Some of my WWI era fuzes, the Mk I and a cutaway, Mk II, Mk III, Mk IV and a cutaway, Mk 5 and a cutaway and a Mk VII. The Mk IV is shown with the Mk II adapter/booster and the Mk V is shown with the Mk III adapter booster.
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WWI Fuzes
- Thread starter EODGUY
- Start date
Very nice.I just picked up one that looks just like the mk111,but mine dosn,t have the screw,can you tell me what that fits?Thank you very much.:tinysmile_classes_t
vinny
First of all, thanks for the positive comments on the fuzes from everyone. There are two variations of the Mk III. I have attached drawings from a WWI period document. The first production did not have the safety device (The screw in the side) added. Feeling that more safety was needed for the fuze, they added the centrifugal safety device. It is normally a positive block to the firing train during storage and handling. The rotation of the projectile will force the internal plug outwards, opening up the firing train for impact.
The Mk VII that I identified is a Mk VII and not a Mk VI. I have attached two drawings of the fuze. It was fielded for the smooth bore trench mortars because since they had no rotation on the projectiles the fuzes used had to arm themselves by setback inertia. The Mk IV and Mk V fuzes required set back, but the low muzzle velocities of the trench mortars didn't provide enough inertia to arm them. They introduced the Mk VII and Mk VII-E to meet the inertia requirements. As you can see the only difference between the Mk VII and the Mk VII-E was the change from a top mounted safety screw, vice a side mounted safety pin, either of which had to be removed before firing. Never ran across a Mk VII-E.
The Mk VII that I identified is a Mk VII and not a Mk VI. I have attached two drawings of the fuze. It was fielded for the smooth bore trench mortars because since they had no rotation on the projectiles the fuzes used had to arm themselves by setback inertia. The Mk IV and Mk V fuzes required set back, but the low muzzle velocities of the trench mortars didn't provide enough inertia to arm them. They introduced the Mk VII and Mk VII-E to meet the inertia requirements. As you can see the only difference between the Mk VII and the Mk VII-E was the change from a top mounted safety screw, vice a side mounted safety pin, either of which had to be removed before firing. Never ran across a Mk VII-E.
