[Suicide Junkie]

Ramming does not always take out both ships, depends on what you have on it, like SJ said, armor, shields etc. the ;more you have the less likely chance the ship will be destroyed.

Actually, I didn't mention how to survive rammings, that was Arkcon

Shields will only protect the defender during a ram. The ship doing the ramming does not use its shields.
Armor, and other hitpoints from internal components (engines, crew quarters, etc) will both protect you and deliver more damage to the enemy when you ram.