48 Orbit G arant 2012 annual rep O rt N OTES TO CONSOLIDATED FINANCIAL STATEMENTS (continued) For the years ended June 30, 2012 and 2011 (in thousands of Canadian dollars, except for earnings per share and option data) 7. INVENTORIES Inventories consist of the following: June 30 June 30 July 1 2012 2011 2010 $ $ $ Spare parts, gross 10,651 7,647 5,242 Consumables, gross 30,301 24,381 16,891 Other 1,084 1,618 575 42,036 33,646 22,708 Spare parts mainly include motors and heads. Spare parts are charged to the statement of income when used on equipment. Cons umables mainly include destructive tools, hammers, muds, wire lines and casing. Consumables are charged to the statement of inc ome when delivered to the feld. The cost of inventory recognized as an expense and included in cost of contract revenue has been recorded as follows: June 30 June 30 2012 2011 $ $ 31,661 27,097 During the year, there were no signifcant write-downs of inventory as a result of net realizable value being lower than cos t and no inventory write-downs recognized in previous years were reversed. The Company’s credit facilities are in part secured by a general assignment of the Company ’s inventory. 8. INVESTMENTS IN ASSOCIATE June 30 June 30 July 1 2012 2011 2010 $ $ $ 6483976 Canada Inc. (Usinage X-SPEC): 4,000 class A shares, representing 40% of the voting shares, equity method — — 838 48,000 class I shares, non-participating, non-voting, maximum dividend of 8% per year, redeemable at the option of the company at $48,000, at cost — — 48 — — 886 9. PROPERTY, PLANT AND EQUIPMENT Changes in the property, plant and equipment balance were as follows for the periods: Buildings and Drilling Land components equipment Vehicles Other Total Cost $ $ $ $ $ $ Balance as at July 1, 2010 761 3,146 33,037 8,519 1,191 46,654 Additions 37 6,047 9,156 2,715 692 18,647 Disposals (69) (526) (1,016) (426) - (2,037) Business acquisitions (note 2) — — 1,053 177 32 1,262 Balance as at June 30, 2011 729 8,667 42,230 10,985 1,915 64,526 Additions 1 613 13,147 3,803 813 18,377 Disposals (293) (75) (2,441) (429) (3) (3,241) Business acquisitions (note 2) 75 557 4,290 235 83 5,240 Effect of movements in exchange rates — — (24) (3) — (27) Balance as at June 30, 2012 512 9,762 57,202 14,591 2,808 84,875