Re: Electronics: complete refit of hull 248, 1999 SM

SV Perigee

We have SM#396 - Perigee, purchased late 2016.

The previous owner had upgraded to FURUNO TZT chartplotter (version 1, which includes a rotary dial), DRS4 radar, new Furuno AIS (50 = Tx+Rx).  And we are glad he did.

We have upgraded the A/P.  Held to Raymarine, but the latest EVO-400 series model, retaining the legacy linear drive (refer also to the last point below about staying with Raymarine).  We replaced the existing linear drive with a new unit, serviced the old, and placed that into spares.  We have only a linear drive, not a rotary drive on the wheel, so our redundancy is provided by the spare drive, another rudder sensor unit, a spare drive controller (the grey box), a spare control head complete wiring harness, and the new generation EVO 'brain' which incorporates the heading sensor.

The main issue we have with this setup is getting the radar and AIS data off the Furuno network.  Both are fed to the TZT chartplotter via an Furuno ethernet hub, and NOT then shared on to the NMEA2000 network. We can view the TZT program, including radar/AIS (as if looking at the chartplotter directly) via WiFi and dedicated app on an iPad  - it works, slowly but surely, in both control and 'view-only' modes.

However, I would prefer to be able to extract the AIS data (at a minimum) and share it via the NMEA network - for use by either iSailor (which we run as a continuous iPad-based NAV backup to the Furuno TZT chartplotter), or to OpenCPN (just starting with this), or to be available for use by other displays/devices.

One alternative I am looking at is to have a dedicated AIS that shares it's track-plots via the N2K bus.  I am looking at the Vesper XB-8000 Class B AIS Transponder with WiFi.  (If my understanding is correct, I would then get all info on the N2K bus available via WiFi.)

We replaced the legacy 5x B&G Analogue instruments at the helm with 3x Triton2 displays.  This was due to the failure of the sonic-speed - I wanted to have STW as an input to the NAV system.  If everything had continued working OK (or if I was not finicky about STW), then I would have left 'as-is', and not started down the upgrade path until something else failed. 

That said, we are happy with the result.  With the new Triton2 instruments at the helm, we like the wind and depth tapes for improved situational awareness. The standard set-up is speed info on the left display, wind on the center display, and depth on the right.  We do however have different modes, where each of the helm displays shows different info depending on whether in harbour / shallow water, departure & arrival (Coastal), no wind (motoring to WPT on A/P), and sailing offshore (deep water).  I would also like to be able to feed AIS into the Triton2 helm instruments because one of the available screens can show a plan-view-display of AIS traffic (but then I would likely want a fourth display for that - where does it stop?).

Another consideration.  With the extension of the N2K backbone for wind, depth and boat speed, and now with all data natively on the N2K bus, I wished to remove the NMEA2000<->0183 converter between the TZT chart plotter and the B&G Hydra2000 unit at the navigation station.  This is because I discovered the the converter was introducing noise that was making the HF almost unuseable.  But with the Hydra decommissioned, one loses valuable info at the NAV STN.  Sure, the information is available on the chart plotter, but then one has to power up the chart plotter to see it (which uses more power and generates more heat).  So, to replace the functionality of the Hydra, I settled on a B&G Vulcan7.  More functionality than the Triton2 displays, but with built-in GPS (redundancy), another source of basic charting information should the TZT be out of service (and it has been), wind-tapes at the nav station (great), along with a host of other info not readily available on the TZT.  But without going to the Hydra5000 (because the Vulcan range, with the exception of the no-longer-available V5, has pretty much the same functionality as the new Hydras, that is, IF you have a dedicated chart plotter such as the Furuno TZT).

Another thing to think about when designing your new N2K system, is how the N2K network is powered.  Mine is powered by the Furuno TZT Chart Plotter.  The TZT does not need to be powered on, but the Circuit Breaker for the NAV station does need to be on.  Meaning that, all the power supplies for any equipment powered by the NAV station 24V bus are also powered up.  Equals power consumption and heat at the nav station.  Meaning also, that the whole N2K bus is powered up, including the displays at the helm. I am still contemplating the next change, which would be to install a switch panel for the independent 24-to-12V converters powered by the 24V bus.  And then split the N2K bus into two (from an electrical supply perspective, but retaining the common data bus).  Firstly to have a power source for the _sensors to nav-station side_ (and this would also be powered independently of the TZT display, allowing the removal of the TZT without having to wire in a separate power supply for the N2K bus).  And a second power supply for the _nav-station to helm_ side of the N2K network.  I would also take the VHF off the general bus, and place it on it’s own breaker (perhaps onto the HF breaker), so that I do not need to power up the whole NAV Station for when I just want the VHF on.

Speaking of VHF, I replaced the VHF with an ICOM IC-424G, which has built-in GPS (yet even more redundancy).  But have not yet wired in the extension command mic to the helm.

Still deciding on the panel layout for the NAV STN, for when I finally get around to removing the original Furuno GP-80 GPS Navigator, and the now superceded Hydra2000 display.

Last consideration.  If you think you might ever wish to control your autopilot from downstairs at the nav station, or using your helm displays, well, with B&G instruments and Raymarine A/P, this is not possible.  Sure, the Furuno TZT chart plotter (and B&G Vulcan7) can output course information that the A/P uses for it’s track functions, and the TZT and V7 can see rudder-position (and other) information coming from the Raymarine A/P.  But to directly control the A/P in heading or wind mode, or to change modes (heading versus wind-vane versus track mode) and so on, this is not possible.  It might be a rare case when you might want to do this - bad weather, short-handed, or failure of the A/P control head at the helm.  But something to think about.  I did not research this closely enough.  If I had been aware of this limitation, then I might have changed to a B&G autopilot (retaining the Raymarine linear drive), in preference to staying with Raymarine for the upgrade.  This would have allowed me to control the autopilot from the V7 downstairs.  The cost of the A/P upgrade would have been about the same.

Hope this provides food for thought, in addition to my prior posting on the forum about electronic upgrades.

Perigee, SM#396,

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