Quanzhou Ship by Schrader - 1:54 - Chinese Junk

[Schrader]

Let’s talk about the stern transom......

 

Binging the Nick document this is what he says.....

 

 

The stern transom

The stern transom appears to be composed of baulks of timber in three layers plus a layer of thin sheathing on the outside. The timber is fairly degraded and it may be that the inner layer has split neatly in two, in which case there are only two layers plus the sheathing. The inner layer(s) are fitted inside the main planking; presumably the ends of the strakes are fastened to this inner transom. The outer layer is aft of the end of the main planking but inside the outer planking layer. The outer planking layer is extended aft of the transom to form a kind of false counter. The outer layer of the transom has a slot cut in it for the rudder stock and is made of baulks of timber only slightly thicker than the diameter of the rudder slot, thus the slot almost cuts them in half and the strength of the transom relies on the inner layer(s). The uppermost of the extant outer transom baulks appears to have its ends cut square, so it did not extend right out to the sheathing planking at its upper face. This suggests that the outer transom did not continue above this height though there would need to have been baulks forming brackets to hold the rudder stock higher in the transom, as there are on traditional vessels of the region today

 

So..... Let’s try to understand this.....

 

• It says that the ship has two layers in the  stern transom  .  Where the external transom is wider.  It is talking about RUDDER SLOT and let’s think about its diameter.  I could not find specs about it but having in consideration its length that could be 6-7 m its should be thicker than I was expecting.......  I went to this photo

...........and having the keel with 40 cm. Then the ruder at least must have 40 cm as well.  That gave me how thick should be the external transom 40 cm. And the 2 or one inner transom should also 40 cm. In total.

 

•  This ship has two-three plank layers.  The inner planks are, according with the same document 8 cm....

... The inner planking of the Quanzhou ship is 80 mm thick

 

So.... the outer transom should be 8 cm wider.....at the end we will end up in something like this....

 

 

• It also says that probably has a third layer of very thin set of lumbers...... I’ll wait because the ruder in these ships has the possibility to move up and down to be able too navigate different water depths so the channel should be open, at least part of its length....

 

This photo is not accurate for this ship but explain really well how the rudder works.....

 

regards

 

 

 

 

 

Edited January 12, 2021 by Schrader

[Cathead]

That vertically movable rudder is really cool! Was that unique to Chinese ships? I don't think I've seen that elsewhere (not that I'm an expert).

[Louie da fly]

I'm really enjoying following the research on this one. Looking forward to further progress!

 

Steven

[Tony Hunt]

Another source that might be useful is the work of Joseph Needham, a Cambridge scholar who devoted most of his life to studying the development of technology in China. It turns out most of everything was first invented in China.  His monumental life work is documented in 27 volumes of Science and Civilisation in China, published by Cambridge University.  I recall from reading his biography (The man who loved China) that one of the fundamental technologies invented in China was the rudder.

 

The synopsis below is from Wikipedia:

Science and Civilisation in China

Main article: Science and Civilisation in China

In 1948, Needham proposed a project to the Cambridge University Press for a book on Science and Civilisation in China. Within weeks of being accepted, the project had grown to seven volumes, and it has expanded ever since. His initial collaborator was the historian Wang Ling (王玲), whom he had met in Lizhuang and obtained a position for at Trinity. The first years were devoted to compiling a list of every mechanical invention and abstract idea that had been made and conceived in China. These included cast iron, the ploughshare, the stirrup, gunpowder, printing, the magnetic compass and clockwork escapements, most of which were thought at the time to be western inventions. The first volume eventually appeared in 1954.

The publication received widespread acclaim, which intensified to lyricism as the further volumes appeared. He wrote fifteen volumes himself, and the regular production of further volumes continued after his death in 1995. Later, Volume III was divided, so that 27 volumes have now been published. Successive volumes are published as they are completed, which means that they do not appear in the order originally contemplated in the project's prospectus.

Needham's final organizing schema was:

• Vol. I. Introductory Orientations
• Vol. II. History of Scientific Thought
• Vol. III. Mathematics and the Sciences of the Heavens and Earth
• Vol. IV. Physics and Physical Technology
• Vol. V. Chemistry and Chemical Technology
• Vol. VI. Biology and Biological Technology
• Vol. VII. The Social Background

See Science and Civilisation in China for a full list.

The project is still proceeding under the guidance of the Publications Board of the Needham Research Institute, directed by Professor Mei Jianjun.

Edited January 21, 2021 by Tony Hunt

[Schrader]

Thanks a lot to you all. Looks interesting VERY.....  the answer about the rudder looks like yes. I have not seen that either. 
 

so far I’m working on the keel and planks. They seem to be something “special”.

 

i’ll be posting some advances soon. 

[Schrader]

Long time since my last posting...... I’ve been working in my Rhino skills....at the same time understanding new subjects about the way these ships works.

 

here my new reproduction in Rhino....

 

It looks much better.  In the frames you can see two different lines.  The red ones are the false frames to build the mold... The blue ones are the Bulkheads-frames.  And this is how those elements are going to look like....

 

The frames that in reality are half frames, work as a connectors between bulkheads and planks.  Because the bulkheads “planks” grain direction, the connection with the hull wouldn’t be that effective so the needed the half frames to serve as a connectors.

 

The real hull resistance is in these three elements

 

PLANKS - FRAMES - BULHEADS

 

THE KEEL.....

 

It has three elements.... the middle one the is originally made of camphor wood and has 12.57 m long (aprox).  The forward part is 4.5 m long made in pine and slopes upwards 35º and the aft keel were made also in pine and slopes upwards 27º.

 

The section of the keel is 42 cm by 27 cm.  In their joints there was an special scarf....that we were trying to replicate....

 

  

Next we are going to talk about Stern and bow transoms and how start the planking....

 

 

 

 

Edited January 30, 2021 by Schrader

[Schrader]

As you probably notice, these ships had transom either in bow as in stern.  The stern one we already described, was used not just to increase capacity, also to received the back piece that was used as a “mechanism” to operate the rudder.....  The internal layer, received also the first planks layer and the second (rudder mechanism) received the second planks layer.....

Well.... here some pictures in the “real life”....

 

YESSS !!!! I have started the planking with all its difficulties..... 

FIRST.....  let’s remember that it need to build PLANKING FIRST FRAMES AFTER.  This is pretty much the same that Vikings and Egyptians.  Also let’s remember it has 2-3 planking layers

 

It is a “kind” of clinker with e very specific distribution.  The first layer, is rabbeted as you can see.  And let me tell you.... I did it. 

 

It really helps a lot to fix the planks.

 

Here some how I’ll try to show how the clinker looks like.....

 

 

We will continue with the planking up to the bulkheads level.... Then we will install the “team” bulkhead-Frame” to complete afterward the planking.  Do not forget this is just the first planking layer.

 

Before going to the second layer we will need to figure out how to proceed with the brackets....

 

 

 

 

Edited February 8, 2021 by Schrader

[Louie da fly]

That planking is looking very good. I take it the bulkheads get discarded after you've got the planking done? Something that happened with me when I built a model on a plug was that the elasticity of the planks pulled the hull sides inward after I'd taken the plug out and before I could put the frames in. I had to put in some temporary structure to push the sides back out to their correct position.

 

In your case you can probably avoid this problem if you replace each bulkhead with a frame, one at a time, rather than taking all the bulkheads out and then putting in the frames.

 

Steven

[Schrader]

Thanks Steven.... I am concern “so concern” about the same thing. It did happen to me in the Byblos and, I solved exactly in the way you are describing.....with a provisional “bulkhead

In this particular case I’ve been checking the hull and is working quite well and the rabbeting (even when I was thinking that not) is helping a lot to keep the strakes in its place.  I’m thinking to stop the planking in the strake No 14 install the bulkheads-frames and then finish it. Right now I don’t see any other option

 

Thanks Steven for always been there

 

Edited February 9, 2021 by Schrader

[Schrader]

On 2/8/2021 at 7:05 PM, Louie da fly said:

That planking is looking very good. I take it the bulkheads get discarded after you've got the planking done? Something that happened with me when I built a model on a plug was that the elasticity of the planks pulled the hull sides inward after I'd taken the plug out and before I could put the frames in. I had to put in some temporary structure to push the sides back out to their correct position.

 

In your case you can probably avoid this problem if you replace each bulkhead with a frame, one at a time, rather than taking all the bulkheads out and then putting in the frames.

 

Steven

Steven

 

in the Chinese ships the bulheads are part of the structure. They with the half frames come like a team to give the strength to the hull and create some compartments that are use to separate the different kind of cargo and also to protect and keep the water in one place in case of. 

[Louie da fly]

I understand. So will you be replacing the current bulkheads (which seem to be made of MDF) with plank-built ones, or won't the bulkheads be visible in the finished model?

[Schrader]

Once I got the plank 14 I’ll take the hull out of the mold. Then...  yes I’ll start to work with the plank built ones. 
 

I’m planning to left part of te ship open

 

in order to allow the people to see what is inside

[Schrader]

Here we go again.  Plank # 14 in place

 

I’m going to take the hull out of the mold.......🤭

 

looks OK!!!!!  The planks definitely were trying to come back.... but I think  it is good enough to sand it and moving on....

 

It is time to try one plank-bulkhead......

 

here we go!!!  It looks good for me..... Next step.....  11 more bulkheads with their frames and brackets 

 

[Louie da fly]

Good to see taking the ship off the mould has worked well for you, Schrader. And thanks for the information about leaving some of the deck open so people can view inside the hull - the planked bulkheads will look good 

 

Steven

Edited February 14, 2021 by Louie da fly

[Schrader]

I just decided to change the wood to a lighter one. CEDAR..... that was the wood used by the Chinese....... here with the half frames

 

Now it is time to start to deal with the brackets.

[Schrader]

Let’s read what Nick says in his document.....

 

“Ju-nails or Gua-ju (iron cramps)

The main planking is fastened to the bulkheads by L-shaped metal brackets gua-ju or ju-nails (Xu Yingfan, 1985 and Li Guo-Qing, 1989). The brackets are recessed into the bulkheads, and the feet of the brackets are recessed into the outer face of the main planking according to Museum of Overseas Communication History, (1987: 20). The brackets vary in length from about 400 mm to 550 mm and they are all about 60 mm wide. They seem to have been not more than about 7 mm thickness, but given the entirely oxidised condition of the remains of the brackets this can only be determined from the width of the slits where they passed through the planking. Most brackets are aligned within about 7–8 ̊ of normal (90 ̊) to the plank that they fasten, when viewed in transverse section; but a few are as much as 10 ̊ from normal. This suggests that the ends were bent over in situ, since if they were pre-bent all brackets could be expected to be bent at the same angle (about 90 ̊) and to lie more or less precisely normal. Like the pattern of plank butts, the positioning of the brackets is symmetrical port and starboard (except for an extra bracket in strake ten at bulkhead eight on the starboard side). The positioning of the brackets is tabulated in figure Y. The strakes immediately below the clinker steps (strakes 5, 8 & 11) have only one or two brackets connecting them to the bulkheads throughout their length. Whereas the strakes immediately above the steps (strakes 6 & 9: too little remains of strake 12 and the bulkheads at the height of strake 12 to constitute a useful sample) have the greatest number of brackets—thus these strakes clamp in place those immediately below them.

The slits where the brackets pass through the planking show that the brackets were only about 5–7 mm in thickness, but in a few cases they were recessed as much as 12 mm into the bulkhead because the slits were not always perfectly positioned in relation to the face of the bulkhead with which they were required to align. This suggests possibilities about the construction sequence. The slits could have been cut before the bulkheads were fitted since the bulkhead positions were predetermined to align with the plank butts.”

 

Regarding their distribution, there is mentioned above the figure y

 

And this is the way I decided to move forward.  

 

First decision was going with metal brackets and the second was trying to the bulkheads with no glue, just using the “real” method the Chinese people suppose to build it. 

 

The Bulkhead number 6  has 4 Brackets in strakes 6 and 9 in each side

 

The bulkhead number 7 has 4 brackets in strakes 2, 4 , 7 and 10 in each side

 

They have no glue!!!!!

 

Let see a couple of pictures......

 

 

Note the little hole in the bulkhead above the keel...... this is to allow the water flow.  We will see also that this particular ship had a 

 

Lime putty, wash or plaster

Everywhere on the hull, inside and out, there is the remains of a layer of lime. The use of this lime is discussed in some detail by Li Guo-Qing (1989). It is in all the seams, behind the brackets, between the layers of planking, and it plugs the tops of holes for fastenings. It is only the lime plugs that show the position of nails used to fasten timbers such as the half frames and the knees at the scarfs in the keel; and it is possible to trace the original outline of the degraded half frames because of the thick line of lime that collected between the upper face of the frame and the face of the bulkhead. Probably the lime in the seams and in the fastening holes, and perhaps that between the layers of planking, was applied as a lime putty, as it is today in the traditional boat and shipbuilding of the region. The oil used to make the putty is tung (t’ung) oil extracted from the nut of the t’ung oil tree (Aleurites fordii [Li Guo-Qing 1989: 279]) In the Song Dynasty, Quanzhou was known as Ci Tong or ‘Tung Harbour’ because of the many tung oil trees in the region (Pers, com. Wu Chunming)

 

So.... it is time to think about it....

 

 

 

 

Edited February 27, 2021 by Schrader

[Schrader]

Ok...... I was not happy at all.  First.....  The brackets should be 90 degrees to the planks....  second.... the bulkheads were not fitting well to the hull..... the half frames were not accurate ....So... as I am custom to......  I started again

 

Before....

After....

 

The lime putty......

 

I made “some” analysis.......  according with the document above, the lime putty was everywhere and in abundance.  The organic material present in the putty was so low.... so the main raw material was lime.  In some books talk about sea shells crashed.

 

Conclusion.....  the lime putty must be white mostly.....

 

I decided to use POLYMER CLAY!!!! and let’s see the result....

 

According with the findings, the brackets should be blended in the first planking layer.....

 

And the nails that fix them to the bulkheads should be bended as well....

 

 

 

 

 

 

[Schrader]

Next step.... the mast footstep.....

 

Fists I had to replace the bulkhead number 6.... this is the equivalent to the master frame.  And start to investigate how the masts system were by then.

 

Definitely the system was a TABERNACLE which means that they were able to lower it with a pivot-pin.... like this

 

 

but according  with the findings the Quanzhou did not have neither the belaying bit nor the pull rope so..... should be like this...

 

Let’s see one picture....

 

In this one, we can see the main mast step and the “hole” in the last timber in bulkhead 5.  This allowed the mast to rotate... and with this information I went to a very simple system in the bulkhead 6

Ready to go with bulkhead 5......

 

 

Edited March 15, 2021 by Schrader

[Tony Hunt]

That is looking really good. Fascinating to see these ancient techniques come to life in the model.

[Schrader]

Thanks Tony

 

it is being really a challenge. Thanks for your support 

[bolin]

It is really an interesting and unusual topic for your model. I very much enjoy following your research and solutions. Thank you for sharing.

[turangi]

A very interesting project! Though you might enjoy this:  https://www.cnn.com/travel/article/dukling-hong-kong-junk-boat/index.html

[Dr PR]

turangi,

 

I can't imagine Hong Kong without junks! There were dozens in the harbor at any time in the '70s, and thousands in the typhoon shelters (Aberdeen, etc.).

[Schrader]

Don’ even think I abandoned my project!!!!!😊.... Thanks to you all for “pushing me” to the excellence. Since you are following this project,  I’ll always do my best to fulfill your expectations and of course mines too.

 

It is been a real challenge moving forward with the bulkheads...... so far 9....

The difficulties that I’m facing now, are that since this hull is planking first, the form is not that “perfect” so it is really necessary to finish the bulkheads/frame first in order to continue with the planking.  I actually realize that there are some misaligned frames that will need to be fixed 

Here you can see the brackets distribution.....  as any western ship, the frames are “looking” to the main frame.  In this case, bulkhead # 6 that is the same one that is carrying the main mast step.

 

The 

[Schrader]

At the same time, I’ve been doing my research about some fittings........

 

Sails......

 

The junks sailing is as most of you already know,  are something that make a junk a real junk 😀.  You can see a lot of different styles..... some examples 

 

Most of you. (Included me) would think that there will be no difference about whatever I choose......

 

BAD NEWS !!!!

 

NONE OF THESE ARE CORRECT!!!

 

Let’s try to explain it.....

 

1. The sails by this era according with the archeologists suppose to be built in “ panels.... like this...This one is a replica that Nick made.  The wicker looks really good, the bamboo “hinges” really interesting.
2. This particular wicker does not represents the region where the Quanzhou is from.  No one can be sure about how the sails were done, however a piece of triaxial bamboo laths was found at the Quanzhou site.....  this picture shows what I’m talking about....And this model shows something similar that what I’m looking for....
3. SQUARE SAILS......  When I first heard about this term..... I thought about “form”. What a surprise!!!!  Nothing more far from the real definition...  Nick sent me some pictures to explain what this “term” is all about....Something new at least for me!!!!

With these three considerations I decided to attack this task.....  so many attempts 

 

Not happy at all.  There were like 6 different att🙃empts.

 

According with the different documentation the real thing should be done with thin laths of split bamboo just 1 or 2 mm thickness and perhaps 20 mm wide.  In this scale that would be really difficult to get.  So I decided to go just with thick paper and 1 mm wide....  and this is the result....

 

We have to make probably 50+ of these elements.  The come double as a sandwich and in the middle..... probably bamboo sheaths!!!!  Those sails were really heavy.  Not practical and tough to handle.  There are stories where the Malay junks had to partly lower the sails when there was hard rain because the rainwater added to the wight of the sails.

 

MORE INVESTIGATION IS COMING!!!

 

 

Edited April 11, 2021 by Schrader

[bolin]

This continues to be a very interesting and informative build. Well done so far.

[Brinkman]

Very interesting about the sails! 

[Schrader]

6 hours ago, bolin said:

This continues to be a very interesting and informative build. Well done so far.

With the expectation to have a happy ending 😀

 

thanks for your comments 

[Schrader]

2 hours ago, silverman834 said:

Very interesting about the sails! 

Yes. I learned a lot. Now ..... a lot of work to do

[Louie da fly]

I'm particularly enjoying the research component of this build. To my mind that's half the fun of modelling and you're really putting in the "hard yards" on this one.

 

Steven