Engine remanufacture breathes new life into pilot vessels

01 Dec 2014
MTU-powered pilot tender ‘Duhnen’

MTU-powered pilot tender ‘Duhnen’

One of the services offered by MTU to its customers is the opportunity to exchange a worn, time-expired engine for a good-as-new remanufactured unit.

The company, part of Rolls-Royce Power Systems, carries out the complete overhaul of engines using a standardised process in-house. Its technology centre in Magdeburg is geared up for series remanufacturing of MTU engines. Old engines from global customers are delivered here and completely overhauled for their new lives.

MTU says that the process provides several advantages for customers. "It's a very sustainable process. The basic materials such as the cylinder heads, crankshafts or crankcase are simply remanufactured. This means there is no need to consume additional raw materials," explains Carola Riedter from Global Reman at MTU Friedrichshafen. "Only wear parts such as gaskets are replaced by new parts." Also, the customer will not notice any changes on the exterior. The engines are identical to those which were returned, and are repainted in the corresponding colour. MTU offers the same warranty on remanufactured engines as on new items, and supports them by the MTU Value Care service portfolio. "Our customers can use all the offers in our service portfolio without restrictions. For example, spare parts can be supplied or entire service or maintenance contracts concluded."

Among the references for the remanufactured, or ‘Reman’ engines, are those in pilot launches. One typical example is the small waterplane area twin hull (SWATH) vessel Duhnen, one of the pilot tenders used between the North Sea and the ports of Hamburg and Cuxhaven, and the Kiel Canal. Along with its sister launches, it operates from one of a pair of larger SWATH pilot station vessels anchored in the mouth of the river, and which are also MTU powered.

The company says that in order for the pilots to undertake their vital and responsible task, they need a vessel that they can rely upon 100%. "The engines must not fail under any circumstances. Particularly when we're bringing the small pilot launches alongside the large tankers to allow the pilots to alight, an engine failure would be potentially fatal," explains Andreas Schoon, managing director of the Cuxhaven branch of the Pilots' Association.

The pilot launches are operated with diesel-electric power, each of the 12V 2000 M70 engine having an output of 788kW, giving the vessel a speed of up to 18 knots. The engines had already operated reliably during their first life, so the Pilots' Association had no problem with reinstalling tried-and-tested engines.

"You can picture the Reman process like paying a deposit on bottles at the supermarket," explains Thomas Geertz, who is responsible for service at MTU in Hamburg. "Customers who have already bought new engines from us can exchange the engine by buying a completely overhauled Reman engine."

The company says that long downtimes can be avoided by the customer informing MTU early on, so that an identical engine can be arranged. The customer pays for the overhauled engine and a deposit which is referred to as the core charge. As soon as the used engine has been returned by the customer to MTU, the core charge is refunded – assuming all the specifications are complied with. For example, all auxiliary parts must be fitted on the engine, and the maintenance intervals must have been complied with. "If the customer insists, it is also possible for him to get his own engine back again. However, this will take several weeks," says Mr Geertz.

The Pilots' Association works with an engine pool. "We always keep a stock of engines so that if we need to exchange one, the downtime for the vessel will be as short as possible," said Mr Schoon.

Each of the pilot vessel engines clocks up between 4,500 and 6,000 operating hours per year. However, the particular challenge is that the engines usually operate for between two and three weeks at a stretch, and, moreover, operate totally reliably, irrespective of whether they are whether brand-new or overhauled. Mr Schoon explains: "In good weather, we can get by using two engines on the station ships, whereas when conditions are rougher, it's quite possible for us to need all four engines to extricate the vessel quickly and safely from a dangerous situation."

OVERTURNING ENGINES

An even more demanding application for MTU engines is powering the lifeboats of Dutch lifeboat service Koninklijke Nederlandse Redding Maatschappij (KNRM). The lifeboat crew in IJmuiden near Amsterdam has recently been testing a new vessel. The Nh 1816 is fitted out with MTU engines designed to keep running even if the boat overturns and re-rights itself, which MTU believes is unique to this ship and the MTU-engined lifeboats used by the UK’s RNLI. Other lifeboats have self-righting capabilities, but this does not normally include keeping the engines running.

The new lifeboat design is intended to eventually replace the Arie-Visser class in the KNRM fleet, once its trials have been successfully completed. The Nh1816 is the first vessel of its type in the KNRM to be built by the Damen shipyard and powered by MTU engines. Two 8-cylinder Series 2000 diesel engines, each producing 895 kW of power, propel the 19m vessel via twin waterjets at speeds up to 33 knots. The engines are housed in two separate, watertight engine rooms, to keep running even if the boat capsizes and completes a full turn around its longitudinal axis. "That is something the engines in our other ships couldn't do," said lifeboat captain Leendert Langbroek who has been involved in the trials.

He had experienced a capsize on a previous vessel. The engines failed and the ship was left floundering. Because the wheelhouse was swamped the electronic systems stopped working too, so on the Nh 1816, all the computer systems are watertight. If one of the engines should fail, the other can still propel the ship.

Because it takes really heavy seas and extreme manoeuvres to overturn a boat like the Nh1816, the capsize trials have been carried out in harbour, using a crane. During that test, the engines did not keep running because the ship turned over too slowly – the engines are automatically switched off if the overturn manoeuvre takes longer than 30 seconds. But they can be restarted straight away. KNRM points out that in really stormy conditions in the open seas, with significant wave height significantly greater than the height of the lifeboat, the Nh 1816 would overturn and right itself in just a few seconds, so the engines would keep running the whole time, as has been proved in MTU’s test-bed trials andthe RNLI’s experience.

CNG TUG PROJECT

Damen Shipyards has been involved with another of MTU’s projects, working with Svitzer of Denmark on a reverse stern drive (RSD) compressed natural gas (CNG) fuelled tug. The eco-friendly RSD CNG tug is intended to combine high power with lower fuel costs and a substantial reduction in emissions, and its official launch is planned for 2016.

The new 16-cylinder pure gas engine being developed by MTU for this application is based on the proven series 4000 M63 diesel engine. It will be equipped with a multipoint gas injection system, dynamic engine control and what is described as an optimised safety concept.

“We are developing our new gas series in order to meet the extreme load profile of the tugboat. The acceleration will be comparable to the level of our diesel engines. Due to the clean combustion concept, compliance with IMO Tier III emission legislation will be ensured without the need of additional exhaust gas after treatment. The 2,000kW MTU gas engine is characterised by high power density combined with low fuel consumption,” said Dr Ulrich Dohle, CEO of MTU parent company Rolls-Royce Power Systems.

Martijn Smit, Damen sales manager Europe, said: “Damen is proud to be building the prototype. With the MTU 4000 engine, this vessel is excellent for ship handling, with very quick acceleration. Manoeuvrability is combined with the vessel being green, clean and efficient.”

Explaining Svitzer’s involvement, CTO Kristian Brauner, said: “As a major harbour towage operator an important consideration is also that this tug will realise a considerable reduction in fuel costs and obviously fuel is a major cost concern for all operators. And crucially, as a market leader it is important for us to stay innovative with regards to performing safe and eco-friendly operations and to reduce emissions. Through the years we have already developed one version of the ECOtug and with this in mind, the choice to develop the new CNG tug is a natural step towards remaining an eco-conscious towage company.”

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