Pinta is officially disqualified

09/10/2010 at 10:51 am | Posted in Uncategorized | Leave a comment
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Its now been 10 days since the last transmission from Pinta. Therefore under Microtransat rules we are now disqualified. Here are two maps showing Pinta’s progress. The first shows the progress during the first 49 hours when the Iridium modem was still sending hourly position updates. The second shows the complete route including the two weeks after the Iridium messages ceased. The maps are coloured to show the speed of the boat, these speeds are simply based on the time and distance between each point and therefore are an underestimate as the boat never travels in a perfectly straight line. Thanks go to OpenStreetMap/OpenCycleMap and gpsvisualizer.com for creating these maps.

No Spot messages for over 36 hours.

01/10/2010 at 12:52 am | Posted in Uncategorized | 6 Comments
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It has now been over 36 hours since the last message from the Spot tracker. So we really have no idea where Pinta is. Based on previous speed measurements she *probably* couldn’t have made it to land by now but its not totally impossible. Ever since we launched the reliability of the Spot hasn’t been as good as we’d hoped for. Between the time we launched and now 32.5% of all messages that we expected have failed to deliver. If you discount the last 36 hours then this rate drops to around 27%. Things have got a lot worse in the last few days though, between the 17th and 26th only 6 messages failed to arrive. On the 27th we lost 2 messages, on the 28th we lost 3 and on the 29th another 2.

There are lots of potential causes for this, here’s a list of just a few that we’ve thought of:

  1. Pinta has sunk or been run over by a ship. Although there’s very little shipping in that area and most of it sails closer to land than Pinta’s last known position.
  2. The keel has broken off and Pinta has capsized.
  3. The Spot has fallen off and sunk or is floating (attached to some foam) but no longer attached to the boat. If this happened gradually it might account for the deteriorating message reliability in the last few days.
  4. Water has entered the Spot box and damaged the electronics. The timings of the messages we have received suggest that the PIC which controls the Spot hasn’t been rebooting and it was very well sealed.
  5. The Spot has run out of battery. This is unlikely unless we miscalculated or overlooked something. We’ve run several long term (up to a month) tests on the Spot and found that it lasts about a month on a pair of AA lithium batteries when transmitting every hour. The Spot on Pinta has 6 batteries and only transmits every 6 hours.
  6. The Spot (globalstar) satellite is having trouble. This has happened before and wouldn’t be a total surprise although its now been going on a long time. If anyone knows of a webpage where you can find out the status of the Globalstar satellites we’d be interested in seeing it.
  7. The higher the waves, the harder it is to transmit. We’ve had problems before when buildings, bits of car, trees, mountains etc have obscured the Spot’s sky view and this has caused messages to fail. It is possible that waves can cause the same problem. The problem is threefold. Firstly the rocking motion might mean any attempt to send data to the satellite is interrupted. The wave period has typically been between 6 and 10 seconds, which should be a lot longer than it takes to send a message. Second if transmission occurs when the boat is in the trough of a wave (especially when wavelengths are very short) it effectively has a wall of water on either side of it which will block transmissions. Finally the boat is likely to be heeled on one side a lot of the time which will reduce the amount of sky seen by the Spot’s antennas.
  8. Spot don’t like us automatically pressing the buttons on their unit and have decided to cut us off. If they have, they’ve not told us!

To see if there was any correlation between wave height and Spot reliability the graph below shows median daily wave heights (in metres) from the closest functioning data buoy to Pinta. This was the M3 data buoy (located near Mizen Head) until September 18th and the K4 data buoy (about 150nm WNW of Westport, 54.550 N 12.367 W) after this date. Unfortunately for much of the time the M1 databuoy to the west of Galway would have been more appropriate but it is not currently functional. The graph also shows the number of Spot messages received each day. This should almost never be more than 4, although as the interval between messages is actually slightly less than 6 hours there have been two days when we expected to receive 5 messages in one day but never actually achieved this. This analysis is probably too simplistic as it doesn’t consider the heading of the boat in relation to the waves and wind which will have a big influence on the angle of heel and the rocking motion of the boat. However, there does appear to be a (inverse) correlation. If we look at the 15th of September the waves increase to 4 metres and the Spot goes from getting 4 to 2 messages. As the waves die down during the 16th and 17th the Spot increases back to 4 messages a day and maintains this until the 22nd when the waves again increase and the number of messages drops. On the 25th the trend breaks as both the waves and number of Spot messages drops, but the Spot recovers again on the 26th while the waves are still relatively small. Since the 27th the waves have again increased in height and the Spot has again decreased in reliability. This still needs to be tested properly with a correlation coefficient but it looks like there might at least be something to the “big waves stop the spot from working” hypothesis. On reflection it is quite impressive looking at the wave graph that a 3 metre dinghy intended for sailing around very calm waters has survived for 17 days in waves almost never less than 2 metres high and sometimes over 4 metres (and with a period range of only 6-10 seconds).

500 kilometres and 12 days

23/09/2010 at 11:50 pm | Posted in Uncategorized | Leave a comment
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Pinta has now sailed for more than 12 days and covered over 500km (based on straight line distance measurements between each data point we’ve received from the boat). Had we managed to sail that in the right direction we’d now be 120km south of our second waypoint at 49 degrees north, 15 degrees west (about 780km west of Brest in France). This only gives us an average speed of about 1.7 km/h although a lot of this has probably been suboptimal sailing. On our best days we’ve seen top speeds of just under 4 km/h, the worst have been less than 1 km/h. Of course all this is based on data points that are 6 hours apart and we are assuming a straight line between those two points. In reality those lines won’t be anything near straight and actual speeds of travel will be faster.

Off out to sea

20/09/2010 at 10:01 pm | Posted in Uncategorized | Leave a comment
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Pinta has spent the last 3 days sailing North West and getting further and further from land and any chance of rescue. The coastguard have said they might be able to organise something if we end up off the coast of Dongeal but at this rate we’ll be more likely to end up in Iceland or Greenland. The wind does look like it might change to a northerly for a couple of days later in the week and that might bring us back closer to shore but we can’t be certain.

Heading for Galway? or the Cliffs of Moher perhaps.

17/09/2010 at 12:39 pm | Posted in Uncategorized | Leave a comment
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After 4 days without a control system Pinta is now near the entrance to Galway bay and about 30 nautical miles off the Cliffs of Moher (the biggest cliffs in Ireland and one of its biggest tourist attractions). If the current course continues then Pinta could sail straight into the cliffs which would be very spectacular for all the tourists, not so good for us. However it would be nice if she went a bit further south and ended up on the nice sandy beach in Lahnich (wishful thinking I know) or slightly further north and inside the relatively sheltered waters of Galway bay where a rescue would be quite easy.

6 minute video of Pinta now available.

16/09/2010 at 1:35 pm | Posted in Uncategorized | Leave a comment
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Computer is really dead.

14/09/2010 at 8:00 pm | Posted in Uncategorized | Leave a comment
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It looks like the control system has really gone. Pinta had spent spent all of Sunday sailing away from its waypoint because the wind didn’t allow sailing directly to the waypoint. However just before the last Iridium message she appeared to have turned around and was heading straight for the waypoint. We’ve now had several Spot messages since the final Iridium message and we are now north of the waypoint again and it should be easily directly sailable. Even if the rudder was broken and the sail still worked it should be possible to make that turn and its not happened. With the current wind forecast it looks like Pinta will sail parallel to the coast for a few days and might end up hitting the Arann islands or somewhere around Slyne head.

Lost contact with Pinta, but we’re on the BBC

13/09/2010 at 6:30 pm | Posted in Uncategorized | Leave a comment
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Pinta is supposed to send us a message via Iridium every hour. Its now been over 2 hours since the last message.

We had a message during the night to say the Gumstix had rebooted. The Gumstix isn’t supposed to reboot so this could be a sign of a loose power cable or water in the electronics box.

So it looks like we only got about 49 hours of autonomous sailing and only covered about 87km. This is still further than our previous record (17 hours and about 25km) and we think its further and longer than anyone else has sailed autonomously before but are not 100% certain of this. Also despite this sailing being “autonomous” we have completely failed to reach waypoint that was only 28km away at the time Pinta was released.

We will have to wait to see if we get any messages from the SPOT tracker to let us know if she’s still afloat or not. Unfortunately since we launched the SPOT hasn’t been very reliable, we’ve lost 4 out of 10 messages from it. We suspect that by mounting it near to the metal frame which houses the solar panels we’ve partially blocked its view of the sky. The large waves we’ve been experiencing may not be helping either as swaying about and having walls of water blocking the satellite view might not help. If Pinta is still afloat it will be interesting to see how long she lasts without any control. It is also possible that the tiller pilot could still be operational despite the rest of the system failing.

In good news there’s an article about us just gone up on the BBC website plus a news item Pinta will be shown tomorrow BBC Wales News and we’re getting a mention on Radio 5 live and on Radio Wales.

We’ve made it back to Wales without Pinta being destroyed.

12/09/2010 at 8:00 pm | Posted in Uncategorized | Leave a comment
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We’ve made it back to Aberystwyth and Pinta is still going! We had been worried that we’d discover it had stranded itself on a rock or sailed back to Valentia before we’d left Ireland and that we’d have to turn around and go and pick it up. With telemetry messages arriving every hour there is this tense moment each hour as we wait for the email to arrive. We nearly thought we’d lost it last night when the email didn’t arrive but it was just the email servers being slow.

Going round in circles

12/09/2010 at 11:37 am | Posted in Uncategorized | Leave a comment
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Since last night Pinta has basically just gone round in a big circle. It looks like the control system has been flipping between thinking it can sail directly to the waypoint and not being able to. This is probably combined with heavy seas which are probably making steering very difficult and meaning it can take 10 minutes to actually get settled on a new course. To make things even more worrying we have not been more than 4 nautical miles from the Skellig Islands, two rather large and very rocky islands just off the coast.

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