SUBSIM Radio Room Forums - Some help for a book please?

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Some help for a book please?

A friend of mine is writing a book, based during WWII, which involves the landing of an agent in the UK from a submarine and knowing my interest in all things submarine he's asked me for some info.

In order to be sure I'm accurate, and as I travel a lot with work so can't always access my own library, would anyone like to assist with some suggested answers for the following questions (I've already included some info I was going to suggest, please feel free to correct me, expand on that or suggest a better option)?

Many thanks in advance!

All of the below are relevant to the scenario of a German U-Boat operating off the southwest coast of Wales in October/November 1940.

1. Type of U-Boat. i.e make, model etc

I’d suggest a type VIIC u-boat, this was the workhorse of the Kriegsmarine (German navy) Ubootwaffe (submarine service) in WWII, and was operating at the time you want.

2. Length

66.5m overall, pressure hull is 50.5m. The extra 16m is from the superstructure around the pressure hull.

3. Displacement (is this the same as weight - there you go, first indication of my total ignorance!)

Displacement is a measure of the weight of water that any floating vessel displaces, the theory is that so long as the physical weight of your ship is less than it’s displacement, it will float.

Put simply, submarines effectively flood internal tanks with water to increase their weight, allowing them to dive, and then use trim tanks to balance themselves while underwater.

The VIIC had a surfaced displacement of around 719 tons, and a dived displacement of around 870 tons. Both displacements depend on fuel, food, fresh water, weapons, crew etc. that was loaded.

4. How many crew? (Assume full compliment) and split between Officers and general crew.

4 officers, 56 ratings.

5. Were the crew conscripts or would they have been regular German Navy prior to hostilities?

In 1940, they were probably mostly regular volunteers.

6. German titles equivalent to:

Captain – Kapitänleutnant (generally referred to as ‘Herr Kaleun’ by the crew)

Helmsman (I think this is the guy who drives it!) – There are several looking after bow planes, stern planes and ballast tanks. Generically known as the ‘Zentrale-Personal’

Second Officer - Wachoffizier

7. Periscope depth, and some idea of how the captain operates the periscope (and the commands that he would use to the crew)

8. How long would it take to surface from periscope depth, and some idea of how they do this?

There are several ways of surfacing:

Quickly and making noise/spray - high pressure air is used to quickly blow the water out of the ballast tanks, this makes the boat bouyant and lifts it towards the surface. This would usually be combined with 'driving' the boat to the surface with a combination of propulsion (speed) and an upward angle on the dive planes.

More stealthily - The boat can be driven to the surface using a slower speed and upward angle on the planes, some ballast would probably need to be blown though, to allow this.

Most stealthy but difficult - the boat can be stationary in the water and the water very slowly blown from the ballast tanks, allowing the boat to slowly rise to the surface.

The boat doesn't always have to surface fully, it can be held at any depth and it wasn't uncommon for them to run with the deck awash, so that just the tower stuck out of the water, to make them less visible and allow them to dive quicker. I don't think you could launch a folboat this way, as they generally come out of the main hatch aft of the tower.

9. The height of the sticky out bit at the top ( the tower?)

The top of the bridge is about 5m above the deck, the standing platform is about 3m off the deck

10. How do they get up to tower (e.g. how many steps, hatches etc) ?

There’s a ladder from the Control Room, through a hatch to the attack centre, there’s then another ladder up to the external hatch which takes you onto the bridge.

11. What would they use to signal to shore? Torch or lantern etc

12. Size and type of small boat that they would have on board. (rigid, inflatable etc) and how would they get this in the water (different hatch? if so where would this be in relation to the tower?)

A Folboat? These were usually brought out of the main hatch aft of the tower, or the torpedo loading hatch fwd.

13. How many men could it hold comfortably? and I presume that it would be oar powered as opposed to any small motor. How many oars etc. Double or single ?

14. If they needed to make 2 or 3 journeys to and from the shore, would they used a fixed line to guide them backwards and forwards?

15. How would the U-boat normally communicate with Germany? Radio etc? Make and model.

They used radio, typical make would be…?

16. Where would the main German U-boat command have been based? And would all communications to the fleet go through this one centre?

17. Rank of officer would could reasonably be expected to be in command at this comms centre and roughly how many men would there be sending and receiving signals etc.

There’s only one person on duty in the radio room at any time, a Petty Officer rating is in charge, the ‘Funkmaat’ or a Radio Operator rating, the ‘Funker’. The radio room is a compartment, about the size of a large wardrobe, immediately fwd of the control room.

I would have a good look at uboat.net for the technical detail.
I would suggest a smaller coastal boat as it would have been easier getting in and out of small coves etc.I would also suggest your friend reads the book Casabianca by Captain J L'Herminier.This was a Free French submarine that did a lot of this type of work in Corsica and he even has a diagram on how to penetrate an enemy blockade.

It's a good concept for a novel, and I wish your friend well. I've done a fair bit of research & writing on secret agents & U-boats, too.

Regarding "the Welsh Connection" I found this tidbit via Google:

Quote:

As detailed later in the section "Terrorism in Wales - The Response", during WW2 the German Abwehr snapped up offers by renegade Welsh Nationalist Arthur OWENS to act for them. OWENS was of course turned and fed false intelligence to his Abwehr controllers, although a website consulted in preparing this article paints Mr OWENS more as a patriot acting alone than a little man scared for his life. One cannot beat good old fashioned revisionist history!

One very interesting find during WW2 is alleged to have been made in the Swansea area of South Wales. The article concerned is a S90/40 CW transmitter, which bears a date stamp of March 1941. The controls bear English lettering but the components are clearly German. It is said to have been seized from an agent/agents landed from a U-Boat on the South Wales coast.

Further the "Abwehr Diaries" record an attempt to land an agent, code named LEHRER [Teacher] on the coast of South Wales together with a wireless operator, the intention being to forge a communications link with Welsh nationalists. An agent of this name was dropped by parachute in the Salisbury area, and having been captured, not turned and found to be of no further use, was subsequently executed.

The set came to light after the war when it was found in the basement of 'Telephone House' in Swansea. It was amongst the amateur radio equipment impounded in 1939 by the GPO. Of the associated receiver there is no trace.

However on the roof of 'Telephone House' during WW2 there was based a radio monitoring centre. A story related by a former GPO employees tells of the Army arresting the operators of a covert transmitter in REYNOLDSTOW, a village near Swansea. Also Swansea is a busy sea port and during WW2 would have been very busy. All shipping to and from the equally busy ports of Cardiff and Newport, and Bristol itself, would have easily been monitored and the times of departure noted and reported from that location, by a person so minded. [Based on an article in 'Radio Bygones' written by Alan Davies, GW3INW].

Among the details to note re German Intelligence: agents planted in foreign countries had their own chain of command through the Abwehr, separate from the Kriegsmarine. It was a source of inter-service tension, which might have been mitigated to some degree by the fact that Admiral Canaris, chief of the Abwehr, had been a U-boat commander in WWI.

Without having all the details at hand, a reasonable assumption would be that agents delivered via U-Boat would share nothing about their mission with the boat's crew, and that would include its skipper & radio operator. If one wanted to underscore the gulf between these people, one could have the agent commandeer the U-boat's radio & Enigma machine to transmit his messages by himself, using his own machine settings.

In such an instance, even if all regular U-boat radio traffic was received & decrypted by Ubootwaffe HQ, the Abwehr traffic would be understood only by Abwehr HQ. Every branch of the military that used Enigmas had their own machine settings & schedules for changing them. However I think it's also self-evident that agents would not risk bringing Enigma machines deep into enemy territory; they would have alternate methods of communication once ashore.

I hope this is of some help.

Mach's gut!
Wayne

Sorry to drift off topic but there was a large POW camp just outside Bridgend called Island farm.There was a large escape attempt in 1945 and the camp also contained some very senior officers:
http://www.islandfarm.fsnet.co.uk/

Quote:

Originally Posted by lesrae (Post 1076524)

3. Displacement (is this the same as weight - there you go, first indication of my total ignorance!)

Displacement is a measure of the weight of water that any floating vessel displaces, the theory is that so long as the physical weight of your ship is less than it’s displacement, it will float.

No.

Displacement (W) is the weight of the volume (V) of the water displaced by a ship. (Volume of water times density of water, or VD) If W exceeds VD, the ship sinks. If its VD exceeds W, it rises. If VD = W, the object has neutral buoyancy.

Archimedes' principle: "Any object, wholly or partly immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object."

Time for some maths!

Quote:

Let's assume a barge-shaped vessel with a surface of 10 meters by 10 meters, floating in water of density = 1025 kg / cubic meter (IE, seawater). If said barge weights 200 metric tons, then:

W / D = V
200 MT / 1.025 = 195.12 cubic meters

The immersed volume of the barge is then 195.12 cubic meters; knowing that it measures 10 meters by 10 meters, we can calculate its draft, since V = L*B*d:

195.12 / (10*10) = 1.95 meters.

Now suppose 100 MT of cargo is loaded unto the barge.

W / D = V
300 MT / 1.025 = 292.68 cubic meter

V / (L*B) = d
292.68 / (10*10) = 2.92 meter draft.

As you can see, an increase in weight led directly to an increase in volume displaced. Once the ship or submarine has no more volume left to displace, it sinks. If it's got more volume than weight (IE, a submarine blowing ballast), it rises until VD = W.

In short, the displacement of a ship is its weight.

I think 56 ratings for a Type VII boat in 1940 is a bit high. That might be close to what a boat would carry in the late war on a Type IX as they carried extra radiomen to operate the radar systems and extra gunners for the increased number of flak guns. But in 1940, I'd say you'd be close to 40 men and 4 officers on a Type VII.

Look at the crews lost on these early war sinkings of Type VIIC's

U-70 - sunk in 1941 with 20 dead and 25 survivors
U-79 - sunk in 1941 with 44 survivors
U-82 - sunk in 1942 with all 45 men lost
U-93 - sunk in 1942 with 6 dead and 40 survivors
U-94 - sunk in 1942 with 19 dead and 26 survivors
U-95 - sunk in 1941 with 35 dead and 12 survivors

A little research and I've found that the manufacturer of the U-boat radio sets was Telefunken: http://www.cdvandt.org/u-boat_equipment.htm

in October of 1940, BdU was based at Kerneval, a chateau near Lorient.

Great stuff, thanks for all your help on this guys.

Another question:

What's a reasonable journey time for a VIIC from Brest to South Wales? I haven't got SH loaded at the moment so I can't do the run to check!

Here's a bit more information about Abwehr activities that might come in handy. From recreation of the "SOE Syllabus":

Quote:

NOTES ON ACTIVITIES OF THE ABWEHR

1.Concentration at the Centre of Operational Zone.
a)From 1933 – 1939 Abwehr was active against Britain and France. About 30 agents were discovered, all controlled by Hamburg. (Mrs. Jessie Jordan, Mrs. Brandy)

11 of these reported themselves.
6 reported by suspicious private persons.
9 caught through using the post to write to cover addresses.
3 by official action.
1 as a result of letter being found.

Development of Auslands Organization in Britain suggested possibility of members being used for sabotage; large number arrested on outbreak of war.

Greatest effort concentrated in France, by corruption of politicians like Laval, and undermining morale.

b)After fall of France activities of Abwehr became more concentrated on the U.K. with invasion in view, working up to a peak in the Fall of 1940, and falling away again after the defeat of the Luftwaffe by the R.A.F. in the Battle of Britain.

Six agents caught in Eire between May and July 1940 (Herman Goertz), may have had a far reaching effect on German strategical plans, which certainly included the invasion of Eire.

September – November 1940, over 25 agents are known to arrived in U.K. by parachute or small boat. Short term agents connected with invasion plans. (Druker, Walti and Eriksen, Ter Braak)

Between March and September 1941 a number of agents were landed by small boats from Norway. Objects varied from naval espionage to penetration by escapees on behalf of counter-espionage (M.V. Hernie).

All this time during 1940 and 1941 a number of long term agents were despatched for various purposes (Gerth van Wijk), and quite a few seamen were sent via the Iberian Peninsula to report on shipping movements, coastal defences, etc. (Timmerman)

Between September 1941 and March 1942, so far as is known, Abwehr activity against the U.K. practically ceased. The “Battle of Britain” had been won, the “Battle of the Atlantic” now occupied the thoughts of the O.K.W.

2.Extension of Activities to the Periphery of Operational Zone.
After the occupation of the Atlantic Coasts of Europe in the summer of 1940 the “Battle of the Atlantic” assumed a more dangerous form, and simultaneously the Abwehr began developing its organization in NORWAY, the IBERIAN PENINSULA, and the WESTERN HEMISPHERE. The BALKANS also assumed importance as a base for the threat to the SUEZ CANAL ZONE, and MIDDLE EAST.

At the same time the Abwehr were also entrusted with the obtaining of Meteorological Reports and for this purpose made special arrangements in GREENLAND and JANMAYEN ISLAND. Many of their other agents were also required to make meteorological reports as a matter of routine.

Norway.

Main functions [of Abwehr branch] were:
i)C.E. or III-F activities against Norwegian and Allied Intelligence in Norway.
ii)I.M. undertakings – small boats to Britain.
iii)Espionage against Russia.