[PSUBS-MAILIST] Pilot fish first dives

Tue Apr 26 15:50:30 EDT 2016

Congratulations on reaching sea trials Antoine! ~ Douglas S.

On Wed, Apr 13, 2016 at 6:03 AM, Antoine Delafargue via
Personal_Submersibles <personal_submersibles at psubs.org> wrote:

> thanks Alan,
>
> currents are too strong to arrive in Cherbourg, however I would love to
> have the sub shown at the museum there after the trip. There were ok for a
> temporary exhibit with little conference but I probably need to ask them
> again.
>
> regards
> Antoine
>
> On Wed, Apr 13, 2016 at 12:25 AM, Alan James via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
>
>> Wow, fantastic Antoine, congratulations.
>> Love those detailed reports with the good & the bad.
>> Emile was the right person to have on the project, he thinks outside the
>> box.
>> The speed you are getting is faster than I thought.
>> Did you consider crossing to Cherbourg (like the Titanic) & getting the
>> submarine museum involved
>> or are the currents too strong up there?
>> Cheers Alan
>> P.S.
>> In case anyone misses it, this TV news item from your facebook page is
>> very good.
>> Le Journal du week-end - Inspirés de Tintin, ils vont traverser La Manche
>> en pédalant dans un sous-marin
>> <http://lci.tf1.fr/jt-we/videos/2016/inspires-de-tintin-ils-vont-traverser-la-manche-en-pedalant-dans-8731854.html>
>>
>> Le Journal du week-end - Inspirés de Tintin, ils vont traverser La Manche
>> e...
>> Traverser La Manche à 2 km/h à l'aide de leurs mollets, c'est le projet
>> fou de deux polytechniciens. Dès...
>>
>> <http://lci.tf1.fr/jt-we/videos/2016/inspires-de-tintin-ils-vont-traverser-la-manche-en-pedalant-dans-8731854.html>
>>
>>
>>
>> ------------------------------
>> *From:* Antoine Delafargue via Personal_Submersibles <
>> personal_submersibles at psubs.org>
>> *To:* Personal Submersibles General Discussion <
>> personal_submersibles at psubs.org>
>> *Sent:* Wednesday, April 13, 2016 9:27 AM
>> *Subject:* [PSUBS-MAILIST] Pilot fish first dives
>>
>> Hello Psubbers,
>> Pilot Fish sub has now made its first dives,
>> What a feeling to live this for real after having imagined it for years!
>> seeing the water fully covering the dome is quite a dramatic view.
>>
>> at last i feel like a real psubber, after having been on this group
>> feeling like a junior kid for ten years... thanks to you all, this project
>> would not be anywhere near it is without your precious advice!
>>
>> some pics and movies can be found at
>>
>> https://www.facebook.com/Projet-Poisson-Pilote-Pilot-Fish-Project-294329844027226/
>>
>> The tests went well overall. we were quite anxious as there were many
>> systems to be tested, some with quite original features. Launching the sub
>> with the trailer and an extension rope was the first unknown. Hopefully
>> Emile came from Amsterdam to help us out. Techno diving lent us some diver
>> phones, and the local dive club helped out which is good for a first dive.
>>
>> First day we stayed in the harbour checking buoyancy. We were a bit
>> heavier and nose heavy than anticipated, so we adjusted for this by
>> removing some solid ballast. We had also a bit of air exiting our emergency
>> regulators so we figured we should add an isolation valve upstream that
>> regulator to prevent such events increasing the pressure of the cabin.
>> once MBT emptied we tried bringing in water into our bladder to be
>> neutral, but I soon realized I had forgotten to remove a little plastic cap
>> protecting the threaded seawater intake outside when prepping the sub. It
>> would be a hard reach to remove even by a diver from outside as it was
>> located inside the tail fairing between oxy bottles.
>> All the tv crews were also there waiting to film our first dive..., we
>> had like 4 go pros and 2 microphones inside the sub recording, and diver
>> cam man, a towing boat in a small harbour trying to keep us away from other
>> boats, some people watching, and for whatever reason I wanted to control
>> most of the tasks inside the sub, leaving michael my copilot only pedaling.
>> So quite a lot of multitasking for a first dive! I would advise to do first
>> dives in a quiet place first!
>> After thinking hard about whether the cap was threaded or not, we decided
>> we should try pumping against it with our manual bilge pump. It did not
>> work initially as our low pressure circuit was full with air so the pumping
>> was not very efficient. So we poured water from our drinking bottle into it
>> and pumped again and this time when reversing the circuit, water came in so
>> we had managed to kick the cap out and we finally started diving. By the
>> way, this was the very first time we tested our bilge pump, and it visibly
>> worked...
>> Having done already several cycles of ballast inflation to adjust solid
>> ballast we did not have enough air to exit the harbour in confidence
>> (although we had plumbed our ballasts to allow divers to inflate our
>> ballasts with direct system connection, which turned out quite useful). so
>> we stayed in, only diving to 1m as the bottom 2m of the lake harbour were
>> covered by very long sea weed on which we were sort of floating.
>>
>> The next day we went out for a tow then dives in 3 to 5 m water depth. We
>> could then check most systems, which worked as anticipated. the task
>> sharing with the pedaller became obvious: pedaller pedals, and takes care
>> of life support and MBT upon instruction from the pilot, the pilot does the
>> rest. We would deflate the ballasts, which turned out quite stable despite
>> the saddle shape. Then we would bring in seawater to fully cover the dome
>> to get neutral buoyancy, then pedal downwards, using the trim tray on
>> rollers beneath the pilot seat. The first surfacing with Emile as a pilot
>> was quite impressive by inflating the ballasts. Nobody filmed it but it
>> felt like we raced upwards with steep inclination.
>> We did another dive with Michael on the same day. We could check oxy
>> consumption, really sober, 0.75L/mn at rest for us two, and 2L/mn at
>> cruising pedaling level. The temperature and humidity did not shoot up as
>> we feared when pedalling to the sweating remained quite efficient and
>> confortable, despite all the body heat. Quite happy too with the scrubber
>> as we had 0.15-0.2 % CO2 only.
>>  Pedaling resistance lower than feared, we ll see next time if we try a
>> more agressive pitch. Our blade design may be a bit basic but the speed
>> looked around the 3km/hr expected. The friction in the drive train and prop
>> shaft seal is impressively low. we can testify that the water lubricated
>> bearing for the shaft outside the hull works well when in the water...
>> During that second dive  a funny thing happened: we beached on the seabed
>> without noticing, as the seabed was moving up, and did not have the
>> altitude sounder installed yet and the ground felt further below due to
>> optical distortion in the dome. Then we used the bow thruster  which sucked
>> sand inside the bow fairing (I had not cut the definitive thruster intake
>> ports in the fairing) which kept us landed. We kept pedalling without
>> understanding why we stopped moving, thinking we may have got caught in
>> something or the prop blades may have loosened?. That was when the surface
>> boat told us they had an engine pb so we came up gently with ballasts and
>> the diver told us we had landed and was wondering why we kept pedalling!!
>>
>> We will do another series to check the speed accurately in deeper water
>> depth area. we will also do longer dives to check the scrubber capacity,
>> and if all goes well spend the night underwater for a 30hours long dive.
>>
>> regards,
>> Antoine
>>
>>
>>
>>
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