In 1941, the Canadian Department of National Defence requested that the Canada Post Office delete all local date stamps on letters arriving from H.M.C. Ships. It subsequently requested that Merchant Marine, Canadian Army, and RCAF mail be treated in a similar manner. Starting in December, 1942, Canada Post Office removed the town names from cancellers used in port cities and designated military areas. Although introduced to censor military mail, these "blackout" cancellers were used on both military and civilian mail.
Mr. Ron Leith' s well-written article Canada World War II Blackout Cancellations published in the July-August 1995 issue of The Canadian Philatelist, provides an excellent review of these devices.
Mr. Leith notes that blackout cancellations from about two dozen locations on the east and west coasts have been reported.
1. Blackout Machine Cancellations
Mr. Leith lists the following four types of machine cancellers in use in Canada during the blackout period : Columbia, Perfect, Universal Model-D, and Pitney-Bowes Model-G. He explains why there are four blackout machine types, as follows:
Dater hubs on these models were not compatible with one another and consequently there are four distinct blackout machine types. In all cases only the hub rim was replaced; the dater and killer bars remained the same after conversion.The Perfect and Pitney-Bowes Model-G blackout cancels are shown in this post. (Columbia and Universal machines cancels not shown)
Prince Rupert, October 2, 1944
Mr. Leith notes that over forty different slogans with blackout machine cancels were in use.
FLY YOUR MAIL
Victoria, July 4, 1944
EPARGNER DU TEMPS
UTILISEZ LA POSTE AERIENNE
Quebec, April 7, 1943
SAVE YOUR SCRAP
Quebec City, June 29, 1945
Quebec, June 14, 1945
SAVE ONE TON
Halifax to Montreal, May 11, 1944
January 18, 1943
b) PITNEY-BOWES MODEL G
Halifax Fleet Mail Office
Halifax FMO to Pinner, England, November 28, 1944
Examined by DB/N 100
Halifax F.M.O., December 10, 1944
Examined by DB/N 100
Victoria, November 29, 1943
(Victoria had 2 Perfect and 1 Pitney-Bowes machines)
ONE TON IN FIVE
Vancouver, January 12, 1943
PAY NO MORE
Vancouver to Ingersoll, October 20, 1944
September 3, 1945
2 . Circular Date Stamps
North Sydney, N.S.
North Sydney, April 26, 1944
Halifax, May 2, 1943
Vancouver, March 22, 1944
Vancouver Special Delivery
Vancouver Special Delivery, December 19, 1944
3. Blackout Duplex Cancellations
Five blackout duplex cancels had been identified by 1995. An example is not shown in this post.