N EWS FLASH - Alewijnse

A challenging 

task 

Electric hoppers 

Short-sea business 

boosted 

Heavy lift carriers 

Major order 

for Australia 

Two support vessels 

Project 

Empowering your business 

NEWSFLASH 

a publication of Alewijnse 

01 | 2013

Contents 

Foreword 

Colofon 

CONTENTS 

Foreword 

Newsflash 01-2013 

A bright year ahead 

Electric hopper | 04 

A challenging task 

Asian market | 14 

Making visible the invisible 

Tenders | 06 

Pride of the Dutch pilotage 

AND MORE 

08 | Short-sea business boosted 

Order for six carriers 

10 | Alewijnse do Brasil 

Order for new pushers 

12 | Alewijnse Marine Galati 

Rename after fourteen years of purchase 

16 | Order for Australia 

Two new support vessels 

18 | AC- or DC- distribution 

Increase in the use of frequency converters 

Welcome to the first Newsflash of 2013, in 

which we visit projects and activities stretching 

from Europe through the Middle East and to the 

Far East. 

The short-sea business is again in the news with 

an order for six new multi-purpose, heavy-lift 

carriers being built close to home, this time for 

Groningen-based Shipkits BV. And Alewijnse is 

showing its broad capabilities on board five pilot 

tenders being built virtually in our own back yard 

for service in Dutch waters. 

In Brazil, Alewijnse continues to play a significant 

role in the building of vessels for the inland 

shipping market. While in Romania, Alewijnse is 

extending its strong ties with Damen Shipyards 

in the area of dredging with a new order for two 

hopper dredgers with electric-propulsion. Also 

of note is the renaming of Galati-based RETEC, 

which has now become Alewijnse Marine Galati. 

Our business development manager for the offshore 

and transport division gives his perspective 

on how Alewijnse is developing its business, 

especially in the context of global activities. 

We then travel to Vietnam where Alewijnse is 

involved in a major order for new support ships 

being built in Haiphong and destined for Australia. 

The two vessels will carry a lot of high-tech 

equipment and go into service in 2015 and 2016 

respectively. 

Finally, we highlight the ins and outs of AC 

and DC distribution and how the latter can in 

certain circumstances offer advantages in terms 

of investment costs and efficiency. 

Happy reading! 

Alewijnse Marine Systems 

Dick Alewijnse 

CEO 

Colofon 

Newsflash is a publication of Alewijnse 

and is distributed free of charge in controlled 

circulation for clients and relations of Alewijnse 

Marine Systems. If you are interested in receiving 

one or more issues, please send an e-mail to 

ams@alewijnse.nl. If you no longer appreciate 

receiving the NEWS flash, you can send an 

e-mail to the same address. 

Editorial and production: 

MARCOM team 

Jeni Brink 

Sandra van Dijk 

Anneke Van Haegenbergh 

Marianne Hendriks 

Carolijn Kuijpers 

You may copy our editorials only when 

approved by Alewijnse Marine Systems. 

Artwork and pre-press: www.rooiepeper.nl 

Printed by: Drukkerij Trioprint Nijmegen B.V. 

Alewijnse Newsflash | 2 

3 | Alewijnse Newsflash

Dredging 

Dredging 

Electric hopper dredger designed, 

produced and commissioned by Alewijnse 

A challenging task 

Alewijnse has supplied the electrical package together with the electrical propulsion 

system and static converter distribution on board a 750 cubic metre hopper dredger, 

built at the Damen Shipyards in Galati, Romania. The 59 meter long, 970 gross tonnage 

vessel is part of an order for two new hopper dredgers as placed by Damen Shipyards 

Gorinchem in 2012. 

The team also worked closely with Damen Engineering to devise the customised solution despite 

the space limitations. One of the main challenges was to provide a solution for the electro-magnetic 

compatibility, which was made difficult by the confined space onboard the vessel, according to Mr. Gigi 

Saptelei, Alewijnse’s installing manager for the project. 

Finally, the 250kW dredge pump motor, the 116kW jet pump motor and all the hydraulic dredging valves 

are controlled and monitored via a distributed dredge master system with programmable logic controllers 

for dependable and integrated operation. 

“Delivering this modern, efficient electrical solution was a challenging task, but we are proud to have 

accomplished it to the agreed specification,” says Mr. Alexandru Munteanu, senior project manager of 

this project, who thinks that the new electrical solution has a wide applicability range and will be more 

and more demands for it. 

The Project Team 

The complete electrical package provided by Alewijnse includes all cabling and switchboards, systems 

for internal and external lighting, alarms, communications, fire detection, dredging control, plus the 

associated automation systems and those for power generation, conversion, storage and distribution 

throughout the ships. Alewijnse was also responsible for the engineering, installation and the commissioning 

of the electrical package. 

The first of the two-vessel order has frequency-driven, water-cooled, electrical propulsion and is equipped 

with three 476 kW generators, two 400kW propulsion motors, plus dredge and jet pumps with electrical 

drives, all of this working on 690V, 60Hz. As onboard systems require power at 50Hz, additional technology 

has been factored in to account, by means of two 200 kW static converters from 690V/60Hz to 

400V/50Hz. A team of 10 engineers worked on the project in cooperation with various Alewijnse departments, 

who succeeded in combining high-tech equipment from world-renowned names in the marine 

industry. 

The vessel, Meotida, is already operational along the sea of Azov in the Ukraine. 



Inland 

Shipping 

Inland 

Shipping 

The Dutch pilot service is busy renewing its extensive fleet and 

work is well underway at Barkmeijer Shipyards in Stroobos and 

No Limit Ships in Groningen on a batch of five new, cutting-edge 

pilot tenders. Three tenders are aluminium hulled and will ply the 

Schelde estuary, while two are steel hulled and will operate in 

more northerly Dutch waters where sea ice is often encountered. 

Alewijnse will provide the complete electrical packages for all five 

tenders, two of which are already in service. 

The 22-metre aluminium-hulled tenders are a further development 

of the Aquila class tenders. The first of these is ‘Lynx’, which uses a 

proven double chine hull shape. Propelled by two water jets she has a 

fixed crew of three and can comfortably accommodate 12 pilots. Currently 

based in Vlissingen, she can be sailed and manoeuvred under all 

weather conditions by a single helmsman. 

The first of the all-new, 21-metre, steel-hulled tenders is ‘Hercules’, 

which has the same double chine hull shape. Based further north in 

Delfzijl, she is manned by a crew of three and can accommodate 

eight pilots. The tenders will all be equipped with two main diesel 

engines, two generator sets, two reversing gear boxes, two shaft 

lines, two fixed pitch propellers and two rudders. 

In addition to transporting personnel from Dutch harbours to sea 

going ships and vice versa, the tenders will also transfer personnel 

between tenders in open sea and in estuaries. This calls for high 

manoeuvrability at full speed as well as when they are alongside 

a ship or quay. Operating up to 30 nautical miles from the coast 

line, the tenders are frequently exposed to rough seas and must 

provide safe embarkation and disembarkation in ship-to-ship 

operations with a wave height of up to 2.8 metres. 

Conducting around 10 boarding operations per day, the tenders 

must withstand high dynamic loads and have sufficient power 

and redundancy to abort any manoeuvre in close proximity to 

other vessels. A sudden, single point failure should not impair this 

capability. For this reason, the electrical systems are designed for 

high availability, even in the event of AC generator failure. The DC 

network is divided into separate systems: one for engine starting 

and one to carry equipment loads. There are also two separate 

systems for emergency and GMDSS (Global Maritime Distress and 

Safety System) equipment. 

Alewijnse’s scope of supply includes all power and lighting distribution 

boards, the complete lighting installation, shore transformer, 

alarm and monitoring system ALMACS, electronic tank sounding 

system, domestic equipment, fire detection system, talk back 

installation, window-wiper system, all cabling, engineering, 

mounting and connection of electrical installation, and commissioning. 

Operations Manager, Martin Terpstra is Alewijnse’s man in charge. 

“These vessels may be only small, but they provide great opportunities 

for us to show our broad capabilities. Work is currently 

being carried out on the second aluminium and second steel 

tender. Work on the fifth and final tender of the batch will 

commence in June for delivery at the beginning of 2014.” 

Martin Terpstra 

Five new, cutting-edge pilot tenders 

New high-speed pilot tenders pride of Dutch pilotage 



Short Sea 

Short Sea 

Order for six 4,200 tonne multi-purpose, heavy lift carriers 

Short-sea business boosted 

Alewijnse has won an order from Groningen-based 

Shipkits B.V. to supply the complete electrical packages 

for six 4,200 tonne multi-purpose, heavy lift carriers 

currently being built in Poland. Four of the vessels 

are destined for Urk-based Hartman Shipping B.V. and 

two for Abis Shipping in Harlingen. The 110 metre long, 

single-screw cargo vessels feature two heavy-duty 150 

tonne cranes and are being constructed specifically for 

the transportation of heavy cargo and containers. 

Despite the heavy-duty equipment and high-tonnage 

cargo that the vessels will carry, the single 4,000 kW main 

propulsion unit will sustain a maximum speed of 17 knots 

at sea. Manoeuvrability is assisted by two (bow and stern) 

300 kW transverse thrusters. The VG4200 heavy lift vessels 

will be the first of their type to have Alewijnse equipment 

aboard, according to Alewijnse’s project manager 

Bertran Smit, who is based in Drachten. “We are a trusted 

supplier to Shipkits and have worked on similar projects 

for them before, but not with the heavy lift capability of 

these new vessels.” 

In addition to building and installing the electrical packages 

when the hulls arrive in the Netherlands for fitting 

out, Alewijnse has also been entrusted with the engineering 

work for all the vessels. For the two vessels that are 

being built at Harlingen for Abis Shipping, Alewijnse is 

delivering the electrical equipment, including all switchboards 

and consoles, which are being pre-assembled in 

Drachten and will be transported to north Holland for 

installation when the respective yard takes delivery of 

the vessels. For the 4 vessels that are being built at Urk, 

Alewijnse is entrusted with the engineering and delivery 

of some equipment. The complete installation will be outsourced 

to Brouwer. 

The first vessel for Hartman is scheduled to arrive in Urk 

early in June and is expected to be ready for trials and 

delivery to the owner in November. The first vessel for 

Abis Shipping is scheduled to arrive in Harlingen at the 

end of September and will be ready in February, 2014. 



Tugs & 

Workboats 

Tugs & 

Workboats 

Alewijnse do Brasil 

wins order for two 

new pushers 

Alewijnse do Brasil is to play a significant role in the building of 

two new 2400hp pusher vessels at Estaleiro Amazonia (EASA). 

This order reinforces the position of leading system integrator 

Alewijnse in the rapidly growing market for inland shipping in 

Brazil. 

Taco Moll 

The project involves the building of two new 2400hp pushers each 

with a length of 22 meters, intended for the transport of grain. Construction 

will take place at shipyard Estaleiro Amazonia in Bélem, 

Brazil. Upon completion in October 2013 the new pushers will go into 

service on the inland waterways of Brazil. 

In its role as system integrator, Alewijnse will perform the electrical 

engineering and deliver a number of important systems including 

the (emergency) lighting installation, batteries, alarm and fire detection 

systems, PA system and cabling. 

Alewijnse do Brasil business partner SKM Tech will produce the 

switchboards and distribution panels to specifications determined 

by Alewijnse. The supervision and commissioning will be undertaken 

by Alewijnse staff, ensuring that Alewijnse’s high standards are met 

in full. 

Naval architecture company Interocean and EASA are pleased to be 

cooperating with Alewijnse. Mr Thiago Lemgruber, managing director 

of EASA, commented “We chose Alewijnse as a key partner for 

this project for its knowledge, expertise and strong track record in 

inland shipping. Choosing Alewijnse as our electrical engineering 

partner allows us to focus on our core business.“ 

Since his appointment as general manager of Alewijnse do Brasil, 

Taco Moll has experienced the rapid growth of inland shipping in 

Brazil, a sector in which Dutch companies have particular expertise. 

As part of its focus on this area Alewijnse do Brasil is playing a leading 

role in the Inland Waterways Workgroup, a subgroup of Holland 

Marine House Brazil (www.hmhb.com.br). Besides inland shipping, 

Alewijnse do Brasil is also focussing on the offshore and transport 

sector. 

“With this significant order Alewijnse establishes its position in 

Brazil’s rapidly growing market for inland shipping,” said Taco Moll. 

“The growing demands of the Brazilian inland shipping and offshore 

markets give Alewijnse the opportunity to utilise its 100 years of 

experience and demonstrate the full scope of its capabilities, from 

engineering, production and installation to connecting, commissioning 

and after-sales service, and to further promote its proven 

record as a reputable electrical system integrator.” 



Romania 

Romania 

Fourteen years after purchase 

Retec renamed Alewijnse Marine Galati 

Electrical system integrator RETEC, based in Galati, Romania, has been renamed 

Alewijnse Marine Galati. This is in recognition of the fact that the company has now 

been fully integrated into the Alewijnse Group, fourteen years after its purchase by 

Alewijnse in 1999. 

RETEC was founded in 1995. 18 years later Alewijnse Marine Galati (AMG) sets out 

with over 300 successful projects to its credit, delivered to a worldwide client-base. The 

company and its workforce have worked on vessels ranging from tugs and workboats, 

coasters and tankers to dredgers and offshore patrol vessels. Via its General Manager, 

Mr Pieter Smit, who is also Manager of International Operations for the Alewijnse Group, 

AMG is also responsible for operations in Qatar, Vietnam, Turkey and Ukraine. 

With its exceptional range of engineering and technical skills and a reputation for 

quality and innovation, AMG provides a full range of electrical engineering services 

including the supply of complete electrical packages and integrated automation systems 

as well as expert on-site supervision, installation, commissioning and lifetime service. 

The merging of the former RETEC into the Alewijnse Group brings benefits for both 

parties involved. Chief of these is the recognition that the new company will receive as an 

instantly identifiable part of Alewijnse, a global business with a reputation for quality and 

innovation in maritime electrical engineering based on many years in the sector. Closer 

links with the parent and its subsidiary companies will also give AMG enhanced access to 

new markets, better internal knowledge transfer and a stronger position when negotiating 

purchasing terms. 

“After 14 years of fruitful cooperation we have decided that now is the right time to 

consolidate under the Alewijnse brand,” said Mr Pieter Smit, General Manager of 

Alewijnse Marine Galati. “Our strategy results in a substantial proportion of our 300 

employees working in countries as varied as Qatar, Vietnam, Indonesia and the Netherlands, 

providing our clients with local support on a global basis. The creation of Alewijnse 

Marine Galati will further support our mission to provide first class products and services 

to ship owners and operators around the world.” 

“RETEC had been a highly valued part of the Alewijnse Group for many years,” added 

Dick Alewijnse, CEO of the Alewijnse Group,” so it now gives me great pleasure to welcome 

the company fully into the family as Alewijnse Marine Galati. The skills that its staff 

offer the maritime industry and their contribution to the Alewijnse Group as a whole will 

now receive the full recognition that they deserve, and our customers will benefit from 

the enhanced unity and cooperation.” 



Offshore 

Offshore 

Serving the Asian market 

Making visible the invisible 

Mark Paasman 

Alewijnse has built up an extraordinary wealth of experience 

over its 120 years in the electrical business. Founded by Cornelis 

Alewijnse in 1892, what started out as a lamp factory has turned 

into today’s extensive organisation. Built on systems integration, 

Alewijnse’s workplace now straddles the world while its 

considerable knowledge has led to phenomenal technological 

developments. Mark Paasman, business development manager 

of the offshore & transport division, based at Alewijnse Marine 

in Rotterdam, outlines why Asia will provide many of the company’s 

new business opportunities. 

for years to come. We are well positioned to serve the developing 

Asian market thanks to our many proven strengths, which include: 

qualified and driven personnel, short and uncomplicated communication 

channels, excellent internal and external collaboration, a 

large resources network and a continuous drive to excel. Our main 

challenge is to make it clear to the Asian market that there is a 

more convenient and less costly option to flying in expertise from 

Europe. And we will achieve this by making visible our formidable 

‘invisible’ services by unveiling our new centre in Singapore.” 

Alewijnse has come a long way in just over a century. We provide 

technical services, innovative electrical engineering and ICT solutions 

in the broadest sense of the word. There are four separate 

factories producing switchboards, control panels and operating 

consoles, based in China, Romania, Holland and Brazil. The 

company is successful in providing turn-key electrical solutions – 

pure system integration. We engineer, produce, transport, install, 

integrate and commission, service and maintain electrical, drive, 

automation and entertainment systems. And our flexibility 

enables us to supply just one part of a total solution when a 

customer so wishes. 

As an innovative knowledge centre manned by dedicated in-house 

electro-technical professionals, our experience and knowledge 

gives us the edge in our industry. And our strategy has led to the 

stable growth of our business. Yet our line of business is much like 

an invisible service. It comes to mind at the moment the lights go 

out. What is not invisible is our vast knowledge and experience of 

working abroad. Now, our strength as a technological leader will 

shortly be felt in a new direction - Asia - as we expand our operations 

from Vietnam and start setting up a sales and service hub in 

Singapore. 

Our long-term vision is to provide the region’s maritime and offshore 

industry with refit and repair capabilities. Converting rigs 

and upgrading OSVs, or refitting an FPSO all fall within the scope 

of our business, the demand for which is projected to continue 



Navy 

Navy 

Contracts for two support vessels 

Major order for Australia 

Last year, Damen Shipyards and DMS Maritime Pty. Ltd. signed 

contracts for the building of two support vessels being built 

at Damen’s partner Shipyard, Shipyard 189 in Haiphong 

(Vietnam). The vessels, the 83-metre EGS (Escape Gear Ship) 

8316 and 93-metre RGS (Rescue Gear Ship) 9316, will support 

Australia’s submarine fleet and be delivered in 2015 and 2016 

respectively. Alewijnse was contracted by Damen Shipyards to 

supply the power distribution, systems, alarm and monitoring 

system, and will also be responsible for commissioning of these 

systems. 

Ciprian Neamtu 

DMS Maritime Pty. Ltd., which operates and maintains a fleet of 

around 75 vessels, is a subsidiary of Serco - an international service 

company working for governments worldwide. The RGS 9316 

and EGS 8316 are based on a proven Damen concept realized for 

Serco UK on behalf of the UK Royal Navy three years ago. 

Alewijnse’s role as a successful co-maker of Damen in this earlier 

project earned the company its place in the team to build these 

latest vessels. 

“Although these vessels are roughly the same length as the Royal 

Navy support ship we participated in building three years ago, 

all comparisons regarding the electrical specification end there,” 

says Ciprian Neamtu, Technical Manager – Alewijnse Marine 

Galati . “The power management system, for instance, has to cope 

with six generators when normally there would be three or four. 

This is because there are more main deck consumers in the form 

of high-tech equipment, such as an ROV, which all have to be supported. 

The first challenge will be to provide redundancy for the 

extra generators.” 

Similarly, the DP2 dynamic-positioning system to be installed also 

has more demanding requirements because the number of modules 

has been increased for redundancy in order to comply with DP 

Class 2 rules. Redundancy has to be provided at all levels to make 

sure that any single failure will not result in loss of position. “The 

electrical equipment aboard both of these ships is very complex. 

One of the most complex vessels we have built,” continues Ciprian. 

“But we like challenges and are used to pushing the limits when 

the need arises”. 

The project team coordinated by senior project manager, Alexandru 

Munteanu, and junior project manager, Gabriel Savin, will 

have plenty of those because Alewijnse has been awarded total 

responsibility for integrating all of the electrical systems on board, 

for which work is already well under way. 

“We quoted for this project 18 months ago and the contract was 

signed at the end of 2012. Detailed engineering began earlier this 

year, which is important for the shipyard because productivity 

needs to be at a high level. As well as supplying detailed drawings, 

cable routing, item and device list, and equipment location. We 

have also made our software database available to them for maximum 

efficiency.” 

The project team was also challenged by having two different 

companies of the Damen Group to work with, namely, Damen 

Schelde Naval Shipbuilding in Vlissingen and Damen Shipyards 

in Gorinchem. Alexandru Munteanu: “We remained in very close 

contact with Damen’s team and made doubly sure that everything 

was crystal clear to them, including all diagrams. This ensured that 

the request was fully understood and that the client was being informed 

correctly regarding the final scope of delivery of the electrical 

system.” 



Products 

Products 

AC- or DC-distribution for installations aboard ships 

Increase in the use of 

frequency converters 

About 15 years ago, no one questioned the type 

of power distribution. Most ships were equipped with 

AC power distribution. The majority of the rotating 

equipment aboard was driven by asynchronous 

motors, which needed an alternating current to be able 

to rotate. 

DC distribution existed only in special cases, such as 

in submarines. Now there is a tendency to choose DC 

power distribution. Why should DC-distribution be 

used 

The answer to that question can be found in the increased 

amount of frequency-controlled electrical equipment. 15 

years ago the amount of frequency-controlled electrical 

equipment was very limited. This was due to the fact that 

the inverter was very new, expensive and not so reliable. 

Today, inverters are commonly available and are reliable 

components at a reasonable price. Frequency-controlled 

electrical equipment is therefore now available to many 

consumers. This has led to a strong increase in the use of 

frequency converters on board, especially for ships that 

have a full or partial frequency-controlled electric drive. 

What is a frequency converter 

The function of the frequency converter must be explained 

to understand the reason for DC distribution. 

Almost all frequency converters consist of a rectifier and 

an inverter. The rectifier recovers the fixed AC and 

converts it into DC. The inverter uses DC and creates a 

variable alternating current by switching the elements of 

the inverter in a fixed order. 

There are two types of rectifiers: the diode front-end 

rectifier and the active front-end rectifier. The diode 

front-end rectifier is a static rectifier that simply rectifies 

the AC voltage supplied. The diode front-end rectifier is 

considered to be static because no active switching takes 

place within the controller. 


Bart van den Bosch 

The most basic diode front-end rectifier is a 6-pulse 

rectifier. Diode front-end rectifiers create harmonic 

distortion on the AC grid. As long as the harmonic distortion 

remains below certain limits, there is no problem in 

using this type of rectifiers. AC-filters can be used in front 

of the diode front-end rectifier to reduce the harmonic 

distortion. When the harmonic distortion level remains 

too high, the number of pulses of the diode front-end 

rectifier can be increased. This leads to more complex, 

more expensive and larger installations. An active frontend 

rectifier can also be used. 

The diode front-end rectifier only allows energy flow from 

the AC grid to the controlled device. This means that if the 

device produces back power, such as in cranes or fixedshaft 

drive lines, a brake chopper must be installed to 

prevent damage to the inverter. The brake chopper converts 

the back power into heat. 

The active front-end rectifier uses switching elements in 

such a way that almost a sine-wave current is obtained 

from the AC grid. The active front-end rectifier needs an 

LCL filter to obtain this. 

It is clear that the active front-end rectifier is more expensive 

than the 6-pulse diode front-end rectifier. The losses 

are also slightly higher. 

The active front-end rectifier can control the flow of 

energy in both directions. This means that if back power 

is expected, and if the auxiliary power consumption of 

the vessel is large enough to consume this back power, 

the rectifier does not require a brake chopper. The back 

power is reused in the ship. 

Since 12-pulse or higher pulse rectifiers lead to more 

complex systems with transformers that have more 

volume, weight and cost compared with active front-end 

rectifiers, they are not considered as attractive alternatives. 

The inverter is in principle the same as an active front-end 

rectifier without the LCL-filter. The inverter creates a variable 

frequency and voltage so that the electric motor will 

rotate at the desired speed. 

When do you apply DC-distribution 

DC-distribution makes the use of standard inverters 

possible without the large filters. Furthermore, DCdistribution 

makes back power exchange possible and 

thereby reduces the need for brake choppers. Other positive 

effects of DC-distribution are: no problems with 

harmonic current and achieving almost unity power 

factor. 

Can we conclude that DC-distribution is always the best 

solution for a full or partial frequency regulated electric 

drive The answer to that question is no. 

The DC power has to be created. Standard auxiliary ship’s 

generators produce alternating current, so a rectifier is 

required between the generator and the DC-distribution 

in order to produce DC power. As with the frequency 

converter, this rectifier can be a diode front-end rectifier 

or active front-end rectifier. If the frequency-regulated 

electrical equipment draws about the same amount of 

current as the current generated, there will be no advantage 

in installation costs or volume. However, if the ship 

contains frequency-regulated electrical equipment that is 

not in simultaneous use, a gain in volume and investment 

can be expected. In that case, the same active front-end 

rectifier is used for several inverters. 

Another reason to use DC-distribution is when variablespeed 

auxiliary generators are used. Variable-speed 

generators deliver alternating current, but not at a fixed 

frequency. As a result, the auxiliary diesel engine can run 

at its optimum working speed, which leads to a better 

efficiency. Depending on the brand and type of diesel 

engine, an improvement of up to 6% can be achieved. The 

auxiliary diesel engine can often supply more power from 

the same engine, since most engines are not designed for 

generator operation, requiring a fixed speed (usually 1500 

or 1800 rpm), but as a drive (for example, a speed range 

between 600 and 2200 rpm). 

If DC distribution is used, the AC generators do not require 

synchronization. The converter between the AC generator 

and DC distribution will adapt to the DC power supply. 

If the voltage is at the correct level, the generator can be 

connected to the distribution system. Since the converter 

is very fast, this will happen even before the auxiliary 

diesel engine is running at normal speed. 

The frequency freedom for the auxiliary generators is 

more than welcome for LNG powered auxiliary engines. 

The reason is that LNG powered auxiliary engines have 

poor dynamic response to load steps and can reduce in 

speed faster than the allowable frequency decrease of the 

AC net. 

DC-distribution should be considered when the ship’s 

distribution system needs a battery for energy storage. 

Battery systems can either be connected directly to the 

ship’s distribution system, or via a converter. When 

connected directly to the ship’s batteries, the ship’s 

distribution system must be DC. In other cases, both 

direct and alternating current can be considered. 

Technical problems with DC distribution 

As described above, DC power distribution has a number 

of advantages. However, it also has some disadvantages. 

Although most electrical power is consumed as DC, the 

rest of the ship is still needs AC power, for which converters 

are needed. The required AC supply is produced 

electronically by the static converter. Normally, two are 

required for redundancy. This is necessary to ensure the 

energy supply to vital equipment. 

Both static converters operate simultaneously and can 

work in parallel. However, this is not recommended. If a 

short circuit occurs on the AC network, the di/dt can 

increase to the point where both static converters are 

disabled, even if the maximum converter current has 

not been reached yet. Therefore the converters should 

be connected to isolated AC nets. This does not apply if 

rotating-converters are applied. 

Another problem is the calculation of the short-circuit 

levels of the DC distribution. 

At present, the classification bodies offer no directive 

on the calculation of short circuit levels for DC systems. 

Lloyds is currently working on guidelines. 

Further calculation of the DC short-circuit current is not 

as easy as for AC distribution. This is mainly due to the 

capacitors in the converters connected to the DC distribution 

system and the very low resistance of the DC 

distribution system. The DC voltage in combination with 

the very low-resistance leads to high short-circuit 

currents. 

Alewijnse uses a simulation program for the correct calculation 

of short circuit. The calculation of a short circuit 

is used to prove that the DC distribution system is strong 

enough to withstand short circuits. 

Conclusion 

As an alternative to AC distribution, DC distribution can 

in certain circumstances offer significant advantages with 

regard to lower investment and higher efficiency. This is 

especially interesting for ships with frequency-controlled 

electrical equipment. The design of a reliable and efficient 

DC distribution system requires extensive calculation and 

an understanding of the electrical system. Based on experience 

with AC and DC distribution systems, Alewijnse can 

help you to find the best electrical solution to meet your 

specific needs and wishes. 


Alewijnse 

Marine 

Systems 

Alewijnse Marine Systems is part of the 

Alewijnse group with over 1100 well skilled 

employees. Alewijnse has a long tradition in 

maritime technology. Every year we make 

sure that more than 150 ships set sail. 

As a full line system integrator we supply 

technical services, innovative electrical 

engineering and ICT solutions in the broadest 

sense of the word. 

Based on the latest maritime and industrial 

technology, we develop a broad range of 

system designs. These designs provide 

energy efficient and environmental friendly 

solutions for generation, distribution, storage 

and consumption of electrical power. Relying 

on a broad network of partners, we combine 

most modern technology with years of 

experience. 

Our expertise - Engineering & contracting - 

Marine automation - System design - Power 

generation & drive technology - Entertainment 

systems - Power & energy management 

- Navigation & communication equipment - 

- Electrical & ICT solutions - Integrated bridge 

systems - Switchboard & console solutions - 

Service & maintenance (24/7 worldwide) 

Together with our companies based in The 

Netherlands, Romania, Denmark, Ukraine, 

China, Brazil, Turkey and Vietnam we ensure 

you best service, worldwide, 24 hours a day – 

seven days a week. 

For more information: 

Alewijnse Marine Systems 

P.O. Box, 49 6500 AA Nijmegen 

The Netherlands 

Tel: +31 (0) 24 371 6571 

Fax: +31 (0) 24 371 6570 

E-mail: ams@alewijnse.nl 

Alewijnse Marine Nijmegen B.V. 

P.O. Box 6973, 6503 GL Nijmegen 

Energieweg 46/c, 6541 CX Nijmegen 


Tel: +31 (0) 24 371 63 11 

Fax: +31 (0) 24 371 63 10 

E-mail: amn@alewijnse.nl 

Alewijnse Marine Rotterdam B.V. 

P.O. Box 16, 2920 AA Krimpen a/d IJssel 

Van der Giessenweg 51, 2921 LP Krimpen a/d IJssel 


Tel: +31 (0) 180 460 555 

Fax: +31 (0) 180 511 871 

E-mail: amr@alewijnse.nl 

Alewijnse Marine Technology B.V. 

P.O. Box 49, 6500 AA Nijmegen 

Energieweg 46/g, 6541 CX Nijmegen 


Tel: +31 (0) 24 371 65 71 

Fax: +31 (0) 24 371 65 70 

E-mail: amt@alewijnse.nl 

Alewijnse Noord B.V. 

P.O. Box 567, 9200 AN Drachten 

Het Gangboord 18, 9206 BJ Drachten 


Tel: +31 (0) 512 570 355 

Fax: +31 (0) 512 549 166 

E-mail: and@alewijnse.nl 

Alewijnse International 

Switchboard Production 

P.O. Box 6993, 6503 GL Nijmegen 

Energieweg 46/e, 6541 CX Nijmegen 


Tel: +31 (0) 24 371 65 11 

Fax: +31 (0) 24 371 65 10 

E-mail: ap@alewijnse.nl 

Alewijnse Marine Galati 

132, Al. Moruzzi Street 

800223 Galati 

Romania 

Tel: +40 (0) 236 448 022 

Fax: +40 (0) 236 449 146 

E-mail: alewijnse@alewijnse.ro 

www.alewijnse.ro 

Alewijnse Ukraine Ltd. 

P.O. Box 179, Ukraine 54050 

1, Zavodskaya Square, Mykolayiv 

Ukraine 

Tel: +380 512 257 170 

Fax: +380 512 670 810 

E-mail: aua@alewijnse.nl 

Alewijnse do Brasil Ltda 

Av. Presidente Wilson 231 

CEP: 20.030-021 

District: Centro 

Rio de Janeiro, Brasil 

Tel: +55 21 9516 2308 

E-mail: adb@alewijnse.nl 

Alewijnse China 

No.5 Jiufeng Street 

Canglongdao Hi-tech Park 

Jiangxia District Wuhan 

China 

Tel: +86 27 819 77440 

Fax: +86 27 819 77441 

E-mail: alewijnse_public@yahoo.cn 

Alewijnse Vietnam 

Harbour View Tower 

4 Tran Phu Street, Haipong, 

Vietnam 

Tel: + 843 1365 23 28 

Fax: + 843 1365 23 29 

E-mail: retec@retec.com.vn 

Alewijnse Türkiye 

Antalya Serbest Bölgesi 

1. Cadde Burla Deposu 

07070 Antalya 

Türkiye 

Tel: +90 242 2593270 

Fax: +90 242 2591719 

E-mail: ams@alewijnse.nl 

Lantic Entertainment Systems ApS 

Nordlandsvej 90, 

8240 Risskov 

Denmark 

Tel: +44 797 4564959 or 

Tel: +31 24 371 63 38 

E-mail: info@lantic-systems.com 

www.lantic-systems.com 

Admarel B.V. 

Van Hennaertweg 17a 

2952 CA Alblasserdam 


Tel: +31 (0)78 692 19 00 

Fax: +31 (0)78 692 19 01 

E-mail: sales@admarel.nl 

www.admarel.nl 

Alewijnse Middle East LLC. 

Ahmed Al-Misnad Building, 

Ground Floor, Office 1 

Mohammed bin Thani Road 

Doha, Qatar 

P.O. Box 22896 

Phone: +974 442 77171 

Fax: +974 442 77117 

www.alewijnse.com 

Empowering your business 

www.alewijnse.com

N EWS FLASH - Alewijnse

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