Series consists of records which were components of Transport Canada's central registry file classification system. The records were organized into central registry blocks that were added to by numerous departments or agencies within the Department of Transport. File classification systems identify, segregate, and standardize documents into fields and subject based files. At Transport Canada, the classification of registry files has developed since the creation of the department in 1936. Nonetheless, the classification system has always been numeric, and consequently, it is relatively easy to follow the evolution of the changes through periods of operational expansion, functional reassignment, or the transfer or dissolution of a departmental activity. For much of the century, Transport has had three main groups of records: Air, Marine and Surface.
Each of the three main Transport fields have been allotted a range of file block numbers. For example, Marine Group records have been filed within the numeric range of 7500-9816. Within this range, the records are further sub-divided according to operational service, organization or subject. Aids to Navigation, for instance, fall within the 8000-8099 block. Further deconstruction of these primary file blocks reveals more detailed subject headings: 8012 refers to 'Fixed Structures (lighthouses)'; and 8012-9 provides the secondary number, for this example, in reference to a specific site. Tertiaries and quaternaries are added when it is necessary to further specify subjects: 8012-9-1 consists of correspondence and reports relating to Red Head Battery- General; 8012-9-2, Red Head Battery - Repairs. As a general rule, individual file numbers become more complex in proportion to the operational need for subject specificity.
Subject file classification is extremely flexible insofar as it permits the creation of classification numbers as the operational need arises. For much of the century, Transport assigned file blocks 1000-3156 to administrative records, file blocks 3200-3862 to Surface Transportation Administration, file blocks 5000-7200 to Air Transportation Administration, and 7500-9816 to Marine Transportation Administration. Nonetheless, there are further complications with the administrative records because there are, on occasion, overlaps between the three operational fields of air, marine and surface. Thus, there may be as many as four files numbered '1500'; the only way to differentiate between them is by way of the prefix to the file number ("A" for Air, "M" for Marine, "S" Surface, "E" for Executive.) Other considerations include the reuse of file blocks following an organizational change. For example, Transport Canada was responsible for the administration of canals from 1936-1972. Files relating to canals were assigned the 4000 file block range. The function of administering canals was transferred to Parks Canada in 1972, and the entire 4000 block was cancelled. In 1985, however, the 4000 block was reactivated and assigned to the newly created Policy and Coordination Group.
Technical drawings consist of items from Transport Canada aircraft registration files ranging from 5008-AAD to 5008-ZSP, and dating from ca. 1940 to 1975.