Based on information from a memorandum dated Mar 12 , 1993
History of Steel Towers in Alberta
The fixed detection system, consisting of 142 lookouts throughout the forest protection area of the province, is the first line of fire suppression. It has increased significantly with the property values, the existing wildlife habitat, wildlife species, recreation etc. that have been the Alberta forest Services priorities since taking over the management and protection of Albertas natural resources in 1930
At the Forest Protection fall workshop December 12 to 15, 1989 at Edmonton it was pointed out that there are 117 steel tower structures in the province requiring maintenance to the steel and/or cupolas.
Of the 117 steel towers provincially there are four basic types:
- 4 Single Pylon
- 14 Ajax
- 97 Manitoba Bridge and Steel
- 2 Imperial
The primary difference in the tower designs are:
Single pylon This is a triangular steel tower and as the name implies is mounted on a single "pylon" or leg and is held erect by sets of three guy wires
Ajax
This is a four legged conventional steel tower with the base of the legs being 27 feet apart on either side. The steel is lighter (2 ¾ inch by 2 ¾ inch angle) than the Manitoba Bridge and Steel.
Manitoba Bridge and Steel
This also is a four legged conventional steel tower with the base of the legs being 27 feeet apart on either side. The steel is heavier (3 ½ inch by 3 ½ inch angle) than the Ajax design plus it has extra corner bracing and verticle strapping.
Note: Two towers (Round Hill and Cambrian) were fabricated in Edmonton by an Edmonton steel fabricator using the same design/drawings as Manitoba Bridge and Steel.
Imperial
This tower is identical to the Manitoba Bridge and steel with the one exception; the legs at the base are 16 feet on either side.
To date a lot of these repairs have been made.