Past Development
1909
The office was first established at 5607 Corson Ave. as "Sidney" and later as "Glendale", at 8th Avenue S.W. and 152hd Street.
1948
The manual equipment was converted to dial with No. 1 crossbar type C.O.E. located at 8th Avenue S.W. and 146th Street. Two units were established — Lodan and Cherry.
1949
Last "Glendale" unit cut to dial — Seattle 100% Dial.
1957
#5XB growth unit installed. Tandem use of #5XB inaugurated.
1958
2L-5N dialing established.
1961
DDD/CAMA established.
1965
ANI installed.
1967
Discontinued tandem functionis in #5XB.
Future Development
For the current view of future developments, please refer to the Seattle section of the "Planning Guide issued by the District Engineer – Planning.