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FriedClams

New England Stonington Dragger by FriedClams - 1:48 POB - A 1920s Western-Rig

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Thanks to all for the nice comments, I really do appreciate them.  And thanks for the likes and taking the time to visit my build log. 

 

It has been a while since my last posting and I hope you are all well and staying safe.  After finishing the trawl winch, I tired of working on the model and dropped it like a dirty sock.  Now after several weeks away from all modeling, it’s calling me back.  

 

Otter Boards

 

Commercial fish trawling on its face seems like a static and unchanging technology, but it has evolved greatly over time.  One of the most significant changes came with the invention of the “otter trawl".

 

Otter trawling was developed in England and came to America around 1910.  It derived its name from the otter board which was the name given to a sheering device that was being used for “hook and line” lake fishing in Ireland.  This rectangular wood board would skate laterally across the waters’ surface and away from the direction it was being pulled.  To some, the water disturbance caused by the board must have called to mind the activities of an otter.  In commercial fishing, two otter boards are used together below the surface of the water to horizontally hold open the mouth of a trawl net.  Like underwater kites, the otter boards are setup to push outward, away from each other, as the hydrodynamic pressure of moving water acts upon them.  This was a major advancement over the “beam” trawl, which as the name implies requires a beam of some sort to keep the mouth of the net spread open.  This beam arrangement severely limited the size of the trawl a single boat could tow.

 

Otter boards used in ground fishing actually skid along the surface of the seabed.  The noise this creates attracts fish and the turbidity helps to conceal the oncoming net.  The fish become fatigued swimming out in front of the nets' cavernous mouth and eventually begin to fall back past a point of no return and end up in the “cod end”.

 

The graphic below is from Seafish with text that I added.

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Otter boards are commonly referred to as “doors" and their design has been greatly improved over the years, but in the 1920s they were typically flat and made of wood.

 

The doors in a trawling system work in equilibrium with drag from the net and pull from the boat.  The doors have to be the right size and weight for the trawl net gear used, but the available horsepower of the towing vessel limits the size of the doors and how much hydrodynamic force can be applied to them.  The doors end up as the pivot point between competing forces and have to accommodate both.  It has been estimated that the doors account for about 1/4 of the total drag on the vessel.

 

Because I have a boat of known horsepower, I can use the formula below from CIFT to determine the maximum square foot area of a single otter board based on tow HP.

 

S=0.105P+4

 

This 45’ dragger is powered by a 100 HP engine, so...

 

 S = 0.105(100) + 4  =  14.5 sq ft.

 

The rectangular ratio of 2 length x 1 height is commonly used to define the boards’ actual dimensions.

 

Doing the math and rounding up gives dimensions of 5’5” x 2’8”.  This is surprisingly close to the ballpark dimensions I estimated from photo scaling.

 

W = 2.7P determines the optimum weight of a single wooden door based on tow HP.  W=2.7(100)  = 270lbs.  Heavier perimeter strapping and a beefier iron skid plate can be added to increase the weight if required.  So if I ever build a full-scale dragger in my back yard - I'll keep this in mind.

 

My drawings below are based on documents from the 1940s and any photos of trawl doors I could find.  The two doors will be identical except that they are mirror images of each other.

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I also draw part cutting and locating templates.

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The wood part of the doors is made from 1/16” basswood, providing a 3" scale board thickness.  The wood is a single piece scribed to imitate individual boards.

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I’m using aluminum beverage can sidewall for the strapping and tin for the skid plates.  This allows me to simulate seabed scraping by exposing the bright metal.  I find this easier than trying to replicate bare metal with paint. 

 

To create the section of strapping with the radius that follows the forward edge of the door, I use a laser printer to transfer that shape to the aluminum.  I first separate out the pieces in CAD to be used as templates.

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The image is printed on regular copy paper and ordinary cellophane tape is placed onto the templates.  The sheet goes back into the printer and this time the image is transferred to the tape.  The only reason for the first printing was to know where to place the tape.

 

I peel the tape from the paper and stick it to the metal and cut it out.  The tape transparency allows me to take advantage of the clean straight edge and square corner of the material.  Clear laser printer labels would work great for this if you happen to have some lying around.

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All strapping and skid plates are glued on.

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The rear rings are made up from thin slices of .120” OD brass tube, which are held captive by a loop of annealed .014" brass wire.  The back plate is cut from 1:87 rivet plate material and the diameter of the rivets are approximately tiny.  I’m pretending that the rivets are actually the heads of bolts.

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The fore bridle is .032” brass rod and the rear chain is 15 links per inch.  The paper clamps as you can see are yet untrimmed.

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Channel iron is glued into place using the drawing templates as a guide and injection molded nut/bolts are added.  The channel iron is styrene strip “I” beams with one side sanded off.  The rear rings are placed and some first attempts at color is added.

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The fore and rear bridles are placed along with the associated bolt plates.  Thin CA is trickled down the chain links to help keep it from slumping.  The rear ring plates are also glued on.

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Holes are drilled around the perimeter of the strapping and square nut heads are glued in.

 

The wood was weathered with chalk and alcohol and the strapping is pigment over a base of flat black enamel.  If I had to do this over, I would use blackened brass rather than the aluminum, as I’ve had to touch up the black enamel several times due to tiny flakes popping off from the constant handling.  So once I finalized the color and was happy with the look, they were over sprayed with a clear flat coat to stabilize everything.

 

A couple of items were intentionally left out for simplicity but mostly because of laziness - flat head screws holding the skid plates on and the tiny bolts for the thin upper strapping.

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I have never set foot on a commercial dragger, but building this model has given me a greater appreciation into how much skill and know-how is needed to bring in a catch of fresh fish.  Describing what an otter board is and what it looks like is one thing, but being able to set it up and trim its attitude to work efficiently underwater is an art learned through years of experience and hard work.

 

Suddenly, I’m hungry for fresh baked haddock with a slightly browned topping of panko and parmesan . . .

 

Thanks for stopping by.   Stay healthy.  

 

Gary  

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So glad to see that you didn't lose interest completely -- your otter boards look amazing. I enjoyed reading your description of their history, as my academic background is in fisheries science (although leaning heavily toward salmonid ecology, not marine fisheries). I do remember trawling techniques being discussed in class, and I had the good fortune to observe an otter trawl on our university's research vessel. I recall that they are devastatingly effective on ground fisheries and not very selective, resulting in a lot of by-catch. Nevertheless, ground fish were a big component of the local catch where I grew up, and therefore otter trawls were an important aspect of the industry. 

 

Cheers!

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5 hours ago, FriedClams said:

fresh baked haddock with a slightly browned topping of panko and parmesan

 

  That sounds so good. My wife and I are going into our fourth week of self imposed isolation without having gone to the grocery store during all this time. I'm so tired at looking at the same thing every time I open the cupboards. 

 Gary, your build is a cascade of triumphs and it's such a pleasure to watch the progress.  

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What's 'panko' ?

 

Yep, very nice progress again.

 

You might be able to cut out the cellophane tape step when transferring patterns by just ironing on the print-out. Simple copy-paper works, but there are also special thermo-transfer sheets with a shiny surface. I have used this to transfer patterns onto bakelite paper and brass shim with a normal ironing iron.

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I love small craft builds on here (MSW) and this is one of the finest .. That weathering is simply amazing and takes me back to my Dad's boats when he fished many years ago ..

Thank you for sharing your process also, tis wonderful to see things go from pristine to 'shabby' as I scroll down. ☺️

 

All The Very Best Gary

 

Eamonn

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Thanks to everyone for looking in and for the likes.

 

 

On 4/2/2020 at 4:04 PM, ccoyle said:

glad to see that you didn't lose interest completely

I just needed a short break and now it feels good to be working on the model again. 

 

I’m glad you found the short history of interest.  I enjoy researching the when and why of whatever I'm modeling.  For me, the story brings the object to life, whether it’s a model or an old woodworking tool that belonged to my grandfather.

 

Thanks for the comment Chris and your continuing interest.

 

On 4/2/2020 at 4:07 PM, Jim Lad said:

That looks a very nice pair of hard working otter boards.

Thank you John. 

 

 

On 4/2/2020 at 4:11 PM, Keith Black said:

That sounds so good. My wife and I are going into our fourth week of self imposed isolation without having gone to the grocery store during all this time. I'm so tired at looking at the same thing every time I open the cupboards.

I have been avoiding grocery shopping also - around 2week intervals, so maybe my mention of baked haddock was a sub-conscious thing.  When all this is behind, I’m going to go out and eat and drink like a Roman emperor.  Thanks for the kind words Keith and for stopping by.

 

 

On 4/2/2020 at 4:43 PM, wefalck said:

What's 'panko' ?

As Paul said – Japanese breadcrumbs.  They provide a nice crispiness, and are great on oven baked chicken.

On 4/2/2020 at 4:43 PM, wefalck said:

You might be able to cut out the cellophane tape step when transferring patterns by just ironing on the print-out

I gave this a try and it works quite well.  I did find that I had to set the line weight a little heavier for a decent transfer, but quite successful otherwise.  I have some laser transparency film in the closet that I'll have to dig out and see if that works also, because I do like to be able to register the image onto the material.  Thanks for the tip and the comment Wefalck.

 

 

On 4/2/2020 at 5:58 PM, egkb said:

Thank you for sharing your process also, tis wonderful to see things go from pristine to 'shabby' as I scroll down

Thanks for stopping by Eamonn and for the nice complement.  I hope you can find something useful here.

 

 

22 hours ago, jgodsey said:

Where will these be mounted on the boat? 

Hello Jim – they are going to dangle off the gallows similar to this more recent boat.  The model will probably end up on a simple diorama with a worker scraping or painting the hull.  Not quite sure yet.  Thanks for dropping by and the kind words.

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Gary

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Thank you Keith for your wise-guy remark and Bedford for your comment.  And thanks to all for the likes and to those following along quietly. 

 

Mounting the winch and some other stuff

Here’s a small up date on the dragger.

 

Before placing the winch onto the deck, I needed to wrap some additional outer layer cable onto the drums and a wrap or two of chain that will terminate at the otter boards (doors).  I had pre-wrapped the drums with cable (beading wire) when I made the winch, so I only need a few wraps of this outer cable to finish it off.  These last few wraps are a little rougher looking than the shiny beading wire underneath.  This outer cable is actually stainless fishing leader wire and if I had to make the winch over again, I would use only this fishing wire and no beading wire at all.  In fact, now that I have “discovered" this fishing wire (some of which was sitting in my tackle box all along), I don’t see myself using beading wire often, if ever again.

 

I have used 7-strand beading wire simple because it looks like scale wire rope.  But fishing leader wire looks even more convincing.  And it is available in small sizes as well.  For example, 10lb 7-strand uncoated is .008".  The image below shows a comparison between .019" coated 7-strand beading wire and 40 lb test (.015") 7-strand uncoated leader wire. 

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Notice how the twist is much tighter on the leader wire.  Here I painted the leader wire black then sanded the surface with 1500 grit, which leaves color deep in the twists and accentuates the cable look.  Most beading wire is nylon coated and little can be done to improve the look.  The fishing leader wire looks great annealed as well. 

 

The winch is glued to the deck and the chains slung over the towing blocks.  Color is added to the deck around the winch and gallows.

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In the image below, the iron straps that prevent the doors from slamming against the hull have been glued on.  They will eventually get fastener heads and weathering once the hull has been painted.  A half round styrene rub rail has been glued on and two different black acrylic paints were applied to the planks above it.  The base coat is flat with semi-gloss dry brushed on here and there for a slight sheen.  This breaks up the monotone look of the solid flat black.  In this photo, the effect is noticeable on the left due to the angle of light and is difficult to see otherwise.  I also added some salt leaching between planks caused by water seepage off the forward deck.

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And the boat gets a name.  The dry transfer lettering is from Clover House in California and is applied one character at a time.  Flat black acrylic is dry-brushed over the top.  A half round iron stem guard has been added.

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The doors won’t be hung off the ends of the chains until the hull is complete.

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Thanks for taking a look.  Stay safe.

 

Gary

 

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Some people like their model flat all over, but I too think that one can play with different sheens in order to give the parts more 'body' or to accentuate different type of materials or paints.

 

Are tethered model planes still used and is there a supply market for them ? I remember that very fine steel wire-rope was made for that, but don't know whether it would be still available.

 

I discovered fly-tying stuff some years ago as raw material for making my own micro-ropes, but didn't know that leaders were available down to 0.008" (which is 0.2 mm in my units), making it interesting for small-scale models too. Good information for a non-angler.

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29 minutes ago, wefalck said:

Are tethered model planes still used

It's funny you should ask, because I was just asking a coworker of mine the same question a couple of days ago. Control-line models were mentioned in one of our products (physics textbook), and I wondered whether high school students today would even know what one was.

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Funnily enough I also discovered fishing leader wire and used it for the shrouds and stay on the "Miss Caroline" model. I used a cigarette lighter to burn the plastic coating off and this had the bonus of aging the cables somewhat, blackened a bit here, dulled a bit there. You can change the appearance by simply running the blackened cable through your fingers which gives the brighter surface and darker recesses. I'm very happy with it and it comes in a really good range of sizes.

 

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 I don't want to be an alarmist but it's been almost a month since Gary has posted anywhere on MSW. I'm concerned as I sent him a PM on May 1st that has still gone unread. Does anyone know Gary's contact information or membership in another modeling club so that I might check up on him? If so, please PM me, thank you.

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