Tamiya 1/350 I-400 STO Class Submarine

Reviewed by Sean Hert

Tamiya's return to the 1/350 ship market is an I400, STO class submarine. It's kind of an odd choice for a subject matter, but Tamiya certainly doesn't blunder on the execution.

Laid down in 1943, this class of submarines were the largest built until the first nuclear powered SSBN's came around. Based on a proposed idea of Admiral Yamamoto to conduct a bombing raid on the Panama Canal, these large aircraft-carrying submarines never performed their intended mission. One of the submarines, the I-402, was completed as a supply tanker.


Tamiya's unique packaging, with the drawings on the inner boxes, always makes me smile. All items are bagged separately, with the upper and lower hulls taped together and placed in one bag.

The upper and lower hulls have the finest detail I have ever seen on a 1/350 plastic kit. These hull sections also show the cleanest and tightest fit I have ever seen on a ship kit in any scale- it hardly needs any glue. It is a wonder, and a sight to behold!

The hull halves both have finely raised hull plating everywhere, and the ballast vents along the bottom of the hull have the fine lines to show the louvers/grills. The only flash or imperfection I could find in the entire kit are two small nubs from the were the lower hull was removed from the sprue at the factory, and these will be very easily fixed.

The upper hull has a variety of hull planking and gratings present. The free flooding limber holes are indented, but do not pass through the part. There is a fine degaussing cable molded on the hull, passing around the entirety of the submarine. There are a number of plates and hatches with very fine detail, like rivets and such, that my camera just cannot capture properly.

There is no special provision for a waterline version other than the separate hull pieces; i.e. no lower plate like Trumpeter offers.

Click images
to enlarge

Sprue A holds the bulk of the parts for this kit, including the running gear; props, rudders and dive planes. There are also an options for retracted dive planes. There are both retracted and deployed periscope/mast options, and the 25mm AA guns are incredibly detailed.
Sprue B consists of parts to make the conning tower and bridge/hanger structures. There is good detail here, and I like how the hanger is basically a separate pressure hull which is visible from the bottom of the conning tower. Adding interior detail to the hanger is a nice touch.

The bridge parts do seem to have a texture to them, but I don't know if this is a manufacturing artifact or an intentional effect.

This kit inlcudes both a base for the submarine- which the instructions call out as a building stand as well, and a hexagonal base to display one of the Aichi M6A1 Seiran aircraft.
A total of 6 Aichi M6A1 Seirans are included, two indentical sprues of three aircraft. Molded in dark green plastic, each sprue offers 2 aircraft in a stowed position, and one with wings extended. There is also on each sprue a copy of the land-based launching dolly, to be used on the aircraft to be displayed on the stand. All the planes are very finely molded, and include a bomb as ordnance.
The stainless steel photo etch fret has an aircraft loading crane, launching dollys, antennas for the conning tower, a really neat internal mechanism for the inside of the watertight hanger hatch, props for the planes and the catapult launch rail. The parts bag has two types of rod for the propshafts and for the posable dive planes, screws for mounting the hull to the display base, and polycaps to make the hanger door and the deck gun movable. And in keeping with Tamiya's new found facination with kits that have heft, there are two steel bag weights to add to the hull (step 2 of the instructions).
A decal sheet is included with simple markings for the submarine, and numerous markings for the 3 Seirans, including a decal for the cockpit glass. Tamiya has also inclosed thin metal, adhesive backed nameplates for the base, in both English text and Japanese kanji, as well as a non-decal sheet of flags.
The instructions are a 20 page booklet with a history of the submarine and the Seiran's development plus an internal breakdown of the submarine. The directions are step by step and cover all the assembly steps. The paint instructions use Tamiya colors.

These are photos from Tamiya's website, showing the completed kit.

Tamiya's return to the 1/350 arena is the best 1/350 plastic kit I have ever seen. While the subject matter won't interest as many builders as some other choices would have, they certainly have raised the bar on the fit of the parts and crispness of detail. I would hope that hull plating will now be standard on all future kits in 1/350 regardless of who made it, and the crisp and flush fit between upper and lower hull halves will continue.

However, even with the photoetch and aircraft, the price of $69.00 seems steep for a kit that only has two sprues of parts- but the detail is impressive!

Purchased at Hobbyland, Columbus OH - MSRP $ 69.00