually and radar plot all surface
>contacts prior to your dive and thus plot known course and speed
>prior to diving so that you may plan your submerged path and
>duration accordingly.
>
>
>Joe
>
>
>>From: "Peter Madsen" <peter@submarines.dk>
>>Reply-To: personal_submersibles@psubs.org
>>To: <personal_submersibles@psubs.org>
>>Subject: Re: [PSUBS-MAILIST] Collision with surface vessel
>>Date: Wed, 9 May 2007 11:26:23 +0200
>>
>>Thijs,
>>
>>Mostly we operate a very low speed...in recreational waters...but a
>>silent sailboat still is a problem. Back when I sailed with Freya
>>in 2002 - I used a diver buoy exactly like you describe. It was
>>bright yellow and hade a big diver flag on it. Unfortunately it
>>attracted recreational boats much more than making them stay clear
>>- so I stopped using it.
>>
>>Once you get hit - it really doesn't matter who were right and who
>>were wrong in accordance to maritime law.
>>
>>I like the idea of using hydrophones and visual systems since I
>>feel its us - the submariners - not the other recreational and
>>commersial vessels that
>>must prevent this problem.
>>
>>Regards,
>>
>>Peter
>> ----- Original Message -----
>> From: Thijs Struijs
>> To: personal_submersibles@psubs.org
>> Sent: Thursday, May 10, 2007 9:37 AM
>> Subject: Re: [PSUBS-MAILIST] Collision with surface vessel
>>
>>
>> Peter,
>>
>> I presume that when you surface you have some speed and you
>>operate in waters were you have to deal with big and noisy ships.
>> For small subs, operating in recreational waters and surfacing
>>at zero speed i was thinking of a buoy as used by scuba divers. The
>>(pressure-resistant) buoy should be attached to a 5 mtr. line. When
>>surfacing you could wait for let's say a minute at 5 mtr.depth
>>before comming to the surface. This works for scuba divers, so why
>>should it not work for subs. If you combine the buoy with a
>>flashing light and a rotating camera it should work even better.
>>
>> Regards,
>>
>> Thijs Struijs
>> ----- Original Message -----
>> From: Peter Madsen
>> To: personal_submersibles@psubs.org
>> Sent: Tuesday, May 08, 2007 11:06 AM
>> Subject: Re: [PSUBS-MAILIST] Collision with surface vessel
>>
>>
>> Jay,
>>
>>
>> Kraka, the diesel-electric boat I pilot have both up looking
>>windows and features a periscope. This is based on four cameras
>>each covering 90 deg of the horizon. By choosing to look a say
>>camera four I know that I am looking aft while no two give me the
>>starborad view - and so on. My idea for the final solution on the
>>collision problem was to make a buoy with say 60 feet of cable on
>>it. Its formed like a long pole with the four camera at the top, a
>>flotation device at the middle and ballast at the bottom. Poles
>>standing in the water like this can be quite stable ( provided the
>>uboat don't make way )
>>
>> My experience is that anything on as submarine must be made
>>with great care. We have had many problems with flooded GPS
>>antennae, moisture in the periscope and broken diveplanes ( they
>>protrude ) and the answer is always to make things better, stronger
>>and more carefully. Most of these problems have solutions that can
>>not be found at the drawing board alone.
>>
>> Solving it - is half the fun...
>>
>> One of our special problems is that our boat in only drydocked
>>once a year so many improvements or repairs comes only in these
>>service periods. One of the features of a trailer based submarine
>>is that it sits in your living room...most of the time. This is
>>just not the case wih Kraka.
>>
>> Regards,
>>
>> Peter
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> ----- Original Message -----
>> From: Jay K. Jeffries
>> To: personal_submersibles@psubs.org
>> Sent: Wednesday, May 09, 2007 1:43 AM
>> Subject: RE: [PSUBS-MAILIST] Collision with surface vessel
>>
>>
>> Peter,
>>
>> I agree with you that a collision on or near the surface is
>>one of the most likely major accidents to happen to a PSUB. This
>>is supported by submarine history demonstrating that this is one of
>>the largest causes of submarines under peace-time conditions.
>>
>>
>>
>> The ABS included the requirements for a small porthole in
>>the hatch so that you could look up while approaching the surface
>>and hopefully see the shadow of a vessel overhead that is silent or
>>stopped. Larger submarines with a periscope have the capability to
>>train the scope's top lens upwards to accomplish the same feat.
>>Many sub's operating procedures include a pause in ascent near the
>>surface to look and listen for other vessels in the near vicinity.
>>
>>
>>
>> If you do not have much internal noise in your PSUB, you
>>should hear most power vessels while still at some distance. A
>>trainable hydrophone will help discern the direction. The cabled
>>camera is a good substitute for a periscope but will be difficult
>>to obtain a stable image with known viewing direction on the
>>surface. Just remember that gadgets just require more maintenance
>>and can detract from pleasurable operating time.
>>
>> R/Jay
>>
>>
>>
>>
>>
>> Respectfully,
>>
>> Jay K. Jeffries
>>
>> Andros Is., Bahamas
>>
>>
>>
>> A skimmer afloat is but a submarine, so poorly built it will
>>not plunge.
>>
>>
>>
>> From: owner-personal_submersibles@psubs.org
>>[mailto:owner-personal_submersibles@psubs.org] On Behalf Of Peter
>>Madsen
>> Sent: Monday, May 07, 2007 6:28 PM
>> To: personal_submersibles@psubs.org
>> Subject: [PSUBS-MAILIST] Collition with surface vessel
>>
>>
>>
>> Hi Psubbers,
>>
>>
>>
>>
>>
>> When people talk of submarine safety the situation most
>>often assumed is a sub in distress on the seabed. This is of cause
>>a very critical situation,
>>
>> and we all design boats that are redundant in many ways so
>>that we hopefully never get in that situation.
>>
>>
>>
>> In my practical experience - however - getting hit by a
>>passing surface vessel when being at or very close to surface is a
>>much more likely incident. Depending on the speed and size of the
>>vessel and submarine any level of damage is possible - and the sub
>>I likely to sink with its pressurehull ruptured to some extent
>>after the collision.
>>
>>
>>
>> We are currently adding hydrophones to Kraka for detection
>>and classification of surface sound contacts, and we are designing
>>a cable camera for the UC3 - that can be send up prior to
>>surfacing. We hope these technical gadgets may make it more safe to
>>operate our subs.
>>
>>
>>
>> The professionel submariners ( navy ) that I have talked to
>>say that they solely depend on their passive sensors - hydrophone
>>arrays - and they have zero way of detecting a drifting - stopped
>>or sailing vessel.
>>
>>
>>
>> What do other non navy submarine operator do - how do you
>>psubbers handle this safety issue ? Most people ask me why we don't
>>just have an underwater radar ?! - or is it sonar - a sea surface
>>hull detection device...like the navy...
>>
>>
>>
>> Well - what do you do ?
>>
>>
>>
>> Regards,
>>
>>
>>
>> Peter Madsen
>>
>>
>>
>>
>>
>>
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>
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