Feature 8 | SEALIFT/LOGISTIC SUPPORT
to the shore. Tis eliminates the need for a secure deep-water port and enables the flow of containerised logistics through as seabase to shore. The LVI Lo/Lo crane consists of a
crane supported by a sensor suite to detect crane, payload and ship positions/ motions, and a control system to automate motion compensation and optimise operator demands. Te crane architecture has two main
subsystems. Te ‘macro crane’ consists of an eccentric arm that attaches to the ship and has the main crane housing at the end of the arm. A boom extends
outward from this crane housing. Te gross relative motions are removed by controlling the movements of the eccentric arm and the boom. The ‘micro crane’ is an eight-wire
‘inverted stewart platform’ hanging from a wrist at the end of the boom. Each pair of wires is attached to one corner of a spreader bar that has twist-locks to attach to the top of a standard 20ſt ISO shipping container. Te micro crane removes the remainder
of the relative motion and matches the motion of the spreader bar to the top of the container and locks the container to
the spreader bar for transfer. When the container is attached to
the spreader bar, it can be controlled in all six degrees of freedom and does not pendulate due to the natural anti-pendulation properties of the inverted Stewart platform combined with the system’s active motion control. At a minimum, when the LVI Lo/Lo
crane system is delivered, it will contain these subsystems: an advanced crane system (electromechanical actuators, machinery control software, energy storage, machinery sensors); and wave/ ship motion sensing and control. WT
TAVTS also tested
Cargotec’s Test Article Vehicle Transfer System (TAVTS) was also recently tested in the US. The trials were carried out by the US Navy’s Strategic and Theatre Sealift Program Office (PMS 385) which is part of Program Executive Office Ships (PEO Ships). “This landmark capability will be a significant enhancement for future sea-basing logistics operations,” said Captain George M Sutton, programme manager for PMS 385. TAVTS is part of a risk-reduction effort by the US
Department of Defense’s Maritime Prepositioning Force (Future) when transferring military vehicles between ships at sea. The aim of the tests and the programme is to provide the US military with the capability for large-scale logistics movements from sea to shore without dependency on foreign ports. “We have a long history of deliveries to PEO Ships, and this latest system is a good example of the innovative technological solutions that Cargotec can offer by drawing on the diverse range of expertise within the company,” said Jeffrey Siegel, regional sales manager. “TAVTS resulted from close co-operation between our ramp technology experts and our offshore specialists, who contributed in-depth knowledge of heave-compensation technologies.” During the trials, the US Navy demonstrated the transfer of vehicles between the surrogate ‘mobile landing platform’
During PEO Ships’ full-scale trials, personnel and vehicles were successfully transferred between the ships in high Sea State 3 and low Sea State 4 during multiple days of testing in the Gulf of Mexico.
(MLP) Mighty Servant 3 and the large medium-speed roll-on/roll-off (LMSR) ship, USNS Soderman. The test demonstrated a self-deploying ramp system installed on the MLP and a new self-deploying sideport platform
installed on the LMSR vessel. Deployment and retrieval of the ramp is controllable by one person. In case of failure, the system can safely continue to support vertical and horizontal design loads and allow emergency ship separation while carrying a vehicle weighing up to 72.5tonnes anywhere along the length of the ramp. Cargotec conducted rigorous harbour trials in Norway in November 2009, and PEO Ships’ full-scale testing conducted
was successfully completed in March this year. All test procedures were performed using the graduated ‘crawl, walk, run’ approach: starting with demonstrations alongside and at anchor, progressing to low sea state conditions in open water, and finishing with increasing sea states in open water. Personnel and vehicles were successfully transferred between the ships in Sea State 3 and Sea State 4 during several days of testing in the Gulf of Mexico. Vehicles transferred included high-mobility multi-purpose wheeled vehicles (HMMWVs), HMMWVs with trailers, medium tactical vehicle replacements, amphibious assault vehicles, M88 tank recovery vehicles, and M1A1 main battle tanks.
36 Warship Technology July/August 2010
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40