OVERALL LENGTH

MAX. BODY DIAMETER

TOTAL WEIGHT

FILLER

EFFECTIVE ILLUMINATION

COLOR

DESCRIPTION:

When the marker has been prepared for use and dropped into water, the water jac-ket fills and the scalloped disc in the main valve and the large disc in the pilot valve are forced against the ledges in the valves, thus preveting too great an ingress of water while it is submerged. Some water, however, enters the main outlet tube, passes through the pressure plate, and reacts with the calcium phosphide. This reaction evol-ves impure phosphine which ignites spontaneously when the marker surfaces. As it sur-faces, the pressure closing the valves is relaxed, and the springs return the discs against the circlips, thus permitting the ingress of water through the scallops in the disc to the bottom of the inlet tube and pilot tube. The water entering the main valve passes through the inlet tube into the perforated tube, and after passing through the perforated diaphragm perclorates through the flannel sheath and reacts with the main charge to give off pure phosphine, which is not spontaneously inflammable. The cap over the free end of the perforated tube prevents the water from percolating through the part of the flannel sheath above the pressure plate.

The water entering the pilot valve percolates through the flannel disc and dissolves the potassium bisulphate and the sodium nitrite, which inter-act and evolve gaseous oxides of nitrogen which mix with the phosphine in the strainer. The mixed gases are spontaneously inflammable in air, and, passing through the main outlet tube, inflame im-mediately on reaching the air. The flame thus produced continues to burn evenly for approximately 2 hours, during the whole of which time the gases remain spontaneously inflammable, so that even if the flame is put out by a wave, it lights up again as soon as contact with air is re-established.

The flame is visible, either from the air or from the bridge of a surface vessel, in daylight over a distance of at least three miles, and at night over a distance of about 20 miles, and white smoke is given off with the flame.

REMARKS:

In damp atmosphere, after removal of the overseals and press-caps, this marker evolves spontaneously inflammable phosphine, and for this reason should be prepared for use only just before it is to be launched.