Catamaran mast compression post step

[Brc45]

Looking at the subject pics of Lagoons. I see four vertical bolts through the plate at the step end of their compression posts.

Into what are those bolts threaded? Is there some big steel fitting embedded in the transverse bulkhead?

How is such a large steel beam bonded to ground?

Have you seen any OEM precautions or instructions about drilling the compression post to attach any gear to it?
Is it the same structurally as drilling and attaching things like winches to the mast above?

https://i1.wp.com/www.svbluepearl.com/wp-content/uploads/2020/10/IMG_6717.jpeg?w=886

 

[Stingo]

Check out the video from two or three episodes back by Parley Revival on YouTube

 

[Stingo]

Give me an hour and I will try get a link of the actual video for you. At the moment, my best guess is that it is one of the two "mast down, rigging replacement" videos

 

[Brc45]

Give me an hour and I will try get a link of the actual video for you. At the moment, my best guess is that it is one of the two "mast down, rigging replacement" videos

Much obliged! We found it!

 

[Brc45]

Check out the video from two or three episodes back by Parley Revival on YouTube

Grateful for the tip!

Wow! That’s quite the rubbish setup for a critical structure in such an expensive boat!

It literally is just fixed in place by the rigging tension on top of that fibreglass channel bulkhead reinforcement!

Most surprising is there’s no ground bonding of any kind at all!

So any lightning current that doesn’t go down the shrouds and stays, blows right down through the bottom of the bridge deck, destroying on the way all electronics with wires coming down through the compression post!

That setup just seems criminally negligent of Lagoon to build, especially for Caribbean service! :[

Given that, seems safe to drill into it at least to bond it to ground, and the place to attach a cable to drop straight down into the water for a real sacrificial ground; a 0000 welding cable seems a simple major upgrade for that.

Thanks again!

 

[dankilb]

Would’ve assumed the OP had watched all of Parley before even looking at a Lagoon…! After all, Colin ‘discovered’ the broken bulkhead issue and devised/negotiated the fix.

…while catching up on the series, the OP would be well advised to observe the economics and general challenges of the project. Even with a massive (network TV) media profile and income, a large and dedicated crew, and prior experience as a super yacht engineer and 200T skipper - Colin is still candid about the fact it cost him more than buying a ‘good’ boat.

The other posts about rocking up somewhere with cheap labour for refit seem wildly over-optimistic (yes, such places exist - but they’ll see you coming and lots of cheap labour still costs lots when you add it up).

 

[Brc45]

Lagoon wasn’t on our list for other reasons.
Neither are we looking at typhoon survivors. I’m instructed to skip those immediately.

I look forward to hearing whether or not with all his marine experience and media income Collin would have been able to afford a boat that wasn’t a wreck in the first place.

I looked at the Lagoon because it is such a common cat, to answer the question why catamarans are so lightning strike prone.
It turned out to be much more obvious than other explanations I’ve heard.

 

[Stingo]

Go on, tell us why cats are so prone to lightning strikes?

 

[Malabarista]

It may be the little bells they wear on their collars?

 

[AntarcticPilot]

Go on, tell us why cats are so prone to lightning strikes?

Well, the mast provides protection from lightning within a cone extending at an angle of about45 degrees from the masthead. For monohulls, that means that the hull is within the zone of protection, except possibly the extreme bow or stern when pitching heavily. But a catamaran is much wider, and the bows and sterns of the hulls may well be outside the zone of protection. Randall Munroe (Today's topic: Lightning) gives an excellent explanation of how it works.

 

[Stingo]

Well, the mast provides protection from lightning within a cone extending at an angle of about45 degrees from the masthead. For monohulls, that means that the hull is within the zone of protection, except possibly the extreme bow or stern when pitching heavily. But a catamaran is much wider, and the bows and sterns of the hulls may well be outside the zone of protection. Randall Munroe (Today's topic: Lightning) gives an excellent explanation of how it works.

Thank you, AP

 

[dankilb]

I look forward to hearing whether or not with all his marine experience and media income Collin would have been able to afford a boat that wasn’t a wreck in the first place.

[Spoiler alert…!] I think Colin’s assessment is that he’s ultimately spent more than he would have on a ‘good’ boat, but less than a new one.

In addition, in the time that it’s taken to refit (4 years?) he could’ve earned the money to buy a ‘good’ (if not new) example. The earnings were also not all directly linked to YT/Parley (I do reckon Below Deck is a decent earner) although he has received lots of valuable freebies.

His experience matches with ours. We’ve also been fixing a ‘bad’ boat for 4 years! (Inc. bulkheads, osmosis and now keel matrix!) We could only ever have afforded the ‘buy in’ for a bad boat. Approx half a good example. I don’t keep count but reckon we’ve now spent close to 3 x purchase price (although in todays market I reckon that’d about buy us the best of a ‘good’ example of our model - a 41’ Jen mono).

Now, those of us with big refit projects may cite the fact that a ‘new’ boat is more comparable price wise - as, in our case, almost everything (from engine to wiring and windlass to standing rigging) is essentially ‘new’. But of course our refitted boats will never be worth what a new boat would be. So it remains a ‘borderline’ economy at best.

 

[Brc45]

I’m viewing his Guatemala period. So sad that he lost that charming woman.

To me, seems he drew the worst possible hand - boat of rubbish design and quality, whose extensive damage was in the component most labour-intensive and stressful to fix.

That’s more a boat salvage with a tonne of charitable contributions, rather than a typical refit. For all that money pre-plandemic debasement, they didn’t even give the poor chap all the equipment that was installed before the typhoon. I’m sure it had a generator previously, for example.

His relatively good looks and pleasant demeanor I’m sure also played a major role In his achievement on this project.

 

[geem]

[Spoiler alert…!] I think Colin’s assessment is that he’s ultimately spent more than he would have on a ‘good’ boat, but less than a new one.

In addition, in the time that it’s taken to refit (4 years?) he could’ve earned the money to buy a ‘good’ (if not new) example. The earnings were also not all directly linked to YT/Parley (I do reckon Below Deck is a decent earner) although he has received lots of valuable freebies.

His experience matches with ours. We’ve also been fixing a ‘bad’ boat for 4 years! (Inc. bulkheads, osmosis and now keel matrix!) We could only ever have afforded the ‘buy in’ for a bad boat. Approx half a good example. I don’t keep count but reckon we’ve now spent close to 3 x purchase price (although in todays market I reckon that’d about buy us the best of a ‘good’ example of our model - a 41’ Jen mono).

Now, those of us with big refit projects may cite the fact that a ‘new’ boat is more comparable price wise - as, in our case, almost everything (from engine to wiring and windlass to standing rigging) is essentially ‘new’. But of course our refitted boats will never be worth what a new boat would be. So it remains a ‘borderline’ economy at best.

Wow! We're you aware of the issues prior to purchase?

 

[Neeves]

Well, the mast provides protection from lightning within a cone extending at an angle of about45 degrees from the masthead. For monohulls, that means that the hull is within the zone of protection, except possibly the extreme bow or stern when pitching heavily. But a catamaran is much wider, and the bows and sterns of the hulls may well be outside the zone of protection. Randall Munroe (Today's topic: Lightning) gives an excellent explanation of how it works.

Except that in most vessels, mono or multi, the electronics are roughly centralised, few have the batteries and management in the extremities, the rest are at the chart table. The only 'major' device outside the 'cone' might be the windlass. For a multi - commonly the bow and transom are sealed compartment - and almost never contain any electronics.

A neighbour, mono, in our mooring field had a lightening strike - all his instrumentation, not far from the mast base as its at the chart table and well within the 45 degree cone was destroyed. No other yachts were affected - his was the tallest mast.

I confess an isolated example and after decades sailing the only example I know. Strange - we do have spectacular lightening shows in Sydney - but reports of yachts been struck seem to be like hens teeth (and there are a lot of yachts ).

Jonathan

 

[AntarcticPilot]

Except that in most vessels, mono or multi, the electronics are roughly centralised, few have the batteries and management in the extremities, the rest are at the chart table. The only 'major' device outside the 'cone' might be the windlass.

A neighbour, mono, in our mooring field had a lightening strike - all his instrumentation, not far from the mast base as its at the chart table and well within the 45 degree cone was destroyed. No other yachts were affected - his was the tallest mast.

Jonathan

If lightning strikes any part of a vessel, the induced electrical fields will fry unprotected electrical devices. It's preventing the strike that is important; if your vessel is struck anywhere, anything electrical is probably toast.

 

[Brc45]

Is the compression post step setup roughly the same on all catamarans?

Do they all have no electrical bonding there at all for some reason?

 

[AntarcticPilot]

Is the compression post step setup roughly the same on all catamarans?

Do they all have no electrical bonding there at all for some reason?

Electrical bonding at the mast step would not be usual in European boats. There is none on mine, and it's something that I'd never give consideration to when looking at boats. Why are you so concerned about it?

 

[geem]

Is the compression post step setup roughly the same on all catamarans?

Do they all have no electrical bonding there at all for some reason?

The only boats that I know of that fit bonding our American boats. Florida get lighting storms like i have never seen in Europe. On a different level.
The San Blas islands in Panama is another lightning strike hotspot. Many boats get hit there. Everything in the boat electronic gets fried.
We were lucky. In both Florida and San Blas, we avoided direct strikes but we did get a near strike that fried our masthead light and deck lights

 

[Brc45]

Electrical bonding at the mast step would not be usual in European boats. There is none on mine, and it's something that I'd never give consideration to when looking at boats. Why are you so concerned about it?

If I understood correctly reading previous lightning threads here, insurance companies consider the mast itself to be the primary lightning rod.
Also, as in this case, it’s a conduit for a lot of wires that are grounded.

As such, seems that it should be bonded well.