Brian Rickard has put together a 2012 calendar featuring the FPB 64. They’re available through Lulu.com, an independent publisher. You can check them out by clicking the link below.

And now for something different. We are pleased to report that FPB-1, Avatar, has just finished her first day of testing with the swim platform extension and get-home engine. The lovely clean release above is at eight knots with the little Yanmar pushing her along.

The first day’s results are in shallow water, with moderate breeze, so we don’t have any real detail to report. What we do know is the following:

• Maneuvering at speed seems unaffected by the addition of the second prop skeg.
• The increased drag of the second prop and full skeg appears offset by the swim step extension’s drag reduction.
• With the Gori feathering prop in normal pitch mode, wide open throttle reaches 3400 RPM– so there is sufficient margin for a fully-loaded boat in head seas (engine prop curve needs only 3200 RPM).
• It looks like 8.5 knots should be possible at around 2800 revs when the prop  is in overdrive mode.
• Maneuverability appears good on the get-home engine at slow speed. Clockwise turns are favored with the offset, of course, but counterclockwise also works.
• Wide open throttle on the main engine yields in excess of eleven knots.

We shall update again when more data is available.

Since we’ve been boring you with technical posts all week why change the rhythm? These photos are from Friday, and cover FPB 64s five through seven. We’ll start with seven, shown above,  the skeleton of which is just starting to be assembled.

These structural elements are cut on a computer driven device that adds alignment marks for assembly as well. There are welding jigs for each of the prefabricated items, like bulkheads and tank tops, which insure accuracy and speed production.

All of this starts as a 3D model of the complete boat, which is then dissected  into cut files. The furniture is designed to fit this same 3D model, which minimizes fitting time (and mistakes). It is this potential efficiency, harvested by Circa’s experience in production, that makes it possible to build to such a high standard yet keep costs moderate. Absent this approach, the price at this quality level and specification would easily double.

Moving on to FPB 64-6, the metal work is nearing completion. We are looking here at the two prop skegs, main on the right and get home, framed but not yet plated, on the left. Both share the same framing and plating scantlings.

Inside the engine room, the prop shaft tube (log) for the get home engine. Note the sump, which slopes down towards the bow, and drains to the main sump. This detail reduces constant wetness from pooling of drips under the “dripless” shaft seal.

The house structure is now welded in place.

Note the structural connection of the house roof assembly. The corner and side window mullions are captured at the top of the coaming, at the deck, and then down the topsides with a partial frame to the upper topside stringer.

Finally, a series on FPB 65-5, starting with this look up at the headliner panel grounds (attachment points).

Looking aft towards the entry way and galley. The large locker at the top of the stairs, formelry for jackets and foul weather gear, is now dedicated to the galley.

The oven will live at the bottom, and then the rest is available for general storage.

Note the angled pipe in the pantry locker which goes to the exterior for mast wiring. The angle downward is to assist any drips in returning to their native environment, rather than visiting the interior where such malevolent entities are most unwelcome.

Bulkheads, furniture grounds, and what will become covers for structural members and raised deck edges are completed in the aft guest cabin. Note the aluminum cable trays. These will shortly be well populated.

And last, the get home engine with its V drive (bottom of photo), thrust bearing, and engine,

After some 5000 cruising miles since delivery in March of 2011, I have some pretty specific thoughts on how Iron Lady is working out. Some were surprises to me. At the top of the list was that I felt safe on Iron Lady. While I can’t necessarily identify all the features that make the boat safe, between how comfortable the boat is at sea, at anchor and how it stood up to the punishment of a grounding all gave me tremendous confidence in the boat. My husband is also much more relaxed about things and that, in turn, makes me comfortable. My other comment was that I never would do what we have done on Iron Lady on our last boat. By the second day out of New Zealand to Tonga on our first really long passage, I was standing watch – something I would never on our last boat.

Our last boat had a traditional pilot house three steps up from the salon/galley area. I was very fond of that arrangement and the galley and wasn’t quite sure about the great room concept that incorporated the helm station, dining area, salon seating and galley all in one area. After 6 months aboard, I like this arrangement better –particularly the spacious feeling and wonderful views created by the ring of windows around the great room. It makes the space feel substantially larger.

To read the rest of Debbi Rossin’s post on the Iron Lady website click here.

It is the eleventh day of the eleventh month in the year 2011, and we have a new batch of photos from Circa, a few of which we’ll share. That’s Avatar, FPB64-1 in the yard, back at her birth spot for a get home auxiliary to be installed. After two years of cruising and many thousands of miles she is looking good. FPB 64-3, Iron Lady, is in the area as well. And then there are FPB 64s five, six, and seven, under construction, which we shall get to shortly.

Last week we posted some data on Avatar‘s fuel burn for the trip south in less than ideal conditions. Having looked at bottom and propeller phoyos, sporting a season of growth, her drags were probably up by five to ten percent a prop efficiency down by at least the same. There are two ways to look at this: it is real world and one should allow for a foul bottom when thinking about range, or with a clean underbody and prop, range would be substantially higher and fuel burn lower.

Metal work on FPB 64-5 is almost completed. You are looking here a the aft deck lockers. The larger of the two hatches is below the dinghy and therefor blocked if the dink is board. The smaller hatch is clear of the stored dinghy and gives you access to much of the adjacent space.

The systems and interior are coming along smartly.

This is the sump at the forward part of the engine room. The large strainer is connected to the damage control pump.

There are three reed float switches shown. The two centered run the twin bilge pumps. There is a third top center and somewhat further off the hull plate for a high water alarm.

Switching now to FPB 64-6. Note the sharp trailing edge of the skeg ahead of the prop. This reduces the turbulent flow from the skeg into the prop, a major gain in efficiency.

Still on FPB 64-6, the forward bath module being lowered into the great room.

And the stabilizer mechanism coffer dam, with its watertight lid open. Note the reinforcements around the mechanism carrier flange.

Finally, the prefab parts for FPB 64-7 which will shortly begin to form a recognizable shape.

The various rules to which yachts are built are based on seagoing loads. If you design to ABS or Lloyd’s, odds are you will be OK  offshore, but there is little extra margin for the mistakes which are a part  of cruising. With an ABS keel structure, if you go aground, it is almost certain a trip to the boat yard is in your immediate future. But if you engineer to four times ABS, you are probably going to continue with your cruising.

We have tested these these theories ourselves, and had our owners repeatedly test them on our sailing designs. Now we have some real world verification of the FPB 64′s factors of safety.

The photos which follow were taken of one of the FPB 64s after it tangled with a reef in the Fiji Islands. She has been hauled to replace a damaged stabilizer fin. At the end of this post is a link to the details of the event which has some excellent lessons for us all.

Pete Rossin, Iron Lady’s skipper, told us “We dragged along the reef for close to 2 hours although more intermittently as time went on. The first hour was horrible. Tide was coming in – we hit the reef about an hour or so after low. My analysis is that we JUST clipped the outer reef edge with the bow on the stbd side as we were trying to exit to deeper water – another few meters off to to port and we would have been fine.  The wind then blew us around on to the outer side of the reef and pinned us but also blew us along the reef.  There were deeper stretches in between the heads and that is why we drifted and bumped slowly along the reef until we made deeper water…”

Read Pete’s full account by clicking here.

There is superficial paint damage forward which coincides with a water depth of about 3.5′ (1.05m). The damage is mainly in this area and  all the way aft, indicating coral head tops with deeper water between.

This is the leading edge of the prop skeg, here about the same depth as the forward abraided paint area.

The abrasion on rudder tip and skeg bottom show the same water depth as is found forward.

The rudder probably cut into the coral on impact. We have used a factor of twice ABS on our rudders for many years. This is an indicator twice ABS is on target.

The fact that the prop coating is mainly intact tells us the skeg is doing its job.

Several factors helped to mitigate the damage incurred and the time spent on the reef:

• Shallow draft reduces the amount of sea bottom (or coral) in contact with the hull and appendages. Even a foot/30cm more draft and the ability to float free would have been severely curtailed.
• The rounded canoe body (hull) of the FPB type yacht skids easily on the bottom and does not dig itself in as is the case with hulls that have chines or harder edges.
• The fact that the lee stabilizer fin broke free should be considered a benefit in that it could not anchor the boat in place.
• Becoming trapped on a rising tide, rather than the reverse, was good luck. Whereas the crew of Iron Lady had the luxury of waiting, has they hit on a falling tide fast action to free themselves would have been advised. As an aside, knowing the state of the tide when on soundings, is always good practice.
• A structurally sound full depth skeg ahead of and below the propeller protected the prop from damage.
• Although not a factor here, the double bottom, water tight bulkheads, and oversized drive line components allow a range of tactics to save the boat that would not otherwise be available.

(For more information on cruising in coral, and getting out of situations like this, see  Practical Seamanship.)

If you are going to spend extended periods cruising, incidents like this will occur. Not often mind you, but like handling severe weather, it is better to be prepared for the worst, rather than just hoping for the best. Although we cannot foresee all eventualities, nor protect ourselves from everything, we like knowing that we have a design under us which will mitigate the results of operator error, the capriciousness of Mother Nature, or just plain bad luck.

For more information on the FPB Series, e-mail ToddR@SetSail.com