USN Thresher/Permit Class SSN
SSN-593 USS Thresher

1/350th scale model kit
By Blue Water Navy

In-box review and buildup by: John Sheridan

The Ship:

The SSN-594 Permit class was the world's first modern, quiet, deep-diving fast attack submarines, integrating such advanced features as a hydrodynamically shaped hull, a large bow mounted sonar array, advanced sound-silencing features, and an integrated control/attack center with the proven S5W reactor plant. These submarines were a major advance over previous submarine designs, and established the pattern of all successive American attack submarine classes, in several extremely important respects: Although they were larger than the previous SSN 585 Skipjack class, and used the same nuclear power plant, their hull design did not compromise their underwater speed. Designed for prolonged periods submerged, they were limited only by the amount of food that she can carry, and were capable of sustained operation at high speed.

These submarines were originally designated the THRESHER class, but the USS Thresher (SSN 593) was lost 200 miles off the coast of New England on 10 April 1963. According to investigators, a seawater pipe in the aft engine spaces broke, spraying water into the engine room and shorting one of the main electrical bus boards. The sub lost electrical power and couldn't operate the reactor. Darkness, a sea mist, and sheer terror inhibited the crew from manually actuating the valves. The aft part of the sub filled up with water and tilted down. With no power to get back on line, the sub drifted down to crush depth and imploded. A ghastly death for an entire crew, and one the US Navy vowed never to allow happen again.

The ill-fated USS Thresher (SSN-593) and her crew did not suffer in vain. Out of that terror and the lessons learned grew the SubSafe Program. Through this program, every submarine in the US Fleet, every pressure hull integrity-related system aboard those subs, and every pressure-related part within those systems must be certified as being 100% safe for use on a submarine. The goals are to ensure that in case of a casualty, the ship and its crew can be recovered and to ensure that the integrity of the material used on the ship can operate at design test depth. Directly related to the Thresher tragedy, sea-connected joints can no longer be brazed; they must now be welded. The SubSafe program brought other controls, too. Now when an emergency arises aboard a sub, all vital equipment which sailors would need quick access to in the event of an emergency is clearly marked and easily accessible. At all times an operator is one second away from flipping the emergency main ballast tanks to vent, so the sub can rise to the surface.

Thresher/Permit Class SSN Data

3540 tons (surf.), 4200 tons (submerged)

Max Speed
20 kts (surface) 30 kts (submerged)
Length 278 feet
Crew 143
32 feet 
Test Depth 400+ feet
Power Plant   

S5W Pressurized Water Nuclear Reactor,
2 geared turbines at 15,000 shp to one shaft 

Armament 4 Torpedo Tubes

Recommended Reading

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The Kit:

thresher1.jpg (89329 bytes)The 1:350th scale Blue Water Navy kit of the SSN-593 USS Thresher is a multimedia kit consisting of Resin, White Metal, and Photo-etched parts. 

The resin parts consist of the hull which a solid one-piece chunk of resin with all the detail cast in. Hatches, access-ports, and other openings are scribed into the hull. The hull has a large casting plug on the keel that will have to be removed and sanded smooth. The dive planes and scopes  are made of White Metal and require a light sanding to fit in their place. Several choices of propellers are offered in photoetch brass. The propeller you use is determined by the time period you wish to display the model.  The instruction sheet is a one-page two-sided affair that clearly shows where the parts go. A decal sheet with hull numbers, pennants, and rescue markings round out this kit. 


thresher5.jpg (173408 bytes)I started construction of this kit by removing the large casting plug on the keel of the hull. I used a dremel tool to grind-away most of the material and by doing this, greatly speeded-up the process. When I had the remains of the plug down to a manageable level, I used 100 grit sandpaper to remove the remains. When the plug was completely gone, I used finer grits of sandpaper to smooth out the hull. I then used Bondo Automotive Putty to fill in any imperfections on the surface and to clean up any scratches that remained from sanding. 

The next step is to add the dive planes, rudders, stabilizers, and periscopes. I cleaned up the parts using 150 ad 220 grit sandpaper and test fitted each part to make sure there were no gaps. The trick to adding these parts to the kit is to add a metal post so the part has something hold it stable when attached to the kit. I started by marking points on the hull where I wanted to attach these parts. I then used my trusty Dremel tool to drill out holes in the resin. As I completed each hole, I filled the void with Gap-Filling ACC Cement and inserted .019 Brass rod and allowed the cement to cure. While the posts were curing, I turned my attention to the add-on parts that required drilling. I placed each piece in a vice and drilled small holes to accept the other end of the rod. I added each part to the hull and cemented them in place using ACC gap-filling cement. I added all of the parts to the hull and allowed them to dry for about 30 minutes.

thresher4.jpg (134981 bytes)The next step was to fill any voids in the diving surfaces. I took a trick used by the Aircraft modelers and applied some Microscale Krystal Clear(tm) to the section where each part joins the hull. What this does is fill any voids that you might have missed during test fitting. You apply the Krystal Clear to the area you wish to fill making sure all voids are filled. When you are finished doing this step, you then take a Q-Tip dipped in water and remove the excess Krystal Clear from places you don't want it to be. Once you have done this to all the parts, set the kit aside to dry overnight.


Modern USN Submarines are easy to paint. You do need to decide if you want to paint the boat during trials or in service. Most submarines on builders trials have the anti-fouling paint all the way up to the the waterline of the sub while most sub in service have the anti-fouling paint only half way up the hull. Some Subs had no anti-fouling paint applied and were completely painted black while others were painted with Ocean Gray sails. You need to pick a period when your model is to be and, as always,  photographs are a big help. I found a photo of USS Thresher early in her career painted black while she was still carrying her hull numbers so I chose that photograph for depicting my model. 

thresher6.jpg (127058 bytes)I started by making the paint mix for my Black color. I took Pollyscale Flat Black and mixed in about 15% Pollyscale Flat White. This gave me a nice dark gray color that looked the way I wanted. Since I was building more than 1 sub kit at this time, I made enough so I would have a consistent color for all of my subs. For my anti-fouling red, I chose Pollyscale Boxcar Red from their model RR colors. This is a nice reddish-brown color that looks very close to the reds I've seen on the hulls of USN warships. 

I first sprayed the Boxcar Red to about 3/4's the way up the hull to ensure that I covered everything I needed to with this color. It was allowed to dry for about 2 hours (Pollyscale Paints is very fast drying). I then masked the hull 1/2 way up with 3M Automotive tape making sure I had a nice straight line down the length of the hull. I then sprayed my "black" over the rest of the kit covering the areas that needed to be black and set the entire kit aside to dry. After about 2 hours, I removed the masking tape and cleaned-up any overspray with a fine brush. Next came the periscopes which were painted Ocean Gray with Navy Blue splotches (Medium Green splotches are also acceptable).  


thresher3.jpg (127591 bytes)Blue Water Navy provides a nice decal sheet for this model (drawn my yours truly).  The only decals I used were hull numbers. My photograph did not have any draft marks or rescue markings so these were omitted. The decals were applied with setting solution and snuggled down to the model with no silvering. 

The next step was to apply the propeller. The photo-etch fret comes with 2 different types; the early 5-bladed version and later 7-bladed version. I chose the 7 bladed version since most subs commissioned after 1960 had this type. I glued the prop to the stern and added the hub. I allowed these parts to thoroughly dry before attempting the next step.  I took each blade and, using a pair of needle-nosed pliers, bent them outwards so they looked like the real thing.

I then mounted the model to a Maple display base using brass tubing to hide the screws that secured the model. Once this was complete, The entire model was over sprayed with Future Floor Wax mixed with Tamiya X-21 Flat Base. This gave the model a nice flat consistent finish and sealed the decals.


This is a great kit for a person who is looking for a simple, yet very detailed resin kit to build. Those who have never built a resin kit would find this kit to be an excellent first-time kit to build. Assembly time took me about 1 hour for all the parts. Painting and finishing took about 6 hours total due to drying times of the paints I used.  I would highly recommend this, or any other Blue Water Navy submarine kit to anyone

Shots of the unassembled Model

ssn593_side.jpg (51243 bytes) ssn593_sail.jpg (146743 bytes) ssn593_parts.jpg (29533 bytes) ssn593_photoetch.jpg (24623 bytes)