- Inside of the INJ Kongo -

INJ Kongo – Hudson/Tyler (launched 2011)

4.5 units, 24 seconds, Japanese Battlecruiser

The INJ Kongo is a wood hull built by Tyler for Hudson. She was launched in the fall of 2011. The strengths of the Kongo are that it is a fast ship at 24 seconds and that has 3.5 sidemounted guns, which is a huge amount of firepower. The primary weakness of the Kongo is that like all class 4 ships, the rudder area is fairly small relative to class 5 and 6 ships, and since it is a fairly long ship it is difficult to get it to turn well. Kongos are also quite heavy so a larger prop is needed to have good acceleration, however this further detracts from turning.

The Kongo’s superstructure is nearly entirely 1/16 inch ABS plastic affixed to itself with ABS cement. The ABS is then screwed to the deck. The turrets are commercially available molded and the barbettes are ABS plastic pipe. The ABS holds up very well to damage over the years and as of 2019 when this article is written, it has very mild superstructure damage in her 8 years of service.

The Kongo has two very typical turrets towards the bow of the ship, the bow most is armed with a 50 round gun and the 2^nd turret has a dummy barrel to hopefully confuse the other battlers as to which side has the active gun. Some people prefer to use the higher turret for the gun but the effective range is decreased significantly when you put the full 20 degrees of down angle on a gun, and in a bow gun that is already harder to get on target, it is better to keep the depression angle more gentle. You can see the sections of removable deck in this picture as well. The bow 12 inches is not removable. The section containing both forward guns slides into place from stern to bow. The cut between this and the middle section is seen under the superstructure.

The stern most turret is aimed to starboard, this is the strongest gun on the ship and is the 75 round gun. It has very good placement close to the water line and near the stern of the ship. The more elevated and more forward turret houses a 50 round gun to port. The way that the casemated section of the Kongo steps back in this part of the ship allows for more down angle than similar ships with similarly placed turrets such as the HMS Tiger. On the Kongo the elevated stern sidemount is a fair bit to the middle of the ship unlike a Nagato or a Queen Elizabeth and in that way forces more exposure to incoming fire in order to use it.

One of the frustrating features of the Kongo is how far amidships the elevated stern turret is. In order to get to the internal compartments that need routine access such as batteries, guns, and gas, a section of deck containing a gun is removed. Generally I dislike having to move a deck containing a gun with much frequency, because it is tethered to the ship via gun hose and can make manipulating the ship while open a bit tricky. This middle section slides from stern towards the bow and locks in place with deck latches on the uppermost portion and the open area that locks down both the middle section and the stern most section. The gun magazine is straight and is loaded by taking the deck section off. I prefer no more than 3 deck sections for most ships but I have been tempted to cut just in front of the turret so that section could be left alone more often.

This is a pretty good look at the latching system and gun magazine, which I generally will zip tie to the deck in one way or another.

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The bow section of decking is removed in turn via slides as well. The forward most gun is also has a straight magazine and is loaded by removing the entire deck piece. The bow portion of the ship also houses the CO2 bottle.

The stern section is also secured with latches and slides from bow to stern to lock it in. The lip at the bow most part of this deck piece sort of snaps down and to be removed you have to push up on it from the underside and slightly bend the deck. It has a very good seal and keeps water out fairly effectively.

The two rudders have small white gears attached and are turned together via a larger plastic gear. There isn’t quite enough room to have the larger gear mounted directly to the servo itself, so push rods provide the linkage. I like 4-40 threaded stainless steel rod. I bend a 90 degree angle and lock tight nuts on with a little play so it doesn’t bind.

The motor mounts are accessed in the stern most section. The stern gun solenoid is held relatively secure via the CO2 hose being strapped to the ribs. The depth is a bit hard to appreciate, but just astern to the gear boxes the bottom of the hull is filled in with balsa wood and epoxied over, this prevents water from unnecessarily accumulating in the extreme stern of the ship. As seen in other pictures a similar approach is taken in the extreme bow. Water should be directed to the middle of the ship where the pump is located. This also serves to keep incoming water to accumulate in the extremes of the ship and effect performance.

The pump mount is a C shaped piece of wood that I generally would zip tie the pump motor to. The pump outlet is on the lower section of deck on the top part of the picture. The middle gun’s solenoid sits on the bottom of the hull. Just forward of the pump there is a gap so the bottom part of the gun can sit and to not run into other components of the ship.

The middle of the ship houses the batteries. There are red plastic forms that are glued and screw to the bottom of the hull to lock them into place. Under the cross brace is the water tight electronics box which is held in place with a Velcro strap.

Here it is with the batteries in place. The wires jam between the batteries to help keep them wedged width wise in place as well.

The forward most 12 inches of the ship is not accessible without taking the sides off. The ship narrows significantly up there and it doesn’t really have that much usable space. That entire section is filled with balsa wood up to the bottom of the penetrable window. Under the removable bow deck section is the CO2 bottle and bow gun solenoid.

The bottle has an accepting portion cut out of the water channeling and the regulator sits in an accepting piece of wood as well. This picture has a pretty good depiction of the steps in the water channeling. The lowest part is 1/32 inch ply wood covering just the bottom of the hull where the base plate was cut out to serve as water channeling running under the internal components amidships. Just in front of that it steps up a little so the CO2 bottle still stays low, keeping the center of gravity low, but still disallows water to pile up. Still forward of that the water channeling steps up to a higher level which is even with the bottom of the penetrable area of the ship. It would probably be OK to fill the areas to the side of the bottle in with water channeling as well.

A shot with the CO2 bottle and regulator in place.

The ship is allowed to be fairly heavy and is actually quite big for a class 4 ship. I knew that when I was planning and building it and as such planned to use a bunch of lead just inside the bulge water channeling. The lead strips (duck decoy weights) are screwed to the vertical section of the ribs. The bulges otherwise do have balsa water channeling up to the bottom of the penetrable window.

With measuring tape. Again, the first 12 inches is not accessible.

The ship is 60.6 inches long. An important concept in improving performance is to keep the distribution of weight close to the center of the ship lengthwise, and as wide as able widthwise as able.

Stern with measuring tape. I generally will put a cross brace for structural support just astern of the stern most gun of any ship.

Props are at 6 inches from the stern, Drag disks at 9 inches. Rudder posts at 5.5 inches or so.

The ship was originally built with 1.5 inch props hoping it would turn better, but that didn’t allow it to accelerate worth a darn. It was later refit for 1.7 inch props. The rudders however are original and 1.5 inches tall. It would probably be better to make them as tall as the props.

Props and rudders. The shaft struts were knocked loose in battle/transport so they are gooped up with fiberglass cloth and epoxy in this picture, but will be sanded down smooth again.

The rudders are angled out a touch. There are different theories on whether to do this and how much to do it. The black fins on the tail edge of the rudders are ABS plastic glued on as an afterthought.

Banzai!

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