Early autopilots, the motivation


Check out this recent entry in Maine Boats, Homes & Harbors great series of retro ads. It dimly reminded me of autopilots on the old fishing boats I spend time around in Gloucester, Mass., back in the late 70’s. Some were still using strange schemes to derive electrical signals from a tradition card-in-fluid compass, like a light shining through a hole in the edge of the card to a series of photo-electric cells arrayed in a circle beneath. The Photo-Electric Pilot didn’t make it to the Internet, but I did come across this amazing bit of related marine electronics history:

In 1926, Wood Freeman was salmon trolling along the Pacific Northwest Coast when a boom broke loose, struck him, broke his jaw in three places and knocked out his teeth. Unable to remain standing, he lay on the galley table for three days and steered the vessel home with his feet while watching the ship’s compass in a mirror balanced on his chest.
   During his recovery, Wood — an experienced mining engineer and college chemistry professor — began designing a reliable automatic steering system. Popular but unreliable techniques of the day included steady sails, sea anchors and fishing lead on a trailing line connected to the tiller. Wood continued commercial fishing while working to perfect his steering system. He experimented with magnetic compasses and various ways to detect course error (including fluid conductivity, photoelectric sensors and mechanical pick-off) before determining the best available detection method: fine wires with physical contact on the compass card itself. In 1934, he installed and operated his first production unit, the Metal Marine Pilot Model 1, on the commercial fishing vessel Jean.”

You can learn more at WoodFreeman. Meanwhile, I’m off to San Diego for the NMEA Conference. Write if there’s something particular I should look into at Thursday’s exhibit, and especially if you have questions about DSC and AIS for Ghassen Khalek of the FCC (meeting announced here). I’ve got a couple of interesting boat trips lined up to. Westward ho!


Similar Posts:

The magnetic compass, yay or nay?
August 30, 2005

Swingship, and getting a compass right
September 8, 2005

New Simrad Autopilots, 100% NMEA 2000, almost
November 9, 2007

Small-boat autopilots
March 9, 2004

Ben Ellison

Ben Ellison

Panbo editor, publisher & chief bottlewasher from 4/2005 until 8/2018, and now excited to have Ben Stein as very able publisher, webmaster, and editing colleague. Panbo is going to the next level in 2019 and beyond.

7 Responses

  1. anontrol says:

    > if you have questions about DSC and AIS for Ghassen Khalek of the FCC
    The DSC’s MMSI seems not very well thought out. I’ve read a couple of articles about bogus MMSI information popping up. Why wasn’t a more stable method of assigning MMSIs chosen (and I come from a a aviation and computer network background, so when I see something like this I just shake my head, because we don’t have the same problem with Ethernet MAC addresses or DME equipment in aircraft)… and just so I’m not poking people with a stick, if I had to design the MMSI assignment system, it would have started with a manufacturer ID prefix and then serialization by the manufacturer of the remainder of the ID. The FCC/Coast Guard/BoatUS/whomever would be responsible for making the *association* between the physical layer ID and the vessel identification.
    I’m also curious to know of anyone has done any real world technical analysis of the Self-Organized Time Division Multiple Access SOTDMA (particularly with respect to vessel density; the DME system is limited to ~100 aircraft) used by AIS and how the algorithm differs across implementations and what GP&C Systems International AB (the single patent holder) is doing to insure quality control across the wide range of implementations.

  2. Russ Cooper says:

    I’m at a complete loss as to why nobody has offered up an N2K interface to Minnkota trolling motors yet. Given the number of fishermen who already have them, you’d think it would be a no-brainer that they’d make a great auto-pilot engine. I typically use my to dock, also, as it gives me complete control. I can only imagine what it could do if it were hooked up to some sensors or a decent MFD.
    Of course it would be interesting for you to pose my issues about Vendor PGN support claims versus actual fields implemented, and the SET issues with devices.
    Finally, it would be useful to make another call on behalf of the everyday boater for disclosure of the specification itself so those of us who don’t actually want to make a living out of it might very well come up with some cool stuff by tinkering…that’s what got Linux where it is today…heck, IMNSHO that’s what got Windows where it is today. At the very least, perhaps you can get an explanation as to why it isn’t published for the public.

  3. Phil Koken says:

    We have gotten really spoiled by our WH Autopilot aboard Samadhi V, it simply works. To all the folks who helped develop equipment like this… THANK YOU!

  4. Dan (b393capt) says:

    I am worried. We have not heard from Ben since he left for the NMEA conference.
    The Conference.
    The Big One.
    NMEA 2008 Annual Convention & Exposition
    * More exhibit booths !
    * Education Day with 2 sessions to choose from !
    * NMEA 2000® Dealer Training !
    * Advanced MEI Session !!
    * Industry Awards Night
    * Extended Manufacturer and Dealer Moderated Debate
    So much excitement …
    Being a reporter and all … I would expect Ben would be writing and filling us in on some the happenings … especially since N2K has been a big topic this year on this blog. Not everything, just something short each day with a promise to share more when he gets back.
    Instead … nothing .. nada .. silence.
    I am worried.
    I know for sure, even though NMEA advertises this conference as “Fun in the San Diego Sun”, Ben wouldn’t just leave us here, hanging in the blogsphere with no news at all ! Not Ben !
    Something must be wrong. In as there have been people grumbling about some aspects of N2K … maybe there was an uprising or a full fledged riot ? Maybe Ben was injured ?
    If a riot … I bet it happened during the Extended Manufacturer and Dealer Moderated Debate.
    If not, it must be something serious like that … I can’t think of any other reason not to write, can you?

  5. Ben Ellison Ben Ellison says:

    Dan, you worry too much! My yesterday: 6am trip with Airmar out to 2,800′ of water with various fishfinders and transducers, rest of day in the exhibit hall, then evening thermal imaging cruise with Flir. This morning I listend to USCG, FCC, RTCM, and GMDSS Task Force for hours, and will attend two more meetings this afternoon. In short: tons of input, no time for output. Patience please!

  6. Andy Murray says:

    Fitted a FLIR Navigator camera to a NavNet 3D system last week
    Customers words “Simply Amazing”

  7. flee says:

    I’m happy to see the reference to the Wood Freeman autopilot in a blog so often dedicated to the cutting edge.
    Our soon-to-be 40 year old sloop is so equipped and it hasn’t failed us yet. The course setting compass serves as the only one aboard. The system seems rugged enough to last another 40 years. The 1940’s era styling of the control unit is a cool counterpoint to the ST70 display nearby!

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