<html><head></head><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px"><div id="yui_3_16_0_ym19_1_1463915248023_2641"><span id="yui_3_16_0_ym19_1_1463915248023_2640">Antoine,</span></div><div id="yui_3_16_0_ym19_1_1463915248023_2628" dir="ltr"><span id="yui_3_16_0_ym19_1_1463915248023_2627">as you will be side on to the current most </span><span id="yui_3_16_0_ym19_1_1463915248023_2629">of the time, & following the </span></div><div id="yui_3_16_0_ym19_1_1463915248023_2652" dir="ltr"><span id="yui_3_16_0_ym19_1_1463915248023_2653">contour of the sea bed in possible poor visibility conditions, </span><span id="yui_3_16_0_ym19_1_1463915248023_2685"> what is your contingency plan </span></div><span id="yui_3_16_0_ym19_1_1463915248023_2716"><div id="yui_3_16_0_ym19_1_1463915248023_2717" dir="ltr">if you are pinned <span id="yui_3_16_0_ym19_1_1463915248023_2719">sideways against a vertical obstruction?</span></div><div id="yui_3_16_0_ym19_1_1463915248023_2772" dir="ltr"><span>Alan</span></div><div id="yui_3_16_0_ym19_1_1463915248023_2761" dir="ltr"><span></span><br></div><div id="yui_3_16_0_ym19_1_1463915248023_2746" dir="ltr"><span></span><br></div></span><div class="qtdSeparateBR" id="yui_3_16_0_ym19_1_1463915248023_2625" dir="ltr"><br><br></div><div class="yahoo_quoted" id="yui_3_16_0_ym19_1_1463915248023_2624" style="display: block;"> <div id="yui_3_16_0_ym19_1_1463915248023_2623" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yui_3_16_0_ym19_1_1463915248023_2622" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yui_3_16_0_ym19_1_1463915248023_2621" dir="ltr"> <font id="yui_3_16_0_ym19_1_1463915248023_2620" face="Arial" size="2"> <hr size="1" id="yui_3_16_0_ym19_1_1463915248023_2639"> <b><span style="font-weight: bold;">From:</span></b> Antoine Delafargue via Personal_Submersibles <personal_submersibles@psubs.org><br> <b><span style="font-weight: bold;">To:</span></b> Personal Submersibles General Discussion <personal_submersibles@psubs.org> <br> <b><span style="font-weight: bold;">Sent:</span></b> Thursday, May 19, 2016 11:21 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [PSUBS-MAILIST] some further lake tests<br> </font> </div> <div class="y_msg_container" id="yui_3_16_0_ym19_1_1463915248023_2778"><br><div id="yiv0926523310"><div id="yui_3_16_0_ym19_1_1463915248023_2780"><div dir="ltr">Yes Alan,<div>we will do that between 5 and 12 of August</div><div><br clear="none"></div><div>regards,</div><div>Antoine</div></div><div class="yiv0926523310gmail_extra" id="yui_3_16_0_ym19_1_1463915248023_2779"><br clear="none"><div class="yiv0926523310gmail_quote">On Thu, May 19, 2016 at 1:12 PM, Alan James via Personal_Submersibles <span dir="ltr"><<a href="mailto:personal_submersibles@psubs.org" target="_blank" rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>></span> wrote:<br clear="none"><blockquote class="yiv0926523310gmail_quote" style="margin: 0px 0px 0px 0.8ex; padding-left: 1ex; border-left-color: rgb(204, 204, 204); border-left-width: 1px; border-left-style: solid;"><div class="yiv0926523310yqt5947271214" id="yiv0926523310yqt31999"><div><div style="color: rgb(0, 0, 0); font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px; background-color: rgb(255, 255, 255);"><div><span>Excellent report, </span><span>enjoyed reading it.</span></div><div><span>Do you have an anticipated date to cross the channel?</span></div><div><span>Alan</span></div><div><br clear="none"><br clear="none"></div><div style="display: block;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div dir="ltr"> <font face="Arial" size="2"> </font><hr size="1"> <b><span style="font-weight: bold;">From:</span></b> Antoine Delafargue via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org" target="_blank" rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br clear="none"> <b><span style="font-weight: bold;">To:</span></b> Personal Submersibles General Discussion <<a href="mailto:personal_submersibles@psubs.org" target="_blank" rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> <br clear="none"> <b><span style="font-weight: bold;">Sent:</span></b> Thursday, May 19, 2016 9:57 PM<br clear="none"> <b><span style="font-weight: bold;">Subject:</span></b> [PSUBS-MAILIST] some further lake tests<br clear="none"> </div> <div><div><div class="yiv0926523310h5"><br clear="none"><div><div dir="ltr"><div>Hello psubbers,</div><div><br clear="none"></div><div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;">Last week end we
drove to the same lake as the first to do some more test dives for our little
human powered sub. Quite another event rich sequence worth sharing:</span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;"></span><br clear="none"></div><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;">-The preparation session went ok. We just had another tv crew, which is fine but is slowed us down, as they often want you to repeat some moves even when they say they just want to film you do your things. Interviews themselves are really short.</span></div><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;"></span><br clear="none"></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;">-When driving to
the harbour’s launch slope on a bumpy path, we heard a noise a km before
arriving. We found out that our 100kg emergency drop weight had fallen from the
sub. Hopefully it only fell 15cm onto the central beam of the trailer, from
where it could not go anywhere… The vibrations had moved the release pins, and
it also moved apart by a few mm the lower legs of our nose frame, which
normally closely bound each side of the drop weight and where the release pins
go. With a few hands we pushed the weight back up in place. Lesson learned: use
longer pins, retighten the frame and add a thread bar to keep the legs of lower
frame close enough together. Also, we should have the drop weight rest on 3 support
points (2 pins, 1 ledge), not 4 (2pins, 2 ledges) which will never be fully
stable.</span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;"> </span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;">-We then
launched. It went smoothly as we had done it before and knew exactly where to
bring the trailer and its rope extension to have the sub float. </span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;">We then deflated
the ballasts to check the trim inside the harbour. This time it was perfect,
having captured last time’s 25kg discrepancy in our reference excel file and
recomputed the lead weight we needed this time given all the food and stuff we
had taken.</span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;"> </span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;">-then the boat
towed us out, until we reached a 4m water depth to pedal a bit. This went ok.
We were just intrigued by a tiny high frequency vibration coming from the prop
shaft, which was there regardless of rotating speed, but only when pedaling in the forward
direction. It was not there during the first dives, and it disappeared the next
day. We are wondering whether it came from the water lubricated bearing , or the
pressure seal assembly. The length of the prop shaft of over 2m makes it
probably prone to resonance.</span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;"> </span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;">-This time we
had better navigation instruments, a compass mounted right outside the dome in
front of us, on the aluminium dome seat, with quite lower magnetic deviation
due to the hull than we feared. Also a diver depth gauge was there, very
useful. We were eager to test our imagenex sonar/sounder combo, but could not
get it to work for that dive. Will be next time…</span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;"> </span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;">-The sub turned
out quite stable, keeping straight when we stop pedaling, but we noticed that having
a buoy attached at the front of the sub with a short rope to remain clear of
the propeller gave a bit of instability on top of extra drag. Depth control
worked well with our 80kg tray on rollers beneath batteries and pilot seat,
although we were not aiming for very large swings of depth. We just need to
rework a bit the handle so it is more convenient to use, especially when the
sub is at large angles. </span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;"> </span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;">-The oxygen
consumption turned out lower than we expected. Michael and myself are quite
lightweights I should say. We were running at 0.75L/mn for 2 people at rest, it
actually went down to 0.5L/mn during the night, with one sleeping. It also
shooted up to 2L/mn after I went out for a swim around the sub in cold water to
remove our buoy rope from the prop the next day. So feeling warm is really good
to lower oxy consumption, and a down jacket, socks, hat and gloves may be worth
kgs of sodalime in emergency mode! When pedaling it ranged between 1.25 to
2L/mn, not as high as anticipated, but the pedaling resistance and heart rate remained
quite moderate. This brings our ‘theoretical’ life support autonomy to a
whopping 16 days in pedaling mode, and 37 days in rest mode.</span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;"> </span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;">then we went for a tow to a
nice diving spot on the other shore of the lake where we would spend the night
and find deeper water for the next days dives. The tow was quite choppy, and we
occasionally dove a 0.5 to 1 m with dynamic effects, although since the first
dives we moved the towing point below the nose tip which improved considerably
the behavior under tow. At some point we had to slow down the tow as we noticed
that the dome had slightly moved on its seat, under a combination of : effect
of slight internal overpressure caused by temperature increase due to sun light
in the dome and slight CO2 build up, wave action, occasional UW dips, and primarily
because the force on the dome retainer strap was not high enough. </span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;">When we arrived
at the other shore, we moored, inflated ballasts and delicately removed the
dome to check the oring and force on retainer strap. We noticed the oring had a
pinch point towards the dome pressure seat, so we cleaned and re-placed it in a
way to keep low pressure tightness. We also added 1mm spacer between the dome
and retainer strap to increase the strap down force, and ensure a large enough
oring compression so the dome rests on its seat with no gap. the general theory says that a gap
should not be an issue as when you dive, the force closing the gap should be many times higher
than the force pushing the oring in. But here a combination of waves,
overpressure etc may have moved a bit the oring in at some point.</span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;">We also removed
the prop to see if some debris could have caused the subtle vibrations, but
could not find any thing. </span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;"> </span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;">-After that we
had dinner and landed the sub to spend the night near the shore in less than 2m
water depth. Deployed our anchor also to stay put. It worked well. Inside the
sub we deployed our bunker bed and tested switching positions between Michael
and I. We slept one after the other, so we could check on O2 and CO2 levels. Comfort was not bad, because the bunker bed is really nice, but space is really small inside. We can grab all the controls and isolation valves in case of emergency, but you can t help but feel like trapped inside... During the night we used the red lighting as in real subs, to feel like in the submarine movies, it was really cool!</span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;"> </span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;">-Next day, after
a beautiful sun rise seen from underwater, we went for a dive to 10m water
depth where we could have space above and below us to really operate the water
ballast and trim weight tray on rollers. Thanks to our depth gauge, water
circuitry and hand pump we could get in trim within less than 1 kilo, and feel the inertia of piloting moves. It was
really good feeling piloting that thing in three dimensions. After the dive we surfaced
with our ballast and pedaled we got the rope in our large prop, which led me go
out, take a swim to cut it, and shorten the buoy rope as our dive support boat
had not arrived and our dive support was on the shore. We ll probably add a duct around our prop... Then before I
came back in, some fishermen in another boat came and asked us whether we were
fine, they initially thought we were a boat upside down. It was funny seeing
their hallucinating faces. </span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;"> </span></div><font color="#000000" face="Times New Roman" size="3">
</font><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;"><span> </span><span> </span>-we
then had our own support boat come over and we went on for a stretch of pedaling
at 2m water depth. We could measure our speed at 1.2kt which falls in the ball
park we anticipated. We may gain some without a buoy, and once our composite
shells are polished, and also with a more stable steering than what we had (the
short buoy rope attached to the front of the sub made it difficult to keep a
stable course). On the other hand adding a duct around our large prop may
decrease our speed. But a duct would also increase a bit the power we can put
in at 70rpm, so we might compensate extra drag effect on speed by extra thrust. </span></div><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;"></span><br clear="none"></div><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;">-Over the week end in the sub, we managed to log quite a few hours with our scrubbers. We reckoned we got over 200LCO2 /kg of sodasorb, which is better than the typical figure given by the manufacturer (185LCO2/Kg). The scrubber starts being less efficient indeed at around that amount but we can still manage <1% in the cabin some time after that. On top of that, we have probably extra absorption capacity from our nearly worn scrubbers as we saw it can still run with an exhaust lean in CO2 in parallel or series to our second fresher scrubber. But it is difficult to measure how much we can extend the absorption capacity with this technique. </span></span></div><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;"></span><br clear="none"></div><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;">regards,</span></div><div style="background: white; margin: 0cm 0cm 0pt;"><span lang="EN-US" style="color: rgb(34, 34, 34); font-size: 7pt;">Antoine</span></div><font color="#000000" face="Times New Roman" size="3">
</font></div></div></div><br clear="none"></div></div>_______________________________________________<br clear="none">Personal_Submersibles mailing list<br clear="none"><a href="mailto:Personal_Submersibles@psubs.org" target="_blank" rel="nofollow" shape="rect" ymailto="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br clear="none"><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank" rel="nofollow" shape="rect">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none"><br clear="none"><br clear="none"></div> </div> </div> </div></div></div></div><br clear="none">_______________________________________________<br clear="none">
Personal_Submersibles mailing list<br clear="none">
<a href="mailto:Personal_Submersibles@psubs.org" target="_blank" rel="nofollow" shape="rect" ymailto="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br clear="none">
<a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank" rel="nofollow" shape="rect">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none">
<br clear="none"></blockquote></div><br clear="none"></div></div></div><br><div class="yqt5947271214" id="yqt01318">_______________________________________________<br clear="none">Personal_Submersibles mailing list<br clear="none"><a href="mailto:Personal_Submersibles@psubs.org" shape="rect" ymailto="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br clear="none"><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank" shape="rect">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none"></div><br><br></div> </div> </div> </div></div></body></html>