Convoy ZigZag Patterns

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Convoy ZigZag Patterns

#1

Post by Andy H » 07 Sep 2004, 17:23

Whilst reading book about the incident involving the Queen Mary, where she cut the light cruiser Curacoa in halve, it mentions that the Queen Mary was sailing in a Number 8 ZigZag pattern.

I presume that there are patterns 1-7 and maybe more beyond, but can anyone throw any light on these different patterns

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#2

Post by Aufklarung » 07 Sep 2004, 18:33

Hi Andy

At first I thought you were talking about a paint scheme and had prepared a quick post with examples but then I came to reallize you were speaking of manouver patterns for the ships themselves!! :oops:

For now; try this:
http://www.bbc.co.uk/history/war/wwtwo/ ... ntic.shtml
:lol:

regards
A :)


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#3

Post by Xavier » 07 Sep 2004, 21:01

I think zigzag-8 pattern is a zigzag pattern in a straight line, at a given, prearranged interval whitin a convoy, instead of random zigzags, to keep a ship's position inside a convoy.

if you draw two parallels zigzags, (two ships sailing together in the same direction) they join or intersect to form a figure-eight everytime they cross wakes or come close. that may be it

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Xavier
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#4

Post by Andy H » 08 Sep 2004, 19:01

Hi Xavier

Your basic premise for this Number8 pattern seems to be correct in that two ships would criss-cross each others wake at various pre-aranged times, with the depth/distance of the turns being detailed at a earlier meeting.

Still no luck with the others

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Re: Convoy ZigZag Patterns

#5

Post by Andy H » 26 Nov 2012, 01:42

Hi

In a recent book I read they were using zig-zag pattern 11

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Re: Convoy ZigZag Patterns

#6

Post by Ironmachine » 26 Nov 2012, 09:14

I have found what follows. It may be of help:
I am reading a book about a wartime t-boat and the captain often sets different zigzag patterns to avoid being detected.Would any of you point me in the right direction of what these tracks looked like.The book was written in 1954 so i suppose they were still using them at the time hence the lack of detail.
[...]
Thank all of you for your replies.The book describes events in the far east in 1944/5 in a t-boat.I don't think SSK had been invented then.The author Cmdr A.Mars gives the zigzags a letter,eg. Alpha etc.and uses this procedure to avoid detection.How many different patterns were there and what were the differences?
[...]
Several Types - different purposes:
VLLZZ very Long leg Zig Zags - strategic 12-24 hour changes - to disguise the overall desination of a force.
LLZZ- Long Leg Zig Zags - strategic 8-12 hour changes (could be on top of VLLZZ) - to make intellegence for submarine dificult and prevent it getting into the grain (i.e about 60 miles ahead of the general line of advance of the force)
SLZZ- short leg ZZ - to force submarine to sprint/snort/use radar to get into possible firing position if it was already in the grain.
Anto Torpedo ZZ a very SLZZ of 12-3 min legs to disrupt the SM firing solution
NB. Sensible skimmers never steered course of 5 or 10's of degrees cos the boat skipper knoew his sine rule in 5-10's of degres and maybe just maybe it would help.
The whole thing was boiled down in an Allied Tactical Publication post war. VLLZZ had numbers, LLZZ had letters and SLZZ had numbers, VSLZZ were either Z or Y and executed by a time - when you picked up the table of offsets from the SLZZ or LLZZ.
All this reduced the mean speed of Advance - hence you planned your force movememnts at about 8 knots - but ships doing a Anti Torpedo ZZ on top of a SLZZ ontop of a LLZZ etc where doing about 18knts (or just less tham cavitation inception speed) when the SM was about to fire!
Unles you wos the Belgrano - whose LLZZ had her pointing away from the falklands st the time of sinking - but her mean line of advance over the previous 24 hours was towards the falklands.
http://www.navy-net.co.uk/history/30114 ... racks.html

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Re: Convoy ZigZag Patterns

#7

Post by Andy H » 26 Nov 2012, 13:18

Hi Ironmachine

Well that's a great improvement on what I know which is sadly very little :D

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Re: Convoy ZigZag Patterns

#8

Post by LWD » 26 Nov 2012, 16:44

There may be something in here:
http://www.ibiblio.org/hyperwar/USN/ref ... index.html
or here:
http://www.ibiblio.org/hyperwar/USN/ref ... index.html
There are some references mention here that might be of use but they are not hyperlinked:
http://www.admirals.org.uk/records/adm/ ... SectXX.php
Looking at this diagram I get the impression that complex zig zaging by such a force especially if many were merchant vessels would be an invitation to dissater:
http://www.admirals.org.uk/records/adm/ ... ramIII.gif

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Re: Convoy ZigZag Patterns

#9

Post by Andy H » 26 Nov 2012, 18:51

Hi Lee

Yes there was some good info (all round in fact) at : http://www.ibiblio.org/hyperwar/USN/ref ... .html#1200 Though it mentions zig-zaging it was more in answer to another thread query I had regarding Destroyer Screening Patterns :D at http://forum.axishistory.com/viewtopic. ... 4&t=194811

Have downloaded that document for some bath time reading. :lol:

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Re: Convoy ZigZag Patterns

#10

Post by Visionist » 06 Dec 2012, 14:03

Perhaps unrelated, but at what speed did the incessant zig-zag routine no longer prove itself necessary for evading submarines? The Queens could cross the Atlantic at 30 knots and presumably no U boat- not even a XXI- could get into firing position at that speed? The ships would leave the subs behind in short order surely?

I presume zig-zag steaming greatly slowed overall journey times down. If the objective was absolute speed of operations, surely a zig-zag wasn't employed?

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Re: Convoy ZigZag Patterns

#11

Post by Aber » 06 Dec 2012, 19:42

Visionist wrote:Perhaps unrelated, but at what speed did the incessant zig-zag routine no longer prove itself necessary for evading submarines? The Queens could cross the Atlantic at 30 knots and presumably no U boat- not even a XXI- could get into firing position at that speed? The ships would leave the subs behind in short order surely?
True, but they can radio ahead position, direction and speed of the target to U-boats further ahead who could get into a firing position.

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Re: Convoy ZigZag Patterns

#12

Post by Andy H » 13 Dec 2012, 19:26

Visionist wrote:Perhaps unrelated, but at what speed did the incessant zig-zag routine no longer prove itself necessary for evading submarines? The Queens could cross the Atlantic at 30 knots and presumably no U boat- not even a XXI- could get into firing position at that speed? The ships would leave the subs behind in short order surely?

I presume zig-zag steaming greatly slowed overall journey times down. If the objective was absolute speed of operations, surely a zig-zag wasn't employed?
Hi

The Queens used zig-zagging just as much as a slow moving 9kt convoy.

Speed is a defence but its not an absolute one. As mentioned by Aber if a U-Boat could get into a firing position ahead of the target, then a Queen couldn't out run a 40kt torpedo for very long.
The overall distance added when compared to the actual distance had little bearing on convoys as such. Better to arrive a bit later than never at all would be my mantra.

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Re: Convoy ZigZag Patterns

#13

Post by Andy H » 14 Dec 2012, 17:38

Hi

Whilst looking for something else I came across several zig-zag number patterns here, some numbered at over 40 8O :(
http://www.hmshood.org.uk/database/logD ... 1941/04/30

It also seems that there are numbered negative zig-zag patterns as well-Think I'll cry :(

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Re: Convoy ZigZag Patterns

#14

Post by LWD » 11 Mar 2013, 19:55

Recently someone posted the following link where a number of interesting documents can be downlaoded.
http://archive.org/details/usnavalwarcollege
one of the documents there is On his Majesty's service : observations of the British home fleet from the diary, reports, and letters of Joseph H Wellings, assistant U.S. naval attaché, London, 1940-41
On pages 19 and 21 he goes into some detail on the zig zag tactics used by the convoy he acompanied over to Great Britain. There may be more details further on.

There are two threads on zig zaging I'm posting this on both.

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Re: Convoy ZigZag Patterns

#15

Post by Andy H » 15 Mar 2013, 16:00

LWD wrote:Recently someone posted the following link where a number of interesting documents can be downlaoded.
http://archive.org/details/usnavalwarcollege
one of the documents there is On his Majesty's service : observations of the British home fleet from the diary, reports, and letters of Joseph H Wellings, assistant U.S. naval attaché, London, 1940-41
On pages 19 and 21 he goes into some detail on the zig zag tactics used by the convoy he acompanied over to Great Britain. There may be more details further on.

There are two threads on zig zaging I'm posting this on both.
Hi Lee

Appreciate the link.
Have downloaded the doc in full. Its a goldmine of information on various issues. The action reports etc about the Bismarck episode are gripping.
Sadly the zig-zagging issye remains just as elusive. For sure there is some useful additional info but the Appendix where it lists just whats entailed in Patterns 1-10 aren't inc :( It does make mention and show a few Evasion steaming plans :D

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Andy H

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