Chinese Treasure Junks 1421

I just bought the Trumpeter Chengho sailing ship for around CAD$70. It is actually 60CM long, not to 1:60 scale. But checking the size of the doors and windows, I think the boat is actually close to HO scale. So actually the model is 1/2 shorter than what is described in the Chinese history book. I have seen many models of Chengho 'Treasure' ship in Asia, I must admit Trumpeter did capture some essence of those models, but just some. 

The model itself is huge, the largest single plastic moulding I have ever seen. Because the ship is so large, I think I will make the sail working and use it to sail in the pond.

There was an exhibit on the giant treasure junks at the Ventura County Maritime Museum this winter. One piece of evidence supporting the size of the vessels is the remains of a dry dock in China.

An enlarged copy of the plastic kit was used in the display, and sadly, incorporated the obvious goofs. Even if the hull stayed together, the vessel as portrayed would probably have been unmanageable.

It would be an interesting finite element modeling exercise to try and establish the theoretical limits of a wooden vessel. As mentioned in the thread, western shipbuilding methods were self limiting relative to vessel size.  (imagine a deck of cards vs. a block of wood of the same size) and didn't take advantage of compartmentation.  

jwintjes wrote:

I would venture to say that I would never use the term "magna opus" at all as poor "opus" has little in the way of feminine traits... Sorry, I couldn't resist.

Many pardons.   Magna Opa.   

Chuck Fan wrote:

I have restrained opinions of Lionel Casson's book,  and think of it as a popularististic rehash of, and a somewhat vague list of talking points from, other works, some of which are muturally contradictory.   I would never have used the term Magna Opus for it.

I would venture to say that I would never use the term "magna opus" at all as poor "opus" has little in the way of feminine traits...

Sorry, I couldn't resist.  

The main problem with Casson's study is that it is essentially the result of a collection of material spanning two decades. There are indeed some contradictory points, but at the time his study was a huge step forward. You mustn't forget that before Casson just getting at the relevant source material was next to impossible for anyone but the experienced scholar.

Jorit

kapudan_emir_effendi wrote:

Wood is an organic and so, a soft material.

Sorry to quibble, but the hardest earthly substance of them all, diamond, is in fact, properly speaking, an organic material.

:-)

kapudan_emir_effendi wrote:

There is no possibility of preventing the sagging and ,in a short time, breaking in two, of a 400 feet long wooden hull stressed with such superstructures even with bulkheads.

That's what we are disagree about.    I think it is the technical limitation of post classical western ship building techniques that placed the hogging limit at 200 feet, not the strength of optimally appliedd wooden itself.   The basic structure of pre-1800 western wooden ship consisted of planks with no edge jointing, hence a plank hull shell that has little shear resistence; and a frame consisting of essentially all 90 degree angles, hence a frame with little shear resistence.     Contrary to everything quoted in popular nautical works, hogging in a deep sailing ship hull is not primarily the result of a hull's lack of bending resistence.   Hogging is primarily the result of a hull's lack of shear resistence.    Address the ease with which hull planks can slide past one another with little resistence, and the ease with which the 90 degree angles in the hull frames can turn into 89 degree angles, and you've gone a long way to stiffening the hull's shear resistence and increase the hull's ability to resisting hogging.   For western ships, this step first came in 1807, with diagonal framing.   This turned 90 degree right angle frame joints into a series of 45 degree trianglular joints.   This stiffened the frame against sheering, and correspondingly wooden warships grew more in size between 1815 and 1840 than they did in the 400 years before that.
Edge jointing of hull planks to prevent planks sliding past each other was practiced with Greco Roman ships, and with Arab ships.   Regretably western ships will not have edge jointing in their hull planks again until those planks are made of iron.    So even after introduction of diagonal framing, western wooden ships still fell far short of what basic western hull shape could have supported with proper construction technique.
To further strength a hypothetical wooden ship, we can introduce interior bulkheads.  Again western woodenships never acquired them.   Having them would increase the maximum size of wooden ships yet again.
Many authors pointed to the long standing 200 foot limitation, and waved their hands, and never addressed what addressible structural weaknesses are intrinsic in those 200 foot hulls, and how much additional strength each plausible construction technique improvements could have brought; and simple pernounced authoritatively that 200 foot is the limit, as if conventional, often repeated words, spoken with rhetorical grace, allows one to bypass the need to address alternatives.

kapudan_emir_effendi wrote:

Hello Chuck, My all time favourite naval history scholar John F. Guilmartin Jr. in his groundbreaking Galleons and Galleys (Cassel, 2002) refuses the 400 feet theory and puts that chinese treasure ships measured 204 by 37 feet and displaced around 1100 tons.

His porposed hull of 204 feet long and only 37 feet broad has a length to width ration of 6:1.   This is virtually unheard of in any large ocean going wooden vessels until the advant of iron framing.   How this can coexist with his stern and bow castles I'll leave to your imagination.   
 
Regarding the 400 foot Hellenstic galley, Jorit has indicated the source.    But the 40 is not the only giant galley.   There were 30s and 20s.   They were all well over 200 feet long.    They did, or rather each of their twin hulls did, have length to beam ratios of close to what John F. Guilmartin claimed for the Chinese Junk.     Only they didn't go out into deep oceans, and they had the strong cable stayed hulls the Chinese lacked.   

I also have Age of the Galley and Lionel Casson's Ships and Seamanship in the Ancient World.   I have restrained opinions of Lionel Casson's book,  and think of it as a popularististic rehash of, and a somewhat vague list of talking points from, other works, some of which are muturally contradictory.   I would never have used the term Magna Opus for it.   Age of Galley is a good compondium.   However, being able to say "a good case can be made for their existence" is in fact not the same as to be able to say "a good description of design and application, able to stand in an integrated analysis, can be made of them".     Age of Galley is a integrated analysis.   I admit 400 foot galley are too rare, have too little impact, and fall just a little for far inside the gray area of "known but not well known" to really have a place in a integrated, analytical discussion such as those in the Age of the Galley.   
  

kapudan_emir_effendi wrote:

first of all, I really wondered the source mentioning 400 feet mediterranean ships.

The source is Athenaeus 5, 203e - it has "to mekos ... diakosion ogdoekonta pechon" (sorry for the horrible transliteration, I'm seemingly unable to make Greek characters appear here...), which means "a length of 280 cubits", which converts to 420 feet.

I just pulled the Casson from the shelf (it has been a while since I last looked into Hellenistic polyremes in detail), he discusses it on p. 107sqq. Reading through it again confirmed my scepticism to his catamaran solution; it sounds acceptable on paper, but simply seems to be impracticable in reality.

Jorit

Chuck Fan wrote:

I think 400 feet is definitely possible.    Ancient Greeks of Hellenistic era did in fact build wooden prestige ships 400 feet long, supported and kept hog free with a ingenious system of pulleys tensioning highly tensioned hawsers.    Some of those ships had a crew of 6000.

I'd be careful with such an analogy. We simply don't have enough information to interpret the sources on this supposedly 420-feet-long ship, Ptolemaius Philopator's 40, correctly.

While obviously it must have been an enormous ship, there is something decidedly odd about the dimensions related by Athenaeus (quoting Callixeinus) - the ship is claimed to have had a length of 420 feet, a beam of 57 feet and a crew of roundabout 7000 men, roughly 3000 of them marines and sailor. Now, unless the ship had two fighting decks (of which there is no mentioning whatsoever in our sources), you end up with a fighting deck of perhaps 350 x 60 to 70 (allowing for outriggers). That's not much room for 3000 men, mast, gear, catapults and all the other clutter you'd expect on a fighting deck of a Hellenistic warship.

Something is decidedly wrong here; Casson has tried to solve this riddle by pointing to the galley being described as "double-prowed" and "double-sterned" and suggesting a catamaran-type hull based on a length of 420 feet, arriving at a total width of over 100 feet. While this explains the text as it has come down on us, it leaves us with a behemoth of truly gargantuan proportions and a length-to-width ratio of barely 4 to 1. Therefore some criticism has been put forward against Casson's reconstruction, not the least so because he doesn't explain how such a construction would actually have worked in practice.

Other reconstructions have suggested Athenaeus might simply have erred with the width. This may of course be possible; the problem here however is that if we assume one of his numbers is off, we have no way to judge which number is off - methodological problem.

Personally, I think the whole passage is corrupt - while this story originally stems from a local historian who probably had some good information on the ship, it is difficult to estimate which changes it underwent during the course of its transmission.

Incidentally, there is no hard evidence for ships beyond the 220odd-feet mark; of course I know that's not much of an argument.

Jorit

That's the kit I referred to above

Captain Bill

Thanks for putting that on the Forum.I know there's debate on rather it's real possibility or not.But it gave me some looks at these ships.Trumpeter came out with a kit called the Chengho a couple of years ago and its a dead on ringer for these ships.The kit is a very large model with a one piece hull over 24" long approx.1/200 scale.These gives me some leads for research.

Rod

Hello Chuck,

My all time favourite naval history scholar John F. Guilmartin Jr. in his groundbreaking Galleons and Galleys (Cassel, 2002) refuses the 400 feet theory and puts that chinese treasure ships measured 204 by 37 feet and displaced around 1100 tons.

Chuck Fan wrote:

I don't agree with the traditional view that wooden ships can't be more than 200 feet long.   I think 400 feet is definitely possible.    Ancient Greeks of Hellenistic era did in fact build wooden prestige ships 400 feet long, supported and kept hog free with a ingenious system of pulleys tensioning highly tensioned hawsers.    Some of those ships had a crew of 6000. The 200 foot limit experienced by western wooden vessels from post-Roman era to beginning of 1800 were due to the lack of 4 major structural refinements: 1.  Diagonal framing 2.  Internal transverse strength bulkheads 3.  Internal longitudinal strength bulkeads 4.  Internal tensioned cables for keeping the deck in compression. Each of these refinements were possible in a wooden ship constructed using techniques available in 1400.   Their absence from western ships before 1800 was largely a result of design conservatism, not insurmountable technical challenge.   Internal tensioned cables for keeping the deck in compression was a technique well known to the Greeks and Romans, but largely forgotten in the west after the middle ages.    This had enabled the largest Greek and Roman wooden warships to reach well over 400 feet long. Internal transverse strength bulkheads and Internal longitudinal strength bulkeads never came to large ocean going wooden ships of the western world.    They only made their apperence in westen ships after iron has taken over as the main structural material.    But they were possible in wooden vessels.  The Chinese did have both Internal longitudinal strength bulkeads, and Internal longitudinal strength bulkeads in their large wooden junks.   Modern steel vessels derive a great deal of their structural strength from internal bulkheads.

first of all, I really wondered the source mentioning 400 feet mediterranean ships. I have both Conway's Age of the Galley and Lionel Casson's Ships and Seamanship in the Ancient World, the two opus magnums on the subject. They never mention anything like 400 feet ships. Biggest hellenistic-roman polyremes were, at most, as big as 18th century 64 gun SoL. The prestige ships you mention (18 or even 50 banked ships are quoted) were in fact catamarans built by uniting two (or more) galley hulls via an upperdeck. They were not warships either but merely luxury barges. 400 feet long ships of wood are truly impossible and this even more true for chinese treasure junks which are well known to possess heavy fore and sterncastles for archers and warriors. There is no possibility of preventing the sagging and ,in a short time, breaking in two, of a 400 feet long wooden hull stressed with such superstructures even with bulkheads. Wood is an organic and so, a soft material. His limits were well apparent to the shipwrights of past ages.

I don't agree with the traditional view that wooden ships can't be more than 200 feet long.   I think 400 feet is definitely possible.    Ancient Greeks of Hellenistic era did in fact build wooden prestige ships 400 feet long, supported and kept hog free with a ingenious system of pulleys tensioning highly tensioned hawsers.    Some of those ships had a crew of 6000.

The 200 foot limit experienced by western wooden vessels from post-Roman era to beginning of 1800 were due to the lack of 4 major structural refinements:

1.  Diagonal framing
2.  Internal transverse strength bulkheads
3.  Internal longitudinal strength bulkeads
4.  Internal tensioned cables for keeping the deck in compression.

Each of these refinements were possible in a wooden ship constructed using techniques available in 1400.   Their absence from western ships before 1800 was largely a result of design conservatism, not insurmountable technical challenge.  

Internal tensioned cables for keeping the deck in compression was a technique well known to the Greeks and Romans, but largely forgotten in the west after the middle ages.    This had enabled the largest Greek and Roman wooden warships to reach well over 400 feet long.

Internal transverse strength bulkheads and Internal longitudinal strength bulkeads never came to large ocean going wooden ships of the western world.    They only made their apperence in westen ships after iron has taken over as the main structural material.    But they were possible in wooden vessels.  The Chinese did have both Internal longitudinal strength bulkeads, and Internal longitudinal strength bulkeads in their large wooden junks.   Modern steel vessels derive a great deal of their structural strength from internal bulkheads.

Diagonal framing came to western wooden ships only in 1807, when Robert Seppings, surveyor of the Royal Navy, introduced the concept.   This immediately allowed a great expansion in acceptable length.  By 1840, largely wooden first rate ships of the line were already approaching 8000 tons and 300 feet in length.

So based on this, I think it is within the realm of engineering possibility to build 400 foot long mostly wooden sea-going vessels in 1400s.    Whether the Chinese actually did do so we may never know for sure.    But to my knowledge there is nothing that says it really can not be done using 1400 technology.

What I do find impossible are the current reconstruction of what hypothetical chinese 400 footers would look like.    These reconstructions were clearly not done by thoughtful naval architects.    The broad, shallow hull depicted in most reconstructions could not have been very weatherly.   They would have sagged amazingly to leward when sailing in a cross wind.    They would never be able to beat off a lee shore should they be caught in any storm.   These reconstructions do not represent highly sea worthy vessels, in my opinion.   They do not depict ships that could survive a Monsoon season in the Indian ocean or a typhoon season in the China sea.     Any reasonable seawothy vessel must either be far more deep drafted, and narrower, or possess a very large laboard.








 

According to Gavin Menzies, the author of 1421 - The Year China Discovered The World, a relic in the Zheng He Museum in Nanjing is a 36 foot high 'rudder post' supposedly made for one of these ships.  He postulates that the vessel would have to have been 400 feet long.

A wreck of a large ship was discovered at Byron Bay in Eastern Australia which reportedly had a rudder post 40 feet high, but this was tragically (or conveniently) destroyed by sand miners.

Menzies' ideas about the Chinese exploration of the world in the 15th century, especially the idea they may have gotten to North America, have been howled down by the establishment, as is often the case when their carefully constructed and much-cherished view of history is challenged.  The idea that Columbus might actually have known where he was going, because he had a map copied from earlier Chinese explorer's records, is upsetting to some.

I prefer to keep an open mind.

The Trumpeter kit of one of these ships is totally imaginary and, I think, poorly thought out, but the idea of these behemoths roaming the worlds oceans is a tantalizing one.