Niigata Engineering Co., Ltd. on October 3 conducted an open trial run of Blue Arrow 6000 (16V20FX) at its Ohta Plant. This engine was ordered by the Japan Coast Guard as the main engine for its next generation of patrol vessel. At the presentation session preceding the trial run, it was explained that the basic specification concept had been changed from a "two-turbine" configuration to a "four-turbine plus sequential supercharging" formula, and that this resulted in enhancement in not only acceleration but also in economy. Incidentally, no changes have been made to such basic features as the power output (4,000 kW, 1650 min^-1 and the use of marine diesel oil.

Traditionally, the priority given to speed, and accordingly to high power output and light weight, in main engines for high-speed vessel was so overriding that economy was given little consideration. However, year after year, engine builders are increasing their awareness of the cost of engines over their life cycle, with the result that placing primary emphasis on the speed at the expense of economic performance is becoming an outdated idea. The compatibility of economy with high power output and light weight has been demonstrated by this Blue Arrow 6000.

　

Over the whole load range, the specific fuel consumption is improved by about 20 g/kWh at the top end. The flat fuel consumption curve manifested in the medium to light load range indicates an extensive applicability to passenger ships, high-speed ro/ro vessels and fast fishing boats, for which economy and cruising range are matters of considerable importance.

　

Life cycle cost cannot be reduced by fuel saving alone, but extension of the service lives of components and maintenance ease also have significant impacts. The exhaust temperature of Blue Arrow 6000 is 450 degrees centigrade in the high to medium load range, and less than 400 degrees centigrade with a 1/3 load or smaller. This is comparable to medium-speed main engines for ordinary merchant ships, and represents a fundamental denial of the common assumption about highspeed engines that their exhaust valves do not wear long because of high exhaust gas temperature.

　

As container ships and LNG carriers have increased in standard size over the recent years, their electric power needs have also increased, necessitating on-board power sources of greater capacities. The increased capacities of low voltage on-board power sources give rise to problems with the breaking capacity and rated current of the circuit breaker and the economy of outfitting, leading to the use of 6.6 kV. The shaft generating system (SGS), used as a means of saving fuel consumption and maintenance work on board, is also subject to capacity limitation and needs a step-up transformer. To meet the 6.6 kV requirement, Nishishiba has developed a 6.6 kV high voltage SGS, the first such system for marine use to be manufactured in Japan. The new product is outlined below.

The high voltage SGS consists of a shaft generator (SG), a frequency control panel (FCP) and a synchronous condenser (SC). As the system can be directly connected to the high voltage (6.6 kV) main bus to constitute a direct on-line system, the step-up transformer can be disused with, resulting in a simplified configuration. Furthermore, as the current is smaller than that of a lower voltage system, the FCP can be reduced in size and weight. The converter and inverter of the control unit control the high voltage power with highly reliable thyristor elements for high voltage use. The high reliability of system operation has been realized, fully verified by temperature and dielectric test, operation and ventilation tests of the thyristor elements, and ambience and noise tests of the control unit.

　

　

Tsuji Heavy industries, the world's leading cargo handling equipment manufacturer, has recently delivered the first shipsets of the next generation of its standard type bulk carrier cranes. The new cranes are called the "HD series" (Heavy Duty), and are available with lifting capacities of either 30 tonnes, 35 tonnes or 40 tonnes, with maximum outreach from 22 meters to 28 meters. Speeds range from regular speed ("HDRS"), high speed ("HDHS") and super speed ("HDSS").

The new cranes have been developed in close cooperation with shipowners and shipyards, meeting requirements of the changing bulk carrier market. The new robust design was made with due consideration given to crane strength and lifetime, and has been approved by all major classification societies.

Chartering contracts are nowadays more short-term and cargoes are more diverse than they used to be, while ships' trading is no longer on fixed routes. The new HD cranes are all-round models that are suitable for heavy-duty grab handling. Their hydraulic system has been greatly simplified, making maintenance and repairs by the crew easier.

Another important feature is the newly developed shock reduction software. With this new system, hoisting is restricted to low speed until the load is detected and measured, then the speed is increased to the correct speed for that load. This is especially useful during grab handling, where high stress shocks to the cranes from over-slacked wires are frequent.

The insides of these cranes have been redesigned, allowing more space for maintenance and easier access. The crane cabin is equipped with a comfortable seat, joystick controls, window wiper, and fan. Windows open as emergency exits, and normal access to the crane house and cabin is through the pedestal. Tsuji can supply either upper part or the complete pedestal.

The new HD cranes are price-competitive and are available worldwide.