SIGNAL PLANNING SECTION
During the past year (June 1943-1944) the Signal Planning Section has seen a continual growth from
very a small numbers of plans of relatively simple type which were not proving at all secure, to a large number of plans of various types which may be characterised as variable or "V" Plans.
In June 1943 there were some 50 plans of the old type in the Field characterised by relatively small numbers of frequencies available on each plan and a weekly cycle of schedules. In July 1943 the variable type of plan proposed by Brigadier Nicholls and Captain de la Corvette-Valois (now Commander) was first introduced. This plan, whilst giving greatly enhanced security, presented quite a production problem in as much as each plan requires approximately 1500 entries each one of which must be exactly accurate. What are 1500 entries?
Furthermore, the frequencies employed on each plan must still be worked out in accordance with the laws covering radio propagation at the times which the plan is due to be used. In addition each plan had to be supplied with a night-broadcast plan since it had been shown that whilst 2-way working between the agent and the United Kingdom was practicable during some 12 hours of the day, at night such 2-way working could only be accomplished by equipment and methods which would probably seriously endanger the agent. In which way, by using more HF power, or lower frequencies with a much stronger groundwave?
To overcome this difficulty Brigadier Nicholls proposed the broadcast methode of transmission by which the UK high power transmitters emit "blind" messages which may be received by an agent with considerable ease. This system
has been was developed until at the present stage (D-Day) although no acknowledgement are now being made for the messages received, records showed that as high as 90% of all messages transmitted are were correctly received by the Field.
Production of "V" Plans was started by the Planning Section with a staff of only four people and in order to provide the estimated requirements of the Country Sections for this new and much more secure type of plan it was necessary to expand using unskilled personnel and to cope with the difficulty of training such personnel at the same time as production of other types of plans was being carried out.
It was estimated by the Allied French Section that they would require some 70 plans in the year up to D-Day, but in actual fact they have been issued with a figure near 300 and when it is realised that In the production of the plans for this Section alone over half a million carefully worked out entries to plans, each of these plans being produced 10 times, making a total for this Country Section alone 5.000.000 groups of figures or letters.
some idea of the magnitude of the task undertaken and coped with, can be gathered.
Taking the overall picture of French, Allied French and various other country Sections, it has been was necessary to produce nearly 15 million groups of letters and figures all of which
have had to be accurately checked, and each of which had to be correct for the particular operational use to which they are it was put.
The growth of the requirements of the French Section
has followed almost exactly the pattern of that of the Allied French. The Section estimated in August 1943, when they had 24 of the old type of plans in the Field of which 17 were active, that they would in the ensuing year be sending some 120 operators into the field up to D-Day for whom they would require 68 of the "V" type plans. In practice they have so far demanded over 120 plans. This has meant that the basic system of planning has had to be revised under the most trying conditions in order to cope with the increased growth and that extra frequencies have had to be fought for in the face of the growing competition from all Services.
At the same time during the year it
has been was possible not only to improve the production details of the plans but to cut down the time required to produce each plan. This has been was reduced from 8 man hours for each plan to some 4 hours.
which that has had to be continually coped with is was that Country Sections cannot in most cases obtain information from the Field until approximately a week before the moon period deliveries are due to take place which has meant in many cases the production of very large numbers of plans at extremely short notice. Examples of this are the production of 10 plans for the Belgium Section is two days. On the 31st December the production of 10 French plans in three days and since these peaks have had to be coped with at the same time as normal work is proceeding, it has meant that the staff engaged o Signal Planning have had to be prepared to exert enormous efforts in order to ensure that the Country Sections requirements may might be satisfied.
Furthermore not withstanding the continual incidents of these rush demands the plan production had still to be absolutely accurate and when it is realised that the error percentage
has was been kept below o,o1% even during the most trying periods, the strain on the staff can easily be appreciated.
In addition to the normal work of the Signal Planning Section namely catering for agents' work, it was also necessary to provide for the communications required by SOE in conjunction wit the Field Armies taking part in operation OVERLORD. Initial planning for D-Day started in November 1943 and representatives of the Planning Section attended the Inter-Services Conferences set up to co-ordinate the various signals needed by the various services. It was necessary for the Planning Section to:
Present the SOE case in biding for signal facilities
To obtain an equivalent number of frequencies in the D-Day frequency allocation to
that those that were already being used for operational work.
Obtain a larger batch of new frequencies to cater on the one hand for the rapidly increasing growth in agent work, and on the other hand to cater for the special signal facilities needed for operations in conjunction with the military effort.
The result of these conferences from the SOE point of view can be gathered from the following figures:
Number of frequencies allotted to the whole of the Field Armies: 1000.
Number of frequencies allotted to the whole of the Field Air Force: 400.
Number of frequencies allotted to Naval Forces: 75.
Number of frequencies allotted to SOE Clandestine work: 200.
Number of frequencies allotted to SOE Military Commitments in conjunction with operation OVERLORD: 66.
Total numbers of SOE frequencies: 266.
It was mainly as a result of the successful outcome of the conferences that SOE
have been was able to cope so successfully with the rapid expansion of work which has taken took place up to and subsequently to D-Day since for practically all our signals work we had SOE the facility of channel clear of interference from all other Allied radio stations.
It was necessary as a result of operation OVERLORD to review the whole of
our SOE frequency planning and we were forced to change some 90% of our the Home Station frequencies just before D-Day in order that our the signalling arrangements might fit in with the OVERLORD arrangements.
The SOE commitment in conjunction with the invasion originally consisted of planning for 32
operation parties of the Jedburgh type, together with planning for the communication for the whole of the S.F. staffs of the various Army Groups taking part in Military operation.
A very short while after these demands had been formulated by the operational side, it was requested that this provision should be increased to some 120 parties of the
operational Jed burgh type, an increase of 300% over the original demand and not withstanding the comparatively late hour at which the change was made the Planning Section were able to fit in this abnormal requirement and to obtain from SHAEF the extra frequencies required.
In the period of training it was necessary to prepare plans similar to the operational plans and cover the normal work of catering for agents in the field.
When it is realised that the operational plans alone for the Jedburgh type parties called for some 3000 photographic copies and 500 silk copies and required over 5000 crystals, the magnitude of the task of providing for training, reception and operation can be appreciated. Furthermore, it was felt that the only safe basis on which to plan would be that all plans. crystals, etc should be ready to be sent if need to be to the field one week before D-Day and this aim was accomplished.
A further commitment undertaken by the Planning Section was in connection with the provision of signal facilities for the SAS Troops. Some weeks before D-Day, Colonel Moberly approached Brigadier Nicholls in this connection and we were faced with the task of providing all the signal facilities for these Troops since they had absolutely nothing on which to build. It was necessary for the Planning Section to obtain their frequencies, design their plans and provide their crystals, in addition to advice on training. SAS
have very handsomely recognised that SOE made possible the very successful system of signalling which they are now using.
Another aspect of Planning
has been was the provision of communication facilities to cover the recent series of day-light sorties which have been were undertaken by the 8th US Air Force. These sorties which have involved as many as 450 transport planes complete with appropriate fighter cover have involved deliveries to as many as 14 dropping areas. In order to assure the security of the delivering aircraft has been necessary to arrange communication facilities from each of the dropping areas for a period of 12 hours subsequent to the emission of the BBC broadcast message announcing to the field that the operation is to take place. Since the BBC emission is was made at 19.15 hours and again at 21.15 hours, this has forced us SOE to provide communication facilities from the field to the UK during the dusk and early dawn periods. Notwithstanding the complexity of the arrangements and the technical difficulties involved in arranging communication, the signals set-up provided has been such that within one hour of the broadcast message going out from the BBC, all Missions have reported and moreover within a very short time of the period of departure of the aircraft confirmatory messages have been were received and it was found that the Field Operators were so enthusiastic that they even reported back the result of the operation. This work alone has enabled some 10.000 tons of stores to be delivered to the field and naturally helped
the useful outcome of the work of resistance
More recent work being undertaken by the Department, in addition to the ever growing requirement for communications to agents, has been the provision of communications for such Missions as for example the Aloes Mission to Brittany and the planning and supplying of communications facilities, crystals, etc for the Norwegian internal communications network. It would appear that for some little time to come the demand for this type of service is likely to be on an ever increasing scale.
Summing up, the Planning Department has covered and provided for all the demands so far made by the Organisation for communications to and from the field. Such facilities have been virtue of the operational necessities generally been at extremely short notice and although this has meant that all the staff have worked extremely long hours in some cases even to the point of exhaustion, they have responded magnificently.
Towards the end of the battle for France it was also necessary to provide communications for such missions as the Aloes mission to Brittany, etc
were complete circuits to UK and
plans within the mission
were required. The gear ended with the rapid development of the work into the sea
and Low Countries.