75/27 C.K. & A.V. anti-aircraft fragmentation shell.

75/27 Gun-how, shrapnel shell.

75/27 Gun-how, and 75/13 how shrapnel shell.

77/28 How shrapnel shell.

Somewhat similar in appearance to British fuze of the No. 80 type, the fuze protrudes about 2 inches from the nose of the shell and is of combustion type with two time rings and a tensioning cap. The upper ring is fixed and the lower setting ring is graduated to 59 and numbered to 58. The cap is of aluminium and is marked "T" in red. The rings and body are of aluminium alloy, but in some instances the periphery of the platform, bearing the setting index, is of brass. A brass fuze cover may be fitted and secured by a tear-off strip with a finger ring. The cover is also marked with the red "T" and an arrow with the word "TIRARE", indicating the direction in which the ring should be pulled for the removal of the cover. The screwthreaded portion of the fuze for insertion in the shell is 1.96 in-ches in diameter and has eight threads to the inch.

The body of the fuze has the normal type of platform formed around it with an inclined channel leading to the magazine. A felt washer on the platform is perforated to coincide with the channel which contains two perforated pellets of gun-powder. The magazine contains 44 grains of gunpowder and is closed at the base by a screwed plug with a lightly closed hole in its centre. Near its upper end the cylindrical part of the body has two semi-circular recesses for the locking pins of the upper time ring and is screwthrea-ded to receive the screwed retaining collar and the tensioning cap. A cylindrical recess is formed in the upper part of the body to accommodate the detonator assembly. The re-cess has a steel needle fitted in the centre of its base and a flash channel, leading to the upper time ring, in the wall. Two inclined surfaces to receive the arms of the stirrup spring are formed at the mouth of the recess. The lower part of the body, between the magazine and the recess, is solid.

The detonator assembly consists of a cylindrical brass pellet carrying an igniferous deto-nator in its base and supported by a brass stirrup spring. The upper end of the pellet is recessed to seat the larger end of a helical locating spring held between the pellet and a recess in the base of the cap.

The time rings are of normal design each having the usual lightly closed vent containing a perforated pellet of powder at the commencement of the train of fuze powder. The upper ring has two semi-circular recesses in its inner face to coincide with those in the body for the reception of the two locking pins. The flash channel leading into the fuze powder filling in the ring contains no powder. The lower ring is rotated relative to the index on the platform in setting and is graduated from 0 to 59 in a clockwise direction. The gradu-ations are sub-divided to indicate half dimensions and every alternate main graduation (even numbers) from zero to 58 is numbered. The safety setting is indicated by a cross. The assembled rings are secured by the retaining collar screwed to the body above the upper ring and secured by a locking pin. The tensioning of the setting ring is adjusted at assembly by the screwed cap, which is then secured by a fixing screw. Coinciding lines scribed on the cap and the upper ring indicate the position to which the cap was turned to obtain the desired tensioning.

Fig. 10