Simply buying a capital asset is not an expense. It just moves assets from one asset account (cash, for example) to another (fixed asset account).
You then depreciate the asset over the expected life of the asset. So if you depreciate it over 30 years, then in year 1 you would record a depreciation expense of 3.33%. (That's for straight line depreciation.. there are accelerated schedules.)
In other words.. It's spread out over the expected life of the asset.
Also the depreciation usually wouldn't start until the asset has been put into production.