A torpedo net being assembled at a Net Depot is shown in Figure 9. A torpedo net that has been laid, showing stream flotation buoys and end Mark II buoy is shown in Figure 6.

The function of the torpedo net was to fence or stop torpedoes by:
(a)   Creating a continuous barrier (net) across the entrance of a harbor, with a net gate operated by a Net Gate Vessel (YNG)

(b)   Giving protection to Individual ships by placement of net around ship to stop torpedoes before they were near enough to damage a ship if they exploded.

(c)   Non-continuous baffles (sections of nets) which would catch and stop any torpedo fired at the area to be protected, but which would permit the passage of ships without the use of a gate and gate vessel. Baffles were staggered so ships could zig zag through the narrow openings.

It was the only net which could afford protection against torpedoes dropped from aircraft.

There was a great difference in the way a submarine would strike a net as compared to a torpedo striking a net.

Owing to the size of the submarine and the design of the submarine net the stress of the submarine's impact would be immediately diffused through the net structure. Even if some of the mesh ropes first struck broke, the net could still entangle the submarine and overcome its inertia of movement.

The torpedo on the other hand, embodied an entirely different problem for nets. It arrived at the net with a high degree of energy which had to be absorbed smoothly by the barrier if the torpedo was to be stopped without penetrating. The torpedo, because of it's small size, compared to a submarine, concentrated upon one element of the net. If that element failed the net was defeated.

The submarine net, as described on preceding page, was like a fence attached to the ground, secured at intervals by chaining running to heavy anchors on the bottom.