Computing Under the Sea
Computing Under the Sea
By Anthony Whitman
I and several other members of the Navy League had the unique experience of spending almost 24 hours aboard one of the newest Attack submarines in the US Navy, the USS Santa Fe (SSN 763), cruising in and under Sagami Wan.
Of particular interest to me were the computers and computing systems used-these included some rather ancient technology units to the latest Commercial Off The Shelf (COTS), with the easiest way to identify them being their size/color. The former were mostly big and painted navy gray while the latter were in sizes familiar to many with ivory/cream colored exteriors sporting many names that are well known in the PC compatible world. "Ringos" were not to be seen anywhere.
One of the most up-to-date systems was in the Administrative Officer's domain where he had two Pentiums at his disposal, these having recently replaced an old 386. One was a 133Mhz while the other was a 166Mhz unit. Peripherals included a Laser Printer, Scanner, CD-ROM and 28.8 Modem, software included Windows 95, WordPerfect and DB5. Hard Disk assignments were somewhat unique in that one system supported a 2.1GB unit while the other only allowed the use of removable disk units for security purposes.
All together there are some half-dozen desktop systems and 29 laptops in use in various places around the ship. Several crew members also had their own personal laptop units on board, space being a major reason for not having anything bigger.
Being the "Silent Service" also meant that communications from the ship were very limited so e-mail which is accessible to crew members on most surface ships is only available to the members of the Santa Fe when she is traveling in a convoy with other surface ships which can receive the e-mail, compress it and pass it over to the Santa Fe. When traveling alone the crew can periodically get family grams (up to 50 words) to receive the latest news from home, albeit in very cryptic form.
While on the Bridge, one is surrounded by computing systems, supporting the fire control and navigational functions, but it was interesting to note that all the data passed by one man who kept a running log of the ships' heading and all the contacts on a sheet of graph paper called the contact evaluation plot, a job that may finally be computerized in the next generation of submarines.
Particularly when on the surface the fire control systems are being exercised continuously to keep track of the many large and small ships passing in near proximity to the Santa Fe. Both periscopes, the radar and sonar are used constantly to determine the range and bearing to all which is fed to the fire control system to compute the reading/speed of each as well as the Closest Point of Approach (CPA), a critical parameter when navigating in a busy water way such as the entrance to Tokyo Bay.
Another key navigational system is the Inertial Navigation System which is constantly determining the sub's position and is considered to be very accurate even after several days with no updates. Of course there are several GPS units on board but unlike other ships of the navy they can only provide positioning data when traveling at Periscope depth or higher which for today's submarines is kept to the bare minimum as subs go much faster under rather than on the surface.
Finally as was evidenced by me, COTS equipment has left its mark and will no doubt be used even more in the future as the technology keeps improving and the reliability numbers increase or units get smaller so carrying replacements is more feasible.
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