Tamiya 78019 - 1:350 Japanese Navy Submarine I-400

Plastic model kit of the Imperial Japanese Navy submarine I-400 in 1/350 scale

A submarine that carries its own bombers sounds like fiction, yet I-400 was real — and she was the largest submarine of the Second World War. Her watertight deck hangar held three Aichi M6A Seiran floatplanes, launched by catapult once the boat had surfaced. Tamiya 78019 recreates her as a full hull model in 1/350 scale, approximately 348.5 mm long when completed and presented on a dedicated stand.

The kit is based on 2007 tooling and combines plastic sprues with photo-etched parts and metal propeller shafts. The three Seiran aircraft can be built with their wings folded, as they were stowed in the hangar, or with the supplied parts that allow them to be displayed with wings spread and ready for launch. A wide range of assembly options lets you capture the boat exactly as you envisage her.

What's in the box:

• Plastic sprues with hull, conning tower, hangar and deck parts
• Clear parts
• Photo-etched parts (crane arm, aerials, aircraft propellers, transport trolleys, hangar door interior details)
• Metal propeller shafts
• Three Aichi M6A Seiran floatplanes — with wings folded for the hangar plus parts to display them with wings spread
• Assembly options: hangar doors open or closed, periscope raised or retracted, bow planes extended or retracted, crane deployed or stowed
• Movable rudder
• Waterslide decal sheet for the markings
• Display stand
• Illustrated assembly instructions

Model specifications:

• Scale: 1/350
• Product number: 78019
• Manufacturer: Tamiya
• Model length: approx. 348.5 mm
• Version: full hull model on a display stand
• Skill level: beginner/intermediate (elaborate kit with photo-etched parts and many assembly options)

Note: The kit does not include glue, paints or modelling tools. The model is intended for self-assembly.

Building the model:

A submarine hull is simpler to build than the superstructure of a typical surface warship, so this model also suits builders without extensive experience. The photo-etched parts do call for care — the aerials, propellers and transport trolleys are small, and precision tweezers together with cyanoacrylate glue make the work far easier. It is worth deciding early whether to show the hangar doors open, which reveals the interior and the aircraft, or closed, as this affects part of the assembly and painting sequence.

For the paintwork, the dark greys and blacks typical of Imperial Japanese Navy submarines are recommended, with the greens and light shades used by Japanese naval aviation on the Seiran aircraft. Exact paint codes are given in the instructions. Applying the decals over a gloss coat helps to avoid decal silvering, and a matt varnish makes a suitable final finish. To take the detail further, aftermarket upgrade sets are available separately in our shop.

Tools you will need:

• Modelling side cutters for removing parts from the sprues
• Hobby knife or scalpel
• Files and sanding paper for cleaning up sprue gate marks
• Plastic cement (e.g. Tamiya Extra Thin Cement)
• Cyanoacrylate glue for photo-etched and metal parts
• Precision modelling tweezers
• Brushes in various sizes
• Model paints (acrylic or enamel)
• Wash to emphasise detail

About the ship – I-400:

The Sen Toku class submarines, led by I-400, were the largest submarines of the Second World War and remained the largest in the world until the nuclear era. They were designed to carry bomber aircraft over enormous distances and strike strategic targets far beyond the reach of the Japanese fleet — a raid on the locks of the Panama Canal was among the plans considered.

The heart of the design was a watertight hangar running along the deck, holding three Aichi M6A Seiran floatplanes with their wings folded. Once surfaced, the aircraft were rolled out on trolleys, their wings were unfolded and they were launched from the deck catapult. At the same time the boat retained the full armament of a conventional submarine: eight torpedo tubes, a deck gun and anti-aircraft mounts.

I-400 never carried out a combat mission. She surrendered on 27 August 1945, was taken over and studied in detail by the Americans, and was then sunk as a torpedo target off Pearl Harbor on 4 June 1946.

Original specifications (I-400):

• Submerged displacement: approx. 6,560 t
• Length: 122 m
• Beam: 12 m
• Speed: 18.7 knots surfaced, 6.5 knots submerged
• Torpedo armament: 8 x 533 mm tubes
• Gun armament: one 140 mm deck gun
• Anti-aircraft armament: triple 25 mm mounts and one single mount
• Aircraft: 3 x Aichi M6A Seiran floatplanes in a watertight hangar
• Crew: 144
• Surrendered 27 August 1945, sunk as a target on 4 June 1946

About the manufacturer – Tamiya:

Tamiya Corporation is a Japanese model company founded in 1946 by Yoshio Tamiya in Shizuoka, regarded as the heart of the Japanese model industry. The company began in the timber trade and wooden model production, and released its first plastic model kit in 1960. The brand is known for extremely precise injection moulds and excellent parts fit, which is why its kits are equally popular with beginners and experienced modellers. In its newer 1/350 warship kits Tamiya combines plastic sprues with photo-etched parts and metal components, allowing a high level of detail straight from the box. The instructions are clear, richly illustrated and include paint codes from the manufacturer's own range. Alongside plastic kits, Tamiya offers a full range of modelling accessories: paints, glues, tools and brushes. Today the company is present in dozens of countries and remains one of the best-known brands in the hobby.