USS Cape (MSI-2) by Dr PR - 1:48 - Inshore Minesweeper

[Jim Lad]

Just catching up, Phil. She's coming along very nicely.

 

John

[SaltyScot]

You did a nice job on that deck house framing, Phil, very neat and precise. What wood are you using for that?

[Dr PR]

Mark,

 

The 1/8 x 1/8 inch strips are boxwood. This could be anything since it is hidden inside the deckhouse. The deckhouse sides and decks are SIG 1/16 inch plywood - I don't know what type of wood.

 

The deck planks are 1/16 x 1/16 inch strips. That is to scale, but is pretty small. Nibbing will be pretty tricky. The grout was 1/4 inch (6 mm) on the ship. That comes out to about 0.005 inch at 1:48 scale. I think thin black paper would make a nice clean grout, but that means working with a LOT of thin paper strips! I did this on the schooner build. I have experimented with pencil on the sides of the strips, but it is inconsistent and pretty lame looking.

 

Of course I could use some of the original calking goo we used on the Cape - I saved some in a bottle for use on models, and I even planked a model ship deck with it back in the 1970s! But it is extremely messy. No thanks, once is enough!

Edited June 18 by Dr PR

[SaltyScot]

6 hours ago, Dr PR said:

but it is inconsistent and pretty lame looking.

 

Yes, it most ertainly is.I tried that on the Endeavour build. Very disappointing.

[Ras Ambrioso]

Phil, I am amazed at the amount of detail you have put in your model. Your post is always welcome as we can follow the history of this vessel, the detailing and the construction methods you have used. You could write a book on this build. Congratulations

[Dr PR]

I am about ready to start planking the deck. But before starting that I have been making drawings of the deck fittings (deck furniture in the olden days) to determine what parts I need to have made from 0.005 inch (0.13 mm) brass with photo etching. Here are some examples.

 

This is part of the blueprint for the stern roller chock. All of the minesweeping cables pass through the rollers or blocks attached to the "arms" of the top piece.

 

 

This is just a small part of a large blueprint that gives the dimensions of all individual parts and a complete parts list. From this I made a CAD drawing of the assembly, and from it I can make 2D scale drawings of all the parts. I will make the pieces from 0.010 and 0.015 inch (0.25 mm and 0.4 mm) brass and solder them together.

 

 

 

 

Some of the assemblies are more challenging. Here is a side drawing of the minesweeping winch (for towed sweeps to clear moored mines).

 

 

I have top and end drawings as well. However, these drawings only give dimensions for the entire assembly, to be used for planning the mounting arrangement on the deck. No detailed and dimensioned drawings of individual parts are given, and there is no parts list. So I have to do a lot of measuring and calculating to guess the dimensions of all the parts not shown. I do have some photos, but they don't show many parts of the assembly.

 

Here are pictures of how far I have gotten so far. The light brown parts are the wooden mounting base that sits on the deck. The red parts are work in progress for the metal base of the winch. The gray parts are finished. And the rollers on top are close to the natural colors of the reddish-brown polyester coating on the nonmagnetic metal rollers.

 

 

 

This assembly sits forward of the stern roller chock and aft of the much larger winches and reels for the magtail (magnetic mine sweep cable) and the acoustic mine sweep cable (another very complex assembly!). The magnetic and acoustic sweep cables ride on the two large rollers at the top of the frame. The three large reels below are for the two long cables (left and right) to the pigs (floats) for the towed sweeps for cutting the cables of moored mines. The narrower center reel is for a shorter cable that tows a "kite" close behind the ship that pulls the moored sweep cables down deep just aft of the stern so the cables carrying the mine cable cutters will run under the mines to cut their mooring cables. All of these cables run through the stern roller chocks shown above.

 

I do have separate detailed dimensioned drawings of the winch motor, and it is perhaps the most complex part of the assembly. But I have simplified it greatly, leaving off details of bolts and screws. On the model the motor will be about 0.73 inch (18.5 mm) long so the tiny details are too small to make. The whole winch assembly will be 1.7 inch (43 mm) high, 2.2 inch (56 mm) wide and 1.5 inch (37 mm) long. Most of the parts will be made of brass, but I may 3D print the gypsy heads (if I had a lathe I could turn them out of brass). It will be a nice little model in itself.

 

There are about 30 separate deck fittings on the model, so I am just getting started!

 

Edited June 23 by Dr PR

[Jim Lad]

Deck fittings can be such fun, Phil (or not!). 🙂

 

John

[TBlack]

Phil, Looks like you've got some pretty good plans as a starting point.

Tom

[FriedClams]

Nice progress, Phil.  Wonderful CAD work and I'm looking forward to seeing these 30 or so deck fittings come to life.

 

Gary

[Dr PR]

John, Tom and Gary,

 

Thanks. The plans are pretty good, but a large number of dimensions are not given and have to be determined by careful measurements from printed drawings and scaling compared to dimensions shown on the drawings. But that's a LOT better than "photoguestimatiion" using measurements from photos!

 

But I did run into a problem. One blueprint shows the winch control stand at the forward port corner of the winch. Another shows it on the fore side of the winch between the left two brake wheels (white in the images). These images show the two different positions for the control stand. The  three white brake wheels are on the forward side of the winch, and the cables from the winch streamed out from the aft side.

 

 

 

 

If the control stand was at the port corner it would be directly in line with the port gypsy head, and that would interfere with using the gypsy to pull on ropes and cables.

 

None of the photos I have show the control stand clearly, but one that I took while we were streaming minesweep gear does show the white knob on the control stand handle to the right of the port side white brake wheel. So it appears the stand was in front of the winch and not at the port forward corner. But I am not certain where it was. And the photo may show the stand rotated around the vertical 180 degrees from the position shown here, with the handle on the inboard side. But that would put the stand right in front of the brake wheel, making it hard to reach! I will probably put it in the front, with the final position determined by what looks best.

 

The control stand regulated the motor speed. The motor drove a series of step down gears in the long gear box with the rounded corners. The gear box turned the main shaft with the two gypsy heads on the ends for winching ropes and cables, etc. Each cable reel had a brake band around the outside of one side of the spool (inside a protective cover). The brake wheels (white) tightened and loosened the brake bands. Each reel also had a clutch that rotated with the main shaft. To engage the reel the long horizontal handle beside the brake wheel was pulled to the side, pressing the rotating clutch disk against a clutch plate on the side of the reel. The vertical "pawl handle" below the brake wheel was pushed forward to engage a locking pawl against teeth on one side of the reel to lock it in place.

Edited June 30 by Dr PR

[SaltyScot]

14 hours ago, Dr PR said:

photoguestimation

 

That's going in my next Scrabble game!   

[vaddoc]

Honestly Phil, your CAD drawings are pretty amazing. 

Regarding caulking, I ve used in the past Elmers colour changing filler mixed with black acrylic paint. Sanding it all off leaves gray caulking lines. A quick wipe with Tung oil (I suspect any other finish as well or Rennaisance wax which is invisible) makes the lines black again. 

 

Vaddoc

[bdgiantman2]

Very impressive CAD drawings of the deck gear used on Cape during her Navy days.  A lot of detail, going to be fun to see how the scaled equipment turns out.  As for the location of the control box, my personal opinion is it looks less out of way of operations being in front the motor between those two large white wheels instead of the offset position.  This is incredibly cool.

 

Brian D

[Jim Lad]

Phil, I think you're right in thinking that the control box would be in front of the winch rather than off to the side, especially if the side position interferes with the gypsy.

 

John

[Dr PR]

Two winches were combined in one framework. The upper winch was for the towing and power cable for the acoustic minesweeping device. The larger and lower winch was for the magtail - the magnetic minesweeping cables. They had similar controls and motors. The gearbox was the same for both winches but the motors were slightly different in size and power, but manufactured by the same company so they look alike.

 

 

 

 

 

I think this will be the most complex assembly on the model. It will be 4.29 inches (109 mm) long (fore to aft), 3.375 inches (85.7 mm) wide and 2.33 inches (59.7 mm) high. This thing was difficult to model because the four blueprint drawings that show all or part of it give different dimensions! And the dimensions for most parts aren't shown, so it was necessary to measure and scale everything. Worse still, a lot of the framework pieces aren't shown (or are faint outlines) so there was a lot of guesswork and successive approximation until everything fit in pretty good agreement.

 

There were some parts shown in the drawings that simply wouldn't work. For example, there was a cross brace for the framework that would pass through the sides of the cable reels! I have been working on this drawing for 12 days trying to sort out these things. It may not be perfect (there are some parts of the mechanism I won't try to model) but it will be good enough for this model.

 

These 3D CAD drawings serve two purposes. First, they force me to try to understand how the things were built, and determine some reasonable dimensions.

 

But the other purpose is to find parts that should be made by photo etch. I am preparing drawings to send to a photo etch manufacturer (I don't want to mess with doing it myself - that can be pretty frustrating).

 

This is an example of some photo etch pieces from this winch assembly - the deck gratings. I can probably 3D print them - I have done some very small screens and such. But the 3D print material is brittle and these will be thin (0.020 inch or 0.5 mm) and very fragile. They will be more likely to survive handling if they are photoetched brass or stainless steel.

 

I may use 3D printing for the motors and gearboxes. Although the motors were slightly different sizes (about 3% difference) I will probably make them all the same size.

 

Most of the framework will be made of brass pieces soldered together.

Edited Saturday at 10:12 PM by Dr PR

[SaltyScot]

I agree, those CAD drawings are very good, Phil. In case I missed it, are these models going to be 3D or resin printed?

[FriedClams]

Superb 3D modeling of that double winch, Phil.

 

21 hours ago, Dr PR said:

These 3D CAD drawings serve two purposes. First, they force me to try to understand how the things were built, and determine some reasonable dimensions.

 

That's very practical and sort of a virtual rehearsal in making sure it's all going to fit together.

 

Nice progress.

 

Gary 

[Dr PR]

Mark and Gary,

 

Thanks.

 

I have a resin 3D printer, but I haven't used it in quite a while. A few years ago I experimented with a bunch of things for a 1:96 scale model of the USS Oklahoma City CLG-5 and got very nice results with details on very small pieces. But the resin is just too brittle and the small parts can't be handled.

 

I may print some of the more complicated pieces that would be difficult to make by hand - like the winch motors and gear boxes. But I prefer to make things out of brass where possible. Some things like the deck gratings and wheels on the scuttles will be photo etch.

[Jim Lad]

That double winch looks like it will be a lot of fun to make, Phil.

 

John

[Dr PR]

John,

 

I'll let you know how much "fun" it was after it is done.

[Dr PR]

I have made a little progress on the physical model. Most of my time has been spent on planning the build sequence. The deck planking will go down first before the deck house and deck furniture is placed. But I wanted to get the main deck deckhouse pieces glued together before proceeding with the deck planks. That way I can be working on the superstructure off the hull while I am waiting for the planking glue to set.

 

The front pieces of the superstructure fit together at angles so I had to bevel the edges. The sides also come together with the front pieces at an angle. Setting up the disk sander to the proper angles took some trial and experiment. I also need to cut openings for doors and air ports in the pieces before they are assembled.

 

 

I made a wooden block "template" for cutting the door openings. This will ensure that all the door openings are the same size. I am also gluing some of the 1/8 inch (3.1 mm) square framing strips in the corners where pieces come together..

 

 

 

After the holes are cut and the pieces are trimmed to fit I remove the paper pattern and scrape/sand any remaining glue to prepare the surfaces for painting.

 

I am planning to make the 12" air ports with some brass tubing with 1/4 inch (6.35 mm) inside diameter. I want to make the window with 1/4 inch acrylic rod. The outer surface will be polished and the inner surface will be painted with the ubiquitous Navy interior (puke) green.

 

Like the mahogany trim on doors, windows and railings, I will need only a small bit of acrylic rod (~1.5 inch/38 mm). But the smallest piece I have found so far is a 6 foot (2 meter) 1/4 inch rod from McMaster-Carr. It costs only about US$2.50, but the shipping costs will be much more! I will continue looking around. Maybe a machinist friend will have a scrap piece.

 

****

 

Work on the deckhouse brought back some memories from the Cape.  The ship had one Quick-Acting Water Tight (QAWT) door. It was inside the superstructure on the main deck at the forward end of the mess deck. It opened into a companionway and ladder that led down to the crew's berthing compartment in the bow.

 

It was called "quick-acting" because all eight of the "dogs" that clamped the door tight against the water tight seal were operated with a single lever, and not individually as on ordinary water tight doors.

 

I thought this was peculiar for two reasons. First, all the other doors on the ship, including exterior doors, were wooden and non-watertight. For this door to serve a watertight function the main deck would have to be flooded, and that would only happen if the ship was on the way to the bottom.

 

The other odd thing was that QAWT doors were installed in watertight bulkheads to prevent water from flowing from one part of the ship to another. But there was a screen vent over the door in this "watertight" bulkhead. It reminded me of the joke about something being as useful as a screen door on a submarine.

 

For me this door symbolized the Cape. It was almost useless. I say almost, because if the ship was sinking it might delay the flow of water into the crew's berthing compartment below deck, and that might give the men time to escape through a scuttle on the main deck at the bow.

 

Now stop and think - what are the likely causes for a minesweeper to sink? It could be attacked from the air or another ship, but the Cape was so small that just about any bomb or moderately large caliber projectile would blow it to pieces. Small cannon fire could blow enough holes to sink it, so in this case the door might serve a purpose.

 

But given the primary role of minesweepers -  to go into minefields and try to destroy them before they destroyed you -  the most probable cause for sinking was detonating a mine.

 

 

The picture on the left is the 184 foot long minesweeper USS Pirate AM-275 striking a mine. The photo on the right is what's left of the stern of the ship capsizing and sinking. These are grainy photos, but some of the little black dots in the air might be water tight doors. We had these photos posted on the Cape's bulletin board as a reminder of just how crazy it was for us to be anywhere close to a mine!

 

****

 

The mess decks on the Cape were Damage Control Central (DCC) where damage assessment and repair coordination were carried out in combat. Perhaps the QAWT door was there in DCC to give the crew some hope of surviving and reason for attempting damage control.

 

Being the Damage Control Officer for the ship, DCC was my station during General Quarters and when we were conducting damage control training. The Navy scheduled periodic training sessions where expert personnel from Damage Control Schools would come aboard and instruct us in damage control procedures on our own ship. Then we would run exercises and be graded for our proficiency. If we failed we had to do it all over again.

 

During one of these training sessions we were being instructed by an older Damage Control (DC) Chief. While we were waiting for some "evolution" to begin I pointed out the screen vent in the watertight bulkhead to the Chief. He looked at it, then at me, and said nothing.

 

Then I also commented about the sound-powered phone jack box in the mess decks that was about four feet above the main deck. It had a water tight cover over the jack, and I commented it wouldn't be much use if the mess decks were four feet under water. Again the Chief looked at me and said nothing.

 

But I did say the watertight cover would keep the sound powered phone system from shorting out if we were fighting a fire on the mess decks with salt water from fire hoses. To this the Chief replied, in an assertive tone suitable for an instructor teaching a pupil, that sound powered phones didn't use electricity and couldn't be shorted out.

 

"Chief, it isn't water flowing in those wires!" I replied.

 

My leading engineman immediately pulled me aside and said "Mr. Hays, you don't talk to inspectors like that!"

 

We passed the training anyway. But we were being trained by a Chief who had been in the Navy 20-30 years and had absolutely no understanding of how a principle communication system on ships worked!

 

****

 

Damage Control Schools were some of the most interesting times while I was in the Navy. At Officer Candidate School in Newport, Rhode Island, we had engine room firefighting school. We climbed up a ladder on the outside of a three story tall steel structure with a mock-up engine room inside. It was 30 degrees Fahrenheit (-1 Celsius) outside and icicles were hanging from leaky fire hose connections. Inside the metal box at ground level was a 6-9 foot (2-3 meters) wide open tank containing burning fuel oil.

 

When we opened the door to enter the "engine room" a thick cloud of oily black smoke poured out. We had to go inside without any breathing apparatus, walk along narrow catwalks and climb down two levels on vertical ladders while dragging a stiff charged 3 inch (75 mm) fire hose. The space was not lighted so we couldn't see anything, and none of us had been in this thing before! We felt our way along and when we got lower in the engine room we began to see the glow of the fire through the smoke.

 

This was where we started to learn that the Damage Control School guys really knew a thing or two. A DC Chief was leading us and told the lead man on the hose (the nozzle man) to lean out over the blazing oil and hose it down with water!

 

Right! We were going to put out burning oil with water!? But if you are an Officer Candidate Under Instruction (OCUI), a rating lower than Seaman and only slightly above scum - when a Chief says to spray water on burning oil you do it. The OCUI nozzle man bent the hose up in an inverted "U" over his head as we had been instructed, with the nozzle pointing down, and leaned out over the blazing tank. He rocked the "U" back and forth, spraying high velocity water fog over the surface of the oil and the fire went out!

 

Wow! It really worked! The heat from the fire vaporized the water into steam. Steam is heavier than air and formed a layer over the oil that smothered the fire. And the water absorbed a huge amount of heat as it vaporized, and cooled the oil.

 

We were all coated with gooey oil soot when we got back outside. I coughed up black spit for a week!

 

After reporting to the guided missile cruiser USS Oklahoma City I was ordered to fly back from Danang, Vietnam, to Flight Deck Firefighting School in San Diego, California (missiles were built like airplanes and posed many of the same hazards). There we learned to do a few more impossible things.

 

Magnesium burns hot enough to break down water molecules and combine with the oxygen, leaving hydrogen gas to intensify the fire. So when the DC Chief said he was going to put out a burning magnesium airplane wheel with water I was skeptical. And when they said they would put out a burning magnesium flare with water I was even more skeptical. But as we watched the School's DC personnel sprayed enough water on a flaming 3 foot (1 meter) diameter magnesium wheel to cool it to below ignition temperature. And the flare? They just crammed a fire hose into the end of the tube and the steam carried away enough heat to cool the fire and put it out! I wouldn't have believed it if I hadn't seen it with my own eyes!

 

But the main event was rescuing a pilot from a burning airplane. The mockup plane sat at the center of a large (100 feet or 30 meter) wide pan. Below the plane was a pipe that had jet fuel bubbling up and pooling under the plane. Then they lighted the fire, creating a column of flame 20-30 feet (7-10 meters) around the plane.

 

We had two hose teams dressed in ordinary work uniforms. A Chief led us to the downwind side of the blaze so the flames blew right at us! One hose team sprayed high velocity water fog toward the airplane to fight the fire. The second team had a long nozzle extension with a "spud tip" on the end. They followed close behind and held the spud tip above and in front of the first hose team to spray a sheet of low velocity water fog. Then we marched in toward the plane and into the burning fuel!

 

The low velocity fog created a wall of water that beat back and cooled the flames. We followed it into a tunnel of flame that was blowing above, beside and behind us. When we got to the plane a fellow in an asbestos suit climbed up to the cockpit to "rescue" the pilot. Then we all backed out together, having walked through flaming hell!

 

Kids, don't try this at home!

 

The impossible is impossible only if you don't try. Sometimes I think my 3+ years in the Navy was worth it just to have those experiences. It makes "thrill rides" at amusement parks look pretty lame!

Edited 3 hours ago by Dr PR