The Morrison was Portland’s  first bridge and operated as a toll bridge.  The current  design is the third bridge at this location. Both of  the previous structures (1887 and 1905) were swing spans. Design work for this six-lane, three-span, steel deck truss bridge  began in 1928; it was built for $12,841,256 and opened  in 1958. It is  the last moveable bridge built on the  Willamette in Portland.  Like Morrison St., it was named  for a Methodist missionary from Scotland who built the  first house on that thoroughfare.

The Morrison is structurally like the Burnside, but without ornamentation in its railing or its pair of bridge houses (also mounted on the south  face). It serves as a major travel corridor link  between SE Portland and inner-city Portland and to  Interstate 5 on the north.

When river traffic requires that the bridge open, a controller inside the western bridge  house operates a rack and pinion system and gears 36  feet tall. They lift the Morrison’s double-leaf bascule  (each 150 feet long) by means of counterweights, one  for each side. Even though the roadway’s open metal  grating reduces its weight and allows quick run-off of  rain, the counterweights must each weigh 950 tons in order to balance the bascule halves; the mechanism must maneuver the bascule and counterweights safely up and back in place.

Ed  Slavin of Northern Illumination  Co. has led WLB’s efforts to  upgrade the system of  lights on the four Morrison Bridge pier  faces.  Replacing the 16 floodlights with 32 light-emitting diodes   (LEDs) reduces energy use by 7/8 and allows a wide range of   colors to be programmed via computer. WLB will purchase  “green”  energy to run the LEDs.

The  upgrade also  vastly reduces risk and costs of maintaining the   color system by improving access to the pier fixtures and eliminating   the theatrical gels which provide the color to the  current system.  The new fixtures will be hung from  brackets, rather than fixed  to the bridge. This will  allow them to be swung up to the deck  for  maintenance—no more sending workers over the side  to  clean them or replace bulbs and colored filters.

Installation  is expected to be complete by Valentine’s Day 2007.

The  energy  efficiency and use of alternate power for the upgrade   so pleased Pacific Power that is donated $50,000 to the project.   An anonymous donation on behalf of WLB volunteers launched  the  upgrade efforts.

Craig  Marquardt, a  local lighting designer working at PAE Engineering   at the time, did the original design for the Morrison lighting   system, including white floods to outline the metal trusses   which support the bridge’s outer spans and the center   bascule (lift) sections. Those white floods are seldom  used  now due to access difficulties.

Cost  of the  fixtures and labor to install that 1987 system were donated   by the International Brotherhood of Electrical Workers and the   National Electrical Contractors Association.