SECRET
APPENDIX "B"
S10-136-80/5 DO329(ATSC)
7 Dec 60
S949-105 TDO165P(ATSC)
MEMORANDUM
13 Jun 60
A/CCE (thru DADSI)
Siting - CADIN Gap Filler
While a number of basic changes have been made to the CADIN program during the past 12 to 15 months the number of gap fillers to be built has remained unchanged. Thus the progam today calls for 45 gap fillers to be built in Canada.
In the initial CADIN Plan the 45 gap fillers were to have been located at sites determined by Operation Pillow in 1956-57. The 1959 map study and field survey work undertaken by the RCAF and USAF revealed that at least 10 Pillow sites were no longer satisfactory due to radio frequency interference considerations. When winter brought field survey work to an end in late fall 1959, 35 gap filler sites of CADIN had been established, leaving 10 to be done during the summer of 1960. However during the late fall and early winter 1959-60 fundamental changes were made to the CADIN program, changes stemming from operational considerations and from consideration of USAF budget. These changes made it necessary to re-examine the entire 45 gap filler deployment with the result that as of this writing only 23 sites of the 35 mentioned above are satisfactory. Thus the field survey work which remains to be done is 1960 is no longer 10 sites but 22.
The fundamental changes referred to above fall into three categories:-
While these changes have had the effect of negating a percentage of the field survey work undertaken in the summer of 1959, offsetting operational and conceivably financial advantages accrue.
The new search radars deployed as the CADIN program now requires provides much better radar coverage than the early plan and provides a much improved capability in the face of electronic countermeasures-ECM. The low level coverage (500 ft above flyable terrain) together with the planned deployment in front of weapons bases now makes it possible to exploit to the full the low level capability of not only the Bomarc B missile but also the low level capability which the USAF has programmed for their manned interceptors. The financial advantages which derive from the new CADIN Plan are perhaps less apparent than the operational advantages, nevertheles from a North American Air Defence viewpoint the financial advantage is not insignificant. To illustrate, the s-called Master Air Defence (MAD) for which field survey work was begun in Western Canada in the fall of 1959, and which was to have been continued in 1960 in Central Canada, and 1961 in Eastern Canada, will, if resumed, call for a much smaller number of additional gap fillers than would have been necessary under the original plan.
This information is provided in support of your submission for funds for the 22 gap filler field survey task which is to begin 5 July 60 with both RCAF and USAF particpating.
(sgd) (KP Likeness) G/C
ATSC
2-0144
cc: DRDP
DCom
COR/DADR
A/CCE