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MarkBseau

How did davits work on old ships?

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Modern davits are of course obvious, they're pretty much just robotic arms that have only to swing out and then down.

 

But for davits such as on earlier ships, the kind seen in our builds, how is a working boat, life boat, etc., lowered out and over the side?  I'm asking about the kind that are shaped like a shepherd's crook.  I'm sure they must rotate, but - if you have 2 davits say 22 feet apart, and a boat about that same size suspended between them, they can't physically both swing inward at the same time.

 

Maybe I'll be awarded the dumbest question of the year, or something like that, but...  What am I missing?

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Not a dumb question at all Mark. It's not obvious just by looking at them.

 

The boat is first hoisted clear of the chocks, the boat is heaved aft until the bow is clear of the forward davit.  The forward davit is then swung outboard and the boat heaved forward until the stern clears the after davit and the after davit is then swung outboard.  Once the stays securing the davits in position are made fast, the boat is ready for lowering. 

 

John

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Mark,

 

A good question. They are actually moved independently of each other, and turn with the boat. This is how I remember it:

 

First both davits are turned aft, by hauling the boat aft until the bow clears the forward davit; the bow of the boat is then pushed outboard between the davits, the forward davit swinging round to follow it until it points outboard; the stern is then pushed out, the after davit naturally following until it is in the same position. The boat and davits should now be fully outboard, with the boat parallel to the ship. Of course all this is done under control the whole time.

 

Some of the ships I sailed on had boat davits like this, although as you say, one doesn't find them often these days. Even navies seem have largely given up boats in favour of rafts.

 

 

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Usually if the boat is 22 feet long, those types of davits would be 17 or 18 feet apart. Like parallel parking, one end at a time with the falls playing follow the leader. Both davits would be pointing inboard. To start moving the boat outboard release both so they can rotate. The aft davit would be rotated forward, the forward davit would follow and also swing forward. Continue rotating the aft fall outboard, when the stern has moved around the aft fall and outboard of it, the bow will have started moving aft and will need to be helped around the forward davit. When the boat is outboard and the davits lined up with their keepers, latch the falls so they can’t rotate. Now you can use the boat falls to lower the boat and it will clear the side. The above was done using man power aboard the Ammen with her Whale Boat. If the boat was secured outboard to be ready for lowering, it would have been secured by 2 slings which kept the boat from swinging, the slings would also take some of the weight from the falls. Taking the weight back onto the falls and the slings released, the boat could then be lowered.

That is how I remember doing it, may have missed something. Maybe the bows went first.

jud

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.... Even navies seem have largely given up boats in favour of rafts.

Hi Stockholm Tar - not really?

 

In our navy at least they still use boats in the form of Rigid Hull Inflatable Boats (RHIB) predominantly.  What has changed mostly is how they are deployed.  On larger ships mostly by single arm davit or crane and in ships/boats where they deployed quite often (Patrol Boats etc) we are seeing self launch/rapid launch stern ramps.  May be different in some northern navies though?

 

cheers

 

Pat

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Ah, it was simple after all.  Just need some jockeying around.  As Jud said, just like parallel parking.

 

Thank you, gentlemen - I knew I'd get a good explanation here.

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Pat,

 

Although inflatables are used in the RN too, the traditional ship's boat on modern warships seems conspicuous by its absence – excepting survey ships and the like.

 

I suspect the RN Manual of Seamanship may have changed too. The one I have is dated 1972 where one whole chapter, some 41 pages, was devoted to boat handling, including pages on lowering, pulling – and sailing.

 

As has been said, times change.

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Hi Mark,

You did not tell about of time period you are interested on.

Davits and the functioning of an evolved greatly over the centuries.

1 HMS Victory

2-4 HMS Warrior 1860

5-6 Jylland Danish frigate

7-10 Passat

11 Gorge Stage

12 Christian Radich

13-14 Cuauhtemoc

 

Tadeusz

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Tadeusz, thanks for the interesting photos!

Your photos 7-10, even though a late model boat, show the kind of architecture I had in mind, it's interesting to see how the boat is secured there.

I wasn't looking for a very specific time period.  I just wanted to have a better idea how they were physically manipulated to bring in or dispatch a boat, so that I wouldn't be wondering if I was building something that just couldn't make sense.  (If that makes any sense...)

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Modern davits are of course obvious, they're pretty much just robotic arms that have only to swing out and then down.

Hi Mark

 

Not sure if it's a terminology thing or a misconception, modern lifeboat davits are not robotic, they are simply a gravity driven mechanism usually consisting of moving arms running on rollers in a track which angles out then down, sorry don't have any photos available.

 

Any sort of robotics would add unnecessary levels of complexity and points of failure.

 

Retrieval is simply via an electric winch.

 

Mark D

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Hello everyone.

I'd like to apologise for reviving this old topic, but I figure it's the best place to start for my question.
I've read all of the above and would like to thank the contributors, as well as the author of this topic.

Thanks to all of the entries above, I think I can represent to myself the hauling of the boat outboard, like parallel parking. However, I'd like to have more information if possible.

I'm actually interested in understanding how davits (and other mechanisms) worked on older ships (18th century or older). Could some of you experts help me understand how the ships components were physically manipulated to bring in or dispatch a boat.
ex. Where would the boat typically be hoisted from?
How much manpower, or how many crewmembers, were typically required for such an operation?
How long would it typically take?
Do you know of any diagrams or video footage of this, on Youtube or other sites for example?

Are there any books that might satisfy my curiosity?


I found some examples among the impressive Gallery of Completed Ship Kit-Build Models:

A first example is from Boxnote's model of the San Francisco II, a mid 16th century ship if I'm not mistaken:
IMG_1116.thumb.JPG.b1d787b1c8d74b86e43e6cc3644adc90.JPG
A second example would be Ekis model inspired by the Victory 1737:
P3280031.JPG.49349706180ebab76308045692fb24bf.JPG

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Ships boats during the age of sail weren't put in and pulled out using davits.   They used pulleys attached to various stays and rigging and the lower yards of the main and foremast.   The exception would have been ships that had stern davits for an officer's gig.

 

It was a rather time-consuming process as the boat would be raised then swung out over the side. Things had to be coordinated in the raising and then the moving it.

 

I have images of boats being launched on a model of Belle Poule, but they need to be scanned in from The Art of Ship Modeling by Frolich.  

 

 

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Thank you both for the help.

The images from Harland's book are very informative. I'm assuming as few as 3 men are required to hoist a ship a drop it in water?

I searched for both books, Harland's and Frolich's, they appear to be very difficult to acquire indeed ('Seamanship in the Age of Sail' is 952$ on amazon.com, 1070€ on amazon.fr, with some possibility on amazon.co.uk at 45£ but without any delivery date). Is there any additional information available Harland's book? Is it worth acquiring? Any other books to recommend?

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with respect to prices: the second hand book prices on Amazon are ridiculous. (not only for this book, but also for others)

Try this site: www.marelibri.com

 

Jan

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Going back further in time, early 1600’s and before ships’ boats Were quite large some as long as 50ft, so were very hard to hoist on board.  These large boats were usually towed by the parent ship.  Seventeenth Century paintings often show these boats under tow manned by a boat keeper.  It is believed that Vasa’s longboat was being towed when she sank.

 

Roger

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8 hours ago, Sperry said:

they appear to be very difficult to acquire indeed

I also always try Abebooks as they will usually have better prices (than amazon) although since the pandemic hit everything is going up in price.  They will usually have anything you can possibly want and sometimes if you keep looking you can score a great deal there.  I once picked up a great copy of vol I of 74 gun ship by Boudriot for 11$ and 2$ shipping and another time a copy of British Warships in the Age of Sail 1714-1792 by Winfield for 22$

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10 hours ago, Sperry said:


The images from Harland's book are very informative. I'm assuming as few as 3 men are required to hoist a ship a drop it in water?

 

These boats could weigh up to several tons.  There is no way they could be hoisted out or in with just three men.   The three men in the sketch are there to fend the boat off of the side as she is being lowered and to trip the hooks after she hits the water.  Each tackle fall you see there leading aboard the ship would have several men hauling.

 

Regards,

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Another indication of the weights involved is the additional tackles shown in the top illustration rigged to the yards, in the form of a top burton(h) and rolling tackle(i), used to take the additional strain and transfer that strain off the yard and onto the mast.

 

Regards,

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The illustrations Jim Lad posted are excellent examples of how the yards were used as "cranes" for hoisting things over the side - not just boats.

 

In some cases anchors were hauled aboard in a similar fashion and stowed below decks amidships.

 

Cargo could be loaded and unloaded in the same manner.

 

I found it interesting that the term "burton" used for the tackle for lifting the spars is still used (or, at least it was used in the US Navy 50 years ago) for the main heavy lifting tackle. Our burtoning winch was used to transfer boats between on-deck cradles and the water.

 

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