Designing & Building Hammerhead

So, we have decided to start designing and building our own passagemaker "Hammerhead"! After contemplating and discussing how to move ahead, after meeting more than a few naval architects, and after visiting many shipyards for over two years, we pulled the trigger and started the design phase!

We have set a number of parameters and goals:
- Hull lines before lay-out;
- Comfortable, efficient, and safe at sea;
- Couple operated;
- 65 feet LOA and LOW;
- Aluminium, round bilged, slender build with fine entry bow, and narrow stern;
- Single engine;
- Living, eating, cooking, and driving the boat on the same level;
- She should sleep four to six comfortably;
- Stamina, able to maintain high cruising speeds of up to 10 knots.

We hired a naval architect that seems to understand what the mss. and I want (fast displacement explorer with a focus on functionality, low running costs, that deals with various sea states relatively comfortably). Quite a relieve after discussing our plans in depth with two other architects first ... that simply felt better selling us one of their existing designs.

I'll try to inform you guys and galls on our progress. Once I figured out how to post pics, I'll share some designs as well. We are working on a Facebook page and a blog, and a website will follow in a few months.

Regards, Edwin and Veronika (currently owning Bruijs Kotter "Salty Pelican")

looking forward to it.

did you win the lottery?

No. I have been working my *ss off for the last 40 years, and with a successful international business and the kids leaving the nest, I felt it was time to invest time & money in what's become a passion: boating. With the goal to travel the world.

Ah! Succeeded to upload a profile sketch of where we are at.

Great idea

Here are to different boats with the same idea.

https://setsail.com/

https://www.seapiper.com/

Enjoy the build. Pleas keep posting, we will enjoy the build with you.

Cliff

Thanks for sharing, Cliff. The FPB, yes, that is an inspirational story. I must have seen all of their video's at least twice. The Seapiper is a nice initiative. Love small boats with big lungs! Reminds me of our current boat, "Salty Pelican".

Congrats. Very exciting times ahead.

No doubt you are already aware, but just in case others following may not have seen it, your mission seems well aligned to the artnautica design: https://www.artnautica.com/designs/long-range-cruiser-58

Looking forward to the webpage. I've really enjoyed following along with the build of Mobius: https://mobius.world/

I love the simplicity of the LRC. Mobius looks like a great project. Thanks for sharing Blue Yonder.

Today, we visited KM Yachtbuilders in the north of the Netherlands. Impressive shipyard, with an impressive portfolio!

Before deciding on who we'll invite for a tender, I always like to visit a warf, just to make sure that I like what I see and that the vibes are okay.

We spoke to Euwe, the owner, and Jildou, who is responsible for sales. They showed us around, answered all our questions, and proposed we reach out to them whenever we feel they can be of assistance.

We consider the following lay-out:
- Lazaret in the swimming platform;
- Owners stateroom with desk, shower, and toilet in the aft section;
- Cockpit above the owners stateroom;
- Engine and tanks in the middle of the boat;
- Pilot-house (with living and galley) on top of that;
- Day-head and second shower and guest cabin forward;
- Second guest cabin / storage area near the front of the ship.

excuse my ignorance..

what is the cockpit used for?

Sit outside, drive the boat while sitting outside, doing cocktails & smoking cigars, maybe some fishing? Looking to see if we can also adapt it so that - in case of really bad weather - we can temporarily store the dinghy there. Storage in the lockers. BBQ on deck. Fav place of our dog Kifli.

Preliminary calculations are in and we are very happy with them! First, the design is self-righting. The GZ-curve shows values above 0 for anything from 0 to 180 degrees roll.

Secondly, the high cruising speed we aimed for seems to be achievable. She tops out at 11 knots and cruises efficiently at 10 knots.

At a speed of 10 knots, she uses 4.75 gallons per hour. Resulting in an autonomy of 4,000 Nm. Do we drop the speed to 9 knots, then the autonomy increases to 5,000 Nm.

Here is a picture of the 3D-model used in the stability modulations:

Salty Pelican said:

Sit outside, drive the boat while sitting outside, doing cocktails & smoking cigars, maybe some fishing? Looking to see if we can also adapt it so that - in case of really bad weather - we can temporarily store the dinghy there. Storage in the lockers. BBQ on deck. Fav place of our dog Kifli.

Click to expand...

Where is the dinghy normally stored?

On the swimming platform at the back, TwistedTree.

I like more traditional designs, but it's your dime. (or maybe your millions)

pete

Pete Meisinger said:

I like more traditional designs, but it's your dime. (or maybe your millions)

pete

Click to expand...

Amen. To each his own. What matters is that you enjoy your boat.

After visiting loads of offshore cruising boats , I an convinced that locating the engine room as far fwd makes the best layout.

With todays light weight diesels the engine and noisemaker weight are not hassle especially in an over 50 ft LOA

For efficiency a CCP (controllable pitch) prop will probably be chosen which mandates a thrust bearing , so a simple truck style driveshaft is inexpensive and very quiet in operation.

Locating a head & shower and perhaps Fuel filters and house battery bank behind the engine WT bulkhead creates enough barriers that simple sound proofing is all that is required.

To keep the boat in trim there might be a need to be able to move fuel or water while voyaging, depending on how light the boat is built and endurance required.

If the aft cockpit deck was low enough with 2 openings for the transom the dink could be driven part way aboard. This could provide emergency short range propulsion , or simply easy unloading of massive supplies.

Thanks for sharing.

The engine will be located in the middle. The ER will be soundproofed. The engine will be on ... dampers I think the word is. Forward of the engine room will be day head and shower, to further shield the the guest quarters. Behind the ER will be the owners head & shower to create more distance between ER and sleeping quarters of me and the mss.

We haven't decided on prop yet. We'll be investigating a few options. Autoprop is one of them. I don't like CCP because of the combo with a dry exhaust and the additional manual input that's needed to achieve efficiency. Efficient prop, etc. all optimized for the 10 knots cruising speed is another option we are researching. It has shown to achieve 70% overall efficiency.

Backup propulsion will probably be via battery and electric engine. Twin generator set-up to help out with providing power. Dinghy will be third backup, but strapped to the side, and with a special prop for that task.

We are currently setting the tanks up in such a way that they are close to the center of gravity. I don't like to rebalance "en route", and long, wide tanks have big surface areas, that negatively impact stability and are a pain to clean. With centralized tanks, we can minimize free surface area, make 'm easily accessible, and full/half/empty load won't impact COG.

The first design cycle shows that we still have a little bit of work to do there. Center of gravity needs to shift backwards a little bit (or we need to add some buoyancy just ahead of the COG).

To be continued ...

Regards, Edwin.

It looks to be 20m long? What the expected beam, draft, and displacement (actual weight)?


Thoughts on what engine?

What is the thinking behind the plumb / vertical bowstem?

And coupled with what appears to be somewhat narrow shoulders (light buoyancy) it would seem to want to dive into head seas?

Or is it just the angles shown??

We are still tweaking things, but, yes, she will be 20 meters long (65 feet). Width/BOA will be 5 meter (16.5 ft). Beam over water line is closer to 4 meters (a little over 13 feet). Draft is 1m25 (a little over 4 feet).

We are aiming for an empty ship weight (no water, no grey water, fuel tanks empty) of under 30,000 kilo's (66,000 pounds). I am investigating John Deere's portfolio for an M1 engine. The 4045 AFM 85 with 160 bhp looks good. High torque, row rpm.

Anyone here have any experience with John Deere or maybe even that engine specifically? Sound levels, reliability, real world efficiency?

The vertical bow helps maximize length over water. Needed to maximize efficiency and to obtain the high average cruising speed of 10 knots that we are looking for. It is also designed to ever so gently give a slight slow-down to the pitch movement. There is ample buoyancy above the waterline for her not to dive into head seas, but we are taking all precautions, and the model will be tested at the Netherlands National Naval Institute, for finetuning and more.

Interesting project. Thanks for sharing the process. I love your focus on fuel efficiency.

I have a JD4045 TFM75 in my boat. Haven't had it that long, but everything I've read and experienced suggests it's a very good motor. It's a bit rough at < 1000 rpm, but smooths out with a bit of throttle. I think that's true of most 4 cylinder diesels. The more modern CR version may well be a bit more civilized.

The AFM85 looks like a very good choice, and fits well with a 5 gph fast cruise.

While I'm here, I found the earlier self-righting comments interesting. Was that a design goal, or just a byproduct of the above deck design?

Salty Pelican said:

- 65 feet LOA and LOW;

Click to expand...

Note that 20 meters LOA (~65.6 feet) is a point at which the COLREGS requirements change -- better running lights and less choice of placement, must exhibit anchor lights and shapes even in special anchorage areas, more powerful horn, 12" bell, mandatory watch on VHF 16 and VHF 13, etc. While none of these are onerous or particularly expensive in light of the cost of a boat of this size, if it were a close thing, I would choose to be below the 20 meter length.


Jim

I thought there are some additional pilotage rules at or above 20m as well. Dashew addressed with the first of the FPB's if I recall correctly.

Seem to think his answer was a "detachable" stern extension that technically kept it under the 20m limit by formal measurement rules.

Perhaps splitting hairs, perhaps not.

We have a Lugger 1066H -- Deere 6068 -- in our new boat, Morning Light. I would look hard at that -- it's 300 pounds heavier, but the same length. A six will generally be quieter and have much less vibration than a four. The 6068 is a common rail electronic engine, which gives much better fuel consumption at part throttle. The choice between fuel injection pump versus common rail for reliability is not entirely clear, but I am satisfied that with a Lugger/Deere engine it's a toss up. Watching the fuel consumption go down with even 0.1 knot speed decrease is nice.



I would choose a solid prop. CCPs certainly have a good track record and are used in tough services -- icebreakers, anyone? -- but conservatism to me is choosing the least complicated way to accomplish something. I'd rather not depend on a linkage that has to function correctly outside of the boat if I were doing extended cruising.


Jim

Salty Pelican said:

I am investigating John Deere's portfolio for an M1 engine. The 4045 AFM 85 with 160 bhp looks good. High torque, row rpm.

Anyone here have any experience with John Deere or maybe even that engine specifically? Sound levels, reliability, real world efficiency?

Click to expand...

I have that exact engine for backup propulsion and hydraulic power. They are excellent engines and one of the most pervasive in the world. At standard idle speed they are a bit rough, and I've been thinking of stepping mine up to maybe 800 rpm to smooth it out. Above idle they are very smooth, I think much due to the counter balance shaft that's integral to the engine.

Thank you all for chiming in. Much appreciated! Great feedback on the engine. I think we'll keep the boat at 19m99, just to be sure regarding size & additional rules that may apply.

I found self-righting important, so, yes, it was a design goal from the start. One of the reasons I want a high cruising speed, is to be able to sail around the baddest weather. And we designed the aft section in such a way that broaching isn't likely, but if we do get caught out, I want it to be a survivable event.

We weren't sure the design would succeed from the get-go, though, because - as you can see - she has a low profile. A higher profile creates more buoyancy under water in case of being rolled over and gives more inertia to get a boat back right up again. But we pulled it off. I'll try to add a pic of her model at 160 degree heel.

Low profile for added stability and less need for compensational deeper draft. Which in turn results in less wetted area and improved efficiency.

My background is in designing distilleries. By applying what I call virtuous cycles (instead of the vicious ones), more gains lead to more gains. A simple example of what I mean goes like this: if we insulate a distilling machine, more net energy goes into the actual distillation process, so that less expensive heating systems are needed, and more control over the alcohol production process is achieved. Less energy usage results also in a less expensive machine (less heaters needed) and results also in better product.

In the way I approach my boat design, it goes like this: more efficient hull lines result in a boat that uses less fuel, so that we can fit the boat with smaller diesel tanks, which makes the ship lighter, which results in the ship using even less fuel, etc.

In designing distilleries it helped me design units that are 90% efficient, where 30% was like the norm. That's huge. But it is achieved one little step at a time.

Hope that makes sense. It's the way I think and my mind works. Just so you guys know.

By the way, the mss. and I are currently doing a 10 day tour of the Netherlands on Salty Pelican. Today we sailed her from Vianen to Wageningen via the Lek river. 30 Nm trip. Two huge locks. The current against us like 2 to 3 clicks per hour.

Tomorrow we'll move upstream for two more hours, and then take a left and transfer to the IJssel river. Downstream through some pretty impressive scenery, I am told. We'll shoot some pics and post 'm, to give you an idea of where we are.

Regards, Edwin.

Rhenen on the Rhine River ...

If you’re doing what you’re doing and are in Wageningen, are you stopping in for a tour at MARIN? Not sure what they would let you see, but I’m sure it would be interesting.

Hi there, we didn't visit MARIN now. They will work on our new Fast Displacement Explorer though, so that'll happen in the future for sure.

Tonight we are visiting the Lathumer Meer, on the IJssel River. Tomorrow we'll follow the IJssel River and travel through Doesburg and Zutphen to Deventer. Kampen the day after that. Urk or Hindeloopen the day after that.

Will keep you posted!