LamaLo Technology Inc.
Tankers
and Cargo Ships
Click
here for a copy of a paper from LamaLo Technology Inc.
World Maritime Technology Conference (WMTC) 2006 – London, England Paper – PDF File
American Heavy Lift Tankers
(2 x 4650 kW): A modular construction approach will be
employed for a state of the art twin screw, diesel electric, double-hull, IMO
Type II and III product/chemical tanker.
The vessel will have an overall length of 188 meters, a beam of 32
meters and a design draft of 11 meters with a total cargo capacity of
approximately 330,000 barrels. The
vessel will have a twin screw propeller configuration. Each of the 4 bladed fixed pitch propellers
will be driven by a 4650 kW electric motor through a single reduction
gearbox. The propulsion shaftline length
is about 87' (26 m) long, and is supported by a strut, a sterntube and a
lineshaft bearing. The main gearshaft is
supported by two bearings. The motor
rotor shaft is supported by two bearings and is connected to the gearbox via a
gear coupling. LamaLo Technology Inc.
(LLT) was contracted to assist in the propulsion shafting design and conducted
the corresponding alignment and vibration analysis. The first vessel is under construction and is
scheduled to be delivered in 2009.
Veteran Class
MT46 Tankers (1 x 8700 kW): Built at Aker
Philadelphia Shipyards, these 46,000-dwt double-hull ships are 183 meters long,
32 meters wide and have a cargo capacity of 330,000 barrels. The tankers’ design is being provided through
an exclusive five-year agreement with Hyundai Mipo Dockyard (HMD). The vessel has a single screw propeller
configuration. The 4 bladed fixed pitch
propeller is directly driven by a MAN B&W 6S50MC diesel engine with a
rating of 8,700 kW (11,640 HP) at 127 RPM.
The propulsion shaftline is approximately 14.5 m long, and is supported
by two sterntube bearings and one line shaft bearing. Propulsion shaftline theoretical alignment
and lateral (whirling) vibration analysis, as well as strain gauge alignment
measurements were conducted. Strain
gauge alignment measurements were taken both on dock and when afloat, to determine
the affect on shaft alignment of undocking and the requirements for chocking
the main engine prior to floating the hull.
The first vessel MV Overseas Houston was delivered the first quarter of
2007 and the second vessel MV Overseas Long Beach was delivered in June
2007. The propulsion shafting and
engine alignment performance has been reported to be excellent.
MV Mississippi Voyager (1 x 7941 kW): The MV Mississippi Voyager (Voyager) is a
double-hulled petroleum product tanker.
The vessel was built 1998 by Newport News Shipbuilding, with a gross
tonnage 30,400 and a deadweight of 46 MT.
The vessel has an overall length of 183m, a moulded breadth of 32m, a
design draft of 11.2 m and a rated speed of 14.5 knots. The Voyager has a single screw propeller
configuration. The fixed pitch propeller
is driven by a MAN B&W 6L60MC slow-speed diesel engine with a rating of
7,941 kW at 96 RPM. The propulsion
shaftline is approximately 14.7 m long, and is supported by one aft sterntube
bearing and one intermediate shaft bearing.
The aft sterntube seal and sterntube bearing were both found to be
damaged during an inspection in the spring of 2007. The propeller shaft was removed and the
sterntube bearing was inspected and replaced.
LamaLo Technology Inc. (LLT) conducted a failure investigation that
included a shafting system design review, theoretical alignment and whirling
vibration analyses, on-site inspections, strain gauge alignment measurements
and shafting vibration measurements.
Areas of concern were identified.
The investigation is on-going.
MV Marielle
Bolten (1 x 6400 kW): The MV Marielle Bolten (Bolten), a 19,354grt
& 1130 TEU general cargo/container ship, was built in 1997. The vessel has an overall length of 181 m
with a moulded breadth of 26 m and a rated speed of 14 knots. The single fixed pitch propeller is driven by
a MAN B&W 5S50MC slow-speed diesel engine with a rating of 6400 kW at 120
RPM. The propulsion shaftline is
approximately 11.7 m long, and is supported by two sterntube bearings and one
line shaft bearing. There is a shaft
generator fitted aft of the main engine.
On 24 January 2006 the MV Marielle Bolten grounded in poor weather
conditions and the hull and propulsion shafting were damaged.
MV Caribe Merchant (1 x 4900 kW): The MV Caribe Merchant was built in 1984, and is a 160 m long Roll-on/Roll-off Carrier, with a gross tonnage of about 15,400 and a dead weight tonnage of 9,200. The single four bladed controllable pitch propeller is driven by one diesel engine with a rating of 4,900 kW at 500 RPM, through a single reduction gearbox. The propulsion shaft is approximately 10.7 m (35') long, is supported by two sterntube bearings and is connected to a CPP Hydraulic Cylinder with a flanged sleeve coupling, which is then connected to the main gearshaft also by a flanged sleeve coupling. A failure of the aft main gearshaft support bearing occurred in 2006, and damage occurred to the pinion. The gearbox was also repaired and realigned after a previous failure in 2004. LamaLo Technology Inc. (LLT) was contracted to provide specialized engineering analysis services with respect to the propulsion shafting alignment and investigation of the gearbox failures. A theoretical alignment and whirling vibration analysis of the propulsion shaftline was conducted, and the installed alignment condition was measured using the strain gauge technique. The initial measured loads on the main gearshaft bearings were found to be excessive, and it was determined that this misalignment would result in failure of gearing components. To achieve an acceptable alignment condition the gearbox was lowered about 5 mm. The resulting bearing loads and all alignment criteria were satisfactory. The ship returned to service in December 2006 and has been in service without any further failures.
Vessel Being Delivered
Strain Gauge Alignment in “Open Air”
Tote Orca Class
Trailership (2 x 19750 kW): Two of these
vessels were built at National Steel and Shipbuilding Company (NASSCO), MV
Midnight Sun and MV North Star. They are
839' long with a beam of 118', a draft of 32', and a displacement of 45,400
long tons. Each of the 5 bladed fixed
pitch propellers are driven by an Electric Motor rated at 19,750 kW (26,465 HP)
at 125 RPM. Each propulsion shaftline is
approximately 57 m (187') long, and is supported by two sterntube bearings,
five intermediate shaft bearings, and one support bearing which is integral
with the thrust bearing housing. The
motor rotor shaft is supported by two bearings.
An independent assessment and review of the propulsion system overall
design, shaft alignment and vibration was conducted. Design modifications were recommended and
implemented. A unique alignment
procedure was developed with NASSCO that involved installation of the lineshaft
prior to the propeller shaft in “open air”.
It was estimated that this procedures saved over 10,000 man hours of
work. LamaLo Technology Inc. was
contracted to ensure that the propulsion system had a satisfactory alignment
condition when the vessel was waterborne and fully outfitted, for all modes of
operation, which included the installation of a strain gauge based alignment
system. The vessels were delivered in
2003. The alignment performance has been
reported to be excellent.
BP Alaska Tankers (2 x 13,400 HP): Four (4) BP Tankers
are under construction at National Steel and Shipbuilding Company
(NASSCO). The vessels are designed for
maximum flexibility in the transport of crude oil from Valdez, Alaska, to oil
refineries located on the U.S. West Coast.
The vessels have a twin screw propeller arrangement, are 287 m long with
a design displacement of 221,000 MT, and a rated speed of 15.3 knots at 85%
MCR. Each of the 5 bladed fixed pitch
propellers are driven by an electric motor rated at 13,400 HP at 85 RPM. The propulsion shaftline is approximately 33
m (108') long, and is supported by two sterntube bearings, one lineshaft
bearing, and one support bearing which is integral with the thrust bearing
housing. The motor rotor shaft is supported
by two bearings. LamaLo Technology
Inc. was contracted to ensure that the propulsion system has a satisfactory
alignment condition when the vessel is waterborne and fully outfitted, for all
modes of operation. This involved
conducting a theoretical alignment analysis of the shaftline, establishing
comprehensive alignment criteria, developing an installation procedure,
measuring and assessing the installed condition. The later is accomplished by comparing the
measured alignment condition to the results of the theoretical analysis and the
alignment criteria. LamaLo Technology
installed a strain gauge based alignment system and conducted the final
alignment analysis.
Two of the vessels have been delivered as of
2004 and the shaft alignment condition has been reported to be acceptable. Measurements of the alignment condition with
the vessel light and loaded confirmed that the alignment condition does not
change significantly with loading condition.
Vessel Being Delivered
Intermediate Shaft Alignment Crankshaft Web Deflection Measurements
CV2600 Container Vessels (1 x 28,800 kW): Four CV-2600 Philadelphia-Class container vessels
are under construction at Aker Philadelphia Shipyard. The vessels have a displacement of
approximately 30,000 metric tons and are powered by a 28,880 kW slow speed
diesel engine. The propulsion shaftline
is approximately 32 m long, and is supported by two sterntube bearings and two
line shaft bearings. The thrust shaft
has one support bearing between the turning wheel and the thrust bearing. The main engine crankshaft is supported by
nine bearings. For the first two (2)
vessels of this class (MV Manukai and MV Maunawili), LamaLo Technology Inc. was
contracted to ensure that the propulsion system has a satisfactory alignment
condition when the vessel is waterborne and fully outfitted, for all modes of
operation.
Propulsion shaftline final alignment was
conducted using the strain gauge technique.
The vertical and athwartships loads on the sterntube and line shaft
bearings were measured. The shear and
bending moment combination were also measured at the thrust shaft flange. The second vessel was delivered in 2004, and
the shaft alignment condition has been reported to be acceptable on both the
first and second vessels.
In the process of completing this project
LamaLo Technology Inc. demonstrated that significant cost savings and increased
reliability in achieving an acceptable alignment condition can be achieved with
the application of strain gauge alignment techniques for shafting systems with
Slow Speed Diesel Engines.
Vessel Alongside
Dock Strain
Gauge Alignment and Jack-Up Load Tests
579' Car Carrier (1 x 11,060 kW): The MV Jean Anne is a roll on / roll off car
and truck carrier, suitable to carry passenger cars and trucks, in the
world-wide and U.S. coastwise service, with a displacement of 12,850 tonnes,
with a dead weight of 8,850 tonnes. It
is being built by
Propulsion shaftline cold final alignment was conducted using the strain gauge technique in November 2004. The vertical and athwartships loads on the sterntube and line shaft bearings were measured. The shear and bending moment combination were also measured at the thrust shaft flange.
MV Ocean Atlas and Industrial Chief (1 x 5400 kW): The MV Industrial
Chief, and it sister vessel the MV Ocean Atlas, are Heavy Lift Vessels, with a
single screw propeller configuration.
The four bladed controllable pitch propeller is driven by one diesel
engine with a rating of 5400 kW at 500 RPM, through a single reduction
gearbox. The propulsion shaft is
approximately 6.5 m (21') long, is supported by two sterntube bearings and is
connected to the main gear shaft by a sleeve coupling. The main gear shaft is supported by two
roller bearings. Premature failure of a
bearing on the main gearshaft occurred on the MV Industrial Chief. A theoretical alignment and whirling
vibration analysis of the propulsion shaftline was conducted, and the installed
alignment condition was measured on both vessels. The alignment condition on the MV Ocean Atlas
was found to be unsatisfactory, with unacceptable loading on the main gearshaft
bearings. The gearbox was realigned in
June 2006, and the vessel has operated without incidence since then. The alignment condition on the MV Industrial
Chief was found to be satisfactory and no action was recommended.