Designing & Building Hammerhead

[Salty Pelican]

We just arrived in Deventer. Another beautiful Hanzeatic city on the IJssel River. It's raining, so the real inner-city-exploring will start in an hour, maybe two. In time for dinner!

Having further optimized the design, we think 30k in kg's (or 66,000 pounds) could be our half load weight. First calculations on propulsion show an overall efficiency of over 55%.

 

[dannc]

Your design really sounds like an LRC 65. Are you aware of that design?

https://artnautica.eu/lrc65/

The current list of LRC builders are in the NL, NZ and Turkey. I believe one or two LRC 65's are being built in the NL at Aluboat. Since you are in the NL, you might want to visit that yard and see the LRCs. Last I checked there was an LRC 58 for sale at the yard.

Later,
Dan

 

[Salty Pelican]

Yes, I am aware of the LRC 65 design, Dan, thanks for sharing. Nice back to basics design!

 

[Whodgins]

Sounds like you are off to a great start with the design of your new boat SaltyP and it all sounds SO familiar to where my wife Christine and I were about 5 years ago when we made the "crazy" decision to switch from decades of sailing around the world to voyaging under power and set out to design and build our new boat which became XPM78-01 Möbius. To that end, you might find it interesting and fun to read THIS blog post where we summarized our priorities, first principles and use cases and I think you will quickly see how many parallels we have. This took us a LONG time to put together such a summary all the lessons we had learned in our more than 100k nautical smiles on our previous boats, but I can also HIGHLY recommend this process of articulating your own very unique personal combination of principles and use case details as we have continued to loop back to this document with each decision we made along the way and continue to find it to be one of our most valuable resources.

We too had a lot of difficulty finding our "Goldilocks" just right, just for us, designer as they all seemed to want to stick with their "signature" designs whereas we wanted them to help us bring OUR design to life. We finally found our just right designer in Auckland NZ in the form of Dennis Harjamaa at Artnautica Yacht Designs and we still work together with Dennis to this day and could not be happier.

As per the comments here from DanNC and others, Dennis has now designed the LRC58, LRC 65 and XPM78 which appear to be very similar to the sketches and 3D models you have posted here, the LRC65 being the closest. When you are designing to a similar use case and set of principles, I think it is very much to be expected that the resultant designs share a lot of common elements.

In the hopes that it might help you with the design and build of your Goldilocks new boat Christine and I would be happy to be of any assistance we can to you and your wife. We are up to my eyeballs in work getting our beloved Möbius fully commissioned and sea worthy so we can get back to the life we miss so much of cruising the world as soon as possible and we hope to splash back into the water this week after completing the latest round of commissioning and other jobs here in Antalya Turkey. You can read all about our trials and tribulations HERE on our Mobius.World blog where we have been posting weekly updates on the entire design and build process for the past 4 years.

Given that you are now in the Netherlands, if you had the time I think you would also enjoy meeting and talking with Rob Westermann and his wife. Rob runs Artnautica Europe and he and Janet live and have their LRC58 Britt not far from Hindelhoopen. Britt is also now up for sale as they are busy working with Dennis to finalize the design of their next new boat, the LRC65 which has very similar numbers to your new design. Rob will manage this build in the NL and he hopes to start construction later this year so he could be a great resource for you.

Not sure what your travel plans are for the rest of the summer but we will be doing more and more extensive sea trials of Möbius along the coastlines of Turkey between here in Antalya and up to Istanbul for the rest of the season and would be delighted to host you both aboard Möbius should that be an option and of interest to you.

Please don't hesitate to send me a DM here and I can introduce you to RobW if you like and answer any further questions you might have via Email or phone/video calls. In spite of the flurry of non stop work we are currently in, Christine and I vividly remember the challenges of the thousands of questions and decisions required at the phase you are at and we are ever so grateful for all the lessons learned by those who so generously shared their first hand experiential learning from when they had been going through this phase and so we would be delighted to "pay it forward" with others such as yourself.

Looking forward to following along with your process and learning from the decisions you make.
Best wishes,

Wayne & Christine Hodgins

 

[Salty Pelican]

Hi Wayne and Christine,

How incredibly nice of you guys to reach out and to share your wealth of knowledge! The invitation to come over to Turkey is very, very tempting. Thank you so much! Unfortunately, our plans will not take us in that direction this summer. We'll start reading up on the Mobius Blog and if we can make a visit or meeting possible, maybe a bit later, that would be awesome! Please know that the invitation is reciprocal: if you find yourself in the Netherlands (or in Hungary, this summer), please consider yourselves our guests!

After having been inspired by the stories Linda and Steve Dashew, we spoke to two naval architects to see if they could help us out designing our own ship. Indeed, they tried to sell us their designs, and didn't seem to be able to listen to our plans and ideas and principles. Even though we discussed an 18 to 20 meter slender design, one came back with a 15 meter trawler, and there was no deviation possible. He had the design ready, and had two on order. We could be number 3. We declined.

The second one started more promising. At least the first talk did. But the proposal we got back was: 1. If you don't go double engine, you'll be stupid; 2. Let's do two 450 hp Volvo IPS, so you can move around at speed. Again, nothing like we wanted, so that was a no go as well.

We were very excited when we first found out about the LRC-58. Before trying to find our own way forward and designing and building everything from scratch, we had been trying to contact the Dashews to see if they were up for one more FPB-64, or - if not - maybe we could buy their plans and take it from there. We got a no on both, hence we took the step of investigating building our own boat. With little initial success, as explained in the paragraph above. And then we saw a picture of the LRC-58 and thought: "There's a sorta Dashew interpretation to motored passagemaking that we might enjoy!"

We have been in touch with Rob and even sailed Britt with him for a short stint on the Waddenzee over a year ago. He is a great guy and I am super happy to see that much of the feedback we gave found its way into the 65 design: round bilged instead of single chine, a U-shaped kitchen, solar on the roof, and longer, to accommodate a bigger stateroom for the owners. And some other, more technical stuff.

But there are things that we want that are different from the LRC concept. We want an outside steering position for connection to the water. No bottom tanks. A more narrow aft design of the underwater ship. The bigger stateroom, we mentioned before. And an architect closer to home. Via our contacts at Feadship, we finally found our architect. An amazing guy (as I am sure Dennis is), that allowed us to start at this from the perspective that if we were going to spend so much money, it better be the ship we want and not anyone else's interpretation.

Again, I hope that makes sense.

Regards, Edwin & Veronika.

 

[Bkay]

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?

I have that engine (actually two of them) also M1 rated. We have had them right at 1 year and I have 150 hours on them, so no long-term assessment available. But I agree with the comments that they are smooth running and substantial. There are comments above about them running rough at idle - I suppose that is true. But since they are so much smoother than my previous Yanmar, I don't find them unpleasant at idle, just more pleasant as I power up.

The guy that built my boat never paid the supplier for the engines - so I was forced to work with the supplier pretty extensively all the way through sea trials. I've found all the JD suppliers I've interacted with here in the States to be very easy to work with, very responsive, and parts seem to be easy to come by as well.

Good luck with your project.

 

[Salty Pelican]

Thanks, Bkay, for your feedback. It helps confirm that it would be a great engine for our design. What I personally like it the power band. That it gives of 160 bhp at anything from 1900 rpm to 2300. Bkay, have you noticed this in real life? Like that you can run the engines at relatively low rpm? Also, if you do have any insight to give on real world fuel consumption, that would be great. Liters or gallons per hour at x rpm, maybe?

Regards, Edwin.

 

[twistedtree]

The Deere 6068 is another engine you might consider.

 

[Salty Pelican]

I think the 6 might be quieter, yet heavier and slightly les fuel efficient?

 

[Bkay]

Thanks, Bkay, for your feedback. It helps confirm that it would be a great engine for our design. What I personally like it the power band. That it gives of 160 bhp at anything from 1900 rpm to 2300. Bkay, have you noticed this in real life? Like that you can run the engines at relatively low rpm? Also, if you do have any insight to give on real world fuel consumption, that would be great. Liters or gallons per hour at x rpm, maybe?

Regards, Edwin.

I don't have all of my calculations available to me. I keep a spreadsheet of rpm/speed/load/fuel consumption at various engine speeds. But I'm in the process of wrapping up my job and am away from the house and boat.

I can tell you the literature on that engine states 8.8 gph at 100% load and 2300 rpm. In real life I actually get to 100% load at 8.4 gph and 2330(ish) rpm. The John Deere tech who certified my install was very happy with those numbers and the boat is happy to run there all day long - although my fast cruise sweet spot is 2100 rpm and my slow cruise sweet spot is closer to 1400 rpm. I'm sorry, but I don't recall my gph at those speeds off the top of my head.

 

[Bkay]

Oh, one other item, you asked about sound levels...

I have two engines in an aluminum catamaran. I deliberately made some design decisions based on keeping noise under control (i.e. engines under cockpit deck, water tight bulkheads between engine bays and tank room, cabin over tank room and not over engines, noise absorbing materials, etc).

At WOT my db readings at the helm are consistently around 74db with 320 hp being produced and traveling at around 17 knots. That is better than my single 110 hp Yanmar in an open lobster boat (I recall that was around 79db at 3000rpm moving at 14 knots). I think 74db is the equivalent of street noise and I can talk to someone without shouting - so I consider that acceptable. Obviously, you'd be looking at 1/2 the explosions per minute with only a single engine. And with the size of your boat, you have the opportunity to put more noise absorbing "stuff" between you and The Beast.

Obviously things are pretty quiet at 8 knots.

 

[Salty Pelican]

Thanks Bkay, much appreciated,

Edwin.

 

[Salty Pelican]

Just read up on the noice levels. Thanks! Great news. For The Beast, we are putting the engine in a separate bulkhead space. The engine will be on "springs". There will be an AquaDrive to disconnect prop shaft from engine (allowing for softer engine springs). Sound insulation material. And front and aft there will be shower / toilet and more in between engine room and sleeping quarters.

 

[Salty Pelican]

We just had two amazing boating days! Yesterday, we sailed from Hasselt to Echtenerbrug. Really, if you ever have the opportunity to visit the Netherlands by boat: it does not get more scenic than that!

Today we sailed, via the Frisian lakes, to Workum, where we did a short stint on the IJsselmeer (former South Sea) to Hindeloopen. Bf 5 on the nose was okay, but from the side? No fun.

Tomorrow, we plan to do some more IJsselmeer sailing. Hoping for Bf 3. The problem with the IJsselmeer is that water depth is only 4 meters (13 feet), so wind energy translates into steep, frequent waves. Less than a meter high, but they bombard you like every 2 to 3 seconds. Relentlessly.

For now, we are preparing for the night in the Hindeloopen marina. The dog is sleeping. Veronika is sewing a fancy bag. I am finishing up on online things, both business and pleasure.

Regards,
Edwin & Veronika.

 

[Salty Pelican]

Today we are doing some more sailing on the IJsselmeer. Yesterday we did a 50 click trip from Hindeloopen to Urk. Today, we'll sail from Urk to probably Hoorn. Bf2, so light conditions. Stabilizer kicked out once yesterday. Hope that doesn't happen again, otherwise service is needed.

On the fast displacement expedition ship that we are designing, well, we just planned another meeting with our architect for coming Thursday. Very exciting stuff!

Regards, Edwin & Veronika (picture of the great food in Urk!)

 

[Salty Pelican]

The IJsselmeer (former Zuiderzee) is addictive. Today we sailed from beautiful Urk to Edam. Picture of Salty Pelican in the Edam harbor and me enjoying a beer. Need to try out some of the local cheeses today.

As for designing and building Hammerhead, we are investigating building the interior out of lightweight material. Any weight we can spare, will directly result in better performance. Or can be used on other places, for instance closer to the bottom of the ship. Anyone any ideas?

Regards, Edwin & Veronika.

 

[Salty Pelican]

Here's an impression of Hammerhead's raised cockpit design. BBQ, cooking/cleaning station on port. Sitting area on starboard side. Solar roof for shade and electricity. Master bedroom (aft) is situated under the raised cockpit. Allows for 2 meters of standing room, a kingsize bed, and more. Woman in bikini is optional!

Regards, Edwin.

 

[Circumnavigator]

Three thoughts on the rendering above:


Do I see a helm to port? Or is the person just standing there? On this side of the pond, helms to port are on boats meant for people who have never driven a boat, only cars. I much prefer a center helm, but if you must put it on one side, make it to starboard, because vessels coming from that side have the right of way.


Unless you or others who might be in the master cabin are unusually tall, I would reconsider the two meter headroom there. Dropping the cockpit even 50 mm will improve stability.


On the other hand, I'd like to see cockpit sides higher than the woman's waist. You want a feeling of security in the cockpit. The rendering doesn't show railings, but I'd want a triple rail with a gate across the back. I'd take the cockpit rail straight up from the yellow deck aft of the cockpit and put the stairs there. Even with rails around it, the yellow deck is useless space.


Jim

 

[dannc]

I assume the low to the water and large stern area is for the dingy?

Later,
Dan

 

[Salty Pelican]

Thanks for the feedback, gentlemen!

Helm set-up should be center stage, I totally agree. It's a concept, I should have mentioned that. Or even taken out all together and replaced by a different set-up I have in mind. Triple rails will be added. The yellow deck at the back serves as entrance to deck, cockpit, and swimming platform. Could be smaller. Large stern is for dingy storage, yes. Lowering ceilings to 1m95 is an option we'll explore further.

Regards, Edwin.

 

[dannc]

...The yellow deck at the back serves as entrance to deck, cockpit, and swimming platform. Could be smaller. Large stern is for dingy storage, yes. Lowering ceilings to 1m95 is an option we'll explore further.

Regards, Edwin.

The yellow deck vs dingy storage area is a tough design choice.

I would be inclined to make a swim step the size of the yellow deck and increase thus increase the size of the deck behind the cockpit. This would increase the head height of the space aft of where I assume the aft cabin is located, which should be useful since storage and/or machinery space is often in constrained.

One of the design issues with this design, along with the LRC's and FPB's, is the lack of access to the side decks from the helm but I think that can be handled by remote helm controls. Remote helm controls would negate the need for an outside helm position which is using up valuable cockpit space. No matter where one placed the outside helm, there will be times when it is in the wrong place. At least one of the early LRC 58's had an outside helm but I don't think they have been included in the later designs.

Later,
Dan

 

[Salty Pelican]

Our architect was thinking of adding two sorta sail boat seats near the aft section of the cockpit and use remote controls to steer from one of those outside positions. Not sure why it didn't get implemented in this iteration, but we'll meet up and discuss on Thursday.

First LRC had a raised platform for outside steering. Ours will not be raised, since our cockpit is situated significantly higher.

Regards, Edwin.

 

[dannc]

Our architect was thinking of adding two sorta sail boat seats near the aft section of the cockpit and use remote controls to steer from one of those outside positions....

To be clear, when I mentioned remote helm controls, I meant something like this, https://www.kobelt.com/products/mar...alk-about-controller/electronic-control-heads
.

I believe Mobius is using this device. It is wired and allows you to walk around the boat as one is docking, anchoring, getting on a mooring, etc. I believe their are similar devices that are wireless but wireless gives me the willies.

Later,
Dan

 

[Salty Pelican]

Raymarine and DockMate have wireless systems. Before we refitted Salty Pelican she had an older Raymarine system. Limited in functionality, but it worked okay. Now I am thinking of a remote, wireless system, with a few docking/holding stations with power around the boat.

It allows you to operate the autopilot, to engage the engine forward and in reverse, and also manages bow and stern thrusters.

Regards, Edwin.

 

[Salty Pelican]

So here's a first update of our meeting with our naval architect. Just some tit-bits. More info tomorrow or the day after. Your feedback has been taken into account, so, again, thanks for sharing!

We'll investigate the 6 vs. 4 cylinder JD engine option. Aft deck will be smaller (so cockpit longer). Side bulwarks will be higher. Railing along the outside of the boat will be 1 meter high and have 4 lines. That's on top of a 15 cm (half a foot) bulwark.

We'll probably lower the belly with 10 centimeters to optimize bottom angle raise towards the stern. This will also positively impact stability. Beam over water will stay at 4m20. A more narrow design negatively impacts stability.

Interior height was 2m10 in the salon and 2m in the forward and aft sleeping quarters and showers and toilets. We'll lower the salon height to 2 meters. Internationally, I think we could get away with 1m95, but given how tall the Dutch are, 2m might be better for future resale value. Solar pannel roof over the cockpit will be of a lightweight design.

Horseshoe-design fuel tanks will be reorganized, with the "opening" of the U-shape set-up facing ship forward instead of backwards. This helps move the center of gravity of the fuel as close as possible to the SOG of the ship overall. This also creates an extra sound barrier towards our sleeping quarters. Engine room access door will move from aft (via wet cell of owner sleeping quarters) to forward.

Still contemplating a cockpit window or screen. To limit wind entering the cockpit. Maybe one of those negatively mounted screens you see on fly bridges? What say you?

Also still contemplating the crane/davits for the dingy. Maybe something light and manual that can be put at various places, like a baby davits?

https://www.atlascarbonproducts.com/products/baby-davit

On the other hand, I like it to be electrically operated to minimize manual workload.

Regards, Edwin & Veronika.

 

[Jmarsh203]

Think your best bet would be jd 6068, will be much smoother and will be working much easier compared to a 4045. The hp rating you are looking at would be asking a lot over the long term and you would have a considerable higher life expectancy out of the larger 6068 engine. If you wanted to go for mechanical injection and not be reliant on common rail electronics an older rebuilt C series Cummins would also fit the bill very nicely, the fuel efficiency on that wouldn’t be very far off of what the common rail jd would be, would also be just as reliable. But I’m a jd fan, I’ve seen the 6068 on 100kw generators break 45,000 hours without the head ever coming off, nothing but oil changes, belts, and a few idler pulleys. If money were no object the jd6068 all the way. At least until you get to the 300hp range. Than Cummins 855big cam takes the cake in that class.

 

[Jmarsh203]

Also suggestion would be whatever you decide when it comes to engine, it being a single engine keel cooling is your best bet for reliability, and ease of service. No sea strainer to clean or raw water pump impellers to change always at the most inopportune times they always choose to mess up.

 

[Salty Pelican]

Thanks for the info, Jmarsh!

 

[Jmarsh203]

And unless autoprop has started making something new that I don’t know about putting one on your boat wouldn’t be a very good idea. They make sailboat propellers not powerboat propellers and they won’t come close to the efficiency of a standard fixed pitch propeller, or cpp for that matter. If you plan on running at 10mph almost exclusively and always having about the same amount of weight aboard than a fixed pitch is you best bet. If you plan on extended long range cruising and you have massive fuel reserves that you plan on using that fuel on a regular basis(massive weight swings) and possibly varying your speeds than a cpp propeller would be a good investment. Keep in mind 1000 gallons of diesel is 7,100lbs so as you use fuel you can put more pitch into the prop at the same rpm. Btw I have no clue why your boat being dry stacked has any barring on the propeller you choose. Also changing the pitch of your propeller is not something you do regularly, it’s a set it and forget it thing, maybe mess with it every day or every other day if that. You put the engine in gear and to the rpm you desire and load the engine with pitch keeping an eye on egt. Boom that’s it. Done as fast as it took to read this. It also allows you to properly load your engine at most rpm so you engine will last longer and will wet stack less when at lower rpm. Btw I much prefer cpp with a transmission over direct drive. I’ve had too many things wrap around propeller shafts to ever consider not being able to spin that shaft in the other direction.

 

[Salty Pelican]

Hammerhead does have a gear box. I understood that to manage a CCP you need insight in exhaust temps, and a dry stack is what is needed? If there are other options, I'd love to learn.

The path we are leaning towards now, is to optimize - via fixed prop - for 10 knots. Gives us plenty of efficiency gains at that speed.

Regards, Edwin.