In the sand casting process wooden patterns are used to create the void (mold) that is filled with molten steel to create the actual parts, which are then machined to size and completion. The patterns shown are from the Canadian Locomotive Company in Kingston and were found on site when the buildings were demolished. The serial numbers on them probably refer to the D7, D8, D10 Tenwheelers of the CPR that the company built.
Previous post on the CLC; http://progress-is-fine.blogspot.ca/2012/04/we-used-to-make-things-in-this-country_22.html
and a post on patterns http://progress-is-fine.blogspot.ca/2012/10/pattern-making.html
|CLC Pattern shop|
|CLC Carpenter shop|
B&Ws from the 1999 book by
Donald McQueen and William Thomson; Constructed in Kingston
Patternmakers worked mostly with handtools in stable woods; mahogany, cherry and pine and the results are art in themselves, not even considering they worked to thousandths of an inch accuracy. Their layout lines, lineup pin holes and precision woodjoints are visible in the parts below.