THE DEVELOPMENT OF SOE SIGNAL PLANNING


Section A.               General Principles




The task of the Signal Planning Officer is the organisation of the detailed time tables for the working wireless circuits. Arrangements are controlled by the two main sets of conditions:

a. The circumstances of the Outstation.
b. The circumstances of the Homestation.

Under both catagories the future as well as the present must come under consideration. The organising of SOE signals is Always complicated by the extreme variations in circumstances that must be allowed for, since outstations vary from securely placed sets at sub-headquarters to secretly camouflaged sets in an enemy controlled city - traffic may vary from the complete unimportant to last-minute details of a supplies dropping operation or reports of enemy movements behind a fluid fighting front, even the homestation resources may vary from the "more than adequate" now, to the "woefully inadequate" in three months time.

The following details that must be considered;

a. The Outstation.

1. Graphical location
2. Equipment that can be carried.
3. Later re-supply position.
4. Degree of clandestinity of the operator, combined with the enemy situation in the area.
5. Type of traffic and quantity of traffic likely to be handled.
6. Future changes in the operational situation
7. Personality and ability of the operator.


b. The Homestation.

1. Availability of working terminals, i.e. equipment, aerials, operators at the optimum periods.
2. Otherwise the future use of existing terminals at less suitable times.
3. The operating standard of personnel available.


It was the fundamental rule of SOE signals to give all condersiration to the outstation, but rapid expansion of comitments together with equipment and man-power shortages has often caused the planning to be at least partially controlled by the Homestation situation.

Experience has shown that adequate planning can assure for average operators a reasonable degree of succes. Supreme succes with individual circuits must rest on the skill and resources of the operators at both ends. Planning and procedure rules can aid overall efficiency but must not hamper individual circuits. Every circuit team consists of HQ Planning, technical and training staff, Homestation Control, homestation operator and outstation operator.
The peaks of succes depend on the last two.

The section that follow give a brief outline of the types of Signal Plans used, their deficiencies and where possible the reasons for later changes.

The sections that follow give a brief outline of the types of Signal plans used, their deficiencies and where possible the reasons for later changes. The appendices show example of the plans as issued, but no attempt is made to explain their use in detail; the general use is self-evident.

Many other types of planes were issued, due usually to the special circumstances of operations, but as they all had to fit into the general plan of control of the homestation, they were approximate to one of the examples or possibility of two.


Vicarage type Plans. (see app. D)

Had to cater for teams going to P.O.W. camp areas at unknown future dates and in areas not previously defined in detail. Uncertainty as to distance and time of year was covered by the introduction of three emergency channels on frequency bands other than those used for the fixed schedules. No broadcast plan was included as night transmissions had tented to become less successful after D-Day and in addition the homestation was no longer hard pressed, nor was it necessary to restrict as much as possible outstations for the sake of security. (
Wat wordt hier nu precies bedoelt?).



Section D
.   Clandestine Operations. (see app. B)

Were easily intercepted and logged and gave no assistance to the operator, and soon ceased to considered a clandestine plan.



Old V-Plans. (see app. E)

Gave facilities fot two fixed and two extra schedules daily, also greater opportunity of frequency changing. Schedules, times, callsigns and code-groups changed throughout a monthly period and gave alternate day working. The reservation of four hours daily per station, of which three were probably not used, was however too un-economical when operations expanded.



V-Plan. (see app. F)

Gave one reserved fixed schedule either daily or alternate days, but afforded facilities for extra schedules at any daytime hour usually daily. Outward traffic for security reasons was by night broadcast. The plan worked well in France and other occupied countries but had two weaknesses that became apparent in Holland and Denmark especially where outstations were in cities and closely watched. The stations of the same country were working with the same home-frequency and call-sign. This could easily be watched by interceptor units. In addition, once any "V' plan was known, every one could be intercepted and logged in a 15 day period.



The X-Plan. (see app G)

Was used in Holland and broke the date sequence of the "V" plan, but did not cure the other V-plan defects. It gave only temprary respite to the users.



The Z-Plan. (see app H)

Used first in Denmark and later in Holland to a large extent cured the "V" plan defects. The homestation used three frequencies per channel in irregular rotation and changed call-sign every schedule. Thus individual plans took four months to log completely, reduced to one month only if another plan on the same channel was captured.



The Marker Plan. (see app. I)

Was introduced to solve the difficulties of proposed operations in Germany to give the German Security police something new to think about.

The difficulties facing Signal Planning were:

a. No knowledge of internal conditions
b. Need to use smallest possible equipment and lowest possible power.
c. Initially few operators at widely varied distances and lasting from spring well into summer period.
d. Necessity for outstations to be able to use any possible times for transmission, perhaps of short duration
    and few and far between

The system employed transmission channels that were used for day and night broadcasts and gave 24 hour indication to the outstation of the best frequency channel for his location and time of day.

The homestation kept permanent listening watch on caller frequencies in each band.


The advantages obtained were:

a. Outstation had complete freedom of choice of time for working.
b. He was afforded a chance of choosing his optimum frequency to make for his low power.
c. Plan fitted any change of location and worked well equally well with change of season.
d. System easily adaptable to very light or very heavy traffic and became suitable for 'open' communications with
   heavy traffic when the outstation was over-run.


The disavantages were:

a. The need to change from Caller to Traffic frequency for each contact. This was found to be unimportant when
    a reasonable good operator chose the right transmission band.
b. The homestation could not call the outstation for two-way contact exept by broadcast message. Otherwise it
    must await an outstation to call.



From a planning angle the "Marker" system proved extremely flexible and once started adapted itself admirably to all types of special problems. Even in the short time it was in use before VE-Day it was employed not only for German operations but for:

a. Supplementary plans to Danish "Z" plans.
b. Emergency channels for Norwegian "V" plans.
c. Emergency channels for Vicarage plans.
d. Special Short Term sea operation plans for ships in Norwegian waters.





Sorry, I just deleted Appendix H and I by accident, one week's work down the drain... ;-(


















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