Topic - 17 Fore End Construction

Framing

1.      Deck Longitudinals

Each deck longitudinal, in association with the plating to which it is attached, is to have a section modulus SM not less than that obtained from the following equation:

SM_req = 7.8chsl² cm³                    (3-2-5/3.1)

                                                 = 102.4 cm³

   Minimum depth obtained from Rule book = 165.67mm

   Depth considered = 357.19mm = 14 1/16 in.

   Web thickness = 3/4 in.

   Flange thickness = 1 5/16 in.

   Flange width = 14 in.

                                         SM_obtained = 560.2 cm³

2.       Deck Transverses

Each deck transverse, in association with the plating to which it is attached, is to have a section modulus SM not less than that obtained from the following equation:

SM_req = 4.74chsl² cm³            (3-2-5/3.3)

                                                                                    = 62.22 cm³          

     Minimum depth obtained from Rule book = 236.472mm

     Depth considered = 357.19mm = 14 1/16 in.

     Web thickness = 3/4 in.

     Flange thickness = 1 5/16 in.

     Flange width = 14 in.

                                         SM_obtained = 560.2 cm³

3.       Bottom and Side Longitudinals

Each bottom and side longitudinal, in association with the plating to which it is attached, is to have a section modulus SM not less than that obtained from the following equation:

SM = 7.8chsl² cm³                      SM = 0.0041chsl² in³           (3-2-5/3.5)

 SM (bottom Longitudinals) = 59.349cm³ 

 SM (side Longitudinals)      = 55.362 cm³

Minimum depth obtained from Rule book (for both bottom and side) = 354mm

Depth considered = 357.19mm = 14 1/16 in.

Web thickness = 3/4 in.

Flange thickness = 1 5/16 in.

Flange width = 14 in.

                                         SM_obtained = 560.2 cm³

4.       Bottom and Side Transverses

Each bottom and side transverse, in association with the plating to which it is attached, is to have a section modulus SM not less than that obtained from the following equation:

SM = 4.74chsl² cm³                         SM = 0.0025chsl² in³       (3-2-5/3.7)

SM (bottom and side Longitudinals) = 47.10 cm³ 

     Minimum depth obtained from Rule book for side transverses = 354mm

     Depth considered = 357.19mm = 14 1/16 in.

     Web thickness = 3/4 in.

     Flange thickness = 1 5/16 in.

     Flange width = 14 in.

                                         SM_obtained = 560.2 cm³

      Minimum depth obtained from Rule book for bottom transverses = 441.79mm

     Depth considered = 17 7/6 in. = 442.91mm

     Web thickness = 1 in.

     Flange thickness = 1 3/4 in.

     Flange width = 15 7/8 in.

                                         SM_obtained = 1333.33 cm³

  

5.       Proportions

Deck and bottom chords and transverses and side transverses are to have proportions complying with the following:

Ø  Deck chords and transverses are to have a depth of not less than 83.5 mm per meter of span l (1 in. per foot of span l).

Depth = 236.472 mm

Finalized Depth = 14 1/16 in = 357.19mm

Ø  Side transverses are to have a depth of not less than 125 mm per meter of span l (1.5 in. per foot of span l).                             

                                                    Side transverses depth =354 mm

Finalized Depth = 14 1/16 in. = 357.19 mm

Ø  Bottom transverses and chords are to have a depth of not less than 156 mm per meter of span       l (1.875 in. per foot of span l).

Bottom transverse depth =441.79 mm

Finalized Depth = 17 7/16 in. = 442.91 mm