Bombs used in

   Mle. 25 – 10-kg G.P.-H.E.

   Mle. 28 – 10-kg and 50 kg G.P.-H.E.

   Mle. 29 – 10-kg Incendiary Model 1927

Fuze used with

   Mle. 1925 and 1928 – Alone

   Mle. 1929 – Tail Fuze No. 3 Bis or Sch.R.

Over-all length

(With booster) Mle. 25

(With booster) Mle. 28

(Without booster) Mle. 29

Width of fuze body

Mle. 25 and 29

Mle. 28

Markings

R.S.A. Mle. 25; or 28; or 29 24131

Similar in function and appearance, these fuzes differ slightly in construction. Mle. 28 and 29 are one-piece; Mle. 25 consists of two pieces screwed together. The upper part of the body contains a Raymondie (or Re'mondy) percussion-arming device, consisting of a cup with a detonator in the base and two vertical slots in the walls to receive the wings of a washer resting on top of the detonator. The striker and cup are held by a shear pin which passes through the fuze body.

Below the creep spring between the striker and washer, a central flash channel leads to the relay pellet and booster in Mle. 25; in Mle. 28, the brass fitting contains a delay pel-let and relay pellet; Mle. 29 is similar to Mle. 28 that except a short booster replaces a long one sealed by lead solder, the fuze being used to ignite incendiaries.

These fuzes are used with or without secondary safety device (other than the shear pin) in the striker. The secondary safety is removed when the bomb is released; no further arming occurs until impact, when the striker and cup are forced back. The shear pin joins them, and comes to a rest against the upper ledge in the fuze recess, while the detona-tor cap sets forward against the washer in slots of the cup and against a creep spring. The detonator and washer overcome the creep spring; the detonator hits the striker, ig-niting the explosive system.

Figure 265
Nose Impact Fuzes R.S.A. Models 1925, 1928, 1929