Voyager 2.5 - Detailed Analysis of Failure 

This article aims to provide a detailed representation and interpretation of each piece of evidence obtained from the voyage and subsequent failure of the Voyager 2.5 within the entrance to Western Port.

Voyager 2.5 was approaching the entrance to Western Port, but stopped sailing near 12th July, 11pm and drifted back out to sea with the tide. This was against the South Westerly wind of around 15 to 20 knots. Rather than drift back into Western Port with the change of tide, she drifted east toward Cape Woolamai, for about 19 hours. 

Then she spontaneously turned left and drift north straight on the rocks near Pyramid Rock.

The whole time she was drifting, the winds remained fairly constant from the South and South West. Despite this, she suddenly changed course and headed for the rocks.

Voyager 2.5 as found at low tide, the next morning

View of Voyager showing the equipment containers still intact

The equipment compartments were intact, but about 50ml of water had leaked in to the main compartment.

The smaller forward compartment containing the satellite tracking equipment remined dry and fully operational.

The electronic components in the main compartment suffered significant electrolytic corrosion around the power circuitry.

The computer includes an SD Card for logging many of the vessels sailing parameters.

Fortunately, the SD card is intact and all log files are accessible.

Path of Voyager after failing to enter Western Port, through to the rocks

Each time the computer boots up, it increments a Boot number.

The mission commenced with Boot #501.

The log files showed that the computer stopped logging data about 18 minutes after the failure occurred.

About 19 hours later, the computer started again with Boot #502 and ran for about 5 minutes.

This coincided with the vessel commencing to drift in shore.

Then the computer rebooted again with Boot #503 and ran for 12 minutes.

It then washed on to a rocky beach. The computer did briefly restart with Boot #504 for a few seconds about 3 hours later.

Detail of movement of Voyager near the time of failure.

Detail of movement of Voyager near the time turn to run ashore

View Log Analyser visualising the vessel state after the failure.

The previous image is taken from the Voyager Log Analyser software. This is part of the Voyager suite of software that is used to visualise the vessel state and sailing parameters.

The wind is coming from the South West, and is confirmed by the AWA in the image.

The vessel is drifting out to sea, as confirmed by the COG in the image.

The vessel is lying beam on to the wind.

The rudder command is trying to turn to port, but the vessel is not responding.

This implies that the steering is ineffective.

This could be due to mechanical damage or electrical damage.

On balance, it is most likely electrical damage, due to water ingress around the Wing Angle Sensor housing.

The following video is a screen recording of the Voyager Log File Analyser.

It shows the first minutes of Boot #502. It shows the moments after the computer has started up and establishes its location. the boat id lying broadside to the wind on the starboard tack. As soon as location is established, then it tries to turn the vessel, and it responds in seconds.

This transition can be seen in the first 20 seconds of this recording.

It is unclear if the vessel can steer properly, but it appears that the vessel does have an intact steering mechanism, and it was responsive to the computer.

The recording also shows that the Wing Angle sensor is probably faulty, constantly showing an apparent wind of -6 degrees, off the bow. If the vessel could steer, it would be constantly trying to bear away from what appears to be a head-on wind.

Detailed log of events

Note: Temperature is measured by the Wing Angle sensor, located within the sensor housing at the base of the mast.

• 11/7/2022 07:27:04 Switch on at Torquay Boot #501
• 12/7/2022 14:53:21 Turn at the Cape Schanck waypoint
• 12/7/2022 16:52:44 Temperature reading drops from 15 to 14 degrees C.
• 12/7/2022 22:50:46 Temperature reading increases from 14 to 15 degrees C, after about 6 hours.
• 12/7/2022 22:52       Approximate time of failure
• 12/7/2022 22:52:09  Steering command is trying turn hard to port, the vessel is not responding.
• 12/7/2022 22:56:46 Temperature reading increases from 15 to 22 degrees C, after about 6 minutes.
• 12/7/2022 23:09:46  Temperature reading increases to 82 degrees C.
• 12/7/2022 23:10:12 End of logging Boot #501

• 13/7/2022 18:04:49 Start logging with Boot #502
  Note: The Steering servo would be commanded to centre as part of boot up.
• 13/7/2022 18:05:13 The rudder is commanded to steer to port.
• 13/7/2022 18:05:16 The vessel has responded and turned 90 degrees to port. No longer lying beam on to the wind. No longer held in hove-to state.
• 13/7/2022 18:10:24 End of logging Boot #502

• 13/7/2022 18:10:35 Start logging with Boot #503
• 13/7/2022 18:23:16 End of logging Boot #503

• 13/7/2022 21:05:39  Boot #504, a few seconds only.

Link for plot of positions reported via satellite:

https://maps.findmespot.com/s/VG5D

Interpretation

It appears that the steering failed.

This could be due to mechanical damage or electrical damage.

On balance, it is most likely electrical damage, due to water ingress around the Wing Angle Sensor housing.

It appears that the temperature sensor within the Wing Angle Sensor started to return faulty data in the minute or two prior to the failure. 

The implication is that the sensor was suffering water damage, in the minute or two prior to failure occurring.

The boat drifted in a hove-to situation for 19 hours after the failure.

For this to occur, the rudder would be turning the vessel to starboard, trying to steer too high to the wind.

It seems likely that the steering failed when the rudder was steering to starboard, and then didn't return.

The vessel left the hove-to position at 6:05pm the next day, at the same time that the computer booted up a second time.

When the computer boots up it initially commands the steering servo to centre the rudder.

It appears the steering may have been partially working, to allow the rudder to move and release the vessel from a hove-to state. She then drifted ashore.

This further reinforces the point that the rudder was mechanically operational while at sea, and the failure was due to electrical faults, due to water ingress.

Further Leak Testing 

Water was found in the equipment compartments, and it must be understood how it got in.

The equipment compartments (excluding the Wing Angle Sensor housing) were tested by placing under water with a covering depth of about 20mm for 12 hours. 

There was no measure water leak during this time.

The Wing Angle Sensor housing was tested separately by placing it under water for 12 hours.

A significant amount of water leaked in.

Voyager 2.5 Sailing for 39 hours

 Voyager 2.5 - 39 hours of Ocean Sailing Data 

This article will summarize some the key real world statistics established after 39 hours at sea.

This information is only available because we are able to retrieve the vessel from rocks and read the on-board SD Card.

Voyager sailed well for about 39 hours until she stopped sailing due to water ingress.

Power Consumption 

The Battery was a pack of 14 x 18650 Cells, made up as 7P x 2S.

One of the cells had been tested and verified as having better than 3000mAhr in the voltage range of 4.2Vdc down to 3.0Vdc.

The main battery dropped from 8.30V to 8.12V over the mission.

This corresponds to 0.18Vdc drop over  39hours, or 0.11Vdc drop per day

Assuming a constant rate voltage drop, this would yield 20 days expect life, allowing for a 2.2Vdc drop, from 8.3Vdc to 6.1Vdc .
The actual rate of voltage drop would increase as voltage drops.

The Voyage Controller employs switching regulators to drop the 2S voltage down to 5Vdc for the servo, and 3.3Vdc for the electronics. As the supply voltage drops, the supply current increases to maintain a constant power consumption.

The Wing Sail battery voltage dropped from 4.16V to  4.08V over the mission.

This corresponded to 0.08Vdc drop over  39hours, which is 0.05Vdc drop per day.

This yields 20 days expect life

The Battery consists of 2 x 3Ahr 18650 Cells x 1S

Steering Servo Usage

The steering servo made 67k movements over the mission in 39hours

This corresponds to 1.8k movements per hour.

The Wing Sail Trim Tab made 9,895 movements over the mission, 39hours.

This average out at 250 movements per hour over the mission.

The rate of movement was 10 movements per hours over the first 6 hours.

Pitch

The variation of Pitch over mission was not extreme. The largest value of pitch was 10 degrees, at the start, while on land. The next largest was 9 degrees down, but typical values were less than 4 degrees.

 

Roll

The variation of roll over mission was not extreme. The largest value of roll occurred on land. The next largest was 40 degrees, but generally under 20 degrees.

Temperature

The temperature is measured in Wing Angle Sensor located in the Wing Angle Senor housing located at the base of the mast.

The measured temperature varied in accordance with the diurnal cycle over the 39 hours of the voyage, except for the last half hour where the measured temperature increased dramatically.

This was most likely due to water damage. 

Atmospheric Pressure

The barometric pressure sensor is collocated with the compass sensor.

Link for plot of positions reported via satellite:

https://maps.findmespot.com/s/VG5D

Voyager 2.5 Ocean Voyage

 Voyager 2.5 Two Day Ocean Voyage

Dawn on Monday morning July 11, 2022, Voyager 2.5 was launched from Torquay Beach for a mission through to Western Port, on the eastern side of Melbourne, Victoria.

It is a journey into Bass Strait with distance of around 50nm or around 80km. The mission was made up of around 8 waypoints, expect to take just under 48 hours.

Voyager 2.5 undergoing lake trials in 15 to 20 knots.

Planned course from Torquay heading east to Cape Schanck and into Western Port

Voyager 2.5 on Torquay beach just prior to launch 7:30am 11/7/2022

She sailed well for the first day and a half, but near the 39th hour Voyager stopped sailing. She drifted back out to sea with the tide, and then drifted along the coast of Philip Island for about 20 hours, and drifted ashore on the rocks.

Sailing well past the Cape Schanck waypoint heading into Western Port at 6:30pm 12/7/2022 - 35 hours

Voyager stopped sailing just before reaching the the West Head waypoint 10:59pm 12/7/2022 - 39 hours, then drifted back out to sea.

Voyager drifted east for another day coming ashore on rocks at Redcliff Head, Philip Island at 9pm 13/7/2022

Fortunately we were able to recover the boat from the rocks the next day. This was valuable, and has helped us work out what went wrong.

The onboard SD Card that logs many of the boats operating parameters is intact and can be analysed.

View from Pyramid Rock looking west toward Flinders, showing Redcliff Head, at around the time of coming ashore.

Voyager 2.5 as found on Thursday morning at low tide, perched on  a rock.

The preliminary review of the evidence suggests that the boat stopped sailing because water leaked into the main equipment compartment and damaged the controller.

The evidence suggests that the water leaked through the Wing Angle Sensor housing. This is a 3D printed component. It appears to be watertight, but over a period of two days, a small amount of water can leak through the walls of the printed component. In future, this component will be assembled using different methods to avoid the leaking problem.

Voyager 2.5 suffered a lot of damage on the rocks. It is likely that she will patched up yo be able make another ocean voyage to further test the systems.

The next article will discuss some of the overall results from the voyage. A further detailed article will cover the evidence and events surrounding the failure.

Link for plot of positions reported via satellite:

https://maps.findmespot.com/s/VG5D

 Voyager 2.0 returns to sailing as Voyager 2.5

After Voyager made an ocean voyage in May 2021, she was retired, and focus shifted to Voyager 3.0. But after some thought it was decided to refurbish and upgrade Voyager 2.0 to become Voyager 2.5 with aim of completing an ocean voyage.

The main features of the upgrade of Voyager 2.5 are:

• Aluminium mast replaced with Carbon fibre.
• Aluminium fin increased in thickness from 3mm to 5mm, to increase stiffness and strength.
• Sail Plan reduced in height by 100mm to reduce heeling moment, but increased length cord low down. The overall sail area was increased, but heling moment was reduced.
  Overall, its a much better sail plan.
• Updated Wing Sail Controller PCB. Improved design and an improved software increased battery life of Wing Sail from around 8 days to 20 days. The radio link was changed from Bluetooth 4 to Bluetooth 5 (with other methods in between).
• Updated Voyager Controller PCB, with new Teensy 3.6 microprocessor, rather than the Arduino Mega2560. Improved design and an improved software increased battery life of main controller from around 8 days to 20 days.
• Improved fastening of the equipment cases to the hull to prevent them being lost.

Voyager 2.0, with a similar setup used for the ocean voyage in May 2021

Voyager 2.0 refurbished as 2.5, under-going final lake trials prior to going to sea, June 2022.

Voyager 2.5 on Torquay beach, preparing to go to sea