This publication provides introductory technical guidance for civil engineers and other professional engineers and construction managers interested in forces that ice imposes on structures. Here is what is discussed: 1. INTRODUCTION, 2. MECHANICAL PROPERTIES OF ICE, 3. ENVIRONMENTAL FORCES, 4. FORCES LIMITED BY ICE FAILURE, 5. FORCES LIMITED BY THE MOMENTUM OF AN ICE FEATURE, 6. CANADIAN AND AMERICAN CODES, 7. VERTICAL ICE FORCES