During the 20th century, AT&T operated a shortwave "radiotelephone" service for vessels on the high seas. Ships could contact an operator, who could connect them with any landline telephone number they wished.
The North Atlantic station, callsign WOO, occupied expansive transmit and receive "antenna farms" in marshlands near the shore in central New Jersey.
Rendered obsolete by satellites, the service ceased operation on November 9, 1999.
There were three AT&T radiotelephone sites in the continental US, each with its own transmit and receive antenna farms: Ocean Gate, NJ (shown here, serving the North Atlantic), Miami (serving the Caribbean and the Gulf), and Point Reyes, CA (serving the Pacific).
All the sites have by now been razed, either for redevelopment or as nature preserves. The antennas are mostly gone.
Ships on the high seas occasionally still make some use of shortwave radio, but its importance has greatly diminished in the last few decades. The Coast Guard still maintains a "watch" on emergency shortwave frequencies, listening for distress calls, but most transoceanic ships are now equipped with more modern, higher-bandwidth satellite communications systems.
@mattblaze Thanks Matt for this information. I wasn't aware that shortwave radio was so diminishing in importance.
Back in the 1970s and 1980s I used shortwave radio to listen to other countries' news broadcasts a lot.... But I haven't since then. I only learned recently that Radio Moscow went off the air in 1993.
I still have my shortwave receiver (Radio Shack special!) in storage...
@mattblaze A few years back (actually a couple of decades back) we worked with the FAA with regard to communications by commercial pilots out over the Pacific. The radios of that era, except for legacy VHS ones, did not have the range to reach shore. So they depended on satellites or were experimenting with inter-airplane relay (each aircraft was an IP router.)
It was an interesting project, particularly as pilot-controller English is a limited subset amenable to encoding as textual words rather than voice - thus vastly reduced bandwidth - and able to withstand significant ask/answer response latency.
(We participated because we (iwl.com) build gear that can, among other things, introduce lots of issues into communications channels, including many kinds of latency patterns.)
@mattblaze@karlauerbach Probably a lot easier on ships—far more space, including for antennas, lots of power, few weight restrictions, lower speeds mean easier aiming, etc. And ships don't have the advantage of altitude to increase line-of-sight range.
@SteveBellovin@karlauerbach right now all transoceanic fights are equipped with shortwave radio (for controller check in and for emergencies), but only minority of ships are.
@mattblaze@SteveBellovin@karlauerbach I actually worked as a Shipboard Radio-Electronics Officer in the early 80’s for a few years. The tankers were just getting Inmarsat terminals then although I still had to send and receive messages via CW occasionally. The satellite antenna was a one meter dish that was pointed by servo motors linked to the ship’s gyro. Messages came over a Telex machine. Phone calls were $10/min.
@mattblaze If ships still had that position, you could get the experience on a Jones Act covered vessel. I think there are few left that only travel from US port to US port. The El Faro that sank transiting to Puerto Rico sailed under the Jones Act I’m pretty sure. I only had a second class Radio Telegraph license. First class was for passenger ships. It definitely was the end of an era for sure. The crew used to kid me about being replaced by a computer.
@mattblaze As part of the project I was busy suggesting to the FAA and Boeing that they should look into coded voice - codes for words in a limited vocabulary - that would be synthetically articulated at the receiving end. And because pilots and controllers are used to push-wait-talk protocols, that solves a lot of latency/jitter and bandwidth issues and also makes it easier to do packetized voice that gets bounced through satellites at various heights and also other aircraft (we never talked about bouncing via cooperative ship based relays.)
(Some of the geosync satellites at that time had quite long bid-for-transmit-slot times - multiple seconds.)
@mattblaze the Dutch main shortwave station also ceased operations in 1999. The main transmitter remains as a monument. The six 212 meter high antennas were removed.