Trawling (Dragging) Explained Aboard The F/V Pamet

Trawler Pamet, originally uploaded by captjoe06.

The following text is about the best explanation of how Dragging or “Trawling” works in layman’s terms that I’ve run across. It comes from Oregon State University and the credits to the writers will be included at the bottom of the post.  Read the explanation of trawling and then look at the pictures I took this morning with the titles of each thing they are talking about so you can visualize what they are saying. Even though this is from Oregon, our fishermen fish the same way only for different species.

A trawler is a vessel that drags a funnel-shaped net through water to harvest fish or shrimp. The net is wide at the mouth and tapers back to a narrow cod end that collects the catch. The average bottom trawl opening is 40 to 60 feet wide and 8 to 10 feet tall. Bottom trawlers usually tow their nets at 1 to 2 knots on or above the ocean floor. Fishermen might tow midwater trawls faster to catch faster-swimming schooling fish.
Trawlers have a large metal trawl door that is attached to each side, or wing, on the front of the net. The water hits the doors and the pressure of the water passing over the door spreads the net open. The doors are flat, oval, or slightly v-shaped. A steel cable extends from the door to a winch just behind the pilot house. Most large trawlers have square sterns with inclined ramps and are referred to as stern trawlers. The nets are hauled aboard up the inclined Boom Bottom ramp on the stern. Older trawlers without inclined ramps haul their nets over the sides using a haul line and a block on an overhead boom to bring in the cod end of the net.

BOTTOM TRAWLERS

Bottom trawlers tow the net along the ocean floor to catch fish that live on or just off the bottom. These fish include rockfish, cod, sablefish (black cod), ocean perch, flounder, and sole. Trawls can be designed to catch particular groups of fish. A large mesh net (4 1/2 inches to 5 inches) is kept on a stern-mounted reel. The two doors are stored along the rails near the reel.

The net is set off the stern by unwinding the reel so that the cod end is put into the water first. The rest of the net is unrolled from the reel, and then the doors are placed in the water. Water pressure on the doors causes the doors to separate and open the net. Enough cable is then released to place the net at the desired depth. The upper lip of the net is lifted up by floats on the headrope while the lower lip of the net is pulled down by a weighted footrope. This action opens the net vertically.

Rubber discs may be attached to the net to hold it down. There are now restrictions on the size of the rubber discs that can be used on footropes when trawling on the Oregon continental shelf. These restrictions confine trawling to mostly smooth bottoms, such as sand and mud. Tow times can last from 30 minutes to several hours. Depths can range from 5 to 700 fathoms (a fathom equals six feet). Bottom trawlers typically fish from 1 to 40 miles offshore.

The crew hauls in the net by winching in the cables until the doors are back in place and most of the net is on the reel. Once the catch is on board, the net is reset for another tow. Then the fish are separated into deck bins (checkers) and put in the hold, where they are iced or refrigerated.

The Oregon State Research Report Can Be Found Here

Writers: Ginny Goblirsch and Steve Theberge
Consultant: Scott McMullen
Artist: Herb Goblirsch
Editor: Sandy Ridlington
Design: Rick Cooper

12 comments

  • This is why I love your site Joey!
    Thanks

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  • I always wondered what the doors were for. Thanks Joey this was very interesting……..FRANK

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  • Joey, this is just the kind of thing that makes your site so very valuable. It’s one of the reasons I make sure to visit every day! Thanks — and keep up the “education” of us non-fishermen-types.

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    • It’s funny. Some people come to visit for different reasons. Some for the commercial fishing stuff, some for the downtown stuff, some for the local art scene stuff, some for the videos. I always try to keep it a mix so there is something for everyone.

      I love each different part equally. They are all a part of what makes this island great IMO.

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  • Oh, I agree — each part is special to particular readers, and (at least for me), there are many topics you cover that I’m interested in. The fishing (the vessels, and what each piece of equipment is used for) is something I’m trying to learn more about.

    I think your promotion of Gloucester’s merchants is especially helpful, and it’s also nice to read the answers to your “questionnaires” … even the long answers … maybe especially the long answers!

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  • O.K. Joey, Please set me straight. I don’t believe I’m going to say this. When I upload a picture of the vessels in Gloucester I always list them as working boats because I don’t know if their draggers or trawlers. Maybe I should look at the nets again. To me they are all coming off the stern side. I’ll have to take my book out and study it seeing I forgot most everything. But am I wrong to not want to call them draggers or trawlers where I’m not sure. I just feel funny calling a boat a dragger if it’s a trawler. Lobster boats are so much easier. You just have to know the style.

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  • P.S. One day when I was at Jodrey this guy was telling me about a guy that got hurt with the birds. No, not seagulls. The birds on top of the outriggers. When he said why am I telling you this, you probably don’t even know what an outrigger is, I said yes I do. Joey, if you could of seen the look on his face you would of laughed like I did. And when he heard me laugh he was looking straight out towards the paint factory and said I don’t believe it. A women that knows what birds are and I said oh, come on. I’m not the only female that knows and he said no but I don’t know many women that know what they are unless they are married to a fisherman. I really took to the guy. I’ll never forget that day.

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  • Pingback: A Dragger’s Net Spread Out For Mending « GoodMorningGloucester

  • this is great! thank you!
    and then, after your catch is iced, why are they trucked through three states to get down here when you can just cruise the blue line straight down?

    short sea shipping, Capt Joey! load up yer schooner and bring ‘er down!!

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  • And all the while I thought trawling was something done in a bar atmosphere after many drinks….You catch big ones, small ones, striped ones, and you know the rest….Now my early years of nightlife experience has come crashing down. Man trawling is not hanging out at the Glo Ho dragging chicks to the dank floor? Or them dragging you cause it works both ways…If you catch a flounder eyed guy it’s probably just the rabbit dont be alarmed…This should make Joey laugh right off the dock on his apple sorting sea Beatles!! Throw him a flotation device…

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