The Invisible Enemy

[Fisherking]

I too have been away due to technical problems.

Anyway, it all sounds good.

Do it.

[Franconicus]

Chapter 8 – Noon, 18. December

Walker continues his march through the Atlantic Ocean. The leader of the Liverpool bound convoy decides that the time for detours is over. He conveys the captains of the other ships to reduce the zigzags to two turns per hour. He also announces that the convoy will turn northwards during night to take the straight way home.
The weather is getting worse and huge seas reduce the speed of the convoy to some 6 knots, however. There is nothing Walker can do to raise the speed, but at least the Krauts will suffer the same way.
The air patrols have already been stopped and the convoy has to rely on the lookouts. But during daytime of the 17th, nothing happens. After midnight, Walker gives the signal for the three destroyers and soon Blanckney, Stanley and Exmoor sheer out of course and disappear in the night. Soon Walker can hear the sound of detonating ash cans and the shine of snowflakes. The three destroyers are doing a good job to pretend a combat and Walker hopes that his trick will work and lure the Germans away from the convoy. He waits a couple of minutes and the he gives the order to turn northwards, away from the three destroyers and hopefully also away from the enemy.
At 2:00, however, he receives a message that one of the merchants claims that he has spotted a periscope. It is the Benwood, a freight ship in the middle of the fourth column. Minutes of anxious waiting follow, but nothing happens. The merchant ships keep their nerves and stick to the orders.
At 2:42, Lt. Cdr. Sayers from the HMS Rhododendron reports a short ASDIC contact in the western forefront of the convoy. However, the contact soon disappeared.
Walker has to face the fact that the Krauts are still out there waiting for their chance to prey and that the escort is significantly weakened by the withdrawal of the destroyers and the loss of the air patrols.
Fortunately, day breaks and still all of the ships are alright. Walker receives a message from the Audacity. Mac Kendrick complains that the Audacity has lost her escort and is now without any protection.
At December 18th, 12:00, Walker marks the position on his map. It is the cross between the squares CF99, CG77, DH31 and DH32. The convoy is still marching northwards with a speed of about 6 knots. The storm is getting worse and Walker hopes that he can keeps at least the 6 knots.
1) How to rearrange the escorts now that the destroyers are gone?
2) During night, the convoy will pass a awful storm. Any orders regarding this?

[King Kurt]

I would suggest the following for rearranging the escorts.

1) replace the 2 destroyers from the front group with 2 corvettes - so forward group is Stork + 2 Corvettes.
2) Put a corvette on each corner of the convoy. They will patrol the flanks and rear of the convoy.
3) Put Audacity between the front of the convoy and the front group of Stork + 2 Corvettes.
4) This leaves 1 corvette which will take station at the rear of the convoy in the middle. It will lie slightly off the rear of the convoy so it can move to assist on either flank if the convoy is attacked.

As for the storm, we need to use it as much as possible without putting the ships at risk. Franc - could you give us some information on the storm and where it is in relation to the convoy and the UK. For example if the storm is coming in from the West, could we skirt round the storm leaving it to the east of us - i.e. between the convoy and the French/ Spanish coast?

[Fisherking]

I disagree strongly.

The strongest reaction force belongs at the rear and so does the carrier.

Let me get the number of escorts straight.

We had 9 and were reinforced with the 3 of the carrier group?

Now we lost those three and still have the 9 and the carrier?


I would recommend that we have two corvettes at the front and on the flanks.

The two destroyers and a corvette at the rear.

One of the destroyers can reinforce a group where it is needed when a sub is found, but two always need to protect the rear of the convoy.

If the escort is too weak it will invite a surface attack by the U-boats, which is far likelier to succeed than a long range submerged attack. Also at the rear the carrier is afforded better protection. She is every bit as vulnerable as a merchant ship while sailing unescorted.

If we are getting contact reports we need to steer west for a few hours to try and lose them until the storm hits.

Then it is likely we need not worry too much until it blows its self out.

Subs at periscope depth are also effected by the storm and waves. They can even be thrown to the surface.

Report the several contacts and request some reinforcements. It will take days for them to arrive but it is better to alert them now than have to wait while we are in contact and losing ships.

[Franconicus]

Your escort force currently consists of:

2 sloops Depthford and Stork
7 corvettes : Rhododendron, Marigold, Convolvulvus, Penstemon, Gardenia, Samphire and Vetch
1 escort carrier Audacity (Cdr MacKendrick)

In total 10 vessels.

A big storm front is coming from west to east; it already hit you, but the centre is still coming!

[King Kurt]

The position of the escorts depends on where you percieve the threat is most likely to come from. I would have thought that is most likely to come from the front of the convoy, not the rear. U Boats are not fast boats, even on the surface, so they would want to position themselves in our path and attack accordingly. They would have to travel significantly faster than us to come up behind us. I placed the carrier between the front screen and the front of the convoy as that position, on my deployment of escorts, would be in the maximum level of escort. I had also missed the sloop Depthford from my calculations, so that could sail as close escort to the carrier.

Also we are trying to have a 2 layer approach so the U boats have to fight through two layers. The front group are several miles in front of the convoy so they can attack any subs detected. fischer - why do you think our threat is most likely to come from the rear?

As for the storm, I would be hesitant to turn to the west - our most recent detected threat was to the west and by turning to face the storm we will be slowed even more. My inclination is to press on to the North and only turn into the storm - ie to the west if the storm gets so fierce that we need to face it head on for seakeeping reasons - ie to stop waves hitting us side on.

[Fisherking]

U-boats are faster than our corvettes.

They us their surface speed to position themselves for an optimum position for attack.

Directly a head is not that good of a position. It is better to be slightly to the flanks. Head on shots are very likely to miss.

However stalking and trailing the convoy is from the rear. That is where you will most likely see them surfaced. The rear flanks are also where it is easiest to get inside the convoy with a dash on the surface at night.

The Destroyers are considerably faster than the corvettes and the U-boats. Having them in the rear is the best place to reinforce on of the three groups, should they make contact with a U-boat.

Should the front group contact a sub we want to change direction for a time to avoid it anyway.

When and if we are reinforced by more escorts we will strengthen the front group first of all. But at the moment we have early enough to cover the convoy and the escort carrier is a big target. The rear is also the best location for command and control.

We can maintain this heading for a time and then try to shake them off in the storm but if the convoy is sighted the pack will spread out to form a cordon. Until we have clear weather and air cover things are going to stay a bit dicey.

[Franconicus]

Well, you do not have any destroyers:

Your escort force currently consists of:

2 sloops Depthford and Stork
7 corvettes : Rhododendron, Marigold, Convolvulvus, Penstemon, Gardenia, Samphire and Vetch
1 escort carrier Audacity (Cdr MacKendrick)

In total 10 vessels.

A big storm front is coming from west to east; it already hit you, but the centre is still coming!

Could you please precise the position of your escort ships (front/rear, one ring/two rings ...) and their orders in case of an attack or any other event?

[Fisherking]

I stand corrected then, two sloops in back. :P