"Baka" Piloted Rocket BombSpecial Mk 1 Rocket Motor Model 21
Japanese Explosive Ordnance – Bombs, Bomb Fuzes, Land Mines, Grenades, Firing Devices
and Sabotage Devices
Chapter 1 – Section 2
Japanese Navy Bombs
Type 4 Mk 1 Launching Rocket ("Baka" Motors)
Wing Fuselage
Over-all length 65 1/8 inches. 78 inches.
Maximum diameter 10 1/8 inches. 10 1/8 inches.

Description: Three fuselage motors contained after portion of the Baka serve as the main propulsion units. Two wing motors differing only in method of suspension and having shorter venturi tubes may or may not be used in addition to the fuselage motors.

Wing Fuselage
Weight of complete motor 266 pounds.
Weight of propellant 97.8 pounds. 97.8 pounds (44.8 kg.).
Length of propellant stick 19 3/8 inches. 19 3/8 inches.
Depth of propellant stick 4 3/8 inches. 4 3/8 inches.
Weight of ignition charge 120 grams. 120 grams.

Propellant: The propellant consists of 6 sticks of 500 special D.T. (code designation). Chemical analysis of this propellant is: 59.9 percent nitrocellulose, 26.9 percent nitrogly-cerine, 6.1 percent mononitronaphthalene, 2.9 percent ethyl centralite and 1.3 percent volatiles.

Ignition: The motors are igneted by electrically fired squibbs fitted into the nose portion of the motor. The firing circuit is controlled by a selector switch in the cockpit.

Figure 89 - Type 4 Mk 1 Launching Rocket ("Baka" Motors).

"Baka" Piloted Rocket BombSpecial Mk 1 Rocket Motor Model 21