62,080 HP under close scrutiny
Acceptance testing the new main engine of the”HLL Arafura”

Approximately 12 metres high, 18 metres long and 1,470 tons in weight is the new main engine Type 8K 98 MC-C that has just been built in Japan for the new containership”HLL Arafura”. The power pack developing 45,680 kW (62,080 HP) took about three months to build. After the acceptance tests it is to be broken down again into handy units and transported to the shipyard in China.

The eight-cylinder main engine was built at Mitsui Engines MES in Tamano under licence from MAN B&W. Besides the specifications of the design engineers at MAN and those of the Germanischer Lloyd, the giant engine must also correspond to the individual specifications of Hanseatic Lloyd.

The acceptance testing, in the course of which Bernhard Höke checks the new engine from A to Z, takes two days. This starts with an external examination of the whole engine, of pipelines and electrical cables and also of the attached work levels. Being two metres tall, Mr Höke does not even need a metre rule in order to check the clear height of two metres in the three work levels. If a pipeline were to block a free passage here, it would have to be completely relocated – starting from the flanges!

The first day

The focus of interest during the first day of the tests is on the running engine. Superintendent Höke monitors first the starting behaviour and later the different load increments that have to be run through up to 110 per cent output. But it is not only the smooth running of the engine that interests the engineer, various load changes are also tested.”This also means playing through several crash manoeuvres”, states Mr Höke. Incidentally during the test the energy is transmitted via the shaft to a”water brake” so that the engine’s behaviour under load is tested under closely simulated conditions of practice.

For the engine of the”HLL Arafura”, Hanseatic Lloyd ordered a special cylinder lubrication system (Alpha Lubricator), which results in a far more effective use of cylinder lubricating oil and correspondingly lower oil consumption.”An enormous potential for savings”, confirms Superintendent Höke, who checks the control and function of the lubrication system. After all if that did not work properly, in the worst case it would lead to a piston seizing.”The engine sticks its leg out”, is what German seamen say to such an accident, which would result in serious injury and damage to crew and ship. When then in the evening all the tests on the current engine have been completed, Mr Höke’s white boiler suit looks more like a black overall.

The acceptance

The second day is then devoted to the innards of the engine. The”open up” procedure calls for various components to be opened, inspected and in some cases also re-measured. Every second cylinder here has a special liner with a small curved projection of only a few tenths of a millimetre in the upper part of the combustion chamber. This reduces the pressure on the piston rings. Mr Höke has the cylinder cover taken off and then inspects and measures the piston rings. Superintendent Höke also checks the bearings, con rods or crank pins. Clean workmanship, dimensionally accurate assembly or”whether the pressure is evenly distributed”, are the most important aspects which the engineer from Bremen checks out. Finally an outlet valve is also subjected to scrutiny. All the inspection stamps are noted – and passed on to the project manager at the shipyard so that there the proper re-assembly of the engine can be checked again later.

”Any inaccuracies already show up after the first few hours of running”, explains Mr Höke. The perhaps 50 hours of operation of the engine which the latter spends on the test stand are enough to detect faults. 42-year-old Bernhard Höke also served for a few years as an engineer on big containerships – and so he knows the engines, their noises and their significance accurately.

After two days of intensive Testing, the acceptance of the engine is completed satisfactorily.

Finally it was not by chance that Hanseatic Lloyd ordered the engine from Mitsui. Good quality soon pays dividends. For as early as during the running-in operation of a ship, significantly less guarantee work is necessary.

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