Comment on xkcd #3169: EPIRBs
neidu3@sh.itjust.works 10 hours ago
For those who didn’t know: EPIRB = Emergency Position Indicating Radio Beacon. Send an emergency signal via satellite and terrestrial RF. They can be triggered manually, but they also trigger automatically if salt water shorts two exposed pads for a certain amount of time (a minute, I think).
Once triggered it will get a GPS fix and transmit a distress signal via satellite and VHF. It is programmed with the MMSI of the ship it belongs to.
Source: I have a GOC, and I also used to work with marine electronics. I’ve programmed hundreds of these. Mainly Jordan TR60.
Fun fact: A coworker did have to make the phonecall of shame to the coastal radio after accidentally dropping one overboard.
mossy_@lemmy.world 9 hours ago
what does programming them include? Just a ship identifier?
saltesc@lemmy.world 7 hours ago
I have a handheld one—to float with me in a liferaft, etc—and it gets registered to a vessel or vehicle. Whenever I want to use it on something different, contact the federal government, advise of the new vessel ID or vehicle registration, and it’s now associated with the new one.
I don’t think it matters much since it is a beacon after all, but I think it helps in searching. Also, a lot of other details are registered along with it so they know who to send the tens of thousands in fines to if I somehow bypass all three “Are you really sure?” switches and fire the thing off inappropriately.
neidu3@sh.itjust.works 1 hour ago
Any chance what you have is not an EPIRB, but a SART? SARTS are only registered with beacon ID and doesn’t require programming. Shows up on radar and sometimes AIS also. Not sat comms involved.
neidu3@sh.itjust.works 9 hours ago
It’s been a while, but off the top of my head: MMSI (which is basically the radio installation identifier. Same number is used for AIS), and an ID digit (0 in wheelhouse, 1 on starboard bridge wing, 2 on port, etc)
mossy_@lemmy.world 7 hours ago
nice, so plug it into a laptop, get it programmed, then drill it onto the ship?
neidu3@sh.itjust.works 2 hours ago
Yes, except no plugging involved: It’s some sort of inductive way of programming it via a USB dongle. The info is written into this “programming program” which can read and write data to the unit, it’s written, and then you read it to make sure all the info was applied.
Then you label the unit physically with ship name, callsign, and MMSI. In addition to this there are two stickers that come with the unit, denoting the expiry date of the battery and the hydrostatic release. These go on the unit so that’s it easy to check if it’s time to replace them.