The Ship Model Forum

To add to my slowly growing collection of USN Fire Control Directors in large scale (1/48), I began design of the Mk. 37, Mod. 3 as a typical post WWII fire control director that would make an interesting display model. It will have the Mk. 25 RADAR as installed in the early/mid 1950s.

I am still working on the Mk. 34, Mk. 38 FC Directors in addition to this design project. As these were all begun at smaller scales, I am now revising these to all be printed at 1/48 scale and displayed as a group.

Here is the progress on the Mk. 37 to date -

The stbd rangefinder arm is not attached as this will be a separate part (each side). Also, the handrails that are located on 6 faces of the director will also be printed separately. Tom F. has provided a link to some interesting illustrations of the Control Officer's Station, and I will be designing the slewing sight pedestal & it's various components which is located in the cupola of the director. Secondly, the Mk. 25 RADAR will also be designed as a separate unit although I've located the side support arm brackets on the director roof so that it is properly located when assembly takes place.

At the moment, the DSM design program is tending to lock up in one of the commands and this is slowing work to almost a crawl until it does whatever it does to catch up to itself (ain't A.I. just wadderfall ???). So, you're stuck until the program unlocks or you force it to abort which means losing whatever you happened to be working on at that moment (I tend to save after each part is drawn up!).

The illustration above does not show the barbette & base ring which are located below as they are turned off in the active view - I still have to decide what details to show on that part of the unit. The reference mat'l for this project comes from the Warship Pictorial #8 - USS SALEM (CA-139) (Classic Warship Publishing).

Hank

_________________
HMS III
Mocksville, NC
BB62 vet 68-69

Builder's yard:
USS STODDARD (DD-566) 66-68 1:144, Various Lg Scale FC Directors
Finished:
USS NEW JERSEY (BB-62) 67-69 1:200
USN Sloop/Ship PEACOCK (1813) 1:48
ROYAL CAROLINE (1748) 1:47
AVS (1768) 1:48

Hank

It seems to help a bit if you have only the working window open and save the small details like rivets and coiled springs till later. Yes the refusal to cut away things is frustrating and I have had to nibble from different directions. Arrrgh,

Tom

Hank,

I have a lot of information for the Mk 37 from the late 1950s and early 1960s. I have a 3D detailed CAD file (complete with all the nuts, bolts, washers and rivets).




I have converted the CAD file to STL and printed the director at 1:96. It came out OK, but very fragile and the handrails sagged.





If you need anything just ask.

Phil

_________________
A collision at sea will ruin your entire day. Aristotle

Tom/Dr. Pr -
Thanks for the nice comments, etc.

Tom - yes, it's frustrating but one old CAD trick was to move the object a distance (I used 100mm) in one direction and usually it has a positive effect on the results. I recall in MicroStation 2D we used to rotate the object 360° which some how cleared out the elements that were causing a problem. We shall see....! I am also going to go from a different direction to attain the same results on the offending surface.

Dr. Pr - I appreciate it - and I'll let you know. Your photos of your OKY BOAT director are the goal now....you've raised the bar once again!!!
As this is a display item, I can try to put stuff in that normally wouldn't be seen in smaller scales (i.e. the Control Officer's Station in the cupola). Here is what I've got so far - and it's guesstimate on sizing by eyeballing the relative size of the cupola in a couple illustrations I've got -

I've copied the cupola into a new file and then designed the slewing sight console outside of it using the deck footprint as a guide. Not finished, but this gives an idea of what I "think I can get away with" on this model.

Hank

_________________
HMS III
Mocksville, NC
BB62 vet 68-69

Builder's yard:
USS STODDARD (DD-566) 66-68 1:144, Various Lg Scale FC Directors
Finished:
USS NEW JERSEY (BB-62) 67-69 1:200
USN Sloop/Ship PEACOCK (1813) 1:48
ROYAL CAROLINE (1748) 1:47
AVS (1768) 1:48

At this point, I think I've completed the Slew Sight Console & Platform about to where anything more would be overkill (and probably couldn't be seen anyhow.

However, there are a couple panels of controls on the port side of the lower cupola that may need to be added; I'll assess after printing what I've got so far and see how it looks once the director body is printed also.

I've got a 1/48 MK. 38 FC Director printing now and later this afternoon will run a set of the Mk. 37 handrails & the above console to see how they come out. So, working on a couple various mini-projects AS WELL AS my STODDARD destroyer project. all in good time!

Hank

_________________
HMS III
Mocksville, NC
BB62 vet 68-69

Builder's yard:
USS STODDARD (DD-566) 66-68 1:144, Various Lg Scale FC Directors
Finished:
USS NEW JERSEY (BB-62) 67-69 1:200
USN Sloop/Ship PEACOCK (1813) 1:48
ROYAL CAROLINE (1748) 1:47
AVS (1768) 1:48

Hank,

There are a whole lot of things you could model inside the director if you start down that rabbit hole!

I guess you know that the cupola shell did not extend down inside the director shell, but was just welded to the top.




Phil

_________________
A collision at sea will ruin your entire day. Aristotle

Dr. PR wrote -

Phil - Actually NO! I didn't know that, so that's great info to have. I will modify the director face & cupola shell to correct that. I really appreciate your input & illustrations. Which, by the way, (the upper one) is what I've used as a guide. I will make the modification and then rotate the director around to see how much of the interior is visible from the outside and let that be the deciding factor on how much equipment is needed to be shown. I don't really want to get into a whole lot of the interior stuff at this point.

I really appreciate your reply, pictures, & input - thanks much!!

Last night I worked on the Mk. 25 RADAR supports and have gotten quite a bit done -

The diagonal legs in orange were where I left off last night and I'll begin completion at that point later this morning. This is a rather busy piece of equipment and having 3 views to work from and additional photos is a must to get this correct.

Hank

_________________
HMS III
Mocksville, NC
BB62 vet 68-69

Builder's yard:
USS STODDARD (DD-566) 66-68 1:144, Various Lg Scale FC Directors
Finished:
USS NEW JERSEY (BB-62) 67-69 1:200
USN Sloop/Ship PEACOCK (1813) 1:48
ROYAL CAROLINE (1748) 1:47
AVS (1768) 1:48

Careful! That rabbit hole is very deep ...

I am sure there were many variations in the equipment in the director and the positions of each unit.

You can always open the hatches to make more things visible. We had them all open in Nam. Inside was like an oven. We sat on top taking in the rays most of the time when we didn't have a fire mission. It was the best seat in the house!

Phil

_________________
A collision at sea will ruin your entire day. Aristotle

Phil,

I fully understand - the Mk. 37 on STODDARD usually is seen with its front hatches open. I never had the opportunity to get inside one of them, but point well taken. It may take some doing to open up the ones but I won't say "impossible"....

Hank

_________________
HMS III
Mocksville, NC
BB62 vet 68-69

Builder's yard:
USS STODDARD (DD-566) 66-68 1:144, Various Lg Scale FC Directors
Finished:
USS NEW JERSEY (BB-62) 67-69 1:200
USN Sloop/Ship PEACOCK (1813) 1:48
ROYAL CAROLINE (1748) 1:47
AVS (1768) 1:48

After yesterday's mispap with the printer (PCFI), I've gotten things back on line and printed 2 versions of the barbette for the director as well as the rangefinder arms and a new version of the cupola console - with binoculars & slewing sight -

I've finished the initial design of the director and will do a print run tomorrow to see how this goes. It will take two runs to get all the separate parts printed, not including the Mk. 25 RADAR & supports which are still being drawn up.

Hank

_________________
HMS III
Mocksville, NC
BB62 vet 68-69

Builder's yard:
USS STODDARD (DD-566) 66-68 1:144, Various Lg Scale FC Directors
Finished:
USS NEW JERSEY (BB-62) 67-69 1:200
USN Sloop/Ship PEACOCK (1813) 1:48
ROYAL CAROLINE (1748) 1:47
AVS (1768) 1:48

This morning I started the printer for a couple reprints of barbette rings and also the Mk. 37 director. It finished around 8:30pm and came out very nice. Drying now overnight and I'll begin work on cleanup and so forth in the morning. Looks like this is a keeper. I believe the holes I designed for the handrails did come out, but more than likely will need to be drilled thru, not an issue. Only one piece at the back showed any signs of needed repair, so I'm going forward with further work on this unit. I'll copy the file and begin work on the 2nd Edition which will feature open hatches on the angled front face (3). Now working on the Mk. 25 RADAR and supports. This is rather involved, so may take a while.

Here is the printed director body -


I did these in B/W as the MS photo program updated and I haven't figured out this version and it's ins & outs yet. Not sure I like it, but as usual, the public is last to have a say in what some dumbass 20 something graphics programmer thinks we need!

Hank

_________________
HMS III
Mocksville, NC
BB62 vet 68-69

Builder's yard:
USS STODDARD (DD-566) 66-68 1:144, Various Lg Scale FC Directors
Finished:
USS NEW JERSEY (BB-62) 67-69 1:200
USN Sloop/Ship PEACOCK (1813) 1:48
ROYAL CAROLINE (1748) 1:47
AVS (1768) 1:48

Hank,

The earlier Mk 25 radar dish was perforated, with an array of support "arms" on the back. This was a pretty complex structure and a challenge to model.

Sometime in the late 1950s or early 1960s it changed to a solid metal dish with no supports or ribs on the back side. This version is simple and easy to model.

Which version will you be making?

Phil

_________________
A collision at sea will ruin your entire day. Aristotle

Phil,

Great question! A picture is worth a 1k words.. -

Difficult - Yes!! Complex - For Sure!! But, since my references for the director are mostly from the USS SALEM (CA-139) booklet, I'll initially stick with her 1950's era Mk. 25 as the beginning version; for the 2nd Edition (w/open hatches) I may design the later, solid dish version of the Mk. 25 as you described.

Hank

_________________
HMS III
Mocksville, NC
BB62 vet 68-69

Builder's yard:
USS STODDARD (DD-566) 66-68 1:144, Various Lg Scale FC Directors
Finished:
USS NEW JERSEY (BB-62) 67-69 1:200
USN Sloop/Ship PEACOCK (1813) 1:48
ROYAL CAROLINE (1748) 1:47
AVS (1768) 1:48

Due to the side ladders not drying properly, I've gone and made separate parts for those and will print enough this evening for two director bodies. The ones on the 1st edition will be removed, holes drilled, and replaced with the corrected ladders.

I've also removed the RADAR support brackets from the 2nd edition and replaced with holes for pins that will be added to the support brackets on the legs. I had thought ahead about this when printing the 1st edition yesterday. So, this was not an afterthought, but I wanted to see if the brackets would print properly (they did).

Hank

_________________
HMS III
Mocksville, NC
BB62 vet 68-69

Builder's yard:
USS STODDARD (DD-566) 66-68 1:144, Various Lg Scale FC Directors
Finished:
USS NEW JERSEY (BB-62) 67-69 1:200
USN Sloop/Ship PEACOCK (1813) 1:48
ROYAL CAROLINE (1748) 1:47
AVS (1768) 1:48

While working on the open hatch version, I noticed that the hatch hinges were missing from my 1st edition design for one of the front face hatches - and I had missed this in the 1st print run. So, I've corrected this on the open hatch version (in progress), as well as making a few other modifications to the newer design internally and externally - progress to date -

I still have the lower hatches to drop open, so more design work to do! On the 1st print run, I took note that 99% of the holes did come out, but I went ahead and drilled them thru to make sure they were the proper diameter. This particular mount will not be used, but more for a "test bed" - there are a few small imperfections that I think can be remediated with further revision to the internal structure.

A small amount of progress is being made on the Mk. 25 RADAR/supports, so a balance of time is going on between these two design files -

_________________
HMS III
Mocksville, NC
BB62 vet 68-69

Builder's yard:
USS STODDARD (DD-566) 66-68 1:144, Various Lg Scale FC Directors
Finished:
USS NEW JERSEY (BB-62) 67-69 1:200
USN Sloop/Ship PEACOCK (1813) 1:48
ROYAL CAROLINE (1748) 1:47
AVS (1768) 1:48

Hank:

Looks as if you are pushing the complexity boundaries, loos very good. Your prints look very crisp, which is good. You will lear a lot with these exercises!

Regards: Tom

Tom,

Thanks! With the way the program is operating these days, it's certainly eating up a lot of time waiting on commands to be completed (Pull/cut). But slowly making progress. And, as you say - learning quite a bit about how to/not to design items within a particular part.

Hank

_________________
HMS III
Mocksville, NC
BB62 vet 68-69

Builder's yard:
USS STODDARD (DD-566) 66-68 1:144, Various Lg Scale FC Directors
Finished:
USS NEW JERSEY (BB-62) 67-69 1:200
USN Sloop/Ship PEACOCK (1813) 1:48
ROYAL CAROLINE (1748) 1:47
AVS (1768) 1:48

Hank,

When working on my Mk 37 I had to scratch my head a bit trying to understand the wave guide for the Mk 25 radar. Most of it was normal straight and angled wave guide sections, but I couldn't see how they connected to the antenna that rotated up/down.

Finally I realized that they just used a long curving section that flexed as the antenna moved! Since it is metal, and metal develops stress fractures as it flexes, I wonder how often that wave guide had to be replaced?

Phil

_________________
A collision at sea will ruin your entire day. Aristotle

Phil,
I had not examined that part of the overall unit. I do have one photo from the USS SALEM booklet that shows the director from the rear (oblique angle) - it comes out of the back center blister and up and then bends diagonally somewhere inside the support framework. I have a photo from behind/above the fwd. Mk. 37 on WISCONSIN that may show how it terminates, but it doesn't - the wave guide is missing!
This will be an interesting quest to see if this WG can be determined from end to end.

Thanks for bringing up this interesting subject.

Hank

_________________
HMS III
Mocksville, NC
BB62 vet 68-69

Builder's yard:
USS STODDARD (DD-566) 66-68 1:144, Various Lg Scale FC Directors
Finished:
USS NEW JERSEY (BB-62) 67-69 1:200
USN Sloop/Ship PEACOCK (1813) 1:48
ROYAL CAROLINE (1748) 1:47
AVS (1768) 1:48

Here is a drawing and some images that show how the wave guide snaked through the assembly.

One other small detail - there is an arm sticking out horizontally from the right side circular part of the antenna support that has a bracket with two rings attached. You can see it and its shadow on the radar dish in the "Mk 37 director 1 Sep 2016 10 1024.jpg" image. This was a mounting bracket for the alignment telescope. The director could be visually aimed at a distant object and then the antenna position adjusted so the object was centered in the crosshairs of the alignment telescope. All of the gun and missile fire control director radar antennas had a similar alignment telescope. This is a detail that is missing from most photos of the Mk 37.

Phil

_________________
A collision at sea will ruin your entire day. Aristotle