34. E.B. Eddy Digester Tower

Construction: 1901

Architect: Unknown

Location: Adjacent to the Canadian Museum of History in Laurier Park, Hull (now Gatineau)


The E.B. Eddy Digester Tower is a prominent reminder of the Ottawa Valley's early industrial roots.

Ezra Butler Eddy (1827-1906) incorporated the E.B. Eddy Manufacturing Company located in Hull, on the Ottawa River across from Parliament Hill, in 1888. Eddy was one of Canada's most innovative industrialists. The completely automated vertical Digester Tower—the first of its kind—was constructed in 1901 as part of the company's bisulphite pulp factory. 

The purpose of a digester is to render wood particles into a soft pulp suitable for paper manufacture. Built to withstand enormous pressure, the walls of the vertical Tower were constructed of two wythes of uncoursed rubble limestone with a rubble core. The floor was constructed of reinforced concrete supported on steel I-beams or heavy timber. The original cylindrical, brick-lined steel pressure vessel remains in place within the Tower.

On February 21, 1972, the federal government announced its purchase of 44 acres of riverfront property belonging to the E.B. Eddy Company, leading to plans to shut down and demolish the remaining buildings—including the Digester Tower. 

Writing about the Tower in the Ottawa Citizen in 2010, journalist Maria Cook recounted how Heritage Ottawa president Bob Phillips had put a stop to the wrecking crew:

"One summer day in 1972, as Bob Phillips drove over the Alexandra Bridge, he saw bulldozers, “like an army of determined ants,” flattening the E.B. Eddy pulp and paper plant that stood where the Canadian Museum of Civilization is now.

“When they began to nibble the foundations of the digester tower,” Phillips ran to a pay phone, reached National Capital Commission general manager Rod Clack and made “a breathless plea to save Hull’s irreplaceable archaeological heritage until we could sit down and think about it.”

Ten minutes later, the bulldozers stopped."

The Digester Tower was saved, but its longer-term fate remained unsettled.  Feasibility studies regarding stabilization of the structure were not promising.  The NCC filled most of the Tower's window openings with brick or concrete block at this time.  On February 10, 1983, it was announced that a new National Museum of Man (later renamed the Canadian Museum of Civilization, now the Canadian Museum of History) would be located on the former E.B. Eddy riverfront lands at Laurier Park, where the Digester Tower remained standing.

The public was invited to view development models of the forthcoming museum on November 28, 1983. The Tower, and additional archaeological ruins uncovered that same year by Les Recherches Arkhis, did not feature prominently in the plans.

On February 21, 1984, the Federal Heritage Building Review Office proclaimed the E.B. Eddy Digester Tower a recognized heritage building (an honorific designation that includes no protection). On behalf of Heritage Ottawa, then vice-president Mark Brandt investigated possibilities for saving the tower. While establishing the “Friends of the Tower” committee in 1989, he found many enthusiastic supporters representing a wide range of interests including Dr. George MacDonald, the Director of the Canadian Museum of Civilization.

The Museum, along with Heritage Ottawa, the City of Hull, Carleton University’s School of Architecture, the Historical Society of the Gatineau, the Urban League of Ottawa and other interest groups came together in a design charrette to consider new ideas for the adaptive reuse of the E.B. Eddy Digester Tower. The charrette received excellent press coverage. Shortly afterwards, the Department of Public Works and the NCC agreed on a financial plan to save the Digester Tower.

In 2001, the Canadian Museum of Civilization commissioned an engineering study to assess the Tower's structural stability and condition of its loadbearing stone masonry walls. Based on the study's recommendations, seismic strengthening was undertaken.

The Digester Tower is believed to be the last of its kind remaining in Canada. New uses for the Tower have yet to be identified.