Jason M. wrote:
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.
Jason M. wrote: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.