SOE
Page 22
In the case of incendiary devices it was difficult to interpret the results of trials in terms of damage to an actual target, a fundamental problem which was never satisfactorily solved. One could test the reliability of the initiating system, the local temperature achieved and the duration of the flame. But the spread of the fire on an actual target was subject to many variables which individual agents had to deal with. In an attempt to study the factors determining the rate of spread of fire, Bamford wrote a theoretical paper, backed up by experiments, drawing attention to the fact (now well established) that the rate of spread of a fire is enhanced if inflammable material is disposed in such a way that radiation from one fire centre augments that from nearby centres.
Explosive devices were tested in the explosives pit that had been excavated below the terraces of The Frythe and fitted with a reinforced concrete observation cabin with blast-proof windows. Problems arose when an explosive invention failed to detonate. Should one seek the source of failure by dismantling the device, which might be in a dangerous state? After one or two scary incidents involving exotic products of Station XV, it was decided as routine to place alongside each device a counter-charge which could be detonated electrically if the item under test failed to explode, but it was no longer possible to identify the cause of the failure. At times such as these one wished that the team had included a quarryman!
Trials of the ISRB Anti-Tank Mine which made use of four Tyre-Bursters were carried out at Farnborough, while a few trials were done at Station XII.
Much of the time of the Trials Section was taken up in testing individual items leading to their classification as (A) needing no or only minor modifications to enable production to proceed, or (B) needing more extensive modifications and retesting before being handed over to Station XII. A further group (C) were judged either to be unsuitable for further development or, if improvements were possible, it was unlikely that they could be made in the anticipated time available. A list of the major items tested by the Trials Section in the twelve-month period October 1943 – October 1944 is given in Table 1. Most trials were carried out in a day, although some required much longer. The pressure under which the Trials Section worked may be judged by the fact that in one twelve-month period it dealt with 78 devices, carried out 159 trials (three a week) and issued 118 reports (two a week).
TABLE 1
Devices Tested by Trials Section.2
1/10/43 to 1/10/44
A = no or very minor modifications needed.
B = substantial modifications needed.
C = adverse report – reject.
Number of trials
Result A, B or C.
Anerometer Mk I
2
C
Ascent fuse
1
C
MD1 Altimeter fuse
2
B
Adhesive for demolition work
2
C
Bicycle pump gun
1
C
Block incendiary Mk I
1
B
Block incendiary Mk II
1
A
Blowpipe
1
C
Bags, paper, damp proof
1
A
Berg submersible dinghy
3
B
Cigarettes, incendiary
1
A
Clams, filled pentolite
1
A
US short time clock fuse
0 (Report only)
A
Clock, Eureka
3
B
Container location device (bell)
3
A
Container, K-Type
2
A
Cordtex initiators
2
A
Cavity link charges
2
A
C-type containers, water tight
2
B
Container, acid dropping
1
A
Carbine, M1, silencer
1
A
AC delay Mk II
3
B
Directional incendiary
1
A
Firefly (US)
2
B
Fountain-pen gun
1
C
Face cream
1
A
GP grenade
1
A
MD1 3.7-in gun
1
A
Holdfast, magnetic
2
B
Infra-red homing devices
3
A
Infra-red receiver case
1
A
Jet thermite bomb
1
C
Modified limpet keeper plate
1
B
Plastic limpet (US)
1
A
Limpet coupling device
1
A
Multiple detonators
1
B
Night glasses
1
A
Nitrated paper
1
B
Anti-removal fuse (water armed)
6
B
Anti-removal fuse (air armed)
6
B
Nail firing device
4
B
Oil/nitrate incendiary
3
B
Parachutists over boots
1
B
Photoelectric cell (‘Mole’ US)
0
C
Photoelectric switch
1
C
Limpet placing rod
1
A
Pull igniter (US)
1
A
French rail charge
1
B
Extending push rod
5
B
Imber rail switch
6
C
Delay setting pressure switch
2
A
Pyrotechnic delay rail switch
2
B
Type 6 pressure switch, modified
1
A
Seaplane reception lamp
2
C
Silenced Sten
5
B
Sleeve gun Mk I
2
A
Sleeve gun Mk II
2
A
Smoke pistol
2
C
Spike attachment
1
A
Standard charge (2 pellet)
2
A
Speed switch (limpet)
3
C
Silenced outboard motor
3
B
Suction adhesion device
2
C
Sleeping Beauty
2
A
Swim fin Mk II
1
A
Sleeping Beauty limpet
1
A
Telephone cable shorting pliers
1
A
Thermite well charge (US)
2
A
Torch, reception, 5-cell
1
A
Tree spigot
19
A
Tree spigot incendiary ammunition
1
B
Dipsanil V
1
A
Welcase
3
B
/> Welmine
1
C
Welrod 0.32 in
2
B
Welrod 9 mm
2
B
Wirecutters
1
A
Welbum
1
C
78 devices
Accepted (little or no modification)
(A)
47%
Accepted (considerable modification)
(B)
31%
Rejected
(C)
22%
A high proportion of those in category B were subsequently modified and passed later tests.
Besides testing the wide range of devices listed in Table 1, the Trials Section became involved in a number of more extensive programmes. One of these dealt with the location of stores containers in the dark in collaboration with the Air Supply Research Section and is described in Chapter 11.
In the period from October 1944 to the end of the war the work of the Trials Section continued but on a less strenuous basis, since work on the development of new weapons was phased out. A limited amount of work for the Far East was kept on, mainly concerned with the effects of tropical storage on the efficiency and safety of equipment.
As part of the duties of the Trials Section constant liaison with the inventors was essential to ensure that those devising new equipment were well aware of the circumstances in which it would be used. At the same time the Section had to maintain the highest standards of testing and criticism. The essential function of the Section’s work was not calculated to endear them to the designers. Very few inventors enjoy seeing their devices dropped on to concrete, a circumstance which required handling with a good deal of tact.
ELEVEN
OPERATIONAL RESEARCH – THE AIR SUPPLY RESEARCH SECTION
The problems of providing Resistance groups with arms and explosives taxed SOE throughout its existence. Although in the early days stores were landed from fishing and other small boats and submarines, this method became too hazardous for routine use in north-west France and along the English Channel and North Sea coasts. Such methods were, moreover, unpopular with the SIS and the Admiralty who guarded jealously their absolute right to control all seaborne operations. Furthermore, the Royal Air Force was reluctant to spare any of its meagre stock of aircraft for the risky task of dropping agents and stores into occupied Europe, activities which they saw as of lower priority than bombing.
It was only later, in the summer of 1941 that, under pressure from Dalton, the RAF Special Duties Flight of three aircraft was increased to a full squadron. Henceforth, for the bulk of arms and equipment reliance had to be placed on supplies dropped from the air.
AIR DROPPING OF STORES
In the early days of SOE, air dropping of stores was on a limited scale because Resistance groups had not yet been organised in sufficient numbers and the RAF was reluctant to divert even a few of its valuable aircraft for use by SOE. A major effort had therefore to be made to persuade the Air Ministry at the highest level of the importance of the Resistance movements and the need to provide air supply support for their activities. The earlier reluctance to support SOE had doubtless been influenced by the opposition of the Chief of the Air Staff, Lord Portal, who, in a frequently quoted letter, wrote on 1 February 1941 expressing strong ethical objection to the methods employed by SOE: ‘The dropping of men (sic) dressed in civilian clothes for the purpose of attempting to kill members of the opposing forces is not an operation with which the RAF should be associated.’
But this was before Dresden! And it is significant that he ignored (or perhaps did not know of) the vital role played by women in SOE.
A strong argument in support of SOE activities was based on the cost effectiveness of sabotage operations in comparison with large-scale bombing. Because of the inaccuracy of aerial bombardment with its collateral damage and civilian casualties, the huge cost in aircraft and aircrews of a large bombing raid on an industrial target often bore little relationship to the amount of damage it caused to the enemy’s war effort. The same damage to industrial targets could in many instances be inflicted for a fraction of the cost by agents on the ground. Placing small amounts of explosive in exactly the right places in a factory could cause a maximum amount of damage with the minimum harm to the local population.
The classic example of this must be the blackmailing of M. Peugeot, whose car factory was being used to manufacture tank parts for the German Army. Two bombing raids in July 1943 had failed to stop work at the factory and had caused many civilian casualties. The ‘Stockbroker’ circuit in eastern France was organised by the agent ‘César’, whose real name was Harry Rée (later to become Headmaster of Watford Boys’ Grammar School and Professor of Education at York University). He approached M. Peugeot with the proposition: ‘Let my agents in to destroy selected machines or I will arrange for the RAF to attack again with the resultant damage to surrounding areas.’ M. Peugeot let them in and the factory was put out of action for three months. Moreover, when replacement machinery arrived from Germany the barges carrying it were sunk in the canal. This and many other similar examples in which production was halted for a few weeks or many months are listed by Foot.1 No doubt they helped to persuade the RAF of the valuable role that SOE could play in appropriate circumstances. Of course, the relatively small number of SOE agents could not have a decisive impact on German industry, but a succession of smaller operations could play a significant role both physically and psychologically. In the end SOE was successful in obtaining RAF support but this was often given grudgingly and at a lower priority.
In January 1943, with increasing use of air supply, the responsibility for ‘coordination of test work’ and for ‘service trials of special equipment for air and sea supply operations’ was placed with AL/C, the Air Liaison Section of SOE. This involved collaboration between Stations IX, XII and the Training Sections and, from August, with the User Trials Committee. Previously air supply liaison had been carried out by Q-Branch of AL Section (Maj R.H. Buxton followed by Maj J.R. Hare).
In the period up to autumn 1943 the methods of air supply in use involved stores packed in one of two types of metal containers, C-type and H-type, which were carried in and released from the bomb racks of bomber aircraft (see later). They had been designed and produced by the Ministry of Aircraft Production (MAP). Alternatively, stores were packed into wire cages (panniers) and dropped from the side door of a Dakota or through the jump hole in the floor of a Halifax.
From time to time Station IX had been called in by AL Section to undertake development work on a number of topics. These included the design of lightweight containers, waterproofing of containers, development of roller conveyors for despatching from aircraft, reception committee lighting, methods of locating containers in the dark and parachute delay opening devices. In addition, Station IX and DSR HQ personnel were in close contact with the Airborne Forces Experimental Establishments (AFEE) at Sherburn-in-Elmet and Amesbury regarding various other development projects.
Drop testing of new stores to determine their suitability for delivery by air and the introduction of new methods of packing were also carried out by AL Section to meet the requirements of Operational Sections. The rapidly increasing operational commitments of AL Section had, by the autumn of 1943, reduced very considerably the time and care that could be given to drop testing and trial packing and to the compilation of reports on these trials.
The problem was eased in October 1943 when further reorganisation led to the transfer of all problems affecting the transport of stores by air to DSR (Newitt) under AD/Z (Davies). This involved the setting up of the Air Supply Research Section (ASR) as part of D/B Section based at Baker Street under Munn, D/B, but calling upon staff from Station IX as and when necessary. It was headed at first by Holloway until his posting to Force 133 in Cairo in January when Everett took over the headship while continuing his chairmanship of the User
Trials Committee, retaining his symbol D/BT. Organisation of User Trials was later passed to Dr R. Moggridge while Everett concentrated on expanding the Air Supply Research Section.2
Increasingly, bureaucracy had to be negotiated or short-circuited to avoid the work of the ASR Section being held up. The responsibilities of ASR Section and the procedures to be followed were set out in a formal routine order on 15 November. Under the new arrangements, all requirements for research and for the adoption of items as SOE stores were to be put up to DSR in the first instance. D/B Section was made responsible for field, user and acceptance trials and for liaison with MAP, the Royal Aircraft Establishment (RAE) and Airborne Forces on all questions of air transport, except those which were purely RAF matters. E Section (i.e. Station XII), in conjunction with AL/C, was made primarily responsible for liaison with MAP on questions of supply of air transport equipment. The official channel of approach to Station 61, the Special Parachute Section at Henlow and RAF Operational Squadrons working for SOE was via AL. SOE requirements for development work to be carried out by the Air Ministry were to be considered first by D/Plans, be passed to DSR, then to K/AIR.P who would submit them to the Air Ministry. All applications for drop testing of new or existing stores were to be made in the first place to D/B who was to arrange for such tests to be carried out by the most convenient aircraft available. Dropping and other trials for DSR should be carried out by Station 61 and/or by operational squadrons, arranged by AL. However tedious these routes proved to be, compliance with them had to be endured.