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| Drawing and 3D printing of a 1950-70 lifeboat at 1/125 http://shipmodels.info/mws_forum/viewtopic.php?f=13&t=343083 |
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| Author: | Iceman 29 [ Wed Dec 15, 2021 5:15 pm ] |
| Post subject: | Drawing and 3D printing of a 1950-70 lifeboat at 1/125 |
I started the design of this boat this morning for a friend, it will be finished probably tomorrow. Once printed it will be 60 mm long, but can be declined in different sizes. Here is the model on the plan which is almost generic for the time. The boat is covered here, not with a boat cover, but with removable sheet metal plates. The material is more durable and waterproof. This is not the final model because there are still some details to be rectified and added, pulleys etc..              
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| Author: | Iceman 29 [ Fri Dec 17, 2021 3:46 pm ] |
| Post subject: | Re: Drawing and 3D printing of a 1950-70 lifeboat at 1/125 |
These boats are intended for the friend Jean-Louis mounted liner Pasteur (1938) to 1:125, these lifeboat are not commercially available at this scale. There are 30 such boats on this ship before its refit (Liner Bremen), of which 4 near the bridge are smaller Titanic style boats. The davits for the bridge boats are of the well known Walin type, which were used on many ships in the early 20th century, notably the Olympic class. A particularity of the Pasteur is the stacking of the boats in pairs.  So I had to find out how the upper boat was supported. I was missing pieces of the puzzle. Most of the pictures of the Pasteur liner that can be found on the internet are wide shots. No photos taken on board are available. So I called my friend Roland Grard who is the right man for the job when it comes to finding a drawing or a particular photo. I found some HD pictures of the Pasteur, so I was able to zoom in on the part I was interested in, but only from the sea side. As the supports are on the opposite side, I had no idea of their shape and layout. First, some pictures of the Pasteur at the Landevennec boat cemetery (in my region of Brittany, France) in 1957, it will pass there twice, also in 1939 after its launching. "1939 - The ship is requisitioned and goes to the "ship's graveyard" at Landévennec near Brest on 4 September where she is repainted in light grey and equipped at the stern with 2 x 90mm guns (Saint-Etienne 1892 model) and 4 anti-aircraft machine guns arranged around the chimney." "Decommissioned again on 25 January 1957, the Pasteur is again in the "ship's graveyard" at Landévennec. Sold to the German shipping company Norddeutscher Lloyd (NDL) on 18 September 1957, she left Brest on the 26th. From 8 January 1958 and for 16 months, she underwent major transformations at the Bremer Vulkan shipyards in order to increase her transport capacity. The most visible modifications were new masts, a new deck and especially a new chimney. Renamed Bremen on 23 May 1959 (5th of the name), she became the German prestige liner on the North Atlantic from 9 July, on the Bremen-New York route via Southampton and Cherbourg. In just over 10 years of operation under the German flag, the Bremen will carry 360,000 passengers."    Some detail shots of the boats, this nice HD photo found on Flickr was quite useful too: "The French steamship Pasteur, chartered by the Dutch government, with more than 4,000 repatriated soldiers from Jakarta and the surrounding area, is towed through the North Sea Canal by tugs from Reederij Gebr. Goedkoop, 24 February 1950." Photo Ben van Meerendonk / AHF, IISH collection, Amsterdam The HD version, downloadable below right: https://www.flickr.com/photos/iisg/1001 ... xbq-wjU9bF    The red arrow indicates the spinnaker pole for the sounding machine, a system identical to the Olympic class. The 2 Titanic style clinker lifeboats are clearly visible on the bow, probably 30 feet.   All these photos did not show me what I was looking for, Roland allowed me to visualize what I had to draw. These snippets of photos are taken from this beautiful book "Le Pasteur 1938-1980" by Jean-Yves Brouard (French author) published in November 2005. I will surely buy it because this ship is very beautiful and historically interesting. https://livre.fnac.com/a1763510/Jean-Yv ... -1938-1980  The last photo solves the problem. Thanks Roland, now I just have to draw it all.   
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| Author: | Iceman 29 [ Fri Dec 17, 2021 3:50 pm ] |
| Post subject: | Re: Drawing and 3D printing of a 1950-70 lifeboat at 1/125 |
That's it, a few details to rectify. I still have the small lifeboat models to adapt that I already have in stock, it will be quick. I simplified some details in relation with the 1/125 scale and a sailing model. The two kinds of horns are "off-shore derricks", a classic system on this type of lifeboat to prevent it from snagging when it is slumped along the hull (Wall), especially in the event of constant rolling or heeling of the ship which would force it along the hull during the descent, one can compare that to sledge blades. They are released once the boat is in the water to avoid drag, especially if the oars are used to move away from the ship (engine failure).      Looking at the photo above, a small detail amused me and made me think of my job as a former sailor where often common sense governs in order not to get hurt or stay alive, risk prevention is the key word. If you magnify a little, you can see that the control cranks of the Welin davits are mounted upside down, and there is probably one main reason for this: to avoid catching the crank in your legs or pelvis when you are walking around, and secondly, although theoretically this is impossible with a worm, to avoid the davit deviating unexpectedly at sea, as the crank will get stuck in the davit support if it turns alone. Caution should be exercised with davits, a device that has killed more sailors than it has saved. Good bosun and good first mate! :) 
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| Author: | Iceman 29 [ Sat Dec 18, 2021 9:13 am ] |
| Post subject: | Re: Drawing and 3D printing of a 1950-70 lifeboat at 1/125 |
That's it, details to check, massive (!) 3D printing to do, with a prototype first...   
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| Author: | Fliger747 [ Sat Dec 18, 2021 11:47 am ] |
| Post subject: | Re: Drawing and 3D printing of a 1950-70 lifeboat at 1/125 |
Clever and interesting davit setup. Many wakeful nights of brainstorming activity by the design engineers. Do you have any idea how the upper cradles swing out of the way to release the lower boats. On the APA's the racks for the upper boats pivoted sideways. Cheers: Tom |
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| Author: | Iceman 29 [ Sat Dec 18, 2021 12:23 pm ] |
| Post subject: | Re: Drawing and 3D printing of a 1950-70 lifeboat at 1/125 |
I think that the upper cradles stay in place or can be tilted 90° upwards. The photo is not precise enough to confirm the presence of a pivot. Of course you can only launch one lifeboat at a time starting with the upper one, there are two sets of hoists. The davit has to be brought back to position for the lower one of course. This is not very efficient in case of emergency. |
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| Author: | Fliger747 [ Sat Dec 18, 2021 2:06 pm ] |
| Post subject: | Re: Drawing and 3D printing of a 1950-70 lifeboat at 1/125 |
The APA's had (sometimes) three LCVP's hung from the Gravity Davits. They could get away with this as the boats were loaded elsewhere rather than being lowered loaded. I would guess with their practiced crew they could get all three boats offloaded in less than 15 minutes. But yes, the liners were required (after lessons learned the hard way) to have more boats than in the Titanic era when I expect that enough boats for first class was considered socially acceptable. Whether or not the lower boats, considering that the crew seldom if ever deployed them were for just more than show is debatable. The sleigh runners were interesting and I hadn't seen them before. Were there any power winches for hoisting? With the APA the first boat could be deployed in a minute or so and I expect the winch could reset the davit in a similar time. All could be done quickly in a coordinated dance, but then again this was the main battery of this ship and not something to hopefully never be used. Drill, drill, drill. An elegant ship! This reminds me of the liner United States, but with just one stack. Cheers: Tom |
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| Author: | Iceman 29 [ Sat Dec 18, 2021 5:56 pm ] |
| Post subject: | Re: Drawing and 3D printing of a 1950-70 lifeboat at 1/125 |
That's where the difference was in training between the merchant marine and the navy. For the APAs for example the launching of the boats was probably one of the main missions of the crews, on a cargo or passenger ship it's not the same story, you don't do a launching exercise every day, but a simulation every month at best and a real launch every year for the annual visit of the flag country. On a merchant ship in peacetime there are only a few of us, between 7 and 25 sailors at the most, but I must say that nowadays we are much better trained in all this than 40 years ago, thanks to the regulations, the effective controls of the port controls, but also the vettings of the majors, especially on ships carrying petrol and gas. |
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| Author: | Fliger747 [ Sat Dec 18, 2021 7:48 pm ] |
| Post subject: | Re: Drawing and 3D printing of a 1950-70 lifeboat at 1/125 |
During WWII naval vessels often had huge crews. A USN heavy Cruiser late war had a bigger crew than HMS Hood! A WWII Capital ship had huge manpower resources for paint chipping, holystoning decks and on and on. Modern Naval vessels also have smaller crews due to automation of many tasks and different mission profiles. The large numbers of boats and davits on a passenger liner would be a daunting task for a traditional model builder! Cheers: Tom |
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| Author: | DrPR [ Sun Dec 19, 2021 12:15 am ] |
| Post subject: | Re: Drawing and 3D printing of a 1950-70 lifeboat at 1/125 |
The large crews (we had 1200 on the USS Oklahoma City CLG-5) posed a problem. We used epoxy paint in the missile house (a magazine) that needed repainting only every 5-8 years (the white tended to yellow a bit). It was very durable, resistant to chipping and cracking. However, on outside surfaces the Navy gray (Ocean Gray, post war Haze Gray) seemed to wash off fairly quickly, and needed repainting often (several times a year). One day in a discussion with some of the other officers I wondered why we didn't use epoxy paint topside. One of the deck division officers asked what the crew would do when not on watch? "An idle mind is the Devil's workshop." The Navy used cheap paint so the ships always needed chipping, priming and painting, just to give the crew something to keep them busy. The sounds of chipping irons and needle guns were probably the most typical sounds on the ship. Very few of the several hundred photos I have of the ship do not show spots of orange red lead primer. I wonder if this has changed in today's Navy with "cruisers" with just a few hundred crew? Phil |
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| Author: | Fliger747 [ Sun Dec 19, 2021 12:40 am ] |
| Post subject: | Re: Drawing and 3D printing of a 1950-70 lifeboat at 1/125 |
During the war a cruiser like Okie City might have had a crew of over 2000 with all the light AA. Four bunk pipe racks deck to overhead. Good question about the paint. For the museum ships such as the four Iowa's with small maintain crews it's a battle. There was controversy about taking her from the shipyard in Bremerton where she was being maintained in the reserve fleet to Pearl Harbor which is a hotter and (amazingly) wetter climate. We have some members who are involved with these museum ships and it might be a good question for them. Merchant crews are even smaller! Some wartime implements such as aircraft weren't designed for a long lifetime as a major consideration because of the attrition rate. Japanese aircraft used a very light formulation of what they called "Duraluminum" that with time would crystalize loosing much of it's strength. Not a wartime concern. |
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| Author: | Iceman 29 [ Mon Dec 20, 2021 6:46 am ] |
| Post subject: | Re: Drawing and 3D printing of a 1950-70 lifeboat at 1/125 |
The print is of very good quality. The vertical position that I now use systematically to print is a big help, of course you have to hollow out or squared off the inside of the hull to avoid too much tension on the thin supports. But it works. A part of the 30 lifeboats to be printed. They are already printed in their entirety. It will take more than 2 hours to remove the supports from the boats and davits. The 3D printing boards.        
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| Author: | Iceman 29 [ Tue Dec 21, 2021 10:22 am ] |
| Post subject: | Re: Drawing and 3D printing of a 1950-70 lifeboat at 1/125 |
This set is finished. Quite happy with the result. My friend will have little work to paint and assemble it all. The drome of the liner Pasteur (1938) at lifeboat level: 
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