A pit prop or mine prop (British and American usage, respectively) is a length of lumber used to prop up the roofs of tunnels in

coal mine Coal mining is the process of extracting coal from the ground. Coal is valued for its energy content and since the 1880s has been widely used to generate electricity. Steel and cement industries use coal as a fuel for extraction of iron from ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

traditionally supplied pit props to the British market. As coal mining declined in importance and metal supports were used, the term became infrequently used. Though it was merely a log cut to a particular length, it was classified as a finished product and so got around the extra Canadian tariffs on the export of raw lumber. Because of the large quantities exported, it is probable many ended up in British

pulp mill A pulp mill is a manufacturing facility that converts wood chips or other plant fiber sources into a thick fiber board which can be shipped to a paper mill for further processing. Pulp can be manufactured using mechanical, semi-chemical, or ful ...

s. Most pit props were made from the wood of

spruce A spruce is a tree of the genus ''Picea'' (), a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal (taiga) regions of the Earth. ''Picea'' is the sole genus in the subfami ...

trees.

References

Coal mining {{mining-stub