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 Author  Topic: Detailed photos for SO radar and mast?
Bob Steinbrunn

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Bob Steinbrunn   Send Email To Bob Steinbrunn Posted on: Feb 27, 2017 - 9:14am
I'm building the BlueJacket Ship Crafters 1/48 PT boat (PT 187) and have in hand the SO radar with mast from Shapeways as a 3D-printed item. This replaces the early simple mast included in the kit.

The Shapeways part needs a fair amount of additional detailing, such as nuts, bolts, lightening holes, wiring, and such. I have a number of photos pulled from online, but nothing clear enough or detailed enough for my needs.

Dick's DVD has blueprints for the early mast, but nothing that I can find for the SO radar & mast. The best shot I've found is of McArthur standing by the mast looking aft, previously posted here, but this photo only shows the starboard side.

http://www.ptboatforum.com/cgi-bin/MB2/netboardr.cgi?cid=101&fid=102&tid=3749

Is there any possibility that a "walk-around" series of four photos of this mast exists?

Cheers!
--Bob

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  Jerry Gilmartin

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Jerry Gilmartin   Send Email To Jerry Gilmartin Posted on: Feb 27, 2017 - 11:50am
Hi Bob,
A couple of years ago I took some walk around photos of the mast we have on PT658. I will try and find them and post them here. I took several with included tape measure views next to details so you can get a perspective of the size. The most interesting thing I discovered when we installed the SOA radar mast was the big box thing at the bottom. It is the RF Generator (basically a big transformer along with some other electrical components) and the RF energy travels up to the dish via a "Wave Guide" which appears to be about the size of a 2x4 lumber, except it is actually hollow similar to a gutter downspout. So that is what those things are in the picture. I will provide the photos as soon as I can get off work and look through my computer at home.

Jerry Gilmartin
PT658 Crewman
Portland OR

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Daniele Klay

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Daniele Klay  Posted on: Feb 28, 2017 - 1:10am
Hi Bob,take in account that PT 187 seems to have the mast with square top section, opposite to Jerry's pictures/measurements wich are of a round top section mast, so most of the measurements are not applicable.
See this picture

http://www.pt103.com/images/ptpics/pt192/PT192_Galloping_Guillotine2.jpg

I am also having a hard time finding details about this "early" mast.
Regards


Daniele Kly

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TED WALTHER

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of TED WALTHER   Send Email To TED WALTHER Posted on: Feb 28, 2017 - 9:02am
Bob and Danielle;
I never noticed what you are mentioning Danielle, two designs for the radar mast? As you say, there appears to be a difference. The later design looks to be better reinforced with the curved pieces, notice on Jerry's photo the "line" on the inside of the ring that looks as if this is where the pieces meet. This can be seen again, from a different aspect, in the Gen MacArthur photo of PT 490 RON 33. Maybe these photos can help you:

http://www.ptboatforum.com/cgi-bin/MB2/netboardr.cgi?fid=102&cid=101&tid=3563&sc=20&pg=1&x=0

http://www.navsource.org/archives/12/05187.htm

http://www.navsource.org/archives/12/120518901.jpg

http://www.navsource.org/archives/12/120515004.jpg

http://www.navsource.org/archives/12/120514608.jpg

Take care,
TED

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Bob Steinbrunn

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Bob Steinbrunn   Send Email To Bob Steinbrunn Posted on: Feb 28, 2017 - 9:34am
Jerry....thanks very much! I've explored the PT 658 site and have noted many of your photos there. Great stuff.

Daniele & Ted.....I've noticed this myself, but many thanks. I see some SO radar dome bottom sections have a straight-line profile from the mast up towards the bottom of the dome itself, while others have a curved profile.

Moreover, some curved profile bottom units have a transverse channel section at the bottom of the mast both front and rear just under the RF box, some have a flat bar with lightening holes in both. Some straight profile bottom units have have a transverse channel section at the bottom of the mast both front and rear just under the RF box, some have a flat bar with lightening holes in both. So, it appears there were two different radar domes and two different masts, and you could find either on either.

Last, some straight profile domes have a circumferential band around the bottom of the dome where it joins the bottom piece (and some don't), whereas the curved domes seem to lack this. And the fasteners that hold the dome to the bottom section differ between the two types.

Is this esoteric, or what?

Cheers!
--Bob

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TED WALTHER

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of TED WALTHER   Send Email To TED WALTHER Posted on: Feb 28, 2017 - 11:17am
Bob;
Both are included in the 1/35th PT Boat Conversion kit from Italeri, but since you are working in 1/48 s-ways is the way to go.
As for the Real SO radars, as for the changes in the dome profiles, Jerry or Al might have more insight. I think I asked this same question a few years ago. From what I have seen, mostly when the Dome was changed, so did the mast. So more protection from the elements and more stable, is the curved dome.
Take care,
TED


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Jeff D

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Jeff D   Send Email To Jeff D Posted on: Feb 28, 2017 - 12:17pm
Nice catch Daniele! It looks like the square top type had a shorter X brace with the members at 90 degrees to each other. I couldn't find that type on boats later than the 369 in the images I have.

Here are links to a few photos I found, too large to post here. The 369 shots have really nice detail of the forward top:

http://www.pt103.com/images/ptpics/PT_131_With_Rocket_Launcher_Sep1944.jpg

I believe the X brace members taper towards the center:
http://www.pt103.com/images/ptpics/PT_150_Color_BobWieseJGSmilesMachnickLtWest.jpg

http://www.pt103.com/images/ptpics/PT_150_Color_OrmacBay.jpg

http://www.pt103.com/images/ptpics/PT_189_Ron_8.jpg

Another shot that seems to show the brace is tapered:
http://www.pt103.com/images/ptpics/PT_195_Andys_Dad_02.jpg

http://www.pt103.com/images/ptpics/PT_328_Crew.jpg

http://www.pt103.com/images/ptpics/PT_328_Melville.jpg

Cropped from http://www.history.navy.mil/our-collections/photography/numerical-list-of-images/nhhc-series/nh-series/80-G-257000/80-G-257978.html
http://www.pt103.com/images/ptpics/PT_369_37mm_Cropped.jpg

Cropped from http://www.history.navy.mil/our-collections/photography/numerical-list-of-images/nhhc-series/nh-series/80-G-283000/80-G-283915.html
http://www.pt103.com/images/ptpics/PT_369_37mm_Cropped_02.jpg



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Daniele Klay

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Daniele Klay  Posted on: Mar 1, 2017 - 3:51am
Yes Jeff, the "early" radar mast also had solid cross braces,instead of the lightening holes on the cross braces in the later ones..
Does anybody have accurate dimensions/measurements of the radar dome at least?
I saw somewhere 27" diameter by 32" height but has to be confirmed
Greetings

Daniele Kly

Total Posts: 126 | Joined: Jun 23, 2015 - 12:43pm | IP Logged

Jerry Gilmartin

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Jerry Gilmartin   Send Email To Jerry Gilmartin Posted on: Mar 1, 2017 - 1:30pm
Here are photos with measurements

Height from deck to dome top 141 inches Top view


Height from deck to dome top 141 inches Bottom view


From Deck to Bottom of dome 115 inches


Width of yardarms 52 inches


Width of mast at leaning prop hinge pins 24 inches (Outside dimensions)


Width of Hinge Pin end of Folding Mast prop 18 inches


Width across bottom of main mast feet 38 inches


Width across bottom of main mast feet 38 inches (wider view)


Wave guide flexible joint width 5 inches


Folding Mast Prop length 7 feet


Width of Signal Generator box 24 inches


Depth of Signal Generator 13 inches across top


Waveguide length from top of Signal Gen to bottom of dome 76 inches


Waveguide length looking up into bottom of dome 76 inches


Length of X shaped gusset 45 inches


Length of Base Plate 45 inches


Front of Base Plate to Back or folding prop 58 inches


Signal generator shelf and shock mounts height 17 inches


Side view of mast height deck to top of dome 141 inches


I hope these answer some of your questions.
Jerry



Jerry Gilmartin
PT658 Crewman
Portland OR

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Jeff D

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Jeff D   Send Email To Jeff D Posted on: Mar 1, 2017 - 2:44pm
Great work Jerry! I'm sure many modelers will appreciate this.


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