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Some results after looking for more info while whistling "Oh Danny Buoy" all day... @Steve D put one of these buoys on this Vosper-70ft-mtb, I estimate the size at about 24ft (of the buoy, not the model)

 

danbuoy_01.jpg

 

Manual of seamanship, vol II, showing the version aboard HMS Hood; does not to be to any scale.

 

danbuoy_02.jpg


At left (IWM images A 7915/7916) two dan buoys are  ''stored' in the mast of HMS Rockall showing both the buoy and elliptical floaters; the entire buoy is quire large. Different paint scheme's appear to have been applied. While I have not been able to find measurements (the closest thing is Lambert vol 4: L/S/15 HS trawlers Bryher/Farne, but then I end up with a tiny 14ft) , by using the diameter of the depth change shown at right I estimate the dan boy diameter at abut 17-18inch and the staff at about 24ft.

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49 minutes ago, foeth said:

I estimate the dan boy diameter at abut 17-18inch and the staff at about 24ft.

Hi,

 

My buoy was based on Lambert's drawing in Anatomy of the Ship - HMS Agassiz, a flower class corvette.  This has the body of the buoy as 18in diameter and 33in long with the staff (excluding the flag staff) @ 16 ft long.  The flag staff adds another 4 ft or so, it was adjustable.  That anatomy book is a good reference for misc items in case you've not got a copy

 

Cheers

 

Steve 

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Just a quick quiry  with some advice  - I am building the Flyhawk  1/700  kit (its a lovely kit)   but  at 1/700 scale  do  you think the  railings  would have been visiible  dur to th scale difference,   as in one of your pics  looking aft from the weather deck  close to the funnels  the rails  are really hard to see.

 

Erk.

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@ERK For 1:350 you can get the railing more or less exactly to scale , and for 1:700 you'd have to use ultra-fine railing sets. I think it really adds to the overall quality of the model. But I am perhaps not the best person to ask if you can be excused from adding fewer details 🙃

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11 hours ago, foeth said:

@ERK For 1:350 you can get the railing more or less exactly to scale , and for 1:700 you'd have to use ultra-fine railing sets. I think it really adds to the overall quality of the model. But I am perhaps not the best person to ask if you can be excused from adding fewer details 🙃

Thank you kindly  for  replying.

 

Erk.

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  • 3 weeks later...

Thanks @Kevin Aris; what early photo's are not visible?

 

meanwhile2.jpg

 

Forward superstructure ceiling also redone; moved the hatch opening by about half a mm outboard to align with the longitudinal girder and added some ventilation trunks so no mushroom ends "nowhere". Some vent trunks are on the plans, others are totally made up.

 

meanwhile3.jpg

 

Ten Danbuoys completed as well; need to add the flag poles but need some additional tools to solder the hook at the end... would be nice to add a bit on color to the ceiling of the boatdeck!

 

 

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Gidday, I can only see them from about page 4 onwards now. Any earlier and I get some sort of spacer tab instead.

 

That's incredible detail you've done under the deck-head.   Regards, Jeff.

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15 minutes ago, ArnoldAmbrose said:

Gidday, I can only see them from about page 4 onwards now. Any earlier and I get some sort of spacer tab instead.

 

 

Ah, same here 😄 I killed most post on ModelWarships where these early posts link to. Anyway, plenty pics on the blog remain.

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2 hours ago, foeth said:

Thanks @Kevin Aris; what early photo's are not visible?

 

meanwhile2.jpg

 

Forward superstructure ceiling also redone; moved the hatch opening by about half a mm outboard to align with the longitudinal girder and added some ventilation trunks so no mushroom ends "nowhere". Some vent trunks are on the plans, others are totally made up.

 

meanwhile3.jpg

 

Ten Danbuoys completed as well; need to add the flag poles but need some additional tools to solder the hook at the end... would be nice to add a bit on color to the ceiling of the boatdeck!

 

 

good evening 

the first 4 pages of yr log is text, with just an icon (no image)

nkIoiwx.jpg

 

Edited by Kevin Aris
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danbuoy_03.jpg

 

Although I see only one buoy aboard Hood I decided to build around ten.The staff was the most tricky part with the small eye for holding the sinker at the end. I bent a 0.1mm wire around some 0.3 rod using the Hold&Fold, trimming it to size with the chopper. I ordered a few milling bits for my new Proxxon MF70, amongst others a 0.5mm bit and a 0.3mm round bit, and milled a small 0.5mm channel in MDF with a small 0.3mm trench to position the rod. This was then soldered very carefully... The buoys themselves were made on the lathe. It was far easier to first add a chamfer to the end of half a buoy part and then joining both halves on some Albion Allows 0.5mm tube, rather than adding a chamfer to both ends of a single part. The milling machine was again used to drill in the lifting eye near the tube (some wire) that cost me about 5 drills; the lifting eye is now relatively sturdy and well aligned. I threw the buoys in alcohol to remove the flux after soldering and alas; the buoys do not float... probably due to alcohol's lower density...  🤥 At bottom right the buoys are ready for priming.

 

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This is why I love your build.  I posted a single tentative answer a month ago (“Dan buoy?”), and I come back to find that you’ve researched IWM photos, dug out the Admiralty Manual of Seamanship to understand how dan buoys work, milled a special groove in MDF for accurate soldering, broken 5 drills and produced 10 exquisite tiny dan buoys… when you need one.

 

It’s a beautiful madness from which we all suffer.  Hat well and truly doffed!

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I also ordered and read (nearly) "Allied minesweeping in World War 2" by Peter Elliot (1) 😆 Ah, I was so glad that the buoy was identified here on BM; I had no idea what it was and quite glad another Hood mystery was solved. I think I will cheat a bit and add a number of danbuoys to the shelterdeck ceiling to add a bit of colour for people who take the time to have a peak in an otherwise dark area (if there is one, why not more?).

 

And it was a nice exercise with my new milling machine, trying something new with soldering... because without the template I had much more difficulties aligning parts...  (couldn't do it) 🙂 I'm glad I don't have to build 80 for a danlayer though...

 

Now back to the area below the shelterdeck; part of the deck separated from the hull again and needs some fixing 🥶

 

(1) Interesting to learn about these old pressure mines; calculating pressure profiles of frigates/destroyers in shallow water is one of the standard things we do for the navy, even though it (still) seems out of place compared to electric/magnetic/acoustic profiles?

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Gidday Foeth, while I have no way of knowing I would find it surprising if a ship this big would have only one of those dan-buoys. And I don't think it hurts to have small items with colour here and there, particularly on a dark ship. My personal opinion but I think small brightly coloured items such as life rings, fire extinguishers etc can liven up a model that could otherwise look drab due to all the dark. paint.     

     Those dan-buoys you made were exquisite.    Regards, Jeff.

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Dan-buoys were (& are) not confined to minesweeping; they’re used to mark pretty much anything in a seaway where you are not 100% confident of the depth and where speed is important - so a ditched aircraft, for example.

 

Indeed, with appropriate apologies for sullying a Hood build with something so modern, if you look carefully at this photo of Hr.Ms. Kortenaer (noting her “blue nose”, signifying that she’d been operating above the Arctic Circle), you can see something Day-Glo Red on the port side of the quarter deck.  It’s a horizontally-stowed dan-buoy, I imagine attached to a quick-release mechanism to allow it to be released immediately in emergency - man over-board, ditched Lynx, or similar.

 

51786396260_a2816ff5eb_b.jpg


Which means I’m going to have to build one for my Bloys v. Treslong build.  And I can tell you now it won’t be as beautiful as your 10!

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I don't mind non-Hood detours :) The blue nose fact is wonderful, didn't know that (when does the hurting of not knowing stop ;) I've been on a frigate once or twice for measurements but I have no hands-on experience... ). (too many emoticons? I can adapt the age filter and reduce smileys and exclamation marks)  Indeed, I can spot that buoy on several pics of these frigates, functioning as a more modern variant of the life night buoy?

 

No further weekend updates; I tried two building two vent trunks from hell, but had to start over a few times and they are not yet done.

 

 

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32 minutes ago, foeth said:

I can spot that buoy on several pics of these frigates, functioning as a more modern variant of the life night buoy?

 

I hadn't thought of that, but yes - that's the exact analogy.

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I made a few calculation of Hood's wave pattern last year, to be used as a template for the mode. This is the pattern as it changes with speed.

 

Hood_WaveEvelation_EarthFixed.gif

I still have no idea how the make it, but I think I'll try stacking layers of 0.6mm plywood and finishing off using some sculpting clay.

 

For step two I wanted to add a rough water surface, so I implemented a method from a paper by Fréchot (https://hal.archives-ouvertes.fr/file/index/docid/307938/filename/frechot_realistic_simulation_of_ocean_surface_using_wave_spectra.pdf) that took only a few hours to implement. You need to specify the wind speed, some mean wave direction and the wind run fetch (distance in km of the wind acting on the surface creating waves); the method then collects a number of waves and you can add them to get a pattern.

 

Then you need to tilt the graph such that the rendering doesn't look awful (very old Matlab version at home) but I managed

 

Frechot_01.gif

This looks quite convincing! This is a 100m x300m patch of bad weather... wave elevation plotted 5 times larger, so not to scale. Of course, for the model I need to select one instance...

 

In step 3 I'll add the stationary and weather wind patterns and see what happens! The max. wave height of the bad weather pattern is about 1m max, so only a few slices of plywood (that gets REALLY expensive the thinner it gets). No idea if this will work at all, but it is fun finding out.

 

 

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Oh sure, that would be easy, though you need to carve an opening for the hull... and add the hull wave too. And then it would be useless? 🤔

 

Marijn recently made his water surface using a clay that you need to bake (or use two-component with no hope for late corrections), so I may need to do that with the surface cut up in four quarters and hope it will align well afterwards... (why not). This is mainly meant to have the big waves correct (hull waves that is, weathers waves are random and only have to look ok), then add another layer of very small waves at random. The Fréchot paper has some comments on very small waves but I ignored that as these won''t show up in my plywood stack anyway?

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15 minutes ago, foeth said:

The max. wave height of the bad weather pattern is about 1m max,

So not really bad weather then :fool:

 

Interesting modelling project, one thing that really lets down a waterline model for me is an unrealistic seascape, look forward to see what results you get when you combine the static wake pattern with the generated weather wave pattern. Next challenge, can you predict the effect of the vessel changing course?

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