The best way to check fuel consumption is by filling the tank. Ideally this is done before and after a passage so just the underway hours are used in the calculations. When you are in coastal mode, as we have been, some interpolation is going to be required. As we have just topped off with diesel in Gibraltar we thought you might be interested in the figures.
FPB Series Notes
Following are the latest posts on the FPB 64 program. This section covers systems, how the FPB 64s perform in the real world, along with data on why we do things the way we do. For more information be sure to check out SetSail.com/FPB64.
The water injection elbows on the exhausts of Wind Horse’s engines and genset are fitted with temperature sensing bands supplied by AquaAlarm. If these exceed a preset temperature they close a circuit which triggers an alarm. In theory, this is an early warning of salt water flow failure. We are also fitted with sensors on the water flow itself upstream of the engines. None of these devices has ever given us a warning signal.
Avatar and crew are now happily basking in the Southern Hemisphere winter warmth of Vila in the island nation of Vanuatu. We sent her skipper, Rod Bradley, a list of questions about the passage which we was kind enough to answer. Rod’s comments provide an interesting look at how the first of the FPB 64 series performs on an ocean passage. Follow Carol and Mike Parker’s adventures with Avatar on their website by clicking here.
It is now officially warm, we are using our awnings, and even running the air conditioning on occasion. All of which brings to mind the subject of air con capacity. If you are going to have a air conditioning, and it is very nice in some situations, it needs to be looked at in an overall systems context. Typically the major power consumer aboard, if designed without thought for overall efficiency, the penalties can be substantial. The industry norm is to maximize capacity, for the worst possible situation, and then run the air on a low duty cycle. This forces you into big generators because of starting and running loads, which are loafing (bad) when the air is not running.
We think there is a better way.
We’re told open roadsteads, with bouncy sea-states, are not unusual from here on out. For most yachts it can get down right uncomfortable when the wind is at right angles to the chop. Wind Horse is very stable with ocean swells coming into the anchorage. They barely move her. But the short period chop from ferries and dinghies are another story. Which is one of the reasons for her big booms.
We’re anchored off the beach at Sanxenxo. This is an open roadstead, exposed to the Atlantic from the south, which right now is quiet. There is a long period small swell sweeping in which does not affect us. But the shorter period power boat wakes, of which there are a multitude, excite our hull. Hence the booms are deployed with flopper stoppers for the first time in two years.
We have finally found a windless day with flat seas in which to test our new props. What we know so far is that at a little over full payload we can achieve 2400RPM at wide open throttle. Our original target was 10.5 knots at 1600 RPM, at three quarters payload. Lets see how we did on the calculations:
We have just spent three days at anchor. For at least eight hours a day the portable computer and the desk top Imac with its second monitor and three exteral hard drives have been in use. There are two freezers going, a big fridge, and we are cooking electrically. We also don’t overly concern ourselves with power consumption for lights.
The amp hour meter says 930 amps or 310 amps per day average (at 24 volts), and the battery capacity is listed as 50%. If we were to sit another day we’d probably run the genset tonight to do a little battery charging. But as we are moving 38 miles, the engines will do a pretty good job of charging while we are under way.
The following question was posed by the Owner of FPB 64 #3. We thought the technical minded amongst you might have some helpful suggestions.
“We are building a new boat and intend to put a WiFi signal booster on board for routine in port use. In addition, for offshore, we intend to install a Fleet Broadband 150 satellite phone and internet system. As part of the process
We continue to be impressed with our Panasonic NN-CF778S combination oven. Capable of using microwave, convection, and broiling to the same dish, automatically if desired, it is also working well in a straight baking (convection) mode, as attested to by the photo above from last night.
Wind Horse had been closed up for the better part of eight months when we stepped through her entry door last week. Dorade vents and hatches had been sealed, and no outside air had circulated inside. Yet she smelled fresh, most would say new (and this after five years of cruising). How is this possible?
We’ve wrestled for years with the issue of a back up propulsion system, and have covered this in detail in previous blogs. Simply put, the odds are if you lose power the odds are it will be due to fuel problems or damage to the drive line, both of which put get home engines out as well.
So we have concentrated on a system which could, under the right conditions, get us across an ocean without using fuel or a prop.
In the last few days the question of heavy weather has come up a couple of times. Would we rather get caught in a Sundeer 64 or an FPB 64 in a really bad blow? Lets put this in the context of a passage across Drake Channel, between Tierra del Fuego and Antarctica which we were just discussing.
By those who voyage this is considered the worst stretch of water on planet earth. So which boat would we prefer in an ultimate storm?
No aspect of how the FPB Series handle offshore conditions elicits more surprise than their ability to surf. For most powerboats, and all displacement type configurations, surfing brings with it visions of lack of control, broaching, and risk of capsize. Yet the FPBs surf under control, adding speed, reducing fuel burn, and kicking up the needle on the fun meter.
How is this possible?
We’ve been watching video brought to us by the Owners of Avatar, the first FPB 64. It has long and steady shots of Avatar heading upwind with waves on the bow quarter. In discussing what the video shows with current Owners, it was suggested that a recap of the design of the FPB Series and how this impacts comfort, and safety might be in order. Now that we have the ability to embed video within these blogs it will be a lot easier to illustrate the design concepts.
This is a long article, with lots of video, so make yourself comfortable and prepare to do some passaging with us aboard Wind Horse and Avatar.
Thirty-three years ago when we started working on the perfect cruising yacht design we quickly realized that we needed a way to get back aboard if we fell over. The design configurations we were considering were simply too high to pull ourselves up from the water. In an effort to solve this dilemma the swim/boarding/rescue platform was born which has graced the transom of all our yachts.
Both Wind Horse and the FPB 64 Avatar share the same systems logic when it comes to AC and DC power. They are engineered to minimize genset time, running mainly on traction batteries at anchor with power supplied by a pair of 150 amp/28VDC alternators under way. On Wind Horse we have just 550 hours of genset time since launching in 2005, 100 of which came during sea trials when we were breaking in the little diesel and another 50 in Alaska when we were heating the boat with the reverse cycle air. That leaves 400 hours over five cruising seasons.
How have we managed this?
We’ve previously shown you the engine room as it came together during construction. Here is an overall look after completion, now being “lived in”, with tools, manuals, and supplies on hand.
This is what you see from the engine room door.
The Bar BQ/sink cabinet which is integrated with the engine room air intake structure has been the source of substantial dialog on the Dashew Offshore team. Todd and Linda were heavily in favor and wanted a large Bar BQ. Steve was inclined to have the smallest unit possible.
We are always amazed at how much cordage it takes for rigging a yacht. The FPB 64 is proving no exception. That’s Rod Bradley on the foredeck of Avatar, getting ready to stow dock lines and extra rope. Here is what is aboard in the standard specification:
The basement area under the great room on the FPB Series is key to the entire systems approach, not to mention storage. It allows us to position gear so it is easy to inspect and maintain, while providing a huge amount of bulk space.
We will start this tour in the forward port corner looking at half of the ship’s battery bank. Note that the fuel tank tops which provide the basement floor are above the waterline with batteries being a further 800m/32″ above this.
We’ve been learning about the NMEA 2000 Maretron system fitted to the FPB 64s for data management. Our decision to use this system was based on its ability to help the crew process information and make decisions, particularly in an out of the ordinary situation.
Sea trials are a busy time with testing, sorting out the inevitable gremlins that are part of a new boat, and learning how the boat performs. Our time to document the boat is limited – this is being written at 0430 – and we’ll have lots more details to share a week from now. For today here are a couple of items that have caught our eye.
We’ll start with this look at one of the two galley floorboard openings into the “basement”.
Perhaps a few photos of the deck details will be of interest. We’ll start with an occasion of sorts, the first anchoring. The bollards port and starboard work well in high load situations. Note the depressed foredeck well which serves two functions. One, it reduces the height of the windlass and Sampson post so they interfere less with your seated view on watch. Second, the well works to contain mud coming off the anchor.
The fairlead over the anchor and the related Sampson post are not easy to execute, hence a costly exercise (not to mention heavy). But we think this is a good investment in terms of weight and budget. Together these two items perform a number us useful functions:
Handrail design and positioning is a tricky art. You want the rails where they are convenient to use, and easy to grip, but not overbearing aesthetically. The photo above is on the starboard side of the entry landing on the first FPB 64.
We previously wrote about some of the details of the FPB 64 anchor handling system. As Circa just sent us a series of photos of the main anchor (a 240 pound/110kg Rocna) being winched home we thought they might be of interest.
Another batch of photos for art planning, this time of the larger engine room areas, which bring to mind the question about the best color for engine room insulation. Above we are looking at the bulkhead over the workbench. The taped outline is 670 wide x 465 high.
We have mentioned before we are somewhat obsessive about fire (which is why we have never had one). Watching chafe, good systems installation, and a rigorous cleaning and maintenance schedule reduce the risks to the minimum. Still, you want to be prepared for the worst, which brings us to the photo above.
We’ve often wrestled with the decision on dinghy size. Bigger dinks are drier and typically have a more comfortable ride. They also carry more people and gear. On the other hand, past a certain point, the weight of the larger dinghy makes it impractical to drag ashore. For the two of us anything over 300 pounds (136kg) is going to need an anchor off the beach.
The Owners of the first FPB 64 are avid divers. They want a dinghy that can take four passengers and their SCUBA gear at speed to their destination. On their previous yacht (a Sundeer 64) they were limited to an 11 foot (3.4m) inflatable. The FPB 64 aft deck offers more options.
You are looking at a small but important design detail, the window in the engine room door, and the view through it. Note that the mechanical Murphy gauges (center left) are easily noted without opening the door. If you have good eyesight the gauges on the watermaker are also in view.
Dock line cleats are a controversial subject at Dashew Offshore. There are some who swear by them and others who swear at them. For getting the boat tied up,and adjusting position when there is wind or current to fight, winches combined with high modulus dock lines are the answer. That’s why we have three Lewmar #40 winches plus the big electric winch aft.
For longer term docking, and once the boat is secure, a case can be made for cleats.
A properly design anchor chocking system will allow the windlass to jam the anchor flukes tight between roller(s) and the base of the chock weldment. If you get it right, the anchor stays fixed in place, with minimal movement as the bow feels waves, or drives through them. The result is a quiet anchor. Any softness, on the other hand, and the noise of the anchor shifting can drive you nuts.
By the way, that is a 240 pound (110kg) Rocna anchor on the bow of the FPB 64.
If the system used to handle the anchor chain is right, the chain comes in or goes out at the push of a button. If it is wrong, all sorts of problems can occur, typically requiring human intervention to prevent and or remedy the issues. In this report we will show you a few of the details we employ to get this right.
The FPB 64s have a large day tank in the engine room. There are two 1/4HP geared pumps, used one at a time, that fill the day tank from the main supply. These pumps are also used for the fuel polishing system.
The logic and basic control components are the same as we have used for the past 15 years, and the system works as follows:
The valve center bottom in the photo above is a small but important detail. This is the condensation drain on the engine room day tank. Note the pipe plug in the valve as a double check. The valve is threaded into a small sump making it easier for water and other gunk to collect at the low point. Normally a sump like this would be drained once a season and you might find a quart/liter of water at the most.
There are a couple of areas where it is important to know if water is flowing (or not flowing). On the FPB 64 these include raw water feed to the engine and through the damage control pump. The light grey device in the upper left hand corner is a vane type flow meter made by Aqua Alarm. A vane senses flow or lack thereof and triggers a micro switch that can be wired normally open or closed.
On the FPB 64 both of these alarms show up on the Maretron NMEA 2000 displays.
You are looking at a pair of magnetic “reed” switches. The lower unit turns the bilge pump on/off, while the upper gives an alarm signal if the pump fails to keep up. The gray plastic floats contain the magnet which controls the reed switch making the electrical contact.
In the case of the bilge pump, the reed switch is used to trigger a relay through which the current for the pump flows.
We have been using this combination of reed switch and control relay for 25 years and it has proven to be extremely reliable (much better than moisture sensors and mercury float switches).
Stainless steel and aluminum are not happy in direct contact, so we fit a plastic isolating washer between the surfaces, as shown above. The stainless steel fasteners are coated with an anti-corrosive compound (the type varies with depending on the situation).
Here is some tricky detailing in stainless steel. We are looking at the “gates” at the forward end of the flying bridge. These, and the other rails adjacent, will have clear Lexan plastic affixed as a wind screen. The gates are designed so they can be opened when you want air flow, and to allow space for an extra couple of friends to sit across the forward end of the table.
There are three Danfoss compressors, one for each of the two freezers, and a third for the fridge. Combined with evaporator plates and our special box design, with lots of insulation, this system is extremely efficient. We’ve discussed the box design before. What we wanted to show you here are two small, but important details.
We don’t expect fuel or water leaks in our engine rooms, still it makes sense to take precaution where practical with electrical gear. In the case of the two fuel transfer/polishing pumps protection is provided with the drip shields shown above.
You do have to check to be sure that there is sufficient air flow for cooling. During fuel polishing the pump being used could run upwards of fifteen hours, and it will get warm. Circa will be checking for heat build up here during trials.
You are looking here at the top of the raw water take stand pipe. The clear plastic lid provides a view of what is going on inside. If you suck up a large plastic bag or clump of weed, remove the plug and a mop handle can be used to clear the debris. This lid is above the load waterline so in smooth water no leakage should occur with the plug removed.
The upper of the two valves shown here controls the flow to the two diesels and boiler (through their respective filters). Note the bellcrank with attached Morse cable opposite the handle. The Morse cable runs to the bulkhead in the aft starboard cabin where it is in close proximity to the air vent shut off and manual fire extinguisher controls. Should the need arise in an emergency fuel and air can be quickly shut off.
How big should your raw water strainer(s) be? We are not sure, but we have two of these enormous (and very costly) Hayward strainers on the FPB 83 Wind Horse, and they have served us well.
We have never seen more than a quarter of the baskets filled, even in debris filled waters after hundreds of hours of operation. The same pair of overcapacity strainers is being used aboard the FPB 64s.
We have always been amazed at how much space it takes for electronics installations. Not the control heads, but the black boxes and various interfaces. Although we have continued to add space for this over the years, the quantity of gear aboard has grown even faster. With the FPB 64 we have finally caught up.
Systems details make a big difference in longevity, trouble free operation, and security.Over the next few weeks we will be bringing a series of these to your attention, so check back often. We’ll start with the raw water manifold in the engine room.
We have previously mentioned the hard anodized aluminum weldment fabricated by Circa for the raw water manifold. What we want to show you here is one of the two inspection and/or clean out ports.
Small details like this won’t come into play for a few years. But as the boat ages they become invaluable.
Designing an engine room air intake system is a complex process, full of tradeoffs. Before you start you need to have a clear goal for the system. For us this is simple: we want a system that minimizes water incursion through a variety of weather conditions with the boat upright, knocked down, and inverted.
How do we accomplish this?
You are looking at a chafe section on the high modulus dock lines we have been using aboard Wind Horse. After 45,000+ miles of cruising, much of it in rough surroundings when docked, this original inventory is still going strong.
The outer cover is polyester and their primarily as a first line of defense against chafe (it contributes little to overall strength.
We’ve discussed the advantages of high modulus dock lines before, but to recap:
Batteries and DC power systems are a subject of discussion wherever cruising yachts meet. The system we are using in the FPB Series is based on industrial quality traction batteries (so called because they are used in forklifts, railroad systems, and other heavy service applications). Our first experience with traction batteries was in 1988 with Sundeer. Every yacht we have done since has used these wonderful batteries.
Last night we were going through an old stack of yachting magazines and came across a write up on a well known yacht builder’s latest offering. This sixty five footer came with everything, even a tool kit (with a photo in the article). That tool kit was one of the small plastic cases with a variety of basic tools. We had a good laugh, and then thought you might like some ideas on what should be aboard a well equipped cruising yacht.
The basic stuff is easy. It is the specialty items which often make the difference between success on your own or needing outside help. You can have the greatest spare parts inventory in the world, but without the right tools you are helpless. (For a look at the spares which come with the FPB 64 click here).
As the tools for the first FPB 64 have recently been shipped we have a few photos and some comments to share. This selection is based on what experience has taught us over the past 30 years.
Nothing in yacht design and cruising evokes such discussion as anchors and their related gear.One anchor or two, chain or chain + rope, CQR, Danforth, or Rocna anchor type, electric or hydraulic power? We’ve fitted just about every combination you can imagine, and after 40 years of testing here is what we have learned.