A construction worker works near the upper deck of the Portland Aerial Tram, about 125' high, part of a 5-week track line maintenance operation, July 2, 2018. Every 12 years the ropes must be shifted. Each line holds about 124,000 pounds of tension. The tram will reopen on July 30. (OHSU/Kristyna Wentz-Graff)

A construction worker works near the upper deck of the Portland Aerial Tram, about 125' high, part of a 5-week track line maintenance operation, July 2, 2018. Every 12 years the ropes must be shifted. Each line holds about 124,000 pounds of tension. The tram will reopen on July 30. (OHSU/Kristyna Wentz-Graff)

A construction worker walks about 125' up, atop the Portland Aerial Tram lines, part of a 5-week track line maintenance operation, July 2, 2018. Every 12 years the ropes must be shifted. Each line holds about 124,000 pounds of tension. The tram will reopen on July 30. (OHSU/Kristyna Wentz-Graff)

A construction worker walks about 125' up, atop the Portland Aerial Tram lines, part of a 5-week track line maintenance operation, July 2, 2018. Every 12 years the ropes must be shifted. Each line holds about 124,000 pounds of tension. The tram will reopen on July 30. (OHSU/Kristyna Wentz-Graff)

A construction worker walks about 125' up, atop the Portland Aerial Tram lines, part of a 5-week track line maintenance operation, July 2, 2018. Every 12 years the ropes must be shifted. Each line holds about 124,000 pounds of tension. The tram will reopen on July 30. (OHSU/Kristyna Wentz-Graff)

A construction worker walks about 125' up, atop the Portland Aerial Tram lines, part of a 5-week track line maintenance operation, July 2, 2018. Every 12 years the ropes must be shifted. Each line holds about 124,000 pounds of tension. The tram will reopen on July 30. (OHSU/Kristyna Wentz-Graff)

The iconic Portland Aerial Tram cabins are grounded during the 5-week track line maintenance operation, July 2, 2018. Every 12 years the ropes must be shifted. Each line holds about 124,000 pounds of tension. The tram will reopen on July 30. (OHSU/Kristyna Wentz-Graff)

The Portland Aerial Tram is closed for track line maintenance operation, July 2, 2018. Every 12 years the ropes must be shifted. Each line holds about 124,000 pounds of tension. The tram will reopen on July 30. (OHSU/Kristyna Wentz-Graff)

A construction worker walks atop the Portland Aerial Tram lines, part of a 5-week track line maintenance operation, July 2, 2018. Every 12 years the ropes must be shifted. Each line holds about 124,000 pounds of tension. The tram will reopen on July 30. (OHSU/Kristyna Wentz-Graff)

A construction worker walks atop the Portland Aerial Tram lines, part of a 5-week track line maintenance operation, July 2, 2018. Every 12 years the ropes must be shifted. Each line holds about 124,000 pounds of tension. The tram will reopen on July 30. (OHSU/Kristyna Wentz-Graff)

Comparison of Marquam Hill buildings showing site before construction of tram tower and after between 2003 and 2007. (OHSU LIBRARY/Cyril "Kent" Anderson)

Upper station rendering for the Portland Aerial Tram, 2006. (OHSU)

Groundbreaking for the Portland Aerial Tram. (OHSU)

Stephane Diouf, cabin attendant on the Portland Aerial Tram, says the job is never boring, January 24, 2017. (OHSU/Kristyna Wentz-Graff)

Stephane Diouf, cabin attendant on the Portland Aerial Tram, helps passengers board the tram, January 24, 2017. Each of the cabins can hold 79 passengers. (OHSU/Kristyna Wentz-Graff)

Stephane Diouf, cabin attendant on the Portland Aerial Tram, chatting with a colleague, January 24, 2017.(OHSU/Kristyna Wentz-Graff)

Stephane Diouf, cabin attendant on the Portland Aerial Tram, helps passengers board the tram at the upper terminal, January 24, 2017. Each of the cabins can hold 79 passengers. (OHSU/Kristyna Wentz-Graff)

Stephane Diouf, cabin attendant on the Portland Aerial Tram, helps passengers board the tram at the lower terminal, January 24, 2017. Each of the cabins can hold 79 passengers. (OHSU/Kristyna Wentz-Graff)

Portland Aerial Tram passing the Center for Health and Healing, 2006. (OHSU/Tim Jewett)

Groundbreaking for the Portland Aerial Tram. (OHSU)

Portland Aerial Tram cabin with passengers at sunrise. (OHSU/Cyril "Kent" Anderson)

Construction of the lower station, Portland Aerial Tram, 2006. (OHSU)

Cable pull system reels at the lower station, Portland Aerial Tram, 2006. (OHSU)

Painters work on the middle tower of the Portland Aerial Tram, 2006. (OHSU)

Cable pull system reels at the lower station, Portland Aerial Tram, 2006. (OHSU)

Lower station cable motor room, Portland Aerial Tram, 2006. (OHSU)

Lower station gondola bays and cable guides, Portland Aerial Tram, 2006. (OHSU)

Cable pull system reels at the lower station, Portland Aerial Tram, 2006. (OHSU)

Painters work on the middle tower of the Portland Aerial Tram, 2006. (OHSU)

Construction on the upper level, Portland Aerial Tram, 2006. (OHSU)

Installing the upper station counter weight level, Portland Aerial Tram, 2006. (OHSU)

Upper station gondola level, Portland Aerial Tram, 2006. (OHSU)

Upper station gondola level, Portland Aerial Tram, 2006. (OHSU)

Upper station gondola cable guides, Portland Aerial Tram, 2006. (OHSU)

OHSU campus buildings taken from the waterfront. The Portland Aerial Tram cabins are crossing in the lower portion of the photograph, March 2008.
(OHSU LIBRARY/Cyril "Kent" Anderson)

Portland Aerial tram cabin, 2007.
(OHSU LIBRARY/Cyril "Kent" Anderson)

Portland Aerial Tram at sunrise, 2006.
(OHSU/Tim Jewett)

Portland Aerial Tram, 2007.
(OHSU LIBRARY/Cyril "Kent" Anderson)

The upper terminal of the Portland Aerial Tram and the back of the Peter O. Kohler Pavilion, 2007.
(OHSU LIBRARY/Cyril "Kent" Anderson)

Portland Aerial tram cabin with the Ross Island Bridge in the background, 2007.
(OHSU LIBRARY/Cyril "Kent" Anderson)

Portland Aerial tram at upper terminal, 2007.
(OHSU LIBRARY/Cyril "Kent" Anderson)

Portland Aerial Tram, lower tower and shown with a cabin passing the front of the Center for Health and Healing, 2007.
(OHSU LIBRARY/Cyril "Kent" Anderson)

Portland Aerial Tram at sunrise, 2007.
(OHSU/Tim Jewett)

Upper terminal of Portland Aerial Tram and Peter O. Kohler Pavilion at sunrise with Portland, Oregon city center and Fremont Bridge in background.
(OHSU LIBRARY/Cyril "Kent" Anderson)

Portland Aerial Tram lower terminal with a docking cabin, 2007. Bicycles are parked in the foreground. The Center for Health and Healing is visible on the left.
(OHSU LIBRARY/Cyril "Kent" Anderson)

Color digital photograph of Portland Aerial Tram cabin near upper terminal with Ross Island Bridge, Center for Health and Healing, South Waterfront, Willamette River and Terwilliger Boulevard in background, April 2, 2008. (OHSU/Cyril "Kent" Anderson)

Color digital photograph of Portland Aerial Tram cabin near the upper terminal with man looking at the view, March 8, 2007. (OHSU/Cyril "Kent" Anderson)

Portland Aerial tram cabin with Portland and Willamette River in the background, 2007.
(OHSU LIBRARY/Cyril "Kent" Anderson)

Fog over the South Waterfront, January 7, 2015.
(MANDATORY CREDIT OHSU LIBRARY/Gail Marracci)