Wooden merchantmen during WWII

[Ron Sundby]

During the war the Japanese attempted to turn out significant numbers of wooden mechant ships to supplement their logistical abilities. (Even before the U.S. Navy's submarine force sank so many standard Japanese merchantmen.) I have read eyewitness accounts of these being built in both Hong Kong and the Philippines for use throughout Southeast Asia.

“Shipbuilding which heretofore was an anemic and even a dead industry was lately reorganized and placed on a highly efficient footing. With the intensified activity in this line the lumber industry which supplies all the necessary timber for the innumerable dockyards constructed recently has to set up it’s tempo to equal pitch.” Japanese Occupation Papers, University of the Philippines Main Library: National Assembly Yearbook 1943, Wartime Business in the Philippines a General Review

“There were attempts to build new wooden ships and barges. Shipyards for vessels ranging in capacity of 50 to 500 tons were used for this purpose notably in Malabon Rizal; Sta. Mesa in Manila; Caloocan; Mindoro; Legazpi, Albay; and Davao in Mindanao. Japanese experts supervised Filipino labor in these activities. Building activity was frantic and the effort fast. Military Intelligence also observed that the new wooden tonnage did not make much headway in inter-island shipping. The suspicion was that this new tonnage was also undertaken for military, naval, or other war use.”Sicat Gerardo P., The Philippine Economy During the Japanese Occupation 1941-1945, Quezon City, University of the Philippines 2003

“But the Japanese had an inexhaustible supply of mahogany in the Philippines and of teak in Thailand and Burma, both excellent for shipbuilding; and in Hong Kong there was no lack of trained shipwrights. They could build a modified junk, a sailing vessel which they could in some cases equip with motors, and which would have two obvious advantages: it could be built quickly and in considerable numbers, and it would afford a smaller and much less remunerative target for enemy submarines… It was announced that the vessels built were to be employed in ‘the transportation of raw materials and commodities for reconstruction in the Southern Regions, such as crude oil, lumber, and rice.’ The first launched December 8,‘42. Large numbers launched taking forty to sixty-three days construction." Ward Robert S., Asia for the Asiatics, Chicago, University of Chicago Press 1945

Aperently there were a relatively large number of these ships built, but I've never read of their having much affect on the Japanese supply situation. Certainly there was never enough shipping to transfer all of the raw materials gathered in the philippines and ship it to Japan; huge stocks of strategic resources were piled up on the docks during the '43-44 which never got moved.

Does anyone know how many of these ships were built and just how effective they were for the Japanese?

Thanks, Ron

[Brady]

This subject is something of a pashion for me, woden hulled ships (Sea Trucks or shugar dogs) were built all over the Japanese empire to the tune of millions of tons worth of them throught the war, They servedthrought the empire, but could be found in the front lines as they would often be used to carry suplys the last leg of the jurney so to speak, larger more valuable freighters would off load to them an they would take the suplys the rest of the way, in rear areas they would move goods to larger harbors to load onto ships...

p. 38 The Japanese merchant marine in WW2:

"Providing Japanese estimates of the nations shipping needs were accurate, adaquate maritime transport existed for all these roles. At the time of pearl harbor, the merchant fleet amounted to 6.4 million tons. There were in adation, approximatly 1.2 million tons of wodden vessels as well"

BOLD would include fishing vessals as well.

Some Quotes from Parillo's book:

"Over 90% of Woden Hulled Merchant Men built in Japan during the war were of standard designe;the 100-250 ton cargo carrier types acounted for two thirds of the total."

"The largest type of small craft at work in the Paciffic during WW2 was the Kaijo torakku, or sea truck,which served in great numbers from Burma to the Marshalls. The Japanese themslefs losely applied the term to many types of small craft, including tug boats,watter suply ships,salavage vessles,and others, but normaly it denoted a particular class of cargo carrier. The distinguishing carasteristic of the sea truck was it's simple boxlike designe,which minimised the skills nescessary for it's construction. Sea Truck ranged in size from 100 tons to 1,000 or more tons. The Most common type was the SD woden type displacing up to 300 tons. Sea trucks over 300 tons ,called SC's , Ushally had steal hulls.The FTD was a vershion of the sea truck that surpased 1,00 tons. SD's profilerated after the shortage of steal curtailed the construction of the later types.

Sea Trucks carried equipment and aramement suited to their roles and proximity to the combat zones. Radio transimiters were to scarse to alot to all sea trucks, but most all had receivers. SC's in combat areas might mount as many as three MG's, a barage mortar, and a 3 inch gun, while others carried dumy weapons or non at all. Desial or semi desiel engines propelled the sea truck at speads of around 8 knots. It's fuel tanks held about 12 tons of heavy oil, enough for about 10 nights of crusing.

The Sea Trucks functioned as transport, piolet ship, escort, and in countless other capacitys but it's principle use remained in cargo transport, espichaly for suply operations at the front, even an SD could carry 150 tons or so, the equilvent of 7 days rations for an entire Imperial Army Divishion of 16,000 men. Typicaly Sea Trucks took on loads from steal merchantmen at rear basses for the finial segement of the jurney to the front. But unlike most other types of small craft they also sailed alnongside the Steal Hulled merchant men on the high seas voyages of hundreads or thousands of miles."

ONI



AWM:



"In July 1945 SS Bugara (Schade) operating in the Gulf of Siam, sank 12 junks, 24 schooners, 16 coasters, 3 sea trucks and one naval auxiliary, all by gunfire"

VP 108 summary of Combat Operations from 15 March 1945 to 31 August 1945:

ENEMY SHIPPING SUNK OR DESTOYED
6 ??? Sugars
25 Sugar Dogs
2 Motor Torpedo Boats
1 Whale Killer
2 Sub Chasers
6 Trawlers
1 Sea Truck
1 Auxiliary Schooner
1 Powered Lighter
1 Junk
1 Sea Going Tug
2 Landing Craft
68 Victor Ables, Luggers and Sampans

118 Total SUNK

ENEMY SHIPPING DAMAGED
3 ??? Dogs
2 Picket Boats
1 Sugar Baker Sugar
1 Sugar Able Sugar
3 Motor Torpedo Boats
1 Gunboat
1 Sub Chaser
15 Sugar Dogs
1 Sea Going Tug
1 Powered Lighter
4 Trawlers
7 Junks
10 Barges
108 Victor Ables, Luggers and Sampans

159 Total DAMAGED

US Army Air Corp:

Note the sea Truck along side the freighter...

[Carl Schwamberger]

Thirty years ago I met a former crewman on a US submarine of this era. His combat duty was BAR gunner. When attacking these small ships the drill was to surface. He was first onto deck with the BAR & task was to sweep the enemy bridge with a magazine while the gun crews got the MG into action. They usually had the MG firing by the time he expended his first magazine. The ship would be finished off with the deck gun. He remarked they attacked larger ships as well with this technique when unescorted. His service on the subs was from late 1943 to 1945.

[Ron Sundby]

Thanks for the input guys, especially all that detail Brady,

Ron

[dave-pearling]

Hi Brady and all,

Can I ask in your interest in Japanese sea trucks if you came across information about what earlier merchant ships influenced their design. Many Japanese pearling mother-ships from the 1930s that operated in SE Asia look very similar. I wonder if the Japanese decided this mother-ship design was a good standard to replicate for others purposes during the war.

thanks

Dave