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| ITALIAN AND FRENCH EXPLOSIVE ORDNANCE |
| Chapter 4 |
| ITALIAN PROJECTILE FUZES |
| Nose Time Fuzes M900/14 and M900/34 |
| Data |
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Projectile used in |
H.E. Projectiles for Field Gun |
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Over-all length |
3 in. (approx.) |
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Maximum diameter |
Unknown |
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Thread diameter |
Unknown |
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Markings M° 900/14 |
Unknown |
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M° 900/34 |
Stenciled red cross |
| Description |
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The two fuzes are similar execpt for modifications. The M900/34 time rings have a small capacity, but different burning powder is used tu equal the time of burning. The fuze body is aluminum. Assembled on the body are two time rings. A tension cap screw-threads on the body to keep the time rings in position. Two semicircular recesses formed in the cylindrical part of the body coincide with similar recesses in the upper time ring to receive two locking pins which hold the upper time ring fixed. A recess on the forward end of the body contains the detonator holder and striker. The detonator is held off the firing pin by a split brass ring which rests on the shoulder of the recess. The firing pin is fixed to the bottom of the recess. The upper time ring has a powder-filled groove in the underside which extends 310 degrees. Vents are provided for the escape of pressure during burning. The lower time ring also has a powder groove in the underside extending 310 degrees. A flash-hole connecting the commencement of powder groove with the up-per surface of the rings contains a press powder centrally drilled to assist burning. A ve-getable-paper washer with a hole to correspond to the commencement of the groove, and a felt washer perforated to correspond with the flash-hole, are used to seperate the time rings. |
| Operation |
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On acceleration, the detonator sets back through the split brass ring to hit the firing pins. The flash ignites the upper time ring, which burns along the groove. Vent disc blow out due to pressure and prevent variation in the rate of burning. The distance between the commencement of the powder groove in the upper ring and the powder-filled flash hole depends on the angle the lower ring is turned in the setting. When the powder burns around to the flash-hole in the lower ring, the lower ring ignites and burns around to a delay in the fuze base. From the delay, the flash is passed to a solid powder pellet in the flash channel, then to the main charge. |
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Figure 214 |
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