Ship structures under sail and under gunfire By Prof. Francisco Fernández-González TABLE OF CONTENTS SHIP STRUCTURES UNDER SAIL AND UNDER GUNFIRE..................................17.1 Abstract ..............................................................................................................................17.1 Memories ............................................................................................................................17.2 Ships, Men, Yards..............................................................................................................17.3 Spanish Ships-of-the-Line ...................................................................................................17.3 French Ships-of-the-Line.....................................................................................................17.4 British Ships-of-the Line (WATT, LAV1)..........................................................................17.5 On British Ships at Trafalgar (WATT)................................................................................17.6 Timelines ............................................................................................................................17.7 HMS Victory ........................................................................................................................17.7 The Bellona Class of 74-gun ships......................................................................................17.8 The San Juan Nepomuceno .................................................................................................17.8 The Santísima Trinidad .......................................................................................................17.9 The Príncipe de Asturias .....................................................................................................17.9 The Santa Ana .....................................................................................................................17.9 The Rayo..............................................................................................................................17.9 The San Ildefonso ................................................................................................................17.9 Structures ...........................................................................................................................17.10 From the West Indies to Europe..........................................................................................17.10 British versus French construction in Spain in the 1760s ...................................................17.16 The design of the San Ildefonso, 1782 ................................................................................17.17 Scarphs, Joints, Dowels.....................................................................................................17.18 Hull complexity ...................................................................................................................17.18 Doweling .............................................................................................................................17.19 Shear ....................................................................................................................................17.19 Lateral design load of bolted joints (RAWI).......................................................................17.20 Design dowel-bearing strength of wood members in dry condition (12-19% MC)............17.21 Effect of moisture content (MC) .........................................................................................17.21 Ultimate compressive strength ............................................................................................17.21 Modes of Failure of Doweled Joints (AFPA)......................................................................17.21 Dowel Bearing Strength Estimates, F (psi) .........................................................................17.23 Dowel Bending Strength Estimates, Fb (psi) ......................................................................17.23 − 17.i − Application to Ships of the Line of 1805............................................................................ 17.24 Loadings on Hull at Sea.................................................................................................... 17.26 Static loads .......................................................................................................................... 17.26 Dynamic loads .................................................................................................................... 17.27 Hull structures of Romero Landa’s Ships ...................................................................... 17.30 Effect of arming/disarming afloat on hull structures .......................................................... 17.35 Cruising and Launching Drafts (JMJG).............................................................................. 17.36 Launching and Floating Out............................................................................................ 17.37 From land to water .............................................................................................................. 17.37 Lightship condition ............................................................................................................. 17.37 Hull structure weight........................................................................................................... 17.38 Disarming and Careening ................................................................................................... 17.39 Hull Materials.................................................................................................................... 17.42 Stress waves in Wood ......................................................................................................... 17.42 Dynamic Loading................................................................................................................ 17.44 Impact Loads....................................................................................................................... 17.44 Load Duration Factor.......................................................................................................... 17.45 Partial loads and partial durations....................................................................................... 17.45 Mechanical Model............................................................................................................. 17.46 Side shell............................................................................................................................. 17.46 Crushing and Shear ............................................................................................................. 17.47 Bending and Crushing......................................................................................................... 17.48 Deck planking ..................................................................................................................... 17.50 Keel scarphs ........................................................................................................................ 17.50 Frame timbers ..................................................................................................................... 17.51 Effect of chocks between frame timbers............................................................................. 17.51 Cross chocks for frames...................................................................................................... 17.51 Hanging knees..................................................................................................................... 17.52 Lodging knees..................................................................................................................... 17.53 Hooked Wales and Planking............................................................................................... 17.53 Treenails, bolts and nails of a 74-gun ship ......................................................................... 17.53 Application to the San Ildefonso (74) ................................................................................. 17.54 Application to the USS Constitution ................................................................................... 17.55 − 17.ii − Scantling to Rules after 1870 ............................................................................................17.56 Application of the Rules for 1912 .......................................................................................17.56 Application of the Rules for 1871 .......................................................................................17.57 Comparison of iron and wooden knees for equivalent strength and rigidity ......................17.59 Wooden Walls under Gunfire ..........................................................................................17.61 Penetration in wood.............................................................................................................17.61 Alternative model ................................................................................................................17.63 Damage in Combat ..............................................................................................................17.64 Impact Model Tests ...........................................................................................................17.65