Winter Maintenance in London Year2 #1

Hi everyone,
Another long time no post situation.  Two topics today.

Presentations

Over the years we've been asked to give presentations by various organisations.  We've put the PDF versions of the slides online for reference.  They can be found on Dropbox here.

It's interesting that the most common topic is use of satellite imagery in marine navigation.  Our posts on this topic are amongst the most popular.  These can be found by searching the blog for "kap", the result of which is here.

Perspex

Last year we decided to upgrade our perspex washboards.  Washboards fit in the companionway to either lock up the boat or to keep water out of the cabin at sea.  In the past we've "copped greenies" which cascaded water down into the cabin.  In one incident we flooded the cook top and a gas sensor below it.  With closed washboards that shouldn't happen.

Washboards are often in two pieces so that one can be fitted, allowing crew to clamber over it when going on deck or going below.

We have two-part wooden washboards which have steadily reduced in thickness at each refurbishment.  They're now oiled and look good but are a little thin.  The top half has vents which are good for ventilation in harbour but not good in the face of solid water at sea.

We also had a one-part tinted perspex washboard.  This was quite thin and so not up to the job either.

Late last year we ordered new perspex washboards from Project Plastics.  They are 15mm thick and fit perfectly - measure N times, build once!  They are tinted and in two pieces.  The upper board had a cut-out to transfer an inspection hatch.  We transferred other fittings too, including the latch with which the companionway can be locked.

New washboards

The inspection hatch is interesting.  It's purpose is to allow crew on deck to unlock the two barrel bolts below which secure the sliding companionway hatch cover.  It's a sensible safety rule that companionway locks must be operable from on deck and below.

The increased thickness of the new perspex meant we had to rebuild the s/s latch mechanism.  The photo below shows the "kink" we needed in the s/s bar.  Thanks Dave!

Modified hinge

We still have the canvas cover we installed in Darwin some years ago.  It folds up to rest atop the hatch cover.  It's great for privacy, for keeping the sun off computer screens below and for keeping the rain out in light-moderate following winds.

Canvas cover unchanged

Our winter projects are electronics.  We're currently working on SaiLog, an app to display realtime data from our NMEA-2000 network.  More on that in due course - hopefully soon!

Summer Maintenance in London #4

Hi everyone,
Long time no post.  Summer has well and truly passed, so subsequent posts will be on a series of Winter Maintenance topics.  During the autumn we got a lot of work done in the cabin - oiling, varnishing and painting.

For some time we've been replacing varnish on timber exposed to the sun with oil.  This is now complete with the final items being the companionway trim and steps, and the coachroof top hatch trim.  All of these were suffering from the effects of UV.  We like oiling UV-exposed timber since its a simple touch-up needing no sanding and looks good too.

Companionway trim sanded back ready for oiling

 Next we sanded back and varnished the fiddles in the galley, navstation and pedestal/cabin table.

Galley fiddles sanded and ready to varnish

Navstation fiddles sanded and ready for varnish

We also sanded and revarnished the galley and navstation drawers.

Two of four galley drawers being varnished

Galley fiddles varnished and drawers back in place
(note the faded gelcoat nearby) 

Navstation drawers sanded and ready for varnishing

Finally we sanded and painted the 30 year old gelcoated panels in the galley.  We used the same Epifanes paints as in the head refurbishing.

Repainted and reassembled galley

Repainted and reassembled galley

Separately we had Shipshape Bedding provide a waterproof cushion cover for the forepeak.  It will be very useful at sea since the foredeck hatch occasionally lets in a little water.  We like the fabric and are having them make covers for the saloon cushions too.

Forepeak cushion cover

We're now out of time for varnishing and painting since it's getting too cold.  Over the winter we expect to work on various electronics projects.  Stay tuned!

Summer Maintenance in London #3

Hi everyone,
Last week we received a new toy - an Airmar 220WX weather station.  We installed it this weekend.

The 220WX is an impressive instrument  It connects to a NMEA2000 network directly.  It provides the following information:

• GPS (lat, lon, cog, sog, time etc)
• Compass heading
• Wind speed and direction (apparent and true)
• Wind chill (apparent and true)
• Attitude (yaw, roll and pitch)
• Attitude rate (rate of turn, roll and pitch)
• Air temperature
• Atmospheric pressure

Wind is measured ultrasonically in the slot in the instrument.  We've gone without wind data to date and estimated it in our log and blogs.  Wind data may allow our autopilot to "steer to wind" - if we can get it's NMEA2000 input working.  The 3D attitude and rate information may assist a future autopilot in difficult conditions.  Atmospheric pressure and air temperature will assist weather forecasting.

Unpacking

We mounted the unit on the goal post.  In future we may elevate it on a post for clearer air flow.

Airmar 220WX Mounted

On the Pushpit

As usual with goal posts the mounting was easy but running the cable less so.  We had left two unused coax cables running through the s/s tubes - one for an old GPS antenna and the other for our old Iridium GO antenna.  Sadly they both had to go.  Happily the 220WX NMEA2000 cable got through the s/s tube to the lazarette.  Its connector had to lose its collar which was too wide to fit.

Zen Again's NMEA2000 network now includes the following:

• Vesper XB8000 AIS transceiver with WiFi hotspot
• Garmin VHF300iAIS DSC VHF with AIS receiver
• Garmin GPSmap451 chartplotter
• Raymarine SPX5 autopilot (connected but not yet configured)
• Airmar DST800 log, depth, water temperature
• Airmar 220WX weather station

With the 220WX on the network we could see it on the chartplotter.

On the NMEA2000 Network

To test accessibility of the 220WX's data within the NMEA2000 network we setup various data on the GPSmap's data page.  This highlighted the main issue we face with the 220WX - most NMEA2000 displays can't show all data.  In particular attitude and attitude rate are not widely supported.  We can display wind, air temperature, atmospheric pressure and GPS data.

GPSmap ChartPlotter Data Display

The final step was to test accessibility of data beyond the NMEA2000 network via WiFi.  This includes what data the WiFi hotspot server transmits and what data the client app can display.  On our WiFi network we have MacBooks, iPads and iPhones.  The iOS devices run the iNavX general navigation app and Airmar's OnSiteWX instrument display app.

Our XB8000 NMEA2000 AIS includes a WiFi hotspot.  Like many such devices it actually translates NMEA2000 data to NMEA0183 prior to transmission.  Many newer parameters (such as attitude and attitude rate) were not standardised in NMEA0183 since they weren't widely available at the time.  This filters data availability.

We really like the iNavX chartplotter app.  It displays Navionics charts and overlays AIS data neatly. However its instrument page is text-only and has a limited parameter list.  At least it can display wind...

iNavX instrument display

OnSiteWX gets closer to our goal with customisable pages and a wide array of parameters.  However it isn't receiving all the 220WX's data...

OnSiteWX customised Location and Weather display

OnSiteWX customised Wind display

OnSiteWX customised Speeds & Courses display

No attitude data...

OnSiteWX attitude display (no data!)

Another nice feature of OnSiteWX is its ability to display trends.  We're yet to try this.

We've been researching WiFi hotspots to find units which transmit all the data on our network.  Most don't but we think we've found one.  If so that will be the topic of our next blog.

220WX

In the mean time we're very pleased with the 220WX.  The number of sensors in such a small package is impressive.  The price is a little scary until one adds up the cost of getting all the data from a set of instruments.  Works for us!