Grażyna – Part III

Numbers and Stuff
While I am waiting for supplies I will poke about the net a bit and collect some data and crunch numbers. Having at least some idea of the ‘size of things’ will help when trying to create the model in 1:48.
Anchor Size
Anchors: What size and kind of anchor would be used on a 100ft ship? Assume the ship, a freighter was built c.1890. I’m guessing the Stockless Navy Anchor. I found an assortment of this type on this page .. from 11mm-50mm || 7/16-2 in. In the link the dimensions are kinda ‘wonky’ .. example the 16mm shows a size of 14/21 mm or 9/16 x 13/16 inches (measurement being width x length). Now .. being that I’m only slightly mad .. even I can perform some calculations and find that an anchor that measures 9/16 width would be 27 inches in O scale.

Again .. what size anchor for this size ship? I found this page .. which goes up to a 60 ft. boat. How does the Bruce, Danforth, Fortress, Plow and Yachtsman compare in weight to the Stockless (assuming that would be the correct anchor for my ship)

Found this page .. showing Anchor weights for various dimensions which means whatever scale you could translate the dimensions of the earlier model anchors to weights .. example that 27 inch (ok 16mm) model ancho would equal a 500 lb. anchor

Ship Size and Gross Tonnage (GT)
It stands to reason that the size of the ship will affect the size of the anchor. The weight of the ship with cargo .. and the length that the wind or waves might be pushing against all effect the size of the anchor needed. There are other considerations such as type of bottom where the ship is anchored but that is way more than I need ..

I was having little luck trying to find a 100 ft. long freighter. I had better luck with a search for a Trawler. I found a reference to 100-ft Chinese Trawlers.

98 ft. long with 25 ft. beam has a Gross/Net tons of 165/49
100 ft. long with 21ft. beam has a Gross/Net tons of 145/105

then .. ah ha! Found This Page .. showing U.S. Army Coastal Freighters built for the U.S. Army during WWII. The various versions ranging from 99-102 ft. in length are all listed at 180 gross tons.

That’s “Good Nuff” for me .. so … 180 gross tons it is!

Volume and GRT
The following is from the Wikipedia entry on Tonnage ..

Tonnage is a measure of the cargo-carrying capacity of a ship. The term derives from the taxation paid on tuns or casks of wine, and was later used in reference to the weight of a ship’s cargo; however, in modern maritime usage, “tonnage” specifically refers to a calculation of the volume or cargo volume of a ship.

Gross Tonnage (GT): is a function of the volume of all of a ship’s enclosed spaces (from keel to funnel) measured to the outside of the hull framing.

Well .. shoot. My little brain says .. “and .. so what?”

GT is calculated by using the formula :

GT=KV, where V = total volume in m^3 and K = a figure from 0.22 to 0.32, depending on the ship’s size (calculated by : K = 0.2 + 0.02log_{10}V).

A quick look shows that a 24,000\:GT ship has a volume of 80,000\:m^3 .. and another 2,800K\:GT has a volume of 10,000\:m^3. That works out to the volume roughly 3.5\:x\:the\:GT.

180(3.4) = 612 m^3. Plugging 612 into the formula for K gives me .26 .. so … GT=K*V equals .. .26(612) = 159\:GT. Too small.

tried .. 700 and got 180 GT.

Gross Registered Tonnage (GRT): represents the total internal volume of a vessel, where one register ton is equal to a volume of 100 cubic feet (2.83168 m3), a volume that, if filled with fresh water, would weigh around 2,800 kg or 2.8 tonnes

If V stands for the total internal volume in m^3, then the GRT = \dfrac{V}{2.83168}

so .. \dfrac{700}{2.83168} = 247\:GRT

So. Now we have ..

Length = 100 ft\\  GT = 180\\  V = 700 m^3\\  GRT = 247

Sounds good to me. Find the proper anchor for that.

Anchors from Britannica
From 1902 Encyclopedia (Encyclopaedia Britannica, 9th and 10th Editions) .. this is from the Encyclopaedia Britannica, 9th and 10th editions. .. Anchor

From Table 1 – (Ignoring the sheet, stream, stern and kedge anchors as they are basically special purpose – the bower anchors being the ones we normally think of as ‘anchors’.) A ship of 262 tons has 2ea bower anchors – each 7-1/4 Cwts (hundredweight) .. or .. a little over 800 lbs.

(these numbers are in Imperial tons but since 1 imperial ton = 1.01604691 metric tonnes the difference can be ignored .. since after all I am just playing with numbers)

Now. Referring back to the Blue Ocean Tackle chart .. a 750 lb. anchor is 32 in wide and 38 in. tall.

in O scale that is .. ummm … .666 x .791 in. or .. 17 x 20 mm.

The 35246 – Navy Anchor – 16mm measures 14 x 21 mm.

Pretty close.

– or – the easy way …
I posted this to The Whistle Post. Stoker replied back .. “Couldn’t you just measure the one shown on your source ship? It appears that the Grazyna had deck anchors in it’s early life and you can not see them in the pics, but later after it’s refit it had them in an external bow mount.

With this photo attached ..
Grazyna-2

Which .. caused me to sit there for a few seconds with my mouth hanging open. Ahhhh .. says I.

my reply: Well … sure. That would be the LOGICAL way!

So. The photo cropped to the ship length is 516 px. The anchor is 16 px. Dividing 516/16 = 32.25. The ship was 100 ft long so .. 100/32.25 = 3.1ft or 37 inches for the anchor width. My mad math came up with 32 in.

.. pretty darn close if I say so myself!



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