Convoy Question

[Jason M.]

Because I clearly have no life, my mind began to wonder about WWII Atlantic convoys tonight. My limited knowledge of convoy history reminds me that convoys consisted of a number of merchant ships, lined up one in front of the other, stretching for miles. All the while being escorted by an assortment of destoyers, etc.

Wouldn't it have made more sense to run the convoy with the ships, side by side and stretching across the water abrest one another? In my mind, this would have presented U-boats with much less of a target, and kept all of the ships inside the grouping much safer. Rather than putting many ships at risk, put the the most expendable ships on either flank of the convoy. Was this tactic ever used?

In a regular convoy, the straggler in the rear would usually get hit, and if so, that was it. No way to help him. This would reduce that wouldn't you think?

[Dick J]

The convoys were usually in a rectangular array, with several columns side by side. The arrangements had to be compact enough to surround with escorts, but spread out enough to allow some maneuvering. The usual victims were in the outer columns, so naturally, the high priority cargoes went in the middle. Some of the others here could probably explain it better than I can.

[Filipe Ramires]

Hmmmm, interesting question but hard to answer in few words.
Basically the best way to protect the ships, if possible at all, was to compact them in a square type formation. It really still covers a large area but allows the escorts to sail around it more easily and therefore providing more effective protection then in a long line abreast formation. Regarding the uboats spotting the convoy, in whatever shape the formation had, it really didn't have much significance I believe. The ocean is too big and would made little difference really. Besides, U-boats usually operated in patrol lines with average number of units. Knowing in advance the usual convoy route they would establish a patrol line (usually 15-20 miles or so between submarines) and the convoy would eventually had to pass through it. Being then spotted the last ships of column would have suffer greater at the hands of the uboats...they usually suffered in any case. Stragglers were usually left behind to sail independently to their destiny if an escort could not be provided to them...they were usually doomed.
Well, just for starters...I am sure there are more understanding persons on the subject around here...Mr. Laurence and Mr. AR perhaps.
Regards,

Filipe

[mike mccabe]

As Felipe said, basically the biggest loss of shipping would come when a convoy for forced to scatter, as it then became impossible to protect the individual ships, which were left to their own devices. A convoy system of columns allowed the escorts to protect the merchants with the least effort, whilst allowing the individual ships to remain in contact with each other and gain the protection of those escorts. Another important consideration was the speed of the U-boat, if the escorts, or later aircraft, could force the U boat to submerge, it's submerged speed was slower than most convoys so eventually they would lose contact. It was easier to do this if the escorts were covering a smaller area of sea.

Mike

[Filipe Ramires]

Another important consideration was the speed of the U-boat, if the escorts, or later aircraft, could force the U boat to submerge, it's submerged speed was slower than most convoys so eventually they would lose contact. It was easier to do this if the escorts were covering a smaller area of sea.

Good point indeed, Mike. The best way for the submarines attack, even if submerged, would be to place themselves either in front of the convoy or in the sides at appropriate time...therefore, ships on the outer columns or in front of the convoy would usually suffer more. Eventually, depending of the escorts, one or more submarines could penetrate the screen and the columns and take out the more "precious" ships in the inside columns. In case the convoy passes and the submarines are still submerged and can't afford a surface stern chase they will immediately turn to the last ships of the convoy, specially stragglers. However, it was essencial to keep contact with the convoy, even stern chasing it, and warn other possible wolfpacks still ahead of the convoy and give its position away so that another attack can be made.

[bengtsson]

I'de need to consult some of my books to be sure, but I thought that Atlantic convoys most often had more columns than ships per column. i.e. sailing on a wider front. Say 8 columns with 4 ships to column. The ideal target was a stretched out convoy. i.e. 4 columns with 8 ships per column for example.
The "rakes" or search lines the U-boats used were very often defeated by Ultra intelligence. SImply sailing the convoy around the "rake" saved countless merchant ships. The most vulnerable merchant ship was the independently routed ship, usually a fairly fast vessel, they were simply dead meat for a U-Boat. As the war went on it was decided to reduce independent sailings as much as possible for this reason.
A wide front convoy presented a narrow target with the ends secured by escorts. That is why getting in amoung the columns was so important to really make some sinkings. Speed underwater made submerged attacks rare and often futile in the first half of the war. When unable to attack surfaced, getting ahead of the convoy and submerging to await the convoy was a common tactic. But submerged attacks were usually a one shot deal because of the narrow columns.

Bob B.

[Laurence Batchelor]

Wouldn't it have made more sense to run the convoy with the ships, side by side and stretching across the water abrest one another? In my mind, this would have presented U-boats with much less of a target, and kept all of the ships inside the grouping much safer. Rather than putting many ships at risk, put the the most expendable ships on either flank of the convoy. Was this tactic ever used?

As Filipe suggests its hard to cover this topic in only a few paragraphs, it really needs a lengthy article with the various formations of convoy drawn and all the various situations drawn out.
Firstly we need to understand the convoy system is a defensive measure meant to protect vital war material as much as possible and was proved from bitter experience in 1917/18.
By WW2 it requires immense planning, coordination and lots and lots of standing orders to be laid down to every single Captain so each ship has the best possible chance dependent upon the situation they face.
Radio Silence is vital, as is secrecy, and remaining undetected as long as possible is your best weapon.

To answer your question specifically.
If a convoy was lined up as you suggest with each ship side-by-side in 1 continous line the convoy would be a much easier target to detect.
If we consider the convoy comprises 40 merchant ships and they then are 1000yards apart that will make your convoy an extreamly large body of ships moving across the ocean.
It would more likely pass over several U-boats waiting in patrol lines.
Thus this formation would make it easier to detect by U-boats or aircraft, disguised neutrals/raiders etc.
Its better if your convoy is more compact ala a box formation, but with just enough room to move freely and also offer mutual support.

I understand why you think this would be safer as a U-boat would normally be attacking or approaching from the beam and would only be presented with a small target to attack on the horizon, but its too simplistic to think only in that singular dimension.
With the formation you suggest U-boats would find it easier to get ahead of the convoy and form up in numbers.
That is exactly what you don't want as it could overwhelm the escort!
Its easier if your attacked only sporadically and hopefully from only 1 vector at once.
Every time an escort has to leave the screen to attack or investigate the contact it weakens the defensive screen.
What would happen if one wing of your convoy was being overwhelmed?
It would take a very long time for the escort ships on the other wing to steam across this massive line to offer support either in screening or attacking to the exposed wing.

U-boats also would find it easier to move across the single line of the convoy and choose the most valued merchant targets at will i.e. how could you protect the most valuable tankers in the central positions which as they have other ships around them in all directions are harder to target?
Also the U-boats would find it much easier to tail the convoy at a given distant as they could have a large long line to judge their distance from and then just wait for their moment at night.
As Mike points out U-boats submerged speeds were slower than the usualy convoy speed (until the Type XXI & XXIII's came along).
However, U-boats would get around this, especially early war or in the mid-Atlantic gap by shaddowing a convoy submerged during the day a mile or two behind.
Wait until nighttime, surface, and then use their greater speed and attack on the surface with guns or torpedoes.
You could easily have several U-boats doing that in your single line formation as they could space themselves out down the line and all attack at the same time.
I'm still not sure where your escorts would be in this convoy formation but they cannot patrol such a long line of merchant vessel all the way across the ocean aft.
Remember it would be likely the escorts would have to eaither steam back and forth down this line (which uses up too much fuel!) or more likely they would keep in station in a very spaced out line across aft of the convoy.
Either way its a poor defensive situation to be in and again makes this signle line formation unsatisfactory.

Further, where can the Commodore of the Convoy go in his merchant ship?
If he's in the centre of the single line how does he signal the ships on the extream wings? They would probably be out of visual range and perhaps even flares would not be seen in poor visabilty.
Basically he cannot COMMAND and DIRECT the convoy easily in this formation whereas he can in a box formation as pretty much every ship can see him, he can also see the Escort Commander or another escort much easier (as the distances involved are lower) and each ship can offer mutual support.

Another important thing in convoy formation is station keeping.
It would be much harder to keep station in a single line formation through a heavy Atlantic gale than it would if you were in a box formation.
In a box formation you have points of reference in front, abaft and on 1 or both beams (depending on which column your in).
Thus your single line formation is more likely to produce stragglers or victims!

If a box formation worked in 1917/18 why change it if it ain't broken?
The problem with early convoys was a lack of escorts vessels which meant their was not a surplus to form support or 'hunting groups'.
Lack of air cover, especially in the mid-Atlantic gap.
Lack of intelliegence.
Lack of training for escort vessels and understanding how best to combat things like fatigue and to tackle the U-boats at night.
Lack of an ahead throwing ASW weapon, poor quality sonar with 'dead spots' and so on.
Further there was a certain amount of slackness with early merchant Captains who were not use to following rigid standing orders e.g. minimal funnel smoke, all lights black out etc etc.

In a regular convoy, the straggler in the rear would usually get hit, and if so, that was it. No way to help him. This would reduce that wouldn't you think?

No see station keeping above.

[Jason M.]

Holy Cow guys! You are all VERY educated in this field. Thanks for all of the input. Laurence, your explanations and arguments against such a convoy are very well stated, and make a lot of sense. You are considering so many other factors such as communications during radio silence, placement of the Commodore's ship, etc. Plus I learned about the box formation from all of you.

Thanks!!

[bengtsson]

http://www.gordonmumford.com/images/convoy.jpg
http://ahoy.tk-jk.net/Images8/Convoy-ONS-5.jpg

These two bear out what I always understood as a standard Atlantic convoy formation.
The reason given in the history books is the ability to defend the flanks against submarine attack. With an escort sweeping ahead to make the uboats dive, this lessened the chance of attack from ahead, which gave a rotten angle of the bow shot in anycase.
For the U-boats in the "rake" it was the smoke that gave away the convoys position. The smoke high in the sky was visible almost as easily from a wide convoy as a long convoy. In other words, the width did matter, but not very much because sighting of smoke often preceeded the sighting of mastheads and hulls.
Bob B.

[MichelB]

I remember a scene from a Dutch book on convoy duty that one day, with air cover, all ships were ordered a immidiate full stop. Withing minutes the escorting aircraft pounced on u-boats who were appearing from beneath the ships, having been sailing under them with matching speed.

When i read it, it sounded a typical dastardly german trick. With 20-odd extra years (including 5 on this site) of insight, I find this very improbable. Did anything like the above scene ever happen?

Sorry if I hijacked the thread, but I remembered this just right now.

[Deckard]

... I find this very improbable.

Me too.

[Dustermaker]

I have a book that shows some of the common formations and how to escort the convoys with as few escorts a possible. it was a large box formation with de's or amc's on the tips of the square.

[finnfan]

If you want even more detail on convoys, Arnold Hague's book The Allied Convoy System in Second World War is very thorough and I believe is being re-printed

[Laurence Batchelor]

If you want even more detail on convoys, Arnold Hague's book The Allied Convoy System in Second World War is very thorough and I believe is being re-printed

Is it to be expanded do you know?
Which publisher is doing the reprint please?
and finally I think Hague died some years ago do you know if another author is doing this?
Cheers

[bengtsson]

If you want even more detail on convoys, Arnold Hague's book The Allied Convoy System in Second World War is very thorough and I believe is being re-printed

Thanks for the tip. I decided to order an 'as new' copy from the usedbook site. Not a whole lot of copies available and some pretty highly priced. But I got one for about the retail price when new. I thought I'de take the chance rather than wait for the reprint. I have no patience when it comes to Naval History

Bob B.

[Guest]

I got the information from the Ian Allan/Midland Counties website. They say "This title is not currently available, but may be re-printed by the publisher" They are taking pre-orders but will not charge cards unless the re-print happens.

[finnfan]

Sorry, that was me with the reply about Arnold Hague's book. As I am fairly new to the forum I forgot I was not logged in

[Laurence Batchelor]

Thanks for the tip. I decided to order an 'as new' copy from the usedbook site. Not a whole lot of copies available and some pretty highly priced. But I got one for about the retail price when new. I thought I'de take the chance rather than wait for the reprint. I have no patience when it comes to Naval History

Bob B.

I've had the book for a number of years as I've always consider Hague a top naval author and researcher.
No worries about logging in we won't bite!

[bengtsson]

Thanks for the tip. I decided to order an 'as new' copy from the usedbook site. Not a whole lot of copies available and some pretty highly priced. But I got one for about the retail price when new. I thought I'de take the chance rather than wait for the reprint. I have no patience when it comes to Naval History

Bob B.

I've had the book for a number of years as I've always consider Hague a top naval author and researcher.
No worries about logging in we won't bite!

Then it was money well spent, , and that's always good to hear

Bob B.