Macdonald & Lawrence Timber Framing Ltd.

One of dozens of mines in the Drumheller area, the Atlas #4 mine shipped its last load of coal in 1979 at the end of a half century of commercial coal mining in this part of Canada. Since it’s designation as a National Historic Site, it has operated as a museum, with the buildings and some of the mine workings preserved.

One of the most prominent features of the mine site is the very large complex of buildings that comprise the Conveyor and Tipple structures, the processing plant of the mine. A major landmark in this part of the Red Deer valley, the conveyor transported the coal from the mine, to be cleaned and graded in the tipple, and then loaded into box cars for transport to homes all over Western Canada.

The structures are of heavy timber construction with simple bolted connections and some complex geometry driven buy the placement of the foundations, allowing the trains and box cars to pass by and under the conveyor and tipple. Most of the structure is exposed to the elements and after 60 years there were some areas that were a major structural concern for the Museum. A steel support scaffold had been inserted in 2001 to prevent the structure from collapsing and when funding had been secured the Museum sought proposals from contractors for the restoration works with the help of Simpson Roberts Architecture and Interior Design of Calgary.

In the spring of 2010 M&L were selected to carry out the works to conserve and repair one of the conveyors and the tower structure at its top. Initially a full condition assessment was made and a detailed work list and estimate drawn up to provide greater clarity around the scope and budget prior to commencing work.

In the fall an M&L crew surveyed, dismantled, repaired and re-constructed all of the timber posts, struts, walers and braces that make up this impressive structure. Subtle modifications were made to improve water drainage and drying at specific joint locations which had been the cause of the failures being repaired.

Many timbers were scarf joined to replace rotted ends while retaining most of the historic timbers. Most of the original bolts and other hardware were re-conditioned and re-used. After the timber structure was re-installed, the steel support scaffold was removed after 10 years of holding up the rotting structure and it now stands on its own feet once more and hopefully for at least another 60 years.

To this project, M&L contributed a special mix of heavy timer construction expertise; an understanding of heritage conservation ethics and practise; and innovative yet simple solutions designed to improve the longevity of the structure.

External Links

• The Atlas Coal Mine