The Panama Canal

I WAS AMAZED TO SEE THE MlRAFLORES Bridge in the Panama Canal cover picture of the Fall 1996 issue. It is plainly visible at the entrance of the lock, on either side, a drawbridge in its open position. The Bridge of the Americas replaced it; I would have thought it had been dismantled. When I lived in Panama, between 1951 and 1959, the Miraflores Bridge and the nearby Thatcher Ferry were the routes across the canal. Canal traffic took precedence, and until a transiting vessel passed, the bridge opened, the ferry waited, and all vehicle and pedestrian traffic across the isthmus was stalled.

Phyllis R. Heller
Albany, N.Y.

The Panama Canal

FREDERICK ALLEN’S STORY “INSIDE THE Panama Canal,” in your Fall 1996 issue, gave me a much better idea of the operation of the canal than I got from an on-site visit in 1974. While I’m not sure that the steam shovels shown in the picture on pages 14 and 15 are Marions, I do know that shovels built at the Marion Steam Shovel Company played an important role in the work. In Marion we have a saying: “The Panama Canal was built in Marion, Ohio.”

George W. King was president and general manager of the company when he wrote his autobiography in 1915. In it he says, “The writer, after viewing the gigantic undertaking in January, 1913, is proud to say that the Marion Steam Shovel Company should have due credit for the part it has taken in making this mammoth project possible.” He also says, “It was amusing to look over the old French machinery on the scrap heap. Most of the French equipment, when compared to the American machinery used to finish the canal, had the appearance of mere toys.”

Trella H. Romine
Marion County Historical Society
Marion, Ohio

Cable’s Beginnings

I LIKED YOUR ARTICLE ON THE ORIGINS of CATV (“The Birth of Cable TV,” by George Mannes), in the Fall 1996 issue, but I wish you had covered some of the legal problems. I recall a cable operator in New England who decided to embellish his system. During some of the commercial time slots he inserted an ad for local markets. After a while the broadcasters got wind of this and protested. Sure they put out their signals for anyone to pick up freely, but when someone else was making money with their product, they protested. The debate was interesting. Their signal would not have gotten to those CATV subscribers at all if the cable didn’t exist, yet the broadcasters felt ripped off. Maybe the advertisers were miffed.

John D. Fogarty
Columbia, Md.

A Better Black Box Idea?

VANDA SENDZIMIR’S COMPREHENSIVE article “Black Box,” in the Fall 1996 issue, describes some of the many provisions for enhancing the crash survivability of a flight-data recorder. These include titanium cases, thermal insulation, heat dissipation agents, and installation in the rear of the aircraft. It must be designed to withstand 3,400 G’s, stabbing by a loaded steel rod, roasting at 1,100 degrees Centigrade, and dunking in 20,000 feet of seawater, and it must also include a locator beacon, or “pinger.”

Would not the whole system be vastly improved if the recording components were separated from the aircraft and relocated at ground bases receiving data inputs from aircraft by digitized radio transmissions, directly or by satellite? Telemetry is already a well-developed art at aircraft test facilities and, pre-eminently, at NASA.

A few receiver-recorder installations could be strategically sited around the globe to pick up hundreds of parametric signals from thousands of flights simultaneously. The Internet has proved that this level of traffic density is achievable.

May I suggest further that the apparatus could be programmed to identify a sudden loss of signal from any one of the aircraft it is monitoring and initiate an alarm? It might even be possible to detect an incipient anomaly, such as an unusual maneuver or a decrease in altitude or cabin pressure.

If the cost and weight of the transmitting devices seem prohibitive, consider this. The recorders would not have to meet rigorous flight-worthiness and crash-survivability criteria. They could be configured without regard to weight and space considerations. Each recorder would replace thousands of separate airborne devices. For backup purposes they could be duplicated (at more than one location, for instance), and pingers would not be required.

International cooperation and establishment of standards would be prerequisites to full implementation, but the system could be set up initially on the heavily trafficked transatlantic routes. Clearly the black boxes most difficult to recover are those lost in mid-ocean.

Horace Hone
Palm Coast, Fla.

A Better Black Box Idea?

IN VANDA SENDZIMIR’S WONDERFUL article on the black box, mention is made of James J. Ryan’s use of “graduate students and dummies” for automobile safety tests. My graduate students are a bit concerned that this practice may be resurrected now that research budgets are shrinking and the costs for crash-test dummies are increasing. They have requested that I ask if helmets will be provided.

Prof. Mark J. Kushner
Department of Electrical and
Computer Engineering
University of Illinois
Urbana, Ill.