According to a German publication, the German Air Defense League has
requested its members and people living in certain districts to help the antiaircraft
defense by searching for and collecting parachutes and ropes the day after
an enemy raid. These are to be used for "sailing shells," a kind of rope
barrage, somewhat similar to the British balloon barrage. These shells have
rarely been used by the Germans, who have up to the present paid more attention to
the production and improvement of antiaircraft artillery and night-fighter
aircraft. Now, if enemy aircraft approach Berlin, to take an example, a rope
barrage may be put up around the center of the town in addition to the usual air
defense barrage.
German Army testing establishments have carried out a great number of
tests with these shells, which are fired as ordinary projectiles. When they
explode, a rope about 200 yards long attached to a parachute unrolls and sinks
slowly to the ground, forming an obstruction, which, according to German
antiaircraft officers, is much more dangerous to aircraft than the more rigid
British balloon barrage. At one end of the rope there is an explosive adjusted
for time ignition. If no aircraft catches in the rope within 10 minutes, the
explosive charge is automatically detonated.
It is reported that use of these shells has recently begun, and that they
form part of the equipment of every antiaircraft battery.
Comment: The "rope barrage" is in reality, no doubt, a form of aerial
minefield. This sort of thing is perfectly feasible, though such a minefield would
cover only a fairly limited area. It could be utilized to defend an area which was
being heavily attacked. An average height at which aircraft were operating
would be determined, and the barrage fired to that approximate height. The
projectile itself would almost certainly be rocket-fired. Again, there would be no
difficulty in designing a rocket projectile containing a parachute and length of
wire with an explosive charge attached.