LamaLo Technology Inc.
Military Support Vessels
Photos Courtesy of
Lockheed Martin
USS Freedom Class:
The USS Freedom is the lead ship of the Freedom class of Littoral Combat
Ships (LCS) built at
KDX III Class: The
Republic of Korea Navy KDX-III destroyer is intended to be a multi-purpose
destroyer featuring anti-air warfare, anti-surface warfare, anti-submarine
warfare and tactical ballistic missile defence capabilities. The KDX-III propulsion system consists of two
controllable pitch propellers (twin screws) powered by a Combined Gas turbine
and Gas turbine (COGAG) propulsion system, providing 120,000 SHP
altogether. LamaLo Technology Inc. was
contracted by Aker Yards Marine Inc. to provide expertise on the propulsion
shafting system design review and analysis.
Initial operational capability is scheduled for 2008.
Fast Missile Craft (Class): The
vessels will be approximately 203 ft. (62 m) in length and will incorporate
ship signature control technology. High speed and manoeuvrability will be two
of their primary assets, and the vessels will also incorporate numerous combat
system assets and electronic sensors that give them capabilities in
anti-aircraft, anti-surface, and electronic warfare. They would appear to be
envisioned as peers with
T-AKE Class (1 x
11262 kW): T-AKE Class Ships are under construction at
National Steel and Shipbuilding Company (NASSCO). The vessels are to be 689' long with a
displacement of 41,000 long tons and a design speed of 20 knots. The
(i)
Conduct
a review of the preliminary shafting system design. Recommendations for revisions to the
preliminary design were provided and implemented.
(ii)
Conduct
the torsional, lateral, and axial shafting vibration analysis. Submitted to US Navy and approved.
(iii)
Conduct
the shaft alignment analysis and provide recommended alignment condition and
procedures. Submitted to US Navy and
approved.
(iv)
Install
and commission a strain gauge based alignment measurement system.
The strain gauge
based alignment measurement system was installed in the first vessel in
November 2004. Four vessels have been
delivered by 2008, without incident. Ten
vessels are to be built.
T-AKR 310 Class (2 x 23880 kW):
The T-AKR 310 Class
Strategic SeaLift Ships, are 950' long and have twin screw propeller
configurations, each rated at 32,000 HP (23,880 kW). The vessels are part of
the Military Sealift Command's nineteen Large, Medium-Speed Roll-on/Roll-off
Ships and are part of the 42 ships in the Pre-positioning Program. Large, Medium-speed, Roll-on/Roll-off Ships,
or LMSRs, can carry an entire U.S. Army Task Force, including 58 tanks, 48
other track vehicles, plus more than 900 trucks and other wheeled
vehicles. The ship carries vehicles and
equipment to support humanitarian missions, as well as combat missions. The new
construction vessels have a cargo carrying capacity of more than 380,000 square
feet, equivalent to almost eight football fields. In addition, LMSRs have a
slewing stern ramp and a removable ramp, which services two side ports making
it easy to drive vehicles on and off the ship.
The main
strut bearing on the starboard propulsion shaft of the first vessel, the USNS
Watson failed in service and the shaft was seized in the fall of 1998. A main strut bearing on the second vessel,
the USNS Sisler, experienced excessive water contamination. LamaLo Technology was contracted to do the
following:
(i)
Determine
root-cause of bearing failures and develop a least-cost complete solution.
(ii)
Determine
the requirements to obtain a satisfactory alignment condition.
(iii)
Provide
an assessment of the original builder’s alignment specifications and the
installed shaft alignment condition.
(iv)
Measure
and analyse the installed shaft alignment condition of both port and starboard
shafts using the strain gauge technique.
(v)
Measure
hull deflection using advanced DGPS equipment to assess the influence of vessel
loading condition / hull deflection on shaft alignment.
Subsequent to the repair and design modifications, LamaLo Technology was
also contracted to perform the alignment measurements and analysis requirements
for the additional seven vessels under construction at NASSCO in San Diego,
California. The eighth vessel was
delivered in 2002. Since the repair, re-alignment
and design modifications were conducted, the alignment and vibration
performance of the propulsion systems on all the vessels delivered to date have
been satisfactory.
ELSV Class (2 x 2,260 HP): The U.S. Army Enhanced Logistic
Support Vessels (ELSV-7 & 8) were constructed at VTHalter Marine Shipyard
at Moss Point, Mississippi. The vessels
are 314 ft. long with a 60 ft. beam and an overall depth of 19 ft. The ELSV class are able to beach and unload
cargo to floating and elevated causeway systems at the beach. The vessels have a twin screw propeller
configuration. Each of the 5 bladed
fixed pitch propellers is directly driven by a diesel engine rated at 2,260 HP
at 1600 RPM, through a single reduction reversible gearbox. The propulsion shaftline is approximately 46
ft. long, and is supported by a strut, a sterntube, and a pillow block bearing. The main gear shaft is supported by two bearings.
LamaLo Technology Inc. was contracted to
ensure that the propulsion shaftline installed alignment condition is
satisfactory for all modes of operation.
This was accomplished by a combination of theoretical modeling, design
review and assessment, and on-site measurements. Theoretical alignment and whirling vibration
analyses were conducted prior to the installation of the shafting system. An alignment procedure was produced, which
included the strain gauge alignment method.
The shaftline was roughly aligned using optical techniques and a gap and
sag measurements at the gearbox-lineshaft flange connection. The strain gauge technique was used to
conduct the final alignment. Jack-up
load tests were also conducted on the pillow block bearings as an independent
check on the results from the strain gauge alignment results. Alignment measurements were taken again with
the machinery near operating temperature.
The second ship was delivered in 2004 and
the shafting performance has been reported to be excellent on both ships.
USNS Impeccable (TAGOS-23 Class) (2 x
1,850 kW): The TAGOS-23 Class Vessel, a US Navy Swath
vessel, has a twin screw propeller configuration, each rated at 2,500 HP (1,850
kW). LamaLo Technology was contracted to
provide services and equipment to conduct the propulsion shaft alignment
measurement and analysis during construction and delivery. This required the development of alignment
criteria, a theoretical alignment analysis of the shaftline, measurement of the
installed alignment condition using the strain gauge technique, and assessment
of the installed alignment condition.
The later was accomplished by comparing the measured alignment condition
to the theoretical one and the established alignment criteria. Any discrepancies were to be identified, and
remedial action proposed. Shaft
alignment installation procedures were also produced. The vessel was delivered in 2001 and the shaft
performance has been reported to be excellent.
USNS Red Cloud (2 x 23880 kW): The
USNS Red Cloud is a US Navy T-AKR
310 Class Strategic Sealift ship. It is the fourth vessel in a series of
eight vessels that were constructed at NASSCO shipyards in San Diego,
California. Maersk Shipping Ltd
contracted LLT to conduct an investigation to determine the source(s)
of high aft strut bearing temperatures, and to provide the recommended course
of action. A “Systems Engineering”
approach was applied. All aspects of the
shaftline alignment and vibration were investigated by using a combination of
analytical modeling, on-site measurements, and documentation review. The work was carried out at Sembawang
Shipyards in Singapore. The cause of the
high temperature was determined and addressed.
USNS Observation Island (1 x 19,250 HP) T-AGM23 Class (Missile Range Instrumentation Ship):
Propulsion alignment measurements and theoretical modelling. Propulsion shaftline trouble shooting
engineering services (classified).
HMNZS