According to contemporary Admiralty publications, this was published in
1940 and contained 42 different diagrams which ships would utilise to
minimise the chance of a U-boat attack. I am researching a specific
incident in WW2 and need to obtain a copy of Zigzag Diagram No. 9 for
reference. I have checked all the usual British sources (Public Record
Office, MOD Library, National Maritime Museum, Royal Naval Museum,
British Library Official Publications Department etc) but it does not
appear to have survived anywhere.

Seagoing copies were issued as confidential and had lead weighted covers
and were meant to be thrown overboard in the event of enemy attack.

If anyone has a copy or knows where there is one, I would be very
grateful if they would contact me.

According to contemporary Admiralty publications, this was published in
1940 and contained 42 different diagrams which ships would utilise to
minimise the chance of a U-boat attack. I am researching a specific
incident in WW2 and need to obtain a copy of Zigzag Diagram No. 9 for
reference. I have checked all the usual British sources (Public Record
Office, MOD Library, National Maritime Museum, Royal Naval Museum,
British Library Official Publications Department etc) but it does not
appear to have survived anywhere.

Seagoing copies were issued as confidential and had lead weighted covers
and were meant to be thrown overboard in the event of enemy attack.

If anyone has a copy or knows where there is one, I would be very
grateful if they would contact me.

Jeff,

Nope, no radical course changes to defeat the Long Lance 'till
Empress Augusta Bay 2/NOV/43 and the DD engagement at Kolobangara
were some of the Desron commanders recognized the need to change
course to stay away form where torpedos might be headed.

1.) O2 power plant (relatively wakeless) for speed and stealth

2.) Big torpedo (21" diameter) made for longer range -- much greater effective
     range than contemporary     fleet torpedos.  A few times victims thought
     they had struck a mine,      because they believed themselves outside of
     any effective torpedo range.      (Battle of the Java Sea comes to mind
     in this respect.)

3.) Large warhead.  The Long Lance warhead was larger than most contemporary
     fleet torpedos, for a much bigger bang . . . .

4.) Doctrine and Training.  The Japanese devoted a lot of energy to the
     surface torpedo attack, and practiced their tactics continually.  

   As an example, during the first engagement between the IJN and Doorman's
multi-national force in the Lombar Straight, the Dutch light crusier Tromp (?)
was sunk by several long lance hits. The range was so great (the fleets were
outside 8" gun range at the time !) that the attack wasn't recognized as
having come from surfacs ships at all and the destroyers started dropping
depth charges, believing that the torpedoes must have come from a submarine !

--
Olaf Scherdin           Fon: +49 461 32880
Swinemuender Str. 3,    Fax: +49 461 32499
24944 Flensburg, FRG    EMail: t...@checksix.allcon.com