ASTM F1455-92(2001)
(Guide)Standard Guide for Selection of Structural Details for Ship Construction
Standard Guide for Selection of Structural Details for Ship Construction
SCOPE
1.1 This guide provides a recommended list of selected ship structure details for use in ship construction.
1.2 Structural details which have failed in service and are not recommended for use in ship construction are included as well.
1.3 This guide is intended to convey the lessons learned on different configurations of ship structure details, not the dimensions, thickness, or construction methods which would result from structural calculations.
General Information
Relations
Standards Content (Sample)
Designation: F 1455 – 92 (Reapproved 2001) An American National Standard
Standard Guide for
Selection of Structural Details for Ship Construction
This standard is issued under the fixed designation F 1455; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
The principal aim of this guide is to depict recommended practices related to the design of ship
structural details. The importance of structural details is clear:
1) Their layout and fabrication represent a sizable fraction of hull construction costs.
2) Details are often the source of cracks and other failures which, under certain circumstances,
could lead to serious damage to the ship hull girder.
3) The trend toward decreasing ship hull scantlings (that is, increasing average hull stresses) has the
potential of increasing the damage to details.
4) Researchers have largely neglected the analysis of structural details at least in part because the
configuration and purpose of these details vary greatly and are not commonly described or discussed
in the literature.
Due to lack of analytical and experimental effort devoted to structural details, their determination
has been left up to draftsmen and designers, with very little engineering input.
2,3
In two comprehensive reviews of the performance of structural details, 86 ships were surveyed.
These included naval and commercial ship types. The commercial ships included both U.S. and
foreign built. The vessels ranged from 428 to 847 feet in length, from 18,000 to 90,000 tons in
displacement, and from five to twenty-six years in age. The details obtained were grouped into 12
typical families. Knife Edge Crossings (Family No. 6) and Structural Deck Cutout Details (Family No.
9) are shown but not covered in detail in this guide. The remaining ten detail families were further
categorized into 53 groups comprising a total of 611 detail configurations. A number of these
configurations are very similar to others in detail geometry and such duplicates have been excluded
from this guide. A number of others were eliminated because of relatively infrequent observed use. As
a result, a total of 414 details are included herein. However, all 611 details can be found in “Structural
Details,” if desired.
In total, 607,584 details were observed with a total of 6,856 failures. Failures were attributed to one
or a combination of five categories: design, fabrication, welding, maintenance, and operation (see 4.1
through 4.5). This extensive, well documented research, together with engineering judgement,
provides the principal support for this guide.
1. Scope different configurations of ship structure details, not the dimen-
sions, thickness, or construction methods which would result
1.1 This guide provides a recommended list of selected ship
from structural calculations.
structure details for use in ship construction.
1.2 Structural details which have failed in service and are
2. Terminology
not recommended for use in ship construction are included as
2.1 Definitions of Terms Specific to This Standard:
well.
2.1.1 Terms:
1.3 This guide is intended to convey the lessons learned on
2.1.2 beam bracket—a bracket at the end of framing or
stiffening members that is used for increased strength, conti-
This practice is under the jurisdiction of ASTM Committee F25 on Shipbuild-
nuity and end constraint.
ing and is the direct responsibility of Subcommittee F25.01 on Structures.
2.1.2.1 Discussion—see Fig. 1.
Current edition approved Dec. 15, 1992. Published February, 1993.
2.1.3 clearance cut-outs—a hole or opening in a pierced
Jordan, C. R., and Cochran, C. S., “In-service Performance of Structural
Details,” SSC-272, Ship Structure Committee Report, March 1977, available
member to allow passage of a piercing member.
through the National Technical Information Service, Springfield, VA 22161.
Jordan, C. R., and Knight, L. T., “Further Survey of In-service Performance of
Structural Details,” SSC-294, Ship Structure Committee Report, May 1979, avail- Jordan, C. R., and Krumpen, P., Jr., “Structural Details,” American Welding
able through the National Technical Information Service, Springfield, VA 22161. Society Welding Journal, Vol 63, No. 1, January 1984.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
F 1455
FIG. 3 Gunwale Connections (Family No. 5)
FIG. 1 Beam Brackets (Family No. 1)
2.1.3.1 Discussion—see Fig. 2.
2.1.4 gunwale connection—the connection of the sheer
strake to the stringer strake of the uppermost deck of the hull.
2.1.4.1 Discussion—see Fig. 3.
2.1.5 knife edge crossing—the projected point intersection
of members (plate members, stiffeners or bulkheads) on
FIG. 4 Knife Edge Crossing (Family No. 6)
opposite sides of an intervening plate member. An undesirable
condition to be avoided.
2.1.5.1 Discussion—Included for information only, see 3.1.
2.1.5.2 Discussion—see Fig. 4.
2.1.6 miscellaneous cut-out—small holes or openings of a
variety of sizes and shapes used for access, drainage, ease of
fabrication, stress relief, and so forth.
2.1.6.1 Discussion—see Fig. 5.
FIG. 5 Miscellaneous Cut-outs (Family No. 7)
2.1.7 non-tight collar—a fitting at the cut-outs in way of the
intersection of two continuous members that provides lateral
support for the piercing member which does not fully fill the
cut-out area of the pierced member. May be a lug.
2.1.7.1 Discussion—see Fig. 6.
2.1.8 panel stiffeners—intercostal, non-load-carrying mem-
bers used to reduce the size of plate panels.
2.1.8.1 Discussion—see Fig. 7.
2.1.9 stanchion ends—structural fittings at the ends (top and
bottom) of a stanchion to transfer loads from the supported
member to the supporting member. FIG. 6 Non-Tight Collars (Family No. 3)
2.1.9.1 Discussion—see Fig. 8.
2.1.10 stiffener ends—the configuration of the end of an
unbracketed, non-continuous stiffener.
2.1.10.1 Discussion—see Fig. 9.
FIG. 7 Panel Stiffeners (Family No. 12)
2.1.11 structural deck cuts—allow passage through decks
for access, tank cleaning, piping, cable, and so forth.
2.1.11.1 Discussion—Included for information only, see
2.1.13 tripping bracket—a bracket or chock that provides
3.1.
lateral support to framing and stiffening members. Support
2.1.11.2 Discussion—see Fig. 10.
may be provided to either the web or the flange, or to both.
2.1.12 tight collar—as per non-tight collar but the cut-out in
2.1.13.1 Discussion—see Fig. 12.
the pierced member is fully filled and is air-, oil-, or watertight
2.2 Symbols:Symbols:
as required. Tight collars may be lapped or flush fitted.
2.2.1 Symbols are as indicated in Fig. 13. The detail
2.1.12.1 Discussion—see Fig. 11.
identification symbol (Fig. 13, 1-J-1 for example) is the same
as that assigned in the original research reports and is retained
throughout for all details for ease in referring back to the
reports if desired.
3. Summary of Guide
3.1 In this guide, details are shown for the ten families of
structural details identified above and as shown in Fig. 1–3,
5–9, 11 and 12. Knife Edge Crossings, Fig. 4, are not discussed
FIG. 2 Clearance Cut-outs (Family No. 8) further in this guide since none were observed in the research
F 1455
Structural Details”. Data for over 400 details is summarized
and rated in the figures by observed relative successful
performance. Each of the ten families of details include
configurations with no signs of failures. The details without
failures within each family group are shown in descending
order of numbers observed. Those details with failures are
shown in ascending order of failures (percentage are indicated
for each). Thus the first detail shown in each family group has
the best observed service performance and is most highly
FIG. 8 Stanchion Ends (Family No. 10)
recommended while the last has the highest failure rate and
therefore least desirable.
3.3 These details, rated as indicated above, provide guid-
ance in the selection of structural detail configurations in future
design and repair of such details.
4. Failure Causes
4.1 Failures in the details shown in Figs. 14-28 were
attributed to either one or a combination of five categories:
design, fabrication, welding, maintenance, and operation.
4.1.1 Design:
FIG. 9 Stiffener Ends (Family No. 11)
4.1.1.1 Design failures generally resulted from the omission
of engineering principles and resulted in a buckled plate or
flange; the formation of a crack in a plate, flange or web; or the
rupture of the bulkhead, deck or shell. Each of the families,
with the exception of tight collars, had detail failures attributed
to design.
4.1.1.2 Failures directly related to design in structural de-
tails and supporting members were the result of being sized
without adequate consideration of applied forces and resulting
deflections.
FIG. 10 Structural Deck Cuts (Family No. 9)
4.1.1.3 In the beam bracket configurations of family no. 1
(Fig. 14), 20 % of the surveyed failures attributed to design
were caused by instability of the plate bracket edge or by
instability of the plate bracket panel. This elastic instability,
which resulted from loads that produce critical compressive or
shear stresses, or both, in unsupported panels of plating, can be
eliminated when properly considered in the design process.
4.1.1.4 The failures of beam brackets by cracking occurred
predominately where face plates had been sniped, at the
welded connections, at the ends of the brackets, at cutouts in
FIG. 11 Tight Collars (Family No. 4)
the brackets, and where the brackets were not properly backed
up at hatch ends. The sniping of face plates on brackets
prevents good transition of stress flow, creates hard spots and
produces fatigue cracks due to the normally cyclic stresses of
these members. Care must be taken to ensure proper transition
with the addition of chocks, back-up structure, reinforcement
of hole cuts, and the elimination of notches.
4.1.1.5 To reduce the potential for lamellar tearings and
fatigue cracks in decks, bulkheads, and beams, transition
FIG. 12 Tripping Brackets (Family No. 2)
brackets should be made continuous through the plating or
supported by stiffeners rigid enough to transmit the loads.
4.1.1.6 The greater number of failures in the tripping
and fortunately so. This detail represents very undesirable
bracket configurations of family no. 2 (Fig. 18), occurred at
structural conditions and is to be avoided. Structural Deck
hatch side girders, particularly in containerships. This will be a
Cuts, Fig. 10, are not discussed in this guide since this detail
must be considered in relation to the size of the opening and its
proximity to primary structures.
Jordan, C. R., and Krumpin, R. P., Jr., “Design Guide for Structural Details,”
3.2 Evaluation of details shown in Figs. 14-28 is based on
SSC 331, Ship Structure Committee Report, August 1990, available through the
in-service experience as described in “Design Guide for National Technical Information Service, Springfield, VA 22161.
F 1455
FIG. 13 Symbols
continuing problem unless the brackets are designed to carry structure is part of the longitudinal strength structure of the
the large lateral loads due to rolling when containers are ship in addition to being subjected to high local stresses due to
stacked two to four high on the hatches. The brackets must, in the container loading in the upper deck. Openings in this
turn, be supported by properly designed backing structure to structure must be located, reinforced, and analyzed for second-
transmit the loads to the basic ship structure. ary bending stresses caused by high shear loads.
4.1.1.7 Tripping brackets supported by panels of plating can 4.1.1.11 The clearance cutouts of family no. 8 (Fig. 20) are
be potential problems depending on the plate thickness. Brack- basically non-tight collars without the addition of the collar
ets landing on thick plating in relationship to its own thickness plate. Suggestions made for non-tight collars and miscella-
may either buckle in the panel of the bracket, produce fatigue neous cutouts are applicable for this family.
cracks along the toe of the weld, or cause lamellar tearing in 4.1.1.12 Well rounded corners with radii equivalent to 25 %
the supporting plate. Brackets landing on plating with a of the width perpendicular to the primary stress flows should be
thickness equal to, or less than its own thickness, may cause used. Special reinforcements in the form of tougher or higher
either fatigue cracks to develop or buckling of an unsupported strength steel, inserts, coamings, and combinations of the
panel of plating. above should be used where fatigue and high stresses are a
4.1.1.8 The non-tight collar configurations of family no. 3 problem.
(Fig. 21) experienced only a few failures. There are consider- 4.1.1.13 In general, failures in stanchion ends, family no. 10
ations, however, that must be used by the designer to ensure the (Fig. 25Fig. 26), were cracks which developed in or at the
continuation of this trend. The cutouts should be provided with connection to the attachment structure. The addition of tension
smooth well rounded radii to reduce stress risers. Where collars brackets, shear chocks, and the elimination of snipes would
are cut in high stress areas, suitable replacement material reduce the incidents of structural failure. All stanchion end
should be provided to eliminate the overstressing of the connections should be capable of carrying the full load of the
adjacent web plating. These considerations should reduce the stanchion in tension or compression. Stanchions used for
incidents of plate buckling, fatigue cracking, and stress corro- container stands or to support such structure as deckhouses on
sion observed in this family. the upper deck should be attached to the deck with long tapered
4.1.1.9 For detail family no. 7, miscellaneous cutouts, (Fig. chocks to reduce stress flows from hull induced loads, and in
24), the reasons for failure were as varied as the types of no case should “V” notches be designed into such connections.
cutouts. Potential problems can be eliminated by the designer 4.1.1.14 The stiffener ends in family no. 11 (Fig. 27) with
if, during detail design, proper consideration is given to the webs or flanges sniped, or a combination of both, or square cut
following: ends sustained failures. In nearly all cases, the failures occurred
1) Use generous radii on all cuts. in the attached bulkhead plating, the web connection when the
2) Use cuts of sufficient size to provide proper welding flange was sniped, or the shear clip used for square cut stiffener
clearances.
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