From the 1861 Ordnance Manual:
"To spike a piece, or to render it unserviceable.-Drive into the vent a jagged and hardened steel spike with a soft point, or a nail without a head; break it off flush with the outer surface and clinch the point inside by means of the rammer."
There is also a reference to temporarily spiking a piece:
"When the guns are to be spiked temporarily, and are likely to be retaken, a spring spike is used, having a shoulder to prevent its being too easily extracted"
Hope this helps...