Designing & Building Hammerhead

[Xlantic]

On a completely other note: we are thinking of transporting our current 41 feet Bruijs Kotter to Croatia and tour the islands coming summer. Anyone any experience with motor yachting in that area?

Regards, Edwin & Veronika.

Yes, I spent the summer of 2014 there. It is a great place for cruising. Many islands and historic towns to visit.

There is also the Gulf of Kotor in neighbouring Montenegro, just to the south of Croatia. Kotor is not only spectacular but you can fill-up with tax-free fuel on your way out.

A good way to plan your cruise in this area is this site which gives a good high-level description:

https://www.jimbsail.info/mediterranean/adriatic/dalmatia

 

[Salty Pelican]

Thank you Gilberto, that's great info. Much appreciated!

Regards, Edwin & Veronika.

 

[Xlantic]

Just to give a flavour, we had a view of a Roman amphitheatre from the marina we stayed in Pula, in northern Croatia.

 

[JWellington]

Thanks JWellington,

The whole team is working passionately to bring our dream to life! Team meeting tomorrow that'll take the better part of the day for final design directions and considerations. More info on the LM65h project a few days later, that we can share here on the forum.

Thank you all for chiming in and giving your feedback!

Regards, Edwin & Veronika.

Looking forward to updates, thanks. Also, have you also considered hybrid propulsion?

 

[Salty Pelican]

Hi Gilberto, thanks for sharing. I have been in Pula, Croatia, like 35 years ago. Yugoslavia actually still. As a student on a tight budget, not a boater.

Hi JWellington, yes we have! There'll be electric back-up power as well as a kytesail.

Regards, Edwin.

 

[JWellington]

Hi Gilberto, thanks for sharing. I have been in Pula, Croatia, like 35 years ago. Yugoslavia actually still. As a student on a tight budget, not a boater.

Hi JWellington, yes we have! There'll be electric back-up power as well as a kytesail.

Regards, Edwin.

Sounds great and will be looking forward to your progress on it. Just hope it doesnt take like 5 or 6 years as with that Möbius boat somebody is building in Turkey!

 

[Salty Pelican]

Planning to start production in like 6 to 8 months from now. Should take 15 to 18 months to build. Jeez', I hope that doesn't come back around to bite me in the *rse!



Regards, Edwin.

 

[Salty Pelican]

Windscreen wipers!

A (small) update. Working on windscreen wipers!

Regards, Edwin.

 

[JWellington]

Should be a good one. What sort of rating to the windows have?

 

[Salty Pelican]

Not sure but CE-A and Lloyds are the standards we follow ... as is the whole boat, JWellington, so also for the glass.

By the way, the glass is flush mounted. The wipers (3 in total) will sit on the glass that's over the frames, so out of sight when not in use.

Regards, Edwin.

 

[Mako]

Flush mount windows seems to be the trend now even with commercial vessels. At first I was leery but now I believe they are an excellent way to go. Certainly improves the styling!

 

[JWellington]

Flush mount windows seems to be the trend now even with commercial vessels. At first I was leery but now I believe they are an excellent way to go. Certainly improves the styling!

Not sure but CE-A and Lloyds are the standards we follow ... as is the whole boat, JWellington, so also for the glass.

By the way, the glass is flush mounted. The wipers (3 in total) will sit on the glass that's over the frames, so out of sight when not in use.

Regards, Edwin.

OK , thanks, should be good!

 

[Salty Pelican]

Thanks!

The naval architect made the calculations and informed me what glass (type and dimensions) we need. It is one of those things that I do not have an opinion on other that that it should exceed requirements.

We are looking into glass with a foil (?) in between the layers to make sure that heat in the salon is manageable in more tropical conditions. Better heat insulation means less airconditioning means less generator-time leading to less overall noise levels and lower diesel consumption levels ...

Regards, Edwin.

 

[JWellington]

Salty, exactly.

 

[Mako]

Salty Edwin, am curious about your sandwich glass and what thickness it is.

Not sure what you are referring to as a "foil" in-between. Laminated glass is made with a thin plastic (polymer) layer to bond together. Single pane glass has an R-value around 1.0 and laminated usually a bit more than that.

BTW, we generally see tempered glass in boats for strength. When one of mine broke I decided to replace with laminated, in order to maintain its integrity even if broken in a storm. A friend recommended to use non-tempered glass in order to maintain visibility if broken. I did this and it was the right call, when I eventually broke it. If it had been tempered then the entire sheet would have pebble-cracked as opposed to the single long break.

 

[Salty Pelican]

I wil ask the NA, gentlemen!

Regards, Edwin.

 

[Salty Pelican]

An update via our NA on window and glass selection and thickness:

Depending on what producer we select, but for now we follow ISO 12216 requirements. We expect the front windows in the salon to be 8 mm and 4 mm. Side windows 7 and 4. Windows at the back of the salon 5 and 4 respectively. Double layered. All toughened safety glass.

Regards, Edwin.

 

[Mako]

Double pane. Excellent choice especially for high latitudes

 

[Salty Pelican]

Antenna Lay-out

Thanks. We want the ship to have as broad a range and employability as possible.

Here's a picture of the mast and antenna (etc.) lay-out. It's a stand-up/fold-down design. This allows us (or future customers) to traverse France's inland waterways for instance. Total height with the mast down? 3 meters 40 centimeters.

The LM65h will be equipped with radar, ais, IR, and AR. Iridium ... you know what? I'll just post a pic of the equipment list in a few minutes.

Regards, Edwin.

 

[Salty Pelican]

Related equipment list:

 

[Salty Pelican]

Another try:

 

[Salty Pelican]

Here's another picture of the mast set-up and more. I think she's a stunner!

Regards, Edwin.

 

[JWellington]

An update via our NA on window and glass selection and thickness:

Depending on what producer we select, but for now we follow ISO 12216 requirements. We expect the front windows in the salon to be 8 mm and 4 mm. Side windows 7 and 4. Windows at the back of the salon 5 and 4 respectively. Double layered. All toughened safety glass.

Regards, Edwin.

Some of the boats we're looking at have windows that are 3/4, or even 1" thickness, in comparison. But course there are kinds of windows/ glass out there. One recent example is the Mazu 82, which has 22mm , or .9" windows, with PVB interlay.

 

[twistedtree]

Some of the boats we're looking at have windows that are 3/4, or even 1" thickness, in comparison. But course there are kinds of windows/ glass out there.

The size of the windows matters quite a bit as well.

 

[twistedtree]

Another try:

A few other things you might want to consider, considering the voyaging you envision......


- It looks like you have two VHFs. I think that's essential, especially in traffic lanes and where subject to VTS.


- You might consider two radars. You would be seriously impaired if yours failed. I have seen a lot of boats with one open array as primary, and a dome as secondary.


- I would absolutely have a satellite compass as my primary GPS and heading sensor. Your Autopilot and radar tracking will work much better with one.


- I'd have a second mushroom GPS as back up, and a magnetic rate compass as backup. You have both of these devices, but they are your primaries.


- Your AIS will have a GPS mushroom dedicated to it. Some models might have this internal to the main device, but I think external is more common.


- A good external wifi device will utilize two external antennas. And a good LTE/4G device will require 4 external antennas. And all of them have spacing requirements. There are a few domes that include all the LTE antennas, but I think they are inferior to dedicated antennas. Check out Poynting in So Africa. They have really good products, and a lot of good technical info.


- I don't see a weather instrument. I think you will probably want one.


- I don't see any satellite dome, perhaps intentionally. An Iridium Go can cover a lot of needs, but if you are going to be off-grid for extended time, something more than texting and simple email might be needed. So you might want to allocate space for a possible future installation.

 

[Salty Pelican]

Thanks for sharing, Tanglewood.

There will be a weather instrument. And a lightning diffuser. Not sure why these were left out. Two VHS's for sure. Separate mushroom for AIS. The GPS uses satellites and functions as a compass. Not sure though if that's what you mean with "a satellite compass"?

Regards, Edwin.

 

[twistedtree]

Thanks for sharing, Tanglewood.

There will be a weather instrument. And a lightning diffuser. Not sure why these were left out. Two VHS's for sure. Separate mushroom for AIS. The GPS uses satellites and functions as a compass. Not sure though if that's what you mean with "a satellite compass"?

Regards, Edwin.

The AR200 appears to be a combination GPS plus rate sensor. Those are nice because they are all-in-one, but not as accurate as separate devices. And the heading is still magnetic, and subject to interference.


A satellite compass uses 2 or three GPS antennas and measures the difference in reception between them to figure out your heading. It's super accurate (sub 1 deg vs 3 deg with the AR200), not subject to magnetic interference, and gives true heading rather than magnetic heading. The position accuracy is better too. A low end one like a Furuno SC20 costs about $1000 USD, and a higher end one costs $3000-$5000 USD.

 

[Salty Pelican]

Great info! I'll dive in deeper.

Regards, Edwin.

 

[JWellington]

The size of the windows matters quite a bit as well.

Yes indeed. ITMT I remember what the builders told us was the best for windows...laminated glass-clad polycarbonate. One claimed its 100% UV proof, and pretty much burglar proof, bullet proof, pirate proof. Some fighter jets apparently use it too.

 

[Mako]

@TT how good is the satellite coverage in extreme high latitudes, like the Antarctic Peninsula or the NW Passage?