# Tool Talk >  Motion compensating ship personnel transfer gangway - GIF

## Jon

If two of our recent GIFs (Motion compensating ship crane and Boarding a moving cargo vessel) had a child, it would be this GIF: Motion compensating ship personnel transfer gangway.

It's interesting how this is still a one-person-at-a-time transfer.



Your browser does not support the video tag.


Previously:

Boarding a moving cargo vessel - GIF
Motion compensating crane for moving cargo containers at sea - GIF

----------

Captn Roy (Aug 14, 2018),

gunsgt1863 (May 25, 2018),

Moby Duck (May 22, 2018),

NortonDommi (May 24, 2018),

PJs (May 23, 2018),

ranald (May 22, 2018),

rgsparber (May 22, 2018),

Scotsman Hosie (Feb 23, 2019),

Seedtick (May 22, 2018),

Toolmaker51 (Aug 27, 2018)

----------


## rgsparber

It is always cool to see what a simple feedback system can do given enough power. I wonder how the smaller ship senses the position of the big ship before the gangway is deployed. Maybe there are 3 targets on the big ship and distance sensors on the small ship.

----------

ranald (May 22, 2018)

----------


## ranald

Needs more than the 3 police cameras & computer we have today in a patrol vehicle I suspect. Dare I say it............................Y not....................................I'd be all at sea there. :-).

----------


## 12bolts

The larger vessel looks to be an FPSO The supply ship providing the crew most likely has azimuth thrusters to hold position. Connected to a DGPS system they can maintain incredible position accuracyon the high seas. About the only thing the gangway needs to do is compensate for rise and fall due to wave action.

----------

Captn Roy (Aug 14, 2018),

ranald (May 22, 2018),

Toolmaker51 (Aug 27, 2018)

----------


## Jon

3:16 source video:

----------

Captn Roy (Aug 14, 2018),

rgsparber (May 25, 2018)

----------


## Jon

Stewart platform:



Your browser does not support the video tag.


More: https://en.wikipedia.org/wiki/Stewart_platform

----------

Captn Roy (Aug 14, 2018),

KustomsbyKent (May 30, 2018),

PJs (May 28, 2018),

ranald (May 29, 2018),

rgsparber (May 25, 2018),

Seedtick (May 25, 2018),

Toolmaker51 (Aug 27, 2018)

----------


## Jon

The old way of doing it. Transferring from the _USS Rankin_ in 1960.

----------

ranald (May 29, 2018),

Toolmaker51 (Aug 27, 2018)

----------


## ranald

Takes me back to childhood. Flying foxes were fun even if crossing a flooded river.

----------


## Jon

Same concept of motion compensating stabilization, but instead of hydraulics...chicken:



Your browser does not support the video tag.

----------

Moby Duck (Aug 27, 2018),

that_other_guy (Sep 3, 2018)

----------


## mklotz

Amazingly, this ability is present in most birds. Watch flamingoes or Canadian geese in flight. The body and lower neck moves up and down with the pulse of the wings but the head is rock-steady, seemingly inertially stabilized.

I've seen films of woodland owls descending on prey on the forest floor. Flying between two closely spaced trees with the outstretched wings vertical to slip through, the head remains locked on the prey with the eyes horizontal. 

I can see the survival benefit of such ability in raptors but a flamingo vacuums its food out of muddy water with its head upside down so why does it need inertial guidance?

----------

Jon (Aug 12, 2018)

----------


## ranald

cats always fall onto their feet........................................ like some folk i know.

----------

MeJasonT (Feb 2, 2019)

----------


## Jon

Another take on this same concept:



Your browser does not support the video tag.

----------


## Captn Roy

> 3:16 source video:



Hi Jon, These systems are amazing, the evolution of these platforms has gone leaps and bounds in usefulness & the safety factors are excellent. I read a paper on the programming required on one of the older platforms, Back in the early days of the design. They've come a long way and are safe to boot. The folks going across in the video are not falling over or losing their footing anywhere. They look totally relaxed. Thanks for sharing this Jon.
RR

----------


## Frank S

Gone are the days of riding a Bolsens across on a tether.

----------


## Jon

Barrel stabilization of a stern 30mm gun module on Gurza-M class artillery boat for the Ukrainian Navy.



Your browser does not support the video tag.

----------

PJs (Aug 28, 2018),

ranald (Aug 27, 2018),

Seedtick (Aug 27, 2018),

will52100 (Aug 27, 2018)

----------


## Frank S

Now that is some good gyroscopic or more probably computer compensated stability

----------


## ranald

Almost like it is part of the gun.

----------


## Moby Duck

Note that the you don't see the light plastic cup being placed on the barrel, and that the water is being blown away by the wind, and his shirt is being blown by the wind. An empty plastic cup like that would need to be glued to he barrel to prevent it blowing away. If not glued, the initial squirt of water would also have knocked it off. A better test would have been to fill the cup to the brim and see how much water is spilt. If the half filled water level surface is supposed to indicate that it is level, that is the nature of fluids, with or without stabilisation, the water surface will always be level. The shadow of the barrel on the deck shows that the gun has been trained slightly aft, (or the ship turned), but there is little evidence of any relative movement in roll between the fixed structure and barrel, or of the ship actually rolling. When you look at a stabilised barrel it should appear to be moving, relative to the ship. If they want me to believe this, they need to film it in poorer sea conditions, slew and elevate the gun, show me the cup being placed on the barrel without glue, and fire a burst from the gun. My opinion is that this is a fake video, the gun is probably not even turned on.
Something may have been lost in the translation but 30mm guns can hardly be classified as "artillery".

----------

PJs (Aug 28, 2018)

----------


## Toolmaker51

> Something may have been lost in the translation but 30mm guns can hardly be classified as "artillery".



It is, when underway uniform is shorts and tee-shirt. 

Moby Ducks observations are convincing. The jury won't be in deliberations long at all...

Felt urge to examine info on these craft. They and other navies face less opposition from major powers. Littoral craft have been developed to patrol areas more within territorial waters, including our own USN. As a former amphibious sailor, I can tell you there is more action inshore than on the high seas.

----------

PJs (Aug 28, 2018)

----------


## Toolmaker51

> The old way of doing it. Transferring from the _USS Rankin_ in 1960.



Ain't no chair like a Bosun's Chair!

----------

PJs (Aug 28, 2018)

----------


## ranald

I didn't want to say "it seems to be glued" to the "shot Gun" sized artillery & you have gone much further. I did play it a second time to check out if I missed him placing the cup there & if there was spillage when pouring.
Such shots keep our grey matter going. ok ok, I know you know, intended the triple pun.

----------


## Frank S

IT may not be glued but if the shrouding on the gun is magnetic I'd say there is either a magnet inside the glass or glued to the bottom of the glass.
I can't tell if the camera is being moved or if the gun is being slewed aft as it appears in the video by the movement of the shadow There is defiantly at least 1 splice in the video.

----------


## mklotz

I have to agree that the cup is secured to the barrel in some manner. Perhaps they're not trying to show how the cup is balanced on the barrel but rather the fact that the water in the cup doesn't slosh about with the movement of the ship.

MD is dead on with his observation that the viewer should be able to see the ship's deck/gunwale moving about the barrel for it to be impressive. They should have chosen a time when the ship was corkscrewing or at least rolling or pitching. 

I spent some time on the bridge of the USS Boston during a gunnery exercise and I can verify that watching those rotationally stable barrels while the ship rolls and pitches around them is a guaranteed method for giving yourself the worst case of seasickness imaginable.

----------

PJs (Aug 29, 2018)

----------


## Jon

2:14 source video:

----------


## Frank S

I guess the video removes all doubt about the glass being glued to the barrel

----------


## Jon

Maybe just a dab of glue that we can't see? Wouldn't the cup fall off from the wind or the water spray?

----------


## Frank S

You are right Jon a small dab of silicone would have held the cup in place and still have been easy to remove but even watching the last part of the video at .25 speed when he picked it up there was Zero resistance . At 1 time during the swing I thought I saw the glass wobble a bit.
Marv is right about being on board a vessel watching one of these hold nearly rock solid while everything else would be rocking rolling and pitching about is a recipe for creating chum at the railing.

----------


## PJs

In total agreement with Moby Duck!! Cup glued, boat turning and barrel in same position over the the eyelet below...only the shadow moves and the wake changes inward toward the hull, plus the barrel only appears to rise on the horizon because of the boat turning. Call 1-800-Bad-Juju to report fake news...or just use a google AI to generate fake videos.

New video is already disabled...Wow that was fast!

----------


## Frank S

PJs if you click on the line that says Watch this video on U tube it should take you to the video

----------


## PJs

Whelp that changes things a bit for sure, maybe...

It appears the gun does rotate ≈180° and that it does look like a stabilized gun as well that the boat was in a long turn. I'm still having a hard time with the cup not falling even though the sea is relatively calm, but wind and spray and the 180° rotation over a 1 minute interval with an arc of perhaps 40' would not dump that cup sitting there half full and Off Level.

As an adjunct to my link above on AI fakes, this showed up today, although a couple of days old and considering the source who's knows but I like the guys demeanor. 

https://www.cnn.com/2018/08/13/polit...lls/index.html

----------

Toolmaker51 (Aug 29, 2018)

----------


## ranald

LOL Marv. I could imagine that. The sea looks like Moreton bay on a relatively calm day:not even any whitecaps!
Cheers

----------


## Moby Duck

One of the ways to ease sea sickness is to stand on the upper deck and focus on the horizon. In the 1970s there were experiments done where horizontal stabilised laser beams were projected onto all bulkheads in operations rooms and mess decks. I believe that the Royal Canadian Navy might have done some these experiments. The theory was that the eye would automatically pick up this artificial horizon, the brain would have something fixed to relate to, and sea sickness would be eliminated. I understand that it worked well, but I have never heard of it being fitted as standard equipment in ships anywhere. Looking at a horizontal, stabilised gun barrel would presumably have a similar effect. However if the barrel was elevated to say 40 degrees, that might make things even worse as Marv and Frank can attest to. 
Of course the only real way to prevent sea sickness that is 100% reliable for everyone, is to stand under a tree.

----------

Frank S (Aug 29, 2018),

PJs (Aug 29, 2018),

Toolmaker51 (Aug 29, 2018)

----------


## mklotz

> One of the ways to ease sea sickness is to stand on the upper deck and focus on the horizon. In the 1970’s there were experiments done where horizontal stabilised laser beams were projected onto all bulkheads in operations rooms and mess decks. I believe that the Royal Canadian Navy might have done some these experiments. The theory was that the eye would automatically pick up this artificial horizon, the brain would have something fixed to relate to, and sea sickness would be eliminated. I understand that it worked well, but I have never heard of it being fitted as standard equipment in ships anywhere. Looking at a horizontal, stabilised gun barrel would presumably have a similar effect. However if the barrel was elevated to say 40 degrees, that might make things even worse as Marv and Frank can attest to. 
> Of course the only real way to prevent sea sickness that is 100% reliable for everyone, is to stand under a tree.



Staring at the horizon works for me if I stand near the ship's rail and look out so I can't see any part of the ship rotating relative to the horizon. 

It was almost impossible to watch the gun barrels from the bridge without having the ship's bow as background. This meant I saw the ship appear to rotate around the gun barrels. The effect is almost instantly sickening, at least it was for me.

----------


## Frank S

Being that I was Army I wasn't aboard very many ships But I was detailed to travel from Germany to Sydney For prisoner escort in 75 to bring back a couple guys who had stayed there after their leave was over from Vietnam in 1969 To get there and back it was available military only. which wound up being several various sized Naval vessels and a couple of C 130 s. On the trip down the 3 of us learned real quick how not to get rolling sickness. Like Marv said when on deck if possible get somewhere where you don't see other objects if possible especially anything that was moving about the ship in a back forth motion. I found that after a couple of days I had gained my sea legs pretty well. Moderately rough seas didn't bother me near as much as the calmer times.

----------


## Jon

Same boat, with and without a Seakeeper gyroscopic stabilizer:



Your browser does not support the video tag.


Around $42K. More: https://www.seakeeper.com/seakeeper_...seakeeper-5hd/

----------

Frank S (Aug 29, 2018),

PJs (Aug 29, 2018),

ranald (Aug 29, 2018),

Rancher (Aug 30, 2018),

Seedtick (Aug 29, 2018),

that_other_guy (Sep 3, 2018)

----------


## Frank S

makes a huge difference.

----------


## Toolmaker51

Seasickness is one element of sailing I never had. Whale boat, landing craft, frigate...even carriers. Now you might think 'carrier?', but they're huge! Yep they are. But way smaller in the South China Sea, green water breaking over the bow in real storms. Two occasions; first after being aboard just a few weeks. Guys up-chucking all over the place. I was loving it, felt like dirt biking. Got a nickname, that I still hear once in awhile, 40ish years later; this guy.
re: Post #6 http://www.homemadetools.net/forum/s...ght-lies-42152

[Also a shameless drive for uninitiated members to a riveting, dare I say _spectacularly_ entertaining thread...Lol]

----------


## marksbug

living hear at the beach with lotsa boats around & even more partys & drunks on them that glass on the barrel isant impressive, Ive seen drunks do a better job of not spilling a drip in real rough seas...no gyro required, just dont give them a drink on land or it will be on you..... these days there is almost a solution for everything...almost.

----------


## Rancher

I was a boat captain in the Gulf of Mexico oil field and I would've killed for something like that on my vessel... LOL. At 200 feet long and 500 tons loaded, it would've had to be a bit bigger I suppose. But, it would've been appreciated. I weathered a direct hit from Tropical Storm Bill (or maybe it was Lily) offshore. I wonder how a system like that would've handled it? I don't think it could've possibly made it worse.

----------


## Ed Weldon

Neat idea. I hope you can turn that thing off and lock it down when installed in a well designed boat that has to respond to unusual sea conditions. Read about the survival of the 49ft. lobster boat Sea Fever and most of its crew in an Atlantic storm. Wooden Boat Magazine no.264, pg 90 (current issue). I would urge the makers of the device to explore such issues and offer appropriate guidelines for when and when not to turn it on.

----------


## toma

> Same boat, with and without a Seakeeper gyroscopic stabilizer:
> 
> <video controls autoplay loop>
> <source src="https://s3-us-west-1.amazonaws.com/hmt-forum/boat_gyroscopic_stabilizer.mp4" type="video/mp4">
> Your browser does not support the video tag.
> </video>
> 
> Around $42K. More: https://www.seakeeper.com/seakeeper_...seakeeper-5hd/



The right hand one boat is much more exposed to waves.. also it sheltered the stabilized one..! not good for comparison...??!!

----------


## Jon

Your browser does not support the video tag.

----------

Seedtick (Sep 2, 2018)

----------


## Frank S

way too many guys in the hold just standing around like a bunch of dullards.
Only 1 tag line is never a good recipe

----------

PJs (Aug 31, 2018)

----------


## Jon

The Bessemer Saloon Steamship, a gimbaled steamship invented by Henry Bessemer, a prolific (100+ patents) inventor in 1868. Bessemer invented this type of ship to combat his seasickness. It worked nicely in model form, but was never built fullsize.














> Few persons have suffered more severely than I have from sea sickness, and on a return voyage from Calais to Dover in the year 1868, the illness commencing at sea continued with great severity during my journey by rail to London, and for twelve hours after my arrival there. My doctor saw with apprehension the state I was in. He remained with me throughout the whole night, and eventually found it necessary to administer small doses of prussic acid, which gradually produced the desired effect, and I slowly recovered from this severe attack. My attention thus became forcibly directed to the causes of this painful malady, which I, in common with most other persons, attributed to the diaphragm being subjected to the sudden motions of the ship. Hence, as a natural sequence, its cure appeared only to require that some mechanical means should be devised whereby that part of the ship occupied by passengers should be so far isolated as to prevent it from partaking of the general rolling and pitching motions. In this way I entered, almost without knowing it, into an investigation of the subject; and gradually, as my ideas were developed, I determined to make a model vessel, small enough to be placed on a table, and to which the usual pitching motion of a ship was imparted by clockwork.
> 
> On this model was arranged a suspended cabin, supported on separate axes, placed at right angles to each other. I obtained a patent in December, 1869, for this invention, which is represented in two sectional engravings, Figs. 81 and 82, on Plate XXXVII.

----------

KustomsbyKent (Sep 4, 2018),

PJs (Sep 3, 2018),

Seedtick (Sep 3, 2018),

Toolmaker51 (Sep 3, 2018),

will52100 (Sep 3, 2018)

----------


## Frank S

A system like the Bessemer just like anything else depends on having the bulk of the mass below the pivot so the center of gravity is low.
Note in his first design there was a ballast suspended below the ballroom pod. in the last photo it appears that the pivot is much higher up with heavy beams serving as the main structure and ballast for the pod. hydraulic cylinders were most likely incorporated to serve as dampeners for those times when the patrons might all move from side to side suddenly.
Variations of the patents have been incorporated into the design of many skyscrapers to serve as earthquake dampeners even though some have been located in upper floors or near the roof as a completely free floating mass the resting mass absorbs much of the kinetic energy smoothing out the violent shaking

----------


## marksbug

must be for earth quake prone yards......sorry I just couldn't rezist it.

----------

Toolmaker51 (Sep 16, 2018)

----------


## Toolmaker51

I'm struck with a common reaction to Victorian Era patents, with year 1868, era now well underway. Regardless mechanical aspects, physical size, even feasibility; look at detail whose only function is to please the eye. 
Key to this, with 1841 British colonization of Hong Kong, influenced addition of high detail to all manner of product, typified by Oriental design. This doesn't copy the figures as much as the concept, but point was to decorate in so much detail you figuratively never saw the same thing twice. It carried over into everything imaginable; a men's razor, cornice brackets of a roof overhang, hand tools, women's dress, drafting tables, rail dining cars, locomotives, you name it.
They may not realize it, also the clear foundation for current 'steam-punk' movement. Where a rusty iron-legged table all of a sudden goes for $600...Can't imagine clamor if this ship was built and now it's parts were available! 

https://en.wikipedia.org/wiki/Victorian_decorative_arts
https://en.wikipedia.org/wiki/Victorian_era

----------

PJs (Sep 4, 2018)

----------


## PJs

The drawings are pretty spectacular in the fashion of the day and personally enjoy the detail and appreciate the hand work of them. My question of the design is how do they compensate for bow to stern in big seas? Waves of magnitude can be pretty shear and if the Capt. doesn't get it oriented right...oops, regardless of port and starboard compensation (which look to be about 15° in either directions).

PJ

----------


## mklotz

Yes, a strong pitching motion could severely damage the suports of the passenger bearing cage and, if they broke, the whole ship would be in danger. Gimbal lock can be a terrible thing.

I think a better, and far simpler and cheaper, solution would be to suspend Mr. Bessemer in a bosun's chair hanging from a hook in the ceiling in a windowless cabin.

----------


## Jon

Another good example of a boat device that never made it past the model phase is Abraham Lincoln's patented invention: Buoying vessels over shoals.

----------

PJs (Sep 4, 2018)

----------


## mklotz

At least Lincoln and Jefferson designed some practical devices. Name a 20-21st century President who has.

----------

Toolmaker51 (Sep 16, 2018)

----------


## PJs

Some people like Bessemer with a 100+ patents are bound to have a few that don't cut the mustard, but his steel processing changed the world in profound ways.

"In 1898, Scientific American published an article called Bessemer Steel and its Effect on the World explaining the significant economic effects of the increased supply in cheap steel. They noted that the expansion of railroads into previously sparsely inhabited regions of the country had led to settlement in those regions, and had made the trade of certain goods profitable, which had previously been too costly to transport."

----------


## Jon

A container ship flexing from the inside. 2:39 video:




This is the MOL Excellence: 9251377_MOL EXCELLENCE

----------

EnginePaul (Sep 9, 2018),

Frank S (Sep 8, 2018),

Moby Duck (Sep 8, 2018),

Paul Jones (Sep 7, 2018),

PJs (Sep 10, 2018),

ranald (Sep 8, 2018),

Saxon Violence (Sep 11, 2018),

Toolmaker51 (Sep 16, 2018)

----------


## Frank S

Man that is freaky to watch . but these huge ships have to have flex or they would break apart

----------


## Radioman

When it stops flexing like that is when you have to worry!

----------


## ranald

Like P.M's they are all too busy blowing off hot air & saying they understand folk & economics. Trade & Jobs? I see where RECORD (UK) are starting to rebuild their home industry. Sorry , I'm on a side-track again.

----------


## Jon

I am beginning to think we can explore this nautical motion compensating theme forever. Here we have a rotating interior in a racing sailboat.



Your browser does not support the video tag.

----------

PJs (Sep 10, 2018),

Seedtick (Sep 16, 2018)

----------


## Frank S

Not sure I understand the reasoning for having a rotating computer console and coffee pot in the lower cabin of said boat, it doesn't appear to be compensating for anything other than access to other areas in the cabin. Maybe seeing the concept from a different vantage point or seeing it in use while the vessel is underway might help.

----------


## Jon

Per my recently-acquired expertise (5 minutes ago), I can tell you that what's not visible here is that batteries and hydraulics are concealed under that console, so that these heavy items can be moved to windward as desired. Interesting, but probably largely gimmicky; this is for the cruiser who wants to go fast.

More:

Interrior arrangement - JPDICK yachts - JP54
https://www.cruisingworld.com/sailbo...boat-blog-jp54

----------

PJs (Sep 10, 2018)

----------


## Frank S

A friend of mine up in Minnesota bought a 63 ft sailing yacht a few years back I don't know how much it set him back but I do know he said it cost more than 3 of his soybean combines. I don't think it was new but the way he described it, it was posh to the max. One of those things like some top end sport cars you have to be invited to purchase one. He said he and his wife had to spend months in Sweden attending a factory sponsored training course then make 3 5000 mile yachting ventures before they would even sell it to him. I've crewed on a few small regattas and I know he had years of sailing experience prior to wanting the thing so I can't imagine what all was in his yacht. 
Gimmicky? Probably but who's to say

----------


## ranald

Money speaks all languages! How the other half live? Every time a v8 4by4 goes by, my other half exclaims "there goes a block of land" so every time we see a top end sports car (lotus, lambo, ferrari & the like) i exclaim "there goes a house". There's some big bucks just floating in marinas & hardly ever used but that's the owners privilege & most of them have earned it, so it would seem.

----------

Toolmaker51 (Sep 16, 2018)

----------


## Frank S

Never had any problem with the Have mores. Most that I have known were down to earth folks. It was the want-a-be's I encountered who thought they were above everyone else.

----------

MeJasonT (Feb 2, 2019),

Toolmaker51 (Sep 16, 2018)

----------


## Moby Duck

This Racing Yacht doesn't make any sense to me. Don't stand by the sink or kettle when it is moving or it will knock you off your feet.

----------


## Frank S

When you are taking into the wind and the boat is in a 38° list you figure out that the only reason you were asked to help crew was because of your ability to hang on and act like a side car rider in a motorcycle race.

----------


## ranald

Of course Frank. I totally agree; I guess I didn't express that correctly. I know quite a few who have earned their place at the top ( and I have seen & found them very generous to loyal staff & family) & I know many others who live on credit-yuppies we call them. A chap to example was earning 100 + grand a year (in late 70's) & was leasing a Porsche, about his annual salary value, & had to borrow the full 100 odd grand to buy his family a reasonable home. In the meantime the most of us were earning $12 p.h. (in similar admin) and working more than one job to try to get ahead. "You earn it, you spend it" was an old adage. My dad used to reinforce "take care of the pounds & the pennies will look after themselves"-still said it after decimal currency conversion in 1966. Others say the opposite "take care of the pennies and..........". "Penny wise & pound foolish" was another of my father's favourites but then he lived through the two world wars & the great depression etc.
Cheers

----------

Toolmaker51 (Sep 16, 2018)

----------


## ranald

When there is no wind you are invited to plot the course in the engine bay, breathing in the diesel fumes. I just KNEW they wanted me along for some reason other than my magnetic personality! LOL

----------


## Frank S

> When there is no wind you are invited to plot the course in the engine bay, breathing in the diesel fumes. I just KNEW they wanted me along for some reason other than my magnetic personality! LOL



 That's funny have we met? Did you ever sail from Galveston to Veracruz or an open water sail from St Petersburg Fl. to Veracruz? I'm glad I wasn't on the one in 1988 when 33 boats went missing 50 MPH winds 20 ft + seas. All of the gimmicky gadgets in the world cannot protect a yacht from that stuff.

----------


## Loose Ctrl

That's not for a racing yacht. It's to heavy with many things to break down and change the balance of the boat. That's lux for nothing. Gimbel mounts work better and require no power or other systems to operate.

----------

PJs (Sep 16, 2018)

----------


## Jon

I wonder if it's a response to the "catamarans are faster than monohulls" argument.

----------


## Frank S

There are many different classes of yachts used in racing Not always designed for the fastest point a to point b race. There are regattas in which only the very high end lux yachts enter, aimed at the billionaire boys/ girls clubs. after all what is the purpose of owning a 200 million dollar yacht if the only thing you can do with it is to sail leisurely from port to port

----------


## Toolmaker51

> When there is no wind you are invited to plot the course in the engine bay, breathing in the diesel fumes. I just KNEW they wanted me along for some reason other than my magnetic personality! LOL



Wouldn't having you plotting courses be counterproductive? What with the magnetic personality and all?
Sure, we're heading north, if I stand over there...

----------

PJs (Sep 16, 2018)

----------


## ranald

Hi Frank, mother nature can be so unpredictable. I remember a father & son trawling the west coast of Tasmania :trawlers less than 30 miles apart & the father got a call regarding a freak storm, which he could not see on the horizon. All the gadgetry on the sons vessel was totally destroyed from swamping etc, but did not sink. Lucky he did the mayday call to dad and all crew were saved & lucky to be alive. I believe the Great Lakes are wonderful places to lose a ship or plane (bit like bermuda triangle). We seem to know less about what is under the sea than in outer space.
Like Carolina, I've only been to Galveston in my mind.

----------


## Ralphxyz

Hope you don't have a seat on the couch along the sides, you'd lose your legs!!

Ralph

----------


## Jon

Circular Stewart platform. I like how a clock is in the background of this GIF.



Your browser does not support the video tag.

----------

Frank S (Sep 20, 2018),

PJs (Sep 21, 2018),

ranald (Sep 20, 2018),

rgsparber (Sep 20, 2018),

Seedtick (Sep 20, 2018),

Toolmaker51 (Sep 20, 2018)

----------


## Frank S

Yep the clock is running a little fast due to the accelerated gif speed LOL

----------


## Loose Ctrl

That too seems like a lot of stuff to fail in a boat. The last thing anyone wants is a system in a boat that fails and throws of the center of gravity and weight distribution. It could lead to a capsize or knockdown if weather and sea conditions aren't good.

----------


## Frank S

Loose crtl, you are absolutely correct even the simplest form of ballast weight transfer can go wrong at the most inopportune time. the transfer of fuel or water from side to side as ballast is about the simplest there is in larger vessels. Smaller pleasure or racing yachts the crew becomes the ballast. Try forcing yourself to hang over the rails in 20 ft seas on a 40 ft yacht while the captain desperately ties to maintain head way He can't even drop the mainsail because the the throat halyard and gaff are fouled If he could somehow manage to drop it to half mast then the lower portion could be lashed and the remaining would be about the size of a storm sail about the only thing you can hope for is that the peak halyard holds because once it goes the gaff will drop on 1 end and you loose all control.
All of the human ballast is fighting to hang on to scared to be sick. About this time the top sail shears away then suddenly the halyards are free and you manage to lower the main sail to quarter mast get everything lashed now it is just a matter of being able to hold steerage into the waves everything is peachy.
As human ballast you swear never to crew on one of these death traps again.

----------

Loose Ctrl (Sep 21, 2018)

----------


## owen moore

Years ago, one of the model airplane magazines had a project similar to this that had servos that would tilt a glass plate in a similar fashion. The glass plate had a bullseye with concentric rings painted on it. The object was to place a marble on the bullseye and try to keep it there while operating a hand held transmitter. This was a training device for the early days of model helicopter flying. It looked very difficult.

----------


## PJs

That covered quite a number of degrees of movement in the first 40 seconds or so and appears that they changed cameras for the additional 5+ minutes and another rash of degrees movement. 6 degrees of freedom (6DOF) is quite a complex system. 

Here is a doctoral thesis by two Swedish students...a bit long and necessarily math heavy, but the conclusion and their parameters and proofs are sound...I imagine they got their PhD's. _Note_: first part is in Swedish but the body of it is English.

Pretty cool Jon!

----------


## Jon

Passive tanker ship stabilization demonstration from Hoppe Marine. Looks like the strategy here is to remove the baffles?



Your browser does not support the video tag.


More: https://www.hoppe-marine.com/?q=en/node/8

----------

Seedtick (Sep 26, 2018)

----------


## 12bolts

I wonder if that Hoppe simulation would work if the liquid was at a different level. Or did they just carefully calculate and test different levels and baffle heights and numbers, that gave them the worse/best case scenario in a simulation. Ideally, and in the real world, you dont have a single tank with baffles across it, you have individual isolated tanks that can be kept pressed up so that the free surface effect is removed as much as is possible.

Phil

----------

Toolmaker51 (Sep 25, 2018)

----------


## Toolmaker51

I agree with 12bolts. The Hoppe device has two baffles on the stable side retaining fluid opposite lowered side of 'hull' simulator.The fluid is an active counterweight. Not sure how that will be practical in a full size displacement hull. The pair of baffles would need a function to set a particular level for sea conditions at that time.

Don't visit Hoppe's site. This page indicates they have more than a little gray matter at hand....https://www.hoppe-marine.com/?q=en/node/17

----------


## Loose Ctrl

> Passive tanker ship stabilization demonstration from Hoppe Marine. Looks like the strategy here is to remove the baffles?
> 
> <video controls autoplay loop>
> <source src="https://s3-us-west-1.amazonaws.com/hmt-forum/tanker_ship_stabilization.mp4" type="video/mp4">
> Your browser does not support the video tag.
> </video>
> 
> More: https://www.hoppe-marine.com/?q=en/node/8



Yeah left to right would be ok, I'm guessing but front to rear, nooooooo.

----------


## Jon

I like this 3D Motion Compensator attachment for making offshore cranes more precise. 2:49 video:




More: https://www.macgregor.com/globalasse...sets/84094.pdf

----------

MeJasonT (Feb 2, 2019),

PJs (Feb 2, 2019),

Seedtick (Feb 1, 2019),

Toolmaker51 (Feb 1, 2019)

----------


## Toolmaker51

It appears a good method of compensation, and logical. The video rendering, also a fine depiction. I don't know much about floor variety cranes, but the MacGregor version, positioned horizontal is simplicity, regardless how much tech needed to keep it so.

But they forgot to give the ocean going freighter a pointy front end.
Lol.

----------

MeJasonT (Feb 2, 2019)

----------


## MeJasonT

The extension arm only allowing for a small lifting whip will not catch on. I have worked on projects where a 50 tonne crane has been performing 45 tonne lifts putting manifolds etc on the seabed. The industry will be looking for a more substantial lift capacity. What confuses me if they have integrated it into their existing controls then why not upgrade the existing crane and boom and don't bother with the rather light looking extension. market research may also be a great benefit, I worked for MPI installing offshore windfarms.
This was the vessel I was working on, once the pile is installed the pylon is attached. not possible to put a small container on top of the pile as per the video.

https://en.wikipedia.org/wiki/TIV_MPI_Resolution



Certainly one sure way of getting a fixed lifting platform for heavy lifts at sea.

----------

Jon (Feb 2, 2019),

PJs (Feb 2, 2019),

Toolmaker51 (Feb 3, 2019)

----------


## MeJasonT

With regards sailing and unstable boats. MAN UP. Its man against the elements, its all part of the skill and experience. Whats next ice cold fires so idiots don't get burnt.

----------

Toolmaker51 (Feb 3, 2019)

----------


## Toolmaker51

> With regards sailing and unstable boats. MAN UP. Its man against the elements, its all part of the skill and experience. Whats next ice cold fires so idiots don't get burnt.



Lol. McDonald's lawyers sure wish[s] for ice-cold hot coffee after one injury tort case. Poor Stella, 79 years old and still ditzy. 
https://www.google.com/search?client...31.8JPhU4BzWT4

----------


## Loose Ctrl

> Lol. McDonald's lawyers sure wish[s] for ice-cold hot coffee after one injury tort case. Poor Stella, 79 years old and still ditzy. 
> https://www.google.com/search?client...31.8JPhU4BzWT4



Some people's grandmothers.

----------


## Jon

Nauti-Craft marine suspension technology. Looks they're marketing it as a boating solution and a crew transfer solution. 4:23 video:

----------

baja (Apr 28, 2019),

high-side (Apr 28, 2019),

Seedtick (Apr 27, 2019),

Slim-123 (Apr 28, 2019)

----------


## Loose Ctrl

Gimmick is what it's called. Another one to fleece boaters.

----------


## Toolmaker51

> Nauti-Craft marine suspension technology. Looks they're marketing it as a boating solution and a crew transfer solution. 4:23 video:



No Sale here. I owned a Chris-Craft Scorpion 31' while in CA. Twin Merc 225's. The coastal waters from Long Beach to Oxnard or Oceanside were our playground. No reasonable water or wind conditions ever felt hazardous or forced return to port [three axle trailer]. 
Some folks thought $XX amount could have bought a nice used Ferrari or Cobra. Nice, but proper vehicles lean into turns naturally; and hotrods don't float.

----------


## Frank S

I agree with TM51. However the only crafts that I was ever on in deep water were either crew boats, barges or the occasional sailing vessel with up to a 3,500 lb keel.
The way I looked at if you can't stand the motion of the ocean buy yourself a mini van and take the kids to Disney world.

----------


## Jon

Harbor pilot boards cruise ship in high winds.



Your browser does not support the video tag.

----------

Karl_H (May 1, 2019),

Ralphxyz (Aug 26, 2022),

ranald (May 2, 2019),

Seedtick (May 1, 2019)

----------


## Karl_H

I wonder why he doesn't wear a harness - safety line from the ship would be easy to toss, hook it to his harness, then proceed. All the ship's crew are harnessed.

----------

that_other_guy (May 25, 2019)

----------


## Toolmaker51

I haven't boarded underway in decades. Not so much a dance from a launch into a like-sized patrol boat.
Seems a harness would be tough to keep tension on getting him on deck of vestibule; or hang him between pitching yawing hulls.

----------

Karl_H (May 1, 2019)

----------


## ranald

silly blighter couldn't find his sea legs................and arms.A little choppy for a harbour; must be relatively shallow.

----------


## Jon

Your browser does not support the video tag.

----------

