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Saturday, 27 September 2008

Refit Week 4 - Steelwork Completed

Its just on a month since we sailed into Phuket Boat Lagoon, and three weeks since we hauled out of the water. On deck we've been concentrating on steelwork - changes and additions to improve the boat and reduce maintenance in the future. Inside the boat we've started painting - with the lockers empty its a pefect time. Two coats of Jotun Penguard high build primer and two coats of Jotun Hardtop polyurethane and our old cupboards start to look like new again. As you can see in the photo at right, Ley just loves painting....

The guys from Mr.Nop's stainless steel fabrication business have been working very hard. They've fabricated beautiful new pulpit and pushpit railings and completely rebuilt the stern fuel locker in 316 stainless steel. This area was previously fabricated from timber, which was bolted and glued to the steel hull, and it was always a source of rust and maintenance work. Now its fixed and there forever, and our aft railings run forward past the cockpit for additional security.

We've also improved a number of the hard point areas on deck, the ones we didn't tackle in our last refit 8 years ago. This basically involves welding thick 316 stainless plates into the deck, drilled and tapped to take our fittings. Because the holes don't go right through its impossible to get any leaks. The plates are faired into the deck and painted over. Last refit we welded shut 210 (!) holes in the deck, and fitted these welded blocks as hard points instead. For this refit the count is only 53, but it still feels good. The tough one was the mainsheet traveller - 24 precisely drilled and tapped holes in a 10x50mm 316 stainless bar, curved to match the roof of our steel dodger. The guys were having trouble tapping into the hard stainless bar, until Ley's father Ray suggested using Carnation Condensed Milk as a lubricant and cutting compound. I'm sure they thought we were crazy when we brought the can out to them, but after the first hole they'd changed their mind - it really works. All the big 316 bar and plate stock has to be ordered from Bangkok, but things happen pretty quickly here and the job is virtually done.

Our PowerDive hookah gear gets a lot of use cleaning the boat, but its often needed quickly if we pick up a net or line on our propeller at sea. Getting the gear setup on deck in the middle of the night at sea proved kind of frustrating, so we're installing it inside the boat permanently. A fixed airline will run to a new stainless stell compressed air socket at the stern - now we can just throw a switch and plug in a hose to get underwater quickly. We've also put in a new stainless penetration for our aft deck shower hose, and added a welded hardpoint for a pasarelle at the transom. The cost of all this is not insignificant of course, but even with Mr Nop's best "creative" margins in play it is great value, and the local workmanship is outstanding.

Tuesday, 23 September 2008

AIS Part 2 - The Installation Experience

AIS stands for Automatic Identification System, an active primary safety system for vessels at sea. The black arrow in the photo at right, captured from our PC screen, is Crystal Blues. The red arrows (targets) are ships we want to avoid. Clicking on a target reveals the data box seen at bottom left - lots of information on the ship in question (click the image at right to enlarge).

I met a cruising sailor last night who said that my first AIS story (here) was very technical - oops, I guess it is a technical subject. Not sure that I can eliminate the technicalities, but I will try to explain them. First though, an essential technology primer .... I strongly recommend you spend time roaming the excellent PANBO website, specially the AIS pages. Also, here are links for two very informative and useful documents, covering co-axial connectors and co-axial cabling. OK, on with the story ....

We purchased our Class B AIS transponder from Oceantalk in Singapore - in fact we bought four of them, as several other boats wanted to install the system. The unit is a Comar CSB.200, manufactured in the United Kingdom. It was supplied by Oceantalk with a Shakespeare VHF whip antenna and a Sanav GPS antenna.

All Class B AIS transponders require a dedicated GPS receiver and a dedicated VHF antenna. No arguments please - if you want this powerful safety system, you have to install the extra antennae. No, you cannot share signals from existing systems, however the AIS derived GPS position information is available to you as a separate NMEA signal, for chart plotting purposes. You'd better plan carefully for antenna locations, bracket positions and cable runs.

The GPS antenna is a simple patch antenna with a low noise amplifier that sends the received signals (as RF) direct to the AIS system for timing analysis - in other words, the external receiver is just an amplified antenna, and all the complex decoding and mathematical computations to derive your vessel position occur inside the AIS transponder. This is a specific requirement of the IMO AIS regulatory framework - it basically ensures that no one can feed fake vessel positions into the system. That is good to know ...

On the VHF side, AIS Class B uses just 2 watts of radiated power to send its reports outwards (the big ships get 12 watts). It is easy to receive signals from big-ship class A systems, however you better pay attention when installing your VHF cables, connectors and antenna. You want to ensure that all of your 2 watts is actually radiated into the ether. Robin Kidd from Oceantalk stressed this point - make sure your VHF cabling and connection work is good. Installation requires the following :

- Physically mount the AIS box. A U-bracket is supplied, but we used industrial strength adhesive Velcro to mount it on a vertical bulkhead (see photo).
- Run the cables for VHF and GPS antennae
- Install and connect both antennae
- Run cable for DC power with a fuse in line
- Run the data cable to the chart plotter/display system
- Terminate everything and then commission the system

Of course your chart plotter must be compatible with AIS messages in NMEA format to display the targets and information. If it isn't, you can use this very neat AIS display from Vesper Marine, the AIS Watchmate, or a more serious display (with charts) made by Comar, the CSD.200.

Back to the installation. If you power the box from a shared DC circuit breaker (ours is on our navigation instruments circuit) you should include a 5amp fuse in the power feed. Be careful with the VHF antenna cabling - OK, its just RG.58, but you've only got 2 watts to radiate, so make sure you use high quality connectors and fittings.

The GPS receiver supplied by Oceantalk is the RV-76, made by San Hose Technology in Taiwan. It includes a nice 10 metre pre-terminated cable. Its very thin, and easy to run through the boat, but it turns out to be RG.174, which has very high losses (attenuation) at these frequencies (1.5ghz). If you use the supplied cable as-is, with its existing terminations, it will work just fine. However if you need to cut, join, extend or splice (as we did), then you'll have to use a more suitable cable (RG.223). After attempting to extend the supplied cable, and getting no satellite signal, we changed to a Bedea RG.223 with Telegartner crimp connectors - voila, tons of signal. We purchased the cable and connectors from Coastal Electronics in Singapore, though similar cable is made by Belden and others. Make sure you use the correct crimping tool (see photo).

On the VHF side, the Comar AIS box will actually measure and report the SWR (reflected energy ratio) on your VHF transmission line during commissioning - you'll soon know if your VHF cabling and connectors are good or not. Click on the photo below at right to see typical values.

With all that hard work done the rest was easy - plug the box into our PC using the supplied cable and configure the COM port on the PC (baud rate etc) . Then load the Comar software (supplied) and configure the unit. At this point you'll be asked to input your vessel identifier, which is the unique "MMSI number" issued by your National Marine Authority. If you don't have an MMSI number you'd better apply for one now, because you cannot transmit using AIS without one. A Comar Class B transponder will stay in "receive only" mode until you give it your MMSI number. The real trick is that this number can only be entered ONCE by the user - mess it up and you have to send the box back to the dealer for resetting.

I've just learned that Class B systems are FINALLY approved for use in the USA (story here), but that they are not allowing users to configure the MMSI identifiers. I bet that will be fun to administer.... seems the installers or retailers will have to configure the box before handover. The Comar configuration software is simple to use, neat and logical.

So, use only good cables and connectors, get yourself an MMSI number and enjoy the results. Our next story on AIS will conclude the series with our user experiences.

Sunday, 14 September 2008

A Working Holiday In Phuket

Most people come to Phuket for a holiday, but we've come to work - Crystal Blues is here for a major refit. After arriving on August 18, we anchored in Chalong Bay and completed clearance with Immigration, Customs and the Port Captain. Now, four weeks later, that arrival seems like months ago - we've done so much in the past month it's scary. Ley says that it's beginning to feel like real work again - up at 5.30am, breakfast, drive to the boat yard. Of course the drive to work here is a little more interesting than at home in Australia - the local villages, caged monkeys, water buffalo and rubber plantations give this commute a different feel.

Two days after arrival we'd rented a car for six months and were on the road house hunting. Four days later we signed a lease for six months on a large three bedroom home (air conditioned & furnished throughout), in a quiet private estate. Then the fun began - how long would it take to empty the boat of everything ? The answer is forever - we're still not done, though I can say that 95% of the contents were removed in 25 car loads. Half those car loads were filled using the dinghy as transport to shore (it took 2 dinghy trips to fill the car). The rest happened after we moved into the Phuket Boat Lagoon 0n September 4th, where just 3 trolley loads could fill the car. It was messy, hot, sweaty work, but its done.

The ocean tides are big here, which is just as well, as the channel to the marina is dry on the lowest tides ... we motored in on a 3 metre tide but still saw less than 0.5 metres under the keel. They badly need a suction dredge.

We've been lucky with the rental house (check the photo's here)- besides being comfortable, nicely furnished and "homely", its got a SHED ! It also has shelves, a work bench and even a Gerni (high pressure water wash). So the 25 car loads became 1 house load, which we're still trying to sort out. Seriously though, the house is lovely. Lots of light, space and a garden. The neighbour's dogs have adopted us (Lucky, Blacky, Red and Grumpy), and the locals are friendly as well. There are several good restaurants within a 5 minute drive, all very economical. The boat yard is a 10 minute drive.

We've now started a Picassa Web photo album, so family and friends can see the refit as it progresses - you can view it here.

Crystal Blues was hauled from the water last Thursday, September 4. Prior to haulout we'd taken so much gear out of her she was riding over 100mm above her normal marks. The Boat Lagoon crew are really good at this work - Mr Sin runs a very tight ship. They held her in mid-air whilst we disconnected and dropped the rudder out, before expertly blocking her right in front of our contractors shed. Two days later, last Saturday morning, a huge crane truck arrived on schedule at 10.00am and lifted the mast out.

Within an hour the Pro Yachting team had moved a massive frame and tent into position and the boat was covered. Of course not everything went well - we were incredibly lucky that the monsoon rains held back whilst we emptied the boat contents, but the moment we were lifted the heavens opened, and they haven't closed yet. Its raining every day and night. Thank heavens we have that tent over the boat.

And just who ordered these political protests ? No sooner is the boat out of the water than suddenly there's talk of a people power revolution. Politics in Thailand is almost unfathomable - one side (the democratic party) is suggesting democracy be abandoned, whilst the other (the ruling coalition) is determined to re-nominate the prime minister who was sacked yesterday by the courts, basically for corruption. The coalition says he didn't do the country any harm - sure he did, he just stood up and lied in a court of law. Guess that doesn't count if you're a politician. The last prime minister, Mr Thaksin, is now exiled in London. When he was questioned about corruption (by the press) he basically said it was OK because it was everywhere. What a guy.

The political action in Bangkok has left Phuket quite untouched, except for a peaceful sit-in protest that shut down the airport. However last Friday a local friend called early and said he'd heard that the schools might close and that we may lose power if the government workers go on strike. In Phuket no power means no water, as almost all the water is sourced locally from wells. He recommended stocking up on drinking water, washing water and petrol for our portable
generator. So we rushed out and bought two 100 litre plastic containers for washing water, re-filled the water tanks on Crystal Blues, and moved our 200 litre Turtlepac water bladder to the back porch of the house. We now have 1400 litres of fresh water on hand plus 120 litres of petrol in jerry jugs in the shed. We're ready, though I doubt we'll need any of it. The Thai people are too smart to mess with the tourism cash-cow - I'm sure Phuket will remain peaceful.

Over the past 5 days we've stripped the deck of all fittings and have also stripped the winches, tracks and fittings from the mast, boom and spinnaker pole. Mr Sung, the stainless steel expert from Nop Stainless, has demolished our wooden transom fuel locker and re-built it in 316 stainless steel. Next he'll move onto the deck, where we're adding more stainless attachment points and some electrical and air penetrations. The staff at Pro Yachting have been very helpful, every request has been rapidly supported. Right now we're ahead of our program, and very happy with the service here. If only it would stop raining !