Thank you for displaying these.
Your first 152 A1 section shows the ball which is obviously steel. In British service the ‘A’ indicates that the ball is steel not aluminium, otherwise it would have been a 152, so it looks as though Australia went along with this.
If the pin label relates to that fuze there should be a small hole for the pin to go through and lock the ball, hence the label. ‘A.D’. would then mean suitable for air dropping. British references say that a local modification was carried out hastily at that particular time and the letter ‘M’ was put after the ‘A’ to denote suitable for air dropping.
You make a point about the larger cap in the second reply. From what I can see, the larger cap seems to match the 4.2” mortar 152 fuzes, but no technical pamphlets give any width measurements on fuze drawings, yet loads of length measurements. I make the point here that 3” Mor. is an infantry weapon and 4.2” is an artillery weapon and at that time they were only issued fuzed, so the difference would be obvious. Only technical staff in an ammunition depot would be involved in large scale removal of fuzes as part of repair programmes.
There is a note in a 1962 D.I.Arm. fuze publication that “the side walls of the inside removable cap and that the external surfaces of the safety cap are coloured BLUE”.
The last reply Fuze DA 162 Mk10 has the small cap.
Here is a list of 162 fuzes and the associated weapon:
3” 1, 1/1, 1/2, 1/3, 4, 4/1, 4/2, 8, 10.
4.2” 3, 3/1, 3/2,3/3, 5, 5/1, 5/2, 7,9.
Marks 8 and 10 are also used with 81mm Mortar.
Mark 2 was designed and produced in India for their use only.
Perhaps someone with 3” or 4.2” Mortar user manuals could see if there was any specified cap size for the particular fuze mark related to which weapon. Although the cap size variation is small it would be huge to a trained mortarman.
