ASTM F841-84(2006)
(Specification)Standard Specification for Thrusters, Tunnel, Permanently Installed in Marine Vessels
Standard Specification for Thrusters, Tunnel, Permanently Installed in Marine Vessels
ABSTRACT
This specification supplies the general characteristics and requirements, and interface details of propeller-type, fixed-tunnel thruster units that are permanently installed in marine vessels or structures. Thrusters manufactured in accordance with this specification shall be identified by the following types and grades: Type I—fixed pitch; and Type II—controllable pitch; Grade 1—intermittent duty for docking and navigation; and Grade 2—continuous duty for stationkeeping or dynamic positioning. The thrusters shall meet the design, manufacturing, dimensional, and workmanship requirements specified herein.
SCOPE
1.1 This specification supplies general characteristics and interface details of propeller type, fixed-tunnel thruster units permanently installed in marine vessels or structures.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
Note 1—This specification supplies only general design, interface, and purchase information and does not include requirements for use, thruster controls, or associated equipment. The purchaser of the thruster equipment specified herein is cautioned that he must properly correlate the operating requirements with the thruster specified.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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An American National Standard
Designation: F841 – 84 (Reapproved 2006)
Standard Specification for
Thrusters, Tunnel, Permanently Installed in Marine Vessels
ThisstandardisissuedunderthefixeddesignationF841;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope ABS Rules for Building and Classing Steel Vessels
2.3 ISO Document:
1.1 This specification supplies general characteristics and
ISO Recommendation ISO/DIS484/11 (Draft)
interface details of propeller type, fixed-tunnel thruster units
permanently installed in marine vessels or structures.
3. Definitions of Terms Specific to This Standard
1.2 The values stated in either SI units or inch-pound units
3.1 thruster—a device constructed such as to provide a
are to be regarded separately as standard. The values stated in
force or thrust of controlled variable magnitude and direction
each system may not be exact equivalents; therefore, each
to a marine vessel or structure, usually, but not limited to, a
system shall be used independently of the other. Combining
propeller mounted within a tunnel located below water level.
values from the two systems may result in non-conformance
3.2 fixed pitch—(FP)apropellerinwhichthebladesarepart
with the standard.
of, or are rigidly attached to, the hub such that the propeller
NOTE 1—Thisspecificationsuppliesonlygeneraldesign,interface,and
pitch is constant for a given radius.
purchase information and does not include requirements for use, thruster
3.3 controllable pitch—(CP)apropellerinwhichtheblades
controls,orassociatedequipment.Thepurchaserofthethrusterequipment
are attached to a mechanism within the hub by means of bolts
specified herein is cautioned that he must properly correlate the operating
or fasteners, so that controlled movement of the mechanism
requirements with the thruster specified.
causes the blades to change pitch in unison.
1.3 This standard does not purport to address all of the
3.4 tunnel—a part of thruster assembly of circular cross
safety concerns, if any, associated with its use. It is the
sectionwhichhousesstructuresupportingapropelleranddrive
responsibility of the user of this standard to establish appro-
mechanism.
priate safety and health practices and determine the applica-
3.5 peak power—highest horsepower developed by the
bility of regulatory limitations prior to use.
prime mover, or as limited by the thruster manufacturer.
3.6 continuous duty—operation of the thruster continuously
2. Referenced Documents
at any power range, up to manufacturer’s rating, for extended
2.1 ASTM Standards:
periods, but not to overlap into recommended maintenance
A296 Discontinued 1980: Specification for Corrosion-
intervals.
Resistant Iron-Chromium and Iron-Chromium Nickel and
3.7 intermittent duty—operation of the thruster at peak
Nickel-B Alloy Castings; Replaced by A743, A744
power or RPM levels, or both, for periods not exceeding 1 h
F25 TestMethodforSizingandCountingAirborneParticu-
followedbyperiodsof1hatthecontinuousratingorless,with
late Contamination in Cleanrooms and Other Dust-
total running time not exceeding8hin24h.
Controlled Areas
3.8 landing bars—permanent attachments, usually in the
2.2 American Bureau of Shipping:
form of plates welded to the tunnel during manufacture,
intended to provide joining facilities for deck plates or bulk-
This specification is under the jurisdiction ofASTM Committee F25 on Ships heads, or both, at installation. Landing bars are neither in-
and Marine Technology and is the direct responsibility of Subcommittee F25.11 on
tended to be part of the support structure for the thruster, nor
Machinery and Piping Systems.
provide support or transmit forces from the vessel structure to
Current edition approved Feb. 1, 2006. Published February 2006. Originally
the thruster.
approved in 1984. Last previous edition approved in 1998 as F841–84 (1998).
DOI: 10.1520/F0841-84R06.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Withdrawn.
4 5
Available from American Bureau of Shipping (ABS), ABS Plaza, 16855 Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
Northchase Dr., Houston, TX 77060. 4th Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
F841 – 84 (2006)
3.9 prime mover—the motor(s) or engine(s) providing the 5.2.4 Width at waterline.
power to drive the thruster. 5.2.5 Draft, loaded forward after or draft, ballast forward
3.10 grid bars—bars installed at the tunnel entrances in the
after.
form of a mesh to prevent large objects from passing through 5.2.6 Dimension of keel to thruster centerline.
thethrustertunnel.Theareaoccupiedbythegridbarsshallnot
5.2.7 Dimension of bow at waterline to thruster centerline.
exceed 6% of the tunnel cross-sectional area.
5.2.8 Beam at the thruster centerline.
5.2.9 Vessel displacement.
4. Classification
5.2.10 Vessel service and operating environment.
4.1 Thrusters manufactured in accordance with this specifi-
5.2.11 Whether grid bars are to be installed.
cation shall be identified as follows:
4.1.1 Type I—Fixed pitch.
6. Materials and Manufacture
4.1.2 Type II—Controllable pitch.
6.1 General Requirements—The tunnel shall be made of
4.2 Each type of thruster may be manufactured to the
tested steel ofABS quality or equal, fabricated, cast or forged,
following grade:
or a combination thereof. All structural welding shall be in
4.2.1 Grade 1—Intermittent duty for docking and naviga-
accordance with the applicable regulatory agency or the
tion.
thruster manufacturer’s recommendations or both. All welds
4.2.2 Grade 2—Continuous duty for stationkeeping or dy-
exposed to (sea) water shall be overlayed with weld metal
namic positioning.
containing 2½% nickel, minimum. The minimum tunnel
material thickness shall meet applicable classification society
5. Ordering Information
requirements. A replaceable insert may be provided in the
5.1 Requestsforquotationandpurchaseordersshallspecify
tunnel in way of the propeller tips to prevent erosion of the
the following (in absence of specific requirements in ordering
tunnel wall (Fig. 3). The minimum width of the insert shallbe
data, the unit will be provided only as specified herein):
10% of the propeller diameter. If an insert is not used, the
5.1.1 Description of thruster.
tunnel thickness in way of the blades, and for a minimum
5.1.2 ASTM designation and date of issue.
length of 10% of the tunnel diameter, shall be increased by at
5.1.3 Type.
least 10% of the required thickness. Reenforcement rings/
5.1.4 Grade.
stiffeners may be applied at each end of the tunnel by the
5.1.5 Input Shaft Angle—Refer to Fig. 1.
manufacturer. The rings may or may not become part of the
5.1.6 Tunnel Extensions—Refer to Fig. 2.
joint detail to the tunnel extension.
5.1.7 Landing bars or other weldments to the thruster to be
6.2 Propeller blades and hub may be one of the following
shown in a sketch or drawing provided by the purchaser.
materials or other material approved by the applicable classi-
5.1.8 Type of prime mover.
fication society and shall be specified in the ordering data.
5.1.9 Input HP and RPM to thruster.
6.2.1 Ni-Al Bronze ABS Type 4.
5.1.10 Material Options for Hub and Blades:
6.2.2 Stainless Steel Specification A296–77 GR CF-3 or
5.1.10.1 Ni-Al Bronze ABS Type 4.
CF-8C.
5.1.10.2 StainlesssteelSpecificationA296–72GRCF-3or
6.2.3 Manganese Bronze ABS Type 2.
CF-8C or other ABS approved material.
6.3 All fasteners exposed to (sea) water shall be of monel,
5.1.10.3 Manganese bronze ABS Type 2.
stainless-steel, or bronze alloy, unless otherwise specified in
5.1.11 Blade hatch.
the ordering data.
5.1.12 Instruction books (unless otherwise specified, six
6.4 All materials shall be free of imperfections and defects
copies in English).
that adversely affect serviceability.
5.1.13 Tunnel insert (erosion liner).
6.5 All steel surfaces exposed to (sea) water shall be
5.1.14 Paintingorcoating,external(watercontactsurfaces).
cleaned, painted, or coated in accordance with manufacturer’s
5.1.15 Painting or coating, internal (inside hull).
commercial practice or as otherwise specified in ordering data.
5.1.16 Blade Balancing—Manufacturerstandardpracticeor
6.6 All steel surfaces that will be within the hull of the
ISO Recommendation F484 Class II Draft Internation
...
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