Translated material provided by nihontocraft.com
In the Bakumatsu period, the practice of Aratameshi was developed. The obvious difference between Aratameshi and Tameshigiri is that cadavers were not used in this new form of sword testing. Dr. Fukunaga Suiken often mentioned the details of Aratameshi in many of the books he wrote. The following is a paraphrased version of one of his accounts.
Rekko, the Lord of Mito, learned to make swords. He enjoyed the craft and took pleasure in testing swords. The first testing method he developed involved the use of a hardwood staff. The cutting edge, sides and back of the sword being tested were stuck with the staff to surmise the strength of the blade. The hardwood staff was 6 cm in diameter, 181 cm long and made of oak. The second method of sword testing was to use the blade to cut bamboo that was wrapped in straw. This combination of materials simulated flesh and bone. The third method was to cut deer antlers. It is difficult to maintain a balanced ha-niku that is suitable for cutting both straw wrapped bamboo and deer antlers. Because one material is soft and the other is hard, the niku requirements are different. The final method utilized water for testing. A large tub was filled with water and then the sides of the blade being tested were stuck against the water surface flatly. This was done to reveal how well the blade could handle a severe impact. A blade could break during this test if it was not well made.
The above was the basic form of Aratameshi. In the Edo period, Tameshigiri was not like this. Not only are the objects being cut quite different but also the purpose of the test. Tameshigiri tests the cutting ability and durability of a blade on flesh and bone exclusively. It is designed around a strict set of parameters based on movements practiced by trained swordsmen of a given Ryu. The skill of the swordsman is also being tested. In Aratameshi the only object used to simulate the body of a human is the straw wrapped bamboo part of the test. Otherwise the focus of Aratameshi is on the durability of the blade.
There was another form of Aratameshi that took this idea one step further and is the focus of this essay. There is no special Japanese term for it but "Extreme Aratameshi" is an appropriate label. In Extreme Aratameshi the idea was to find out how much abuse a blade could withstand before it broke. No blade could survive this test. The test is not over until the blade being tested is completely broken. It is meant to account for all the variables and unpredictable strain that could be introduced to a blade by unconventional warfare tactics. Before the Bakumatsu period, the target of a blade and the way it would be used was easily predicted. A rigid set of rules dictated how to draw the blade, how to cut with the blade, where to cut with the blade, what form should be used, etc... Therefore, Tameshigiri was quite suitable to test a blade in those times. The development of Aratameshi and Extreme Aratameshi came about from the threat of strange and unfamiliar outsiders preceded by a long period of complacent peace. It can be viewed as a reaction to the panic instilled by the Black Ship. The weapons and warfare methods of the barbarians would certianly be unlike any encountered before. In this context, some may look to find confidence in their warrior's spirit, the sword. Perhaps the goal of Extreme Aratameshi was to prove beyond doubt to all that a fine blade could take all the abuse presented to it and was not only a tool but the ultimate weapon to be depended on to repel any outsider and protect the nation.
The following is an actual account of Extreme Aratameshi. This was documented by Takano Kurumanosuke in the mid ninetieth century.
This testing took place in the home of Kaneko Chubei, a Matsushiro-han retainer of Shinano on March 24th, 1853. Twelve blades were subjected to Aratameshi testing that day. These included 2 katana and 3 Naginata by the famous smith, Taikei Naotane, a shinshinto katana by Tatara Hiroichi , a shinshinto katana by Asahi Kiichi, a koto nagamaki, an Oshu mono koto katana, an Osaka shinto katana, a shinshinto Naonaga katana and finally a katana by Yamaura Masao, the older brother of Kiyomaro.
The testing commenced with Tsuge Kahee, a naginata teacher, wielding an ara nie deki katana by Taikei Naotane made in 1835. Two bamboo sticks were wrapped together and used as the testing object. The circumference of each bamboo stick was about 15 cm each. When the blade struck the target, it penetrated about 80%. This was not a complete cut. Then, a retainer named Saitomasuki tested this katana on a piece of metal that was 0.24 cm thick and 9.0 cm wide. The blade broke in two at the area close to the hamachi. The broken edges looked similar to that of an icicle, very brittle. This katana had been considered well made.
The second blade tested was also a katana by Naotane. This blade had a nioi-deki hamon. It should not break as easily as the first one. After several cuts by Tsuge Kahee on straw wrapped bamboo sticks, a ha-giri developed and the blade was bent. Five other people also tested the katana but none of them could make a complete cut on the straw wrapped bamboo targets. Takano Kurumanosuke then took over the testing and used the katana to cut a helmet filled with iron sand. Another bend developed upon the first cut. Two more cuts introduced another ha-giri. Deer antlers were used as the next target and three cuts were performed. A piece of forged iron was also used for two cuts. This cutting of hard objects produced many ha-giri. After that, Kanekochubee cut a kabuto with it and a severe bend was introduced. He then used the blade to hit an anvil on the mune and on the sides several times and the blade broke.
The 3rd, 4th and 5th blades tested were all nagamaki made by Naotane. They were all bent and ha-giri developed after several cuts. The ha-giri on the 5th nagamaki had a big opening rendering the blade useless.
The 6th blade tested that day was a katana by Tatara Hiroichi, a contemporary smith. It was used to cut a piece of forged metal and the blade was broken.
The 7th blade was also a Shinshinto by a smith named Asahi Kiichi. It broke when cutting a kabuto.
The 8th blade was a koto nagamaki and the 9th one was an Oshu mono koto katana. They were only tested on straw wrapped bamboo and performed well.
Blade number 10 was an Osaka Shinto katana. It was used to cut a tsuba made of shibuichi. The blade broke in two at the monouchi section upon impact.
The 11th blade was a katana by Naonaga, a student of Naotane's. A ha-giri developed after three cuts on the body section of a suite of armor.
A katana by Yamamura Masao was also tested that day. The nagasa was a 65.15 cm. Like the Naotane above, it had ara nie in the hamon. The Masao blade was used to cut wrapped straw eleven times and each cut went about 80 - 90% through the target. Secondly, bamboo staffs were used for six cuts. Each cut penetrated 70 - 80% through the target. Thirdly, an old piece of iron that was 0.303 cm thick and 2.12 cm wide was used as cutting object. The piece of old iron was cut in two pieces upon a single stroke of the sword. However, ha-giri may have developed. In the fourth step, deer antlers were used for six cuts. The fifth test conducted was to cut straw wrapped bamboo twice and the cuts went in about 60%. Then 2 cuts each were executed on a helmet filled of iron sand, iron armor, and a shibuichi tsuba. For the 9th and 10th test, a piece of forged iron and a kabuto were cut once each. Following that, an iron bar was used to hit the mune seven times and a mune-giri developed. In the 12th and final test, the same iron bar was used to strike each side six times and the mune was used to hit an anvil thirteen times. The ha-giri became bigger upon the last test. The side of the blade was then used to hit the anvil three times and the blade finally broke in two.
This demonstration showed how well Yamaura Masao's blade withstood the harsh tests, or should we say abuse, of Extreme Aratameshi performed on that spring day of 1853.
Kubikiri Asaemon Token Oshigata, Fukunaga Suiken, 1970
by Takano Kurumanosuke, Reference Book
Section, Japanese National Library of Congress
NBTHK Journal #263, #579, #580, & #581