TDC.

This is coolbert:

Solution!!

Here is the "weapon" that allowed the U.S. Navy submarine during World War Two [WW2] to decimate Japanese naval and merchant shipping.

The Torpedo Data Computer [TDC].

"The Torpedo Data Computer (TDC) was an early electromechanical analog computer used for torpedo fire-control on American submarines during World War II. Britain, Germany, and Japan also developed automated torpedo fire control equipment, but none were as advanced as US Navy's TDC"

An electro-mechanical analog computer of the most sophisticated design, out-pacing [?] foreign counterparts by a mile! A monstrous "brute" of an apparatus, one man to maintain, one man to operate.

Calculations allowing "solution" to a "shoot" of torpedoes at a prospective target with unerring accuracy, the calculation much more accurate and complete than what had previously been available by hand calculation.

"The TDC performed the trigonometric calculations required to compute a target intercept course for the torpedo. It also had an electromechanical interface to the torpedoes that allowed it to automatically set the torpedo courses while they were in their tubes, ready to be launched."

Inputs to the TDC constantly obtained and updated from a number of sources, all simultaneously. To include:

*  "submarine's gyrocompass".
*  "pitometer log".

*  "periscope readings".

*  "target bearing transmitter radar".

*  "sonar observations".

That "target bearing transmitter radar" keyed by a binoculars used when surfaced for night-time attacks. A line-of-bearing [LOB] and range to a target sent auto to the TDC by a press of a button.

Also, the TDC able to "talk" to the torpedoes, data for correct firing "solution" a must!

That TDC amazingly so, an ungraded version STILL IN USE, EVEN MORE THAN SEVENTY YEARS BEYOND THE ORIGINAL DESIGN AND DEVELOPMENT STAGE OF ENGINEERING!

And this in the age of very sophisticated digital computers too!!

"Two upgraded US Navy World War II-era fleet submarines (USS Tusk and Cutlass) with their TDCs continue in service with Taiwan's navy and US Nautical Museum staff are assisting them with maintaining their equipment."

Submarines sold to Taiwan, the Republic of China, and still on active service, complete to include the TDC!! These boats being the "ROCS Hai Pao (SS-792) ROCS Hai Shih (SS-791)"

And with more info regarding the two subs as currently in the inventory of the Taiwanese navy:

Hai Pao: "The terms of the purchase specified that she [Hai Pao] be used strictly for ASW training, so her torpedo tubes were welded shut before the transfer. The Taiwanese restored the torpedo tubes in 1976 and reportedly received modern torpedoes through Italy from a number of sources. As of November 2008, Hai Pao was still afloat at Kaohsiung Naval Base, although probably limited to shallow dives."

 Hai Shih: "As of April 2011, Hai Shih was still in service."

The active duty status and versatility of these two subs called into question by the group GlobalSecurity:

"The 2 GUPPY-class submarines in Taiwanese service are reportedly in very poor condition. When refurbished in the early 1960s, the boats could dive to 415 feet, though by the late 1990s they were lucky to reach 200 feet. The boats are noisy and Taiwan is experiencing difficulty in obtaining spare parts. Neither is equipped with torpedoes, since Taiwan's Navy uses them exclusively for training. During naval exercises, the submarines are used to simulate PRC subs, allowing surface ships to practice anti-submarine warfare techniques."

Please understand that the TDC does not represent a computer as that word is understood today. The TDC not have an embedded memory [?]! Nonetheless, the TDC at the time represented an impressive feat of engineering that WORKED!

coolbert.