<p class="article__lead-paragraph">The goal for any shipowner or fleet manager is to keep vessels running as efficiently as possible. But if interruptions and problems do occur, it is vital there is a service partner on hand to fix the problem day or night. Steerprop offers customers fast and professional services that can include tailor-made solutions when required. &ldquo;We offer world-class services to back up our robust azimuth propulsors and take pride in ensuring rapid response times&rdquo;, says Mr Kai Arvela, Director, Service and Procurement at Steerprop.</p>

<p>Steerprop designs and manufactures azimuth propulsors with reliability and easy maintenance in mind. This is backed up with our world-class services, which are available globally through an extensive network of international partners. We really ensure that our customers get the necessary attention they require after the sales process.</p>

<blockquote>
<p><em>We are a true partner that quickly helps our customers.</em></p>
</blockquote>

<p>Every propulsor is tested at Steerprop&rsquo;s factory as an entire unit before delivery to the customer. Our propulsor units will provide safe and efficient operation for many years ahead with proper maintenance and correct operational procedures. &ldquo;We also provide on-request training for the customer&rsquo;s staff to enable them to acquire the maintenance and operational knowledge they need&rdquo;, says Mr Arvela.</p>

<figure class="article__figure">
<div class="article__figure__placeholder"><a class="article__figure__link" data-type="image" href="https://flockler.com/thumbs/sites/13425/services_engineer1-26f8a515-257d-4c6d-a62e-ed53a3f04770_s1800x0_q80_noupscale.jpg" target="_blank"><img alt="Steerprop Services" src="https://flockler.com/thumbs/sites/13425/services_engineer1-26f8a515-257d-4c6d-a62e-ed53a3f04770_s600x0_q80_noupscale.jpg" /></a></div>
</figure>

<h2 class="article__heading--h2">Services - when and where you need them</h2>

<p>Steerprop provides Original Spare Parts to all their systems and units when needed. The propulsors also require service at set intervals.</p>

<p>The standard service intervals are every 5-years, aligning well with the classification societies&rsquo; requirements for inspections every 5-years during a docking. Full overhauls are performed every 15 years or 100,000 hours, based on unit load. &ldquo;General service actions mainly concern the overhaul of rotating seals during drydock. The full overhaul at 15 years also includes the transmission line bearings&rdquo;, says Mr Samuli J&auml;rvinen, Service Manager at Steerprop.</p>

<h2 class="article__heading--h2">Condition monitoring for enhanced predictability</h2>

<p>Steerprop allows shipowners to take a proactive approach and avoid potentially costly breakdowns. By taking such an approach, the need for a full overhaul may be extended based on the condition of the transmission line components. &ldquo;Steerprop Care, our condition monitoring system, has been included as a fully integrated part of every propulsor delivery since August 2019. The system allows crew members to follow machinery trends and detect deviations that could affect the propulsion system in the future. This offers the highest possible reliability based on enhanced predictability&rdquo;, explains Mr Arvela.</p>

<p>Steerprop&rsquo;s ability to utilise Steerprop Care condition monitoring to provide in-depth professional analysis on the data created is a clear value-adding enhancement. This feature can also be integrated as a retrofit in older units.</p>

<p>Steerprop Care is available on three levels. In the basic Standalone Level, which is included in every delivery, the condition monitoring feature is available for customers to utilise in their operations. &ldquo;This is designed for propulsion monitoring and gives the onboard crew information about alarms, trends, time waveforms and spectrums. If there is a deviation, the crew can ask us to help them with cause analysis&rdquo;, says Mr Jarkko Sirrola, PDM Manager at Steerprop.</p>

<p>Steerprop&rsquo;s assistance and valuable analysis results are available through different types of agreements. The next level is Care Plus, which, in addition to basic condition monitoring, transfers data to Steerprop&rsquo;s experts, who follow the trends and deliver reports to the crew at agreed intervals. &ldquo;Care Plus monitors the entire propulsion system, including vibration, along with signals and alarms from the control system using advanced techniques based on AI and machine learning. By analysing the data, we can notify a crew well ahead of any development that may cause future disturbances&rdquo;, says Mr Sirrola.</p>

<figure class="article__figure">
<div class="article__figure__placeholder"><a class="article__figure__link" data-type="image" href="https://flockler.com/thumbs/sites/13425/sp_care1_web-c5b66633-2f2a-4bed-9706-4e230f7dd86f_s1800x0_q80_noupscale.jpg" target="_blank"><img alt="Steerprop Care" src="https://flockler.com/thumbs/sites/13425/sp_care1_web-c5b66633-2f2a-4bed-9706-4e230f7dd86f_s600x0_q80_noupscale.jpg" /></a></div>
</figure>

<h2 class="article__heading--h2">Care Premium, the top-level agreement</h2>

<p>The top-level agreement, Care Premium, has quickly gained popularity among our customers in less than two years. &ldquo;The remote online connection, which is also available as a retrofit installation, means that the experts in our monitoring centre receive all the data from the propulsor for analysis. In addition to basic monitoring, Care Premium includes additional vibration measurement points monitoring the main electric motor and the lubrication oil&rdquo;, says Mr Sirrola.</p>

<blockquote>
<p><em>We leave no stone unturned in our search for the cause and the right solution.</em></p>
</blockquote>

<p>According to Mr Sirrola, the oil monitoring system monitors particle levels, water contamination and oil quality. &ldquo;The main benefit of online oil monitoring is that the customer can prevent faults from emerging and correct a situation ahead of time by ensuring a good lubrication condition throughout the entire lifecycle of the propulsion unit.&rdquo;</p>

<p>&ldquo;We can also help the busy Fleet Manager, who finds it tedious to check on the status of several vessels. The subscription service called Fleet Overview provides a real-time dashboard of the condition of an entire fleet&rsquo;s propulsion systems at a glance. It is browser-based, so all you need is an internet connection. This is super handy for any fleet manager with several vessels to manage&rdquo;, concludes Mr Kai Arvela.</p>

<blockquote>
<p><em><a href="/contact-us/contact-services">Contact us</a> to find out how Steerprop Services can enchance your operations.&nbsp;</em></p>
</blockquote>


Steerprop designs and manufactures azimuth propulsors with reliability and easy maintenance in mind. This is backed up with our world-class services, which are available globally through an extensive network of international partners. 

Steerprop Services: Supporting customers by maximising the uptime of propulsion assets

<p class="article__lead-paragraph">Since 2000, we at Steerprop have added value to our customers&rsquo; operations and contributed to their success through our unwavering resolve to perform. Below, please find few carefully selected references. Full reference listing is available on request.</p>

<h2 class="article__heading--h2">Arctic</h2>

<aside class="flockler__media">
<div class="flockler__media__img"><img alt="" src="https://flockler.com/thumbs/sites/13425/baltika-bf7ed06c-40bf-40d2-8e33-617e58d94444_s600x0_q80_noupscale.jpg" /></div>

<div class="flockler__media__body">
<div class="flockler__media__description">
<h3 class="article__heading--h3">BALTIKA &ndash; Oblique icebreaker</h3>

<p class="article__paragraph"><strong>Classification:</strong> RMRS Icebreaker 6<br />
<strong>Power per unit:</strong> 2,500 kW<br />
<strong>Built by:</strong> Arctech Helsinki Shipyard Oy<br />
<strong>Shipyard: </strong>Yantar JSC<br />
<strong>Main propulsion: </strong>3 x SP 60 PULL</p>

<p class="article__paragraph"><strong><a href="/stories/baltika">Read the full story</a></strong><br />
<strong><a href="https://www.youtube.com/watch?v=zwe0MHRaqhA">Watch a video on Youtube</a></strong></p>
</div>
</div>
</aside>

<aside class="flockler__media">
<div class="flockler__media__img"><img alt="" src="https://flockler.com/thumbs/sites/13425/varandey-b49d60bc-8a6c-46c1-8847-c7a3c36f1e5f_s600x0_q80_noupscale.jpg" /></div>

<div class="flockler__media__body">
<div class="flockler__media__description">
<h3 class="article__heading--h3">VARANDEY &ndash; Multi-purpose icebreaker</h3>

<p><strong>Classification: </strong>RMRS LL7<br />
<strong>Power per unit:</strong> 8,400 kW<br />
<strong>Built by: </strong>Keppel Singmarine<br />
<strong>Owner: </strong>Lukoil Kaliningrad<br />
<strong>Main propulsion: </strong>2 x SP O 4.5 ARC</p>
</div>
</div>
</aside>

<aside class="flockler__media">
<div class="flockler__media__img"><img alt="" src="https://flockler.com/thumbs/sites/13425/toboy-26adf0fc-9fd3-4cf3-9ed5-7f8342220980_s600x0_q80_noupscale.jpg" /></div>

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<div class="flockler__media__description">
<h3 class="article__heading--h3">TOBOY &ndash; Ice-breaking supply vessel</h3>

<p class="article__paragraph"><strong>Classification:</strong> RMRS LU7<br />
<strong>Power per unit: </strong>5,200 kW<br />
<strong>Built by:</strong> Keppel Singmarine<br />
<strong>Owner: </strong>Lukoil Kaliningrad<br />
<strong>Main propulsion: </strong>2 x SP O 4.0 ARC</p>
</div>
</div>
</aside>

<h2 class="article__heading--h2">Offshore&nbsp;</h2>

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<div class="flockler__media__img"><img alt="" src="https://flockler.com/thumbs/sites/13425/seven_viking-654915e7-d06d-48b5-a693-270b40db83e6_s600x0_q80_noupscale.jpg" /></div>

<div class="flockler__media__body">
<div class="flockler__media__description">
<h3 class="article__heading--h3">SEVEN VIKING &ndash; IMR vessel</h3>

<p class="article__paragraph"><strong>Classification: </strong>DNV 1A1<br />
<strong>Power per unit:</strong> 3,000 kW<br />
<strong>Built by:</strong> Ulstein Verft AS<br />
<strong>Owner:</strong> Subsea 7 and Eidesvik AS<br />
<strong>Main propulsion:</strong> 3 x SP 35 CRP</p>

<p class="article__paragraph"><strong><a href="/stories/the-seven-viking">Read the full story</a>&nbsp;</strong></p>

<p>​​</p>
</div>
</div>
</aside>

<aside class="flockler__media">
<div class="flockler__media__img"><img alt="" src="https://flockler.com/thumbs/sites/13425/edda_fonn-d4b29d82-e592-40c9-8d39-6144f7a3942c_s600x0_q80_noupscale.jpg" /></div>

<div class="flockler__media__body">
<div class="flockler__media__description">
<h3 class="article__heading--h3">EDDA FONN &ndash; ROV survey vessel</h3>

<p><strong>Classification:</strong> DNV ICE-C<br />
<strong>Power per unit:</strong> 2,200 kW<br />
<strong>Built by: </strong>Myklebust Verft AS<br />
<strong>Owner: </strong>New Zealand<br />
<strong>Main propulsion:</strong> 2 x SP 35 CRP</p>
</div>
</div>
</aside>

<aside class="flockler__media">
<div class="flockler__media__img"><img alt="" src="https://flockler.com/thumbs/sites/13425/bourbon_liberty-4c111c87-9ac5-4424-9586-2994e1612995_s600x0_q80_noupscale.jpg" /></div>

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<div class="flockler__media__description">
<h3 class="article__heading--h3">Bourbon Liberty 100 Series</h3>

<p><strong>Classification: </strong>ABS<br />
<strong>Power per unit: </strong>843 kW<br />
<strong>Built by:</strong> Sinopacific Shipbuilding Group<br />
<strong>Owner:</strong> Bourbon Offshore<br />
<strong>Main propulsion:</strong> 3 x SP 10 D L</p>

<p>Bourbon Liberty 100 series includes over 50 vessels with SP 10 D L propulsors as main propulsion.</p>
</div>
</div>
</aside>

<aside class="flockler__media">
<div class="flockler__media__img"><img alt="" src="https://flockler.com/thumbs/sites/13425/bourbon_liberty_200-185d4234-659d-4b82-8689-b489afb3d8d8_s600x0_q80_noupscale.jpg" /></div>

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<div class="flockler__media__description">
<h3 class="article__heading--h3">Bourbon Liberty 200 Series</h3>

<p><strong>Classification:</strong> ABS<br />
<strong>Power per unit: </strong>1,685 kW<br />
<strong>Built by: </strong>Sinopacific Shipbuilding Group<br />
<strong>Owner: </strong>Bourbon Offshore<br />
<strong>Main propulsion:</strong> 3 x SP 20 D</p>

<p>Bourbon Liberty 200 series includes over 115 vessels with SP 20 D propulsors as main propulsion.</p>
</div>
</div>
</aside>

<h2 class="article__heading--h2">Cruise &amp; Ferry</h2>

<aside class="flockler__media">
<div class="flockler__media__img"><img alt="" src="https://flockler.com/thumbs/sites/13425/flora2-4de876e9-b504-4374-a3de-c5d92948bd5c_s600x0_q80_noupscale.jpg" /></div>

<div class="flockler__media__body">
<div class="flockler__media__description">
<h3 class="article__heading--h3">CELEBRITY FLORA - Expedition Mega Yacht</h3>

<p><strong>Classification:</strong> LR 100A1<br />
<strong>Power per unit: </strong>1,250 kW<br />
<strong>Built by:</strong> Shipyard De Hoop<br />
<strong>Owner: </strong>Celebrity Cruises<br />
<strong>Main propulsion:</strong> 2&nbsp;x SP 20 CRP</p>
</div>
</div>
</aside>

<aside class="flockler__media">
<div class="flockler__media__img"><img alt="" src="https://flockler.com/thumbs/sites/13425/gauthier-b157e896-2026-43f1-9647-deb43228c9ed_s600x0_q80_noupscale.jpg" /></div>

<div class="flockler__media__body">
<div class="flockler__media__description">
<h3 class="article__heading--h3">F. A. GAUTHIER &ndash; Passenger vessel</h3>

<p class="article__paragraph"><strong>Classification:</strong> LRS 1AS<br />
<strong>Power per unit: </strong>7,000 kW<br />
<strong>Built by:</strong> Fincantieri Group<br />
<strong>Main propulsion:</strong> 2 x SP 120 CRP ECO</p>

<p class="article__paragraph"><strong><a href="https://www.youtube.com/watch?v=ZEup0I1oOS8">Watch a video on Youtube</a></strong></p>
</div>
</div>
</aside>

<aside class="flockler__media">
<div class="flockler__media__img"><img alt="" src="https://flockler.com/thumbs/sites/13425/piret-37b61e92-9b54-4437-9658-a446ddefa64e_s600x0_q80_noupscale.jpg" /></div>

<div class="flockler__media__body">
<div class="flockler__media__description">
<h3 class="article__heading--h3">PIRET &ndash; Double-ended ferry</h3>

<p><strong>Classification: </strong>DNV ICE-1A<br />
<strong>Power per unit: </strong>2,150 kW<br />
<strong>Built by: </strong>Remontowa Shipbuilding S.A.<br />
<strong>Owner: </strong>Port of Tallinn<br />
<strong>Main propulsion:</strong> 2 x SP 45 CRP</p>
</div>
</div>
</aside>

<aside class="flockler__media">
<div class="flockler__media__img"><img alt="" src="https://flockler.com/thumbs/sites/13425/bella_desgagnes-a6938ef3-4dc4-4499-963a-e72776d24fed_s600x0_q80_noupscale.jpg" /></div>

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<div class="flockler__media__description">
<h3 class="article__heading--h3">BELLA DESGAGNES &ndash; Passenger vessel</h3>

<p><strong>Classification:</strong> LR 1A FS<br />
<strong>Power per unit:</strong> 2,200 kW<br />
<strong>Built by: </strong>Kraljevica Shipyard<br />
<strong>Owner: </strong>Transport Desgagnes<br />
<strong>Main propulsion: </strong>2 x SP 45</p>
</div>
</div>
</aside>

<p>&nbsp;</p>

<h2 class="article__heading--h2">&nbsp;Workboats&nbsp;</h2>

<aside class="flockler__media">
<div class="flockler__media__img"><img alt="" src="https://flockler.com/thumbs/sites/13425/red_fox-5c7add62-92ba-4f17-91da-e79b516470bd_s600x0_q80_noupscale.jpg" /></div>

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<div class="flockler__media__description">
<h3 class="article__heading--h3">RED FOX (former Romulo) &ndash; Escort tug</h3>

<p><strong>Classification:</strong> GL 100A5<br />
<strong>Power per unit: </strong>2,380 kW<br />
<strong>Built by: </strong>Astilleros Balenciaga S.A.<br />
<strong>Owner: </strong>Remolcadores de Puerto y Altura, S.A.<br />
<strong>Main propulsion:</strong> 2 x SP 35 D</p>
</div>
</div>
</aside>

<p>&nbsp;</p>

<p>&nbsp;</p>


You can find Steerprop propulsion solutions in the most demanding conditions of the planet. See for yourself.

Steerprop References

<p class="article__lead-paragraph">Shipowners and operators are fully aware that minimising operational risks at sea is vital to maintaining profitability. And part of that process is ensuring that critical spare parts are quickly available. Having an old control system may result in the unavailability of obsolete components and parts. To prevent this, Steerprop has upgraded its propulsion control system to provide superior operability for all its customers. &quot;During the next generation development process, we added many new features to simplify the control system while still maintaining the existing systems&quot;, says Juho Rekola, Director, Sales &amp; Project Management at Steerprop Ltd.</p>

<p>Since July 2020, every new Steerprop propulsor delivery comes with the new Steerprop Control System. With the upgraded system, Steerprop&rsquo;s customers can enjoy a product of superior quality, reliability, serviceability, user-friendliness, and flexibility. And the best of all: &quot;The new system can also be installed for older units as a retrofit for any existing Steerprop propulsor. Thanks to our skilled engineers and the flexibility of the control system, we can even integrate the system with other propulsor makes&quot;, explains Mr Rekola.</p>

<h2 class="article__heading--h2">Tailormade all the way</h2>

<p>The older a control system gets, the higher the risk of problems due to obsolete parts. This was also the reality for Steerprop&rsquo;s customers. Therefore, the company wanted to develop a new control system that would eliminate this risk for existing vessels. The result is a system that can be tailored to fit and integrate with current onboard equipment. Steerprop can now ensure the longest possible availability of spare parts for the upgraded control system.</p>

<blockquote>
<p><em>The new system can also be installed for older units as a retrofit project.</em></p>
</blockquote>

<p>The Steerprop Control System is the best option for shipowners wanting superior operational reliability and high quality, which is ensured by control levers with full redundancy, enabling a complete follow-up backup control. &quot;All levers are NAUT OSV compliant and feature non-wearable, maintenance-free sensors for azimuth operation and speed&quot;, says Mr Rekola.</p>

<p>The entire control system, including controllers, cabinets and control panels, is tested together with the propulsor. This is part of Steerprop&rsquo;s rigorous quality assurance. Steerprop&rsquo;s skilled personnel will work closely with you to ensure the best support and results throughout the entire installation process, including adaptation to existing onboard systems. &quot;We will also take care of the start-up, onboard testing and commissioning to minimise the entire retrofit process.&quot;</p>

<h2 class="article__heading--h2">We&rsquo;re with you 24/7</h2>

<p>This next-generation control system is built with modern and proven PLC control technology. The comprehensive backup system has robust features for maximum redundancy and an off-line monitoring mode to increase availability. The upgraded system also allows the customer to have remote service support via the Steerprop remote service module. &quot;This is a modern solution that allows Steerprop&rsquo;s service engineers to do fault tracing remotely and assist the onboard crew without visiting the vessel&quot;, says Mr Rekola.</p>

<p>Every new propulsor comes with the standard Steerprop Care condition monitoring system. The system allows crewmembers to follow up on machinery trends and detect any deviation in advance. &quot;This is a feature that can be easily upgraded to online monitoring for the highest possible reliability and safety, so you are never left alone&quot;, ensures Mr Rekola.</p>

<p>Steerprop&rsquo;s advanced control system is available for newbuilds or as retrofits, regardless of the propulsor make or existing systems. Manoeuvring with this system gives you a first-class steering experience that can be further enhanced with personalised control profiles according to preferences. The Steerprop Control System is a perfect fit for those who want to be in control.</p>

<h2 class="article__heading--h2">Author</h2>

<aside class="flockler__media">
<div class="flockler__media__img"><img alt="" src="https://flockler.com/thumbs/sites/13425/210126-1-373-9acbf1b3-f066-4f16-ac78-c9788b4bcdc9_s600x0_q80_noupscale.jpg" /></div>

<div class="flockler__media__body">
<div class="flockler__media__description">
<p><em><strong>Juho Rekola,&nbsp;</strong>Director Sales and Project Managemen</em>t<em> at Steerprop, has been involved</em> <em>in customer projects and R&amp;D</em><em> in the international maritime industry from the beginning of his career. </em></p>

<p><em>Rekola joined Steerprop in 2017 and is now responsible for sales and project management operations. He is committed to offer our clients the best solution in the market with the excellent customer experice. </em></p>
</div>
</div>
</aside>

<p>&nbsp;</p>


Shipowners and operators are fully aware that minimising operational risks at sea is vital to maintaining profitability. And part of that process is ensuring that critical spare parts are quickly available. The older a control system gets, the higher the risk of problems due to obsolete parts. Therefore, the company wanted to develop a new control system that would eliminate this risk for existing vessels. 

control-retrofit

Retrofit installation of the improved Steerprop Control System puts you back in control

<p class="article__lead-paragraph">Contra-rotating propellers (CRP) in a push-pull configuration take icebreaking capability, manoeuvrability and performance to an entirely new level. The harsh conditions of ice-covered waters demand reliable propulsors that can provide your vessel with that extra thrust when the going gets tough. &ldquo;In addition to higher free running efficiency, Steerprop&rsquo;s Arctic azimuth propulsors with contra-rotating propellers also offer higher thrust in bollard and icebreaking conditions&rdquo;, says Hannu Jukola, Senior Sales Manager at Steerprop Ltd.</p>

<h2 class="article__heading--h2">Contra-rotating propellers provide superior efficiency and fuel economy</h2>

<p>Managing a vessel through thick ice can be a challenging task even for a skilled captain. Any misjudgement or lack of propulsion power can cause a ship to become stuck, which might result in serious damage to the vessel. Ice class requirements often force shipowners to make a compromise between bollard pull/icebreaking thrust and free running efficiency.</p>

<p>The propulsive performance of an ice-class propeller is inferior to that of a non-ice class propeller. This is because an ice-class propeller requires high propeller loading, which is enabled by large blade areas and high hub ratios. On the other hand, nozzled propeller configurations, which are required for high bollard pulls, present challenges with ice-clogging. &ldquo;Shipowners do not need to make these compromises anymore. Our CRP solutions provide superior performance, thus eliminating these challenges&rdquo;, says Mr Jukola.</p>

<h2 class="article__heading--h2">Proven technology with valuable customer benefits</h2>

<p>Azimuth propulsors are the tool of choice for ice management operations. In fact, they have now become the industry standard for ice-going vessels. One of the reasons for this, is their ability to direct the vectored thrust from the propeller (slipstream) in a full 360 degrees, which allows the vessel to use the thrust itself not only to open and widen fairways, but also to blow ice ridges and free Arctic offshore installations from ice pressure.</p>

<p>Steerprop&rsquo;s continuous commitment to R&amp;D has led, among other things, to the contra-rotating propulsor. However, being simply good enough is not enough for this company. That is why Steerprop conducted a series of ice model tests at Aker Arctic Technology&rsquo;s ice laboratory. The ice basin tests were compared against traditional single-propeller propulsors that are currently used in ice-going applications. &ldquo;The results revealed several benefits that CRP propulsors offer. In particular, the slipstream of the CRP propellers provided entirely new opportunities in ice-management operations&rdquo;, says Mr Jukola.</p>

<blockquote>
<p>The unique propeller slipstream from CRP has proven to be highly effective when clearing ice formations and widening fairways.</p>
</blockquote>

<figure class="article__figure">
<div class="article__figure__placeholder"><a data-type="image" href="https://flockler.com/thumbs/sites/13425/sp90crpeco_lm_8_web-17f63825-4b41-4e43-bca7-e93712cee5ac_s1800x0_q80_noupscale.jpg" target="_blank"><img alt="SP 90 CRP ECO LM" src="https://flockler.com/thumbs/sites/13425/sp90crpeco_lm_8_web-17f63825-4b41-4e43-bca7-e93712cee5ac_s600x0_q80_noupscale.jpg" /></a></div>
</figure>

<h2 class="article__heading--h2">Net thrust 10-17% higher than single pulling propellers</h2>

<p>In a CRP unit, the power is split between two contra-rotating propellers. This means a much lower propeller loading, with the second propeller recovering the rotational energy from the forward propeller. Therefore, the propellers are much more efficient without the constraints caused by the high loading of a single propeller. Steerprop&rsquo;s Arctic azimuthing propulsors achieve this through lower blade area ratios, more favourable pitch and RPM settings, as well as a reduction of rotational losses that are not possible with single propellers.</p>

<p>&ldquo;We found that in bollard configurations, CRP provides about a 10% higher thrust with the same power, or the same thrust using 15% lower power when compared to a single propeller of the same diameter. The free-running efficiency is 5-10% better depending on the vessel speed. Test results show that the CRP can bring benefits to several different applications &ndash; ranging from dedicated ice management vessels and Arctic cargo ships to tankers and ice-going offshore support vessels. The net thrust of the CRP was 10-17% higher than a single pulling propeller with the same power&rdquo;, says Hannu Jukola, adding that &ldquo;Ridge penetration times were also significantly reduced because of the unique effectiveness of the slipstream from the CRP-propellers.&rdquo;</p>

<p>Mr Jukola mentions LNG carriers (Liquefied Natural Gas) as an example of an application type that could benefit from Steerprop&rsquo;s CRP solution. &ldquo;The ice resistance was reduced by approximately 10% in level ice, and the speed in brash ice was increased by 50%. Even the ridge penetration time was reduced by about 50%.&rdquo;</p>

<h2 class="article__heading--h2">A reliable partner to support you all the way</h2>

<p>Steerprop has a strong track record, having delivered more than 90 units for ice-classed vessels, including icebreakers. Among these deliveries we include the world&rsquo;s most powerful and highest ice-class mechanical azimuth propulsors. These two SP 110 PULL ARC units with total power of 18 000 kW were installed on the icebreaker Vladivostok in 2014.</p>

<p>&ldquo;We want our solutions to resolve our customers&rsquo; challenges in such a way that they add critical value to their businesses. The best result is achieved when we can support and advise our customers already from the ship design phase. Our support ranges from needs analysis and proposing the best solution to maintenance and service throughout the lifecycle of the solution&rdquo;, says Mr Jukola.</p>

<h2 class="article__heading--h2">Author</h2>

<aside class="flockler__media">
<div class="flockler__media__img"><img alt="" src="https://flockler.com/thumbs/sites/13425/210126-1-222-8cab50a1-a03a-4108-883c-479081b25f70_s600x0_q80_noupscale.jpg" /></div>

<div class="flockler__media__body">
<div class="flockler__media__description">
<p><em><strong>Hannu Jukola</strong>, Senior Sales Manager at Steerprop, graduated as a Naval Architect with a specialization in hydrodynamics, from the Helsinki University of Technology in 1990.</em></p>

<p><em>Hannu joined Steerprop in the year 2000. His responsibilities at Steerprop Ltd. have included hydrodynamics and propeller design, sales in Nordic countries as well as managing R&amp;D programs related to development of high power CRP propulsors for passenger and ice going vessels.</em></p>
</div>
</div>
</aside>

<p>&nbsp;</p>


The harsh conditions of ice-covered waters demand reliable propulsors that can provide your vessel with that extra thrust when the going gets tough. 

Ice-going vessels put their trust in CRP thrust

<p class="article__lead-paragraph">With the recent advent of high-end computing power, computational fluid dynamics (CFD) has become an indispensable tool in the marine industry for selecting the right propulsion units and optimizing the design and the performance of the propulsors. Beyond predicting performance parameters, a detailed flow pattern study enables designers to better design products to avoid undesirable flow features, such as separation on the housing, which, in addition to increased drag, can also subject the propeller to significant non-uniform inflow.</p>

<p>Ship-scale CFD is now gaining traction in a much broader way when it comes to propulsion solutions &ndash; from the predesign stage to final tailoring of the unit&rsquo;s propeller blades. These state-of-the-art computational tools have greatly extended our design capabilities at Steerprop, enabling our designers to offer our customers tailor-made solutions that perfectly match the customers&rsquo; needs and their vessels&rsquo; operational profile.</p>

<p>Below are just some of the ways that ship-scale CFD is bringing new benefits to vessel designers, shipowners and system integrators.<br />
<br />
&nbsp;</p>

<figure class="article__figure">
<div class="article__figure__placeholder"><img alt="Hub vortex" src="https://flockler.com/thumbs/sites/13425/hub-vortex-781593f2-443d-403e-a340-ffcbee2860d7_s600x0_q80_noupscale.png" /></div>

<figcaption><span class="article__figure__caption">Capture of a hub vortex: Identifying energy losses is essential to improving the performance of the propulsor unit.</span></figcaption>
</figure>

<p><strong>Choice of propulsors:</strong> When shipowners select the right propulsion units for their vessels, the decision is still primarily based on comparative performance using model scale tests.</p>

<p>With a greater shift towards using azimuth propulsors in modern ships, however, unit performance is significantly affected by scale effects. The reliability of traditional empirical methods in scaling the performance of these units, especially ducted ones and podded propulsors, is still a great concern. Therefore, there is a need to supplement model scale tests with CFD tools to accurately predict the performance of the azimuth propulsor.</p>

<p><strong>Shape your housing:</strong> An optimized gear housing is essential from the perspective of overall azimuth propulsor unit performance. CFD, coupled with 3D modeling tools, has enabled us to carry out detailed investigations by defining and optimizing the housing in terms of geometrical parameters, like housing length, torpedo diameter, strut distance from propellers and more. A better understanding of their individual and combined effects through interaction on overall propulsor performance has enabled designers at Steerprop to better design our units, even in off-design and steering conditions.</p>

<p>With developed accuracy and confidence in modern computational tools, we can focus on optimizing the housing and thus our units at ship scale, rather than defining the unit&rsquo;s performance with less accurate model tests.</p>

<p><strong>Design your propeller for actual flow conditions:</strong> In times when there are conflicting design requirements for minimum-to-no-cavitation, low-noise and high-efficiency propeller units, it becomes more essential for designers to ensure that the inflow conditions are properly captured and described.</p>

<p>Traditionally, the design of propeller blades considers the nominal wake data obtained from model tests and couples it with not-so-reliable empirical extrapolation schemes. Today, computational tools, like BEM-RANS coupling, further improve the design process by making ship-scale effective wake available.</p>

<p>This has greatly improved our ability to predict behind-the-ship cavitation performance and thus avoid overly conservative designs.</p>

<h2 class="article__heading--h2">A sea of new opportunities</h2>

<p>The integration of these tools in our daily design process, with the level of detail in their prediction, is limited only by computing power. Additionally, the growing availability of on-board monitoring data on modern vessels will further extend the reliability and performance of these tools in days to come. At Steerprop, we&rsquo;re always on the lookout for new ways to put our computational tools to use for providing our customers with improved propulsion power and optimized performance.</p>

<h2 class="article__heading--h2">&nbsp;</h2>


Ship-scale CFD is now gaining traction in a much broader way when it comes to propulsion solutions – from the predesign stage to final tailoring of the unit’s propeller blades. These state-of-the-art computational tools have greatly extended our design capabilities at Steerprop.

Shifting focus to ship-scale CFD in the marine industry

<p class="article__lead-paragraph">In May 2020, Steerprop, together with Suomenlahden Telakka, completed a highly successful retrofitting project for Finferries&rsquo; Prostvik passenger and car ferry. The ferry was originally built in the 80&rsquo;s, and it was high time to up-date the ferry&rsquo;s old diesel-mechanic propulsion system for a new and modern electric distribution system to gain increased reliability, higher energy efficiency, decreased emissions, as well as greater economic advantages.</p>

<p>The Prostvik ferry is one of two ferries that run between Nauvo and Korppoo in the archipelago outside of Turku, Finland. The ferry is one of the busiest ferries in Finland and is absolutely vital to the local population, who are dependent on reliable ferry traffic between the islands in the archipelago. Prostvik operates approximately 8000 hours per year, and carries about 140 passengers and 30 vehicles each journey.</p>

<p>To meet Finnferries needs for more efficient, sustainable and cost-effective operations, the old diesel-mechanic system on the Prostvik was replaced with a totally new and modern electric distribution system using Steerprop&rsquo;s innovative contra-rotating propulsion units (SP 10 CRP LM) with an integrated 400 kW permanent magnet motor. This solution offers much better efficiency compared to a traditional induction electric motor. The delivery also included a state-of-the-art control system and intuitive control panels, which adds substantially to modernizing the operations of the ferry.</p>

<p>Suomenlahden Telakka, the largest small-tonnage vessel repair and maintenance shipyard in Finland, strongly advocated Steerprop&rsquo;s technology to Finferries.&nbsp;</p>

<blockquote>
<p>&quot;We know Steerprop&rsquo;s LM configuration saves space in the vessel and brings a greater level of simplicity to the engine room,&rdquo; says Jukka Jaatinen, Managing Director of Suomenlahden Telakka.</p>
</blockquote>

<p>&ldquo;Additionally, it was a more straightforward installation process for us, since the propulsion system is extremely compact with lower weight.&rdquo;</p>

<p>&ldquo;The good and close cooperation with Finferries and Suomenlahden Telakka made this retrofit project possible. It was essential that we could do all checks onboard during the design phase when the ferry was still in operation as well as at the yard during the conversion,&rdquo; says Olli Knihti, Sales Manager at Steerprop.</p>

<p>Now in operation, the electric propulsion system brings greater economic advantages to Finferries. &ldquo;The diesel engines can run according to the power requirement, and fuel consumption is optimized. The ferry also has a DC link, which allows future upgrades such as adding a battery to the vessel,&rdquo; states Olli Knihti, Sales Manager at Steerprop.</p>

<p>This retrofit project represented a big step forward in the ferry&rsquo;s energy efficiency, fuel savings and decreased emissions, adding real value to Finnferries&rsquo; operations in the Finnish archipelago. In fact, Steerprop&rsquo;s retrofit solution is ideal for any ferry in the world that need to modernize operations to match stricter local and regional environmental regulations.</p>

<p>&ldquo;Steerprop is committed to meeting our customers&rsquo; needs. With our technical solutions and our way of resolving any challenges our customers might have, we really can make a difference and create great results for our customers and their operations,&rdquo; Knihti concludes.</p>

<figure class="article__figure">
<div class="article__figure__placeholder"><a data-type="image" href="https://flockler.com/thumbs/sites/13425/dji_0181-c02905f5-d8f0-4d19-a40d-0d8ab3ff947c_s1800x0_q80_noupscale.jpg" target="_blank"><img alt="" src="https://flockler.com/thumbs/sites/13425/dji_0181-c02905f5-d8f0-4d19-a40d-0d8ab3ff947c_s600x0_q80_noupscale.jpg" /></a></div>

<figcaption><span class="article__figure__caption">The Prostvik ferry in operation</span> <span class="article__figure__credit">Finferries</span></figcaption>
</figure>

<h3 class="article__heading--h3">Quick facts</h3>

<p>The Steerprop innovative contra-rotating propeller (CRP) 10 CRP LM propulsor system offers excellent efficiency. The dual-end CRP combines the exceptional maneuverability of azimuth propulsors with low pressure pulses and noise levels. The integrated vertical permanent magnet motor provides reliable high-power propulsion, increased fuel savings and lower emissions. Steerprop has delivered over 140 CRP units to vessels throughout the world.</p>


In May 2020, Steerprop, together with Suomenlahden Telakka, completed a highly successful retrofitting project for Finferries’ Prostvik passenger and car ferry. The ferry was originally built in the 80’s, and it was high time to up-date the ferry’s old diesel-mechanic propulsion system for a new and modern electric distribution system to gain increased reliability, higher energy efficiency, decreased emissions, as well as greater economic advantages.

More efficient, sustainable and cost-effective operations in the Finnish Archipelago

<p class="article__lead-paragraph">On seagoing vessels, propulsor systems cause two types of noise. There is the noise you hear onboard the ship, called onboard noise, and then there&rsquo;s the kind you hear underwater, also known as underwater radiated noise (URN). Although the former has been of concern for some time, the latter is gaining in importance. Our experts at Steerprop are designing systems and conducting research to reduce both onboard noise and URN.</p>

<h2 class="article__heading--h2">A whale of a problem</h2>

<p>The requirements for noise reduction depend on the type of shipping being done. While onboard noise tends to disturb passengers on passenger ships, underwater radiated noise (URN) is much more harmful to delicate underwater ecosystems. For example, in the sensitive areas of the Arctic or the Antarctic, URN might affect seagoing creatures and habitats.</p>

<p>In the areas surrounding the Port of Vancouver, officials implemented reduced harbor fees for ships that met certain URN criteria, due to the sensitivity of the local native whale and mammal populations. Around the world, fishing vessels are concerned with URN causing evasive behavior of fish, and research vessels often cite this noise as degrading the quality of underwater signal measurements.</p>

<p>Classification societies, such as DNV-GL, have also started implementing noise limits. Currently, not many vessels are URN classified, but that&rsquo;s expected to change in the near future.</p>

<figure class="article__figure">
<div class="article__figure__placeholder"><a class="article__figure__link" data-type="image" href="https://flockler.com/thumbs/sites/13425/noise_figure1-3bff1505-358c-49aa-90da-002700ff1f2c_s1800x0_q80_noupscale.jpg" target="_blank"><img alt="Distribution of sound pressure level" src="https://flockler.com/thumbs/sites/13425/noise_figure1-3bff1505-358c-49aa-90da-002700ff1f2c_s600x0_q80_noupscale.jpg" /></a></div>

<figcaption><span class="article__figure__caption">Example distribution of sound pressure level near a contra-rotating propulsion (CRP) ECO unit.</span></figcaption>
</figure>

<h2 class="article__heading--h2">What causes the noise?</h2>

<p>To meet the demand for new or modified URN classified vessels, designers and shipyards should give due attention to all major noise sources on board.</p>

<p>On the propulsion side, they should concentrate on mitigating the two primary sources of propulsor noise, i.e. designing propellers and drive trains to be more silent. Propellers cause noise through water cavitation, and drive trains make noise with mechanical power transmissions and gears.</p>

<p>At Steerprop, we are addressing both problems. Our contra-rotating propulsion (CRP) solution limits propeller noise by having two separate propellers, each with a lower loading, which helps prevent cavitation and lowers both onboard noise and URN. We have also worked to reduce drive train noise with our special LM unit. Integrated with a permanent magnet (PM) motor, the LM unit removes the upper gear, replacing it with a more silent electric motor.</p>

<figure class="article__figure">
<div class="article__figure__placeholder"><a class="article__figure__link" data-type="image" href="https://flockler.com/thumbs/sites/13425/noise_figure2-4f663f0c-9dac-4645-90ce-aaf3b373d0c9_s1800x0_q80_noupscale.jpg" target="_blank"><img alt="Distribution of sound pressure level" src="https://flockler.com/thumbs/sites/13425/noise_figure2-4f663f0c-9dac-4645-90ce-aaf3b373d0c9_s600x0_q80_noupscale.jpg" /></a></div>

<figcaption><span class="article__figure__caption">Example distribution of sound pressure level on the structure interface of a CRP ECO unit.</span></figcaption>
</figure>

<h2 class="article__heading--h2">Studies for deeper insight</h2>

<p>We also continue to seek new ways of understanding and reducing noise through joint research projects. We have been collaborating with Finland-based ATA Gears to study the impact of various geometries and components on noise. Using FEM calculations, we have studied noise excitation and noise transmission mechanisms in our Z, L and M units.</p>

<p>For a RoPax ferry and an expedition cruise vessel, we have made both structure-borne noise and URN measurements. The latter were made together with Luode Oy, a company specializing in underwater measurements.</p>

<p>While we have made some strides, many issues with onboard noise and URN are still difficult to predict since there aren&rsquo;t any public databases available, especially not regarding URN. For example, navies around the world hold URN data close to their chest, since they can use the URN to determine a vessel&rsquo;s signature and figure out what type of vessel is in the water.</p>

<p>Regardless, we are intent on conducting ongoing research and doing our very best to continue improving our solutions to address the needs of our customers. That includes researching absolute noise levels, as well as gathering data and determining methods to help design and engineer ever quieter vessels.</p>

<h2 class="article__heading--h2">Author</h2>

<aside class="flockler__media">
<div class="flockler__media__img"><img alt="" src="https://flockler.com/thumbs/sites/13425/210126-1-586-c7684e3d-9b0d-429b-9307-d9e96984176c_s600x0_q80_noupscale.jpg" /></div>

<div class="flockler__media__body">
<div class="flockler__media__description">
<p><strong>Kari Kyyr&ouml;</strong><br />
<em>Consulting Naval Architect</em></p>

<p><em>With 25 years working at a shipyard, 4 years for Steerprop and 3 years as an independent consultant, Kari has accumulated vast experience in the various facets of designing ship hydrodynamics. One area in particular that interests him is how to reduce the amount of noise that ships produce, creating more comfort and sustainability with shipping.</em></p>
</div>
</div>
</aside>

<p>&nbsp;</p>


On seagoing vessels, propulsor systems cause two types of noise. There is the noise you hear onboard the ship, called onboard noise, and then there’s the kind you hear underwater, also known as underwater radiated noise (URN). To meet the demand for new or modified URN classified vessels, designers and shipyards should give due attention to all major noise sources on board.

Focusing on minimizing underwater radiated noise

<p class="article__lead-paragraph">When operating in harsh arctic conditions, reliability plays a really critical role. A reliable vessel is a safe and cost-effective vessel.</p>

<p class="article__paragraph"><strong>Jarkko Sirrola</strong>, PdM Manager at Steerprop, is passionate about condition monitoring and seeing any emerging fault before it becomes a costly challenge. For him, predictability, safety and productivity all add up to unrivaled reliability.</p>

<h3 class="article__heading--h3">Want to hear more?</h3>

<p>Watch the video and find out why predictive maintenance is important in arctic shipping.</p>

<div class="article__embed-code"><iframe width="560" height="315" src="https://www.youtube.com/embed/AQKLZa7ZQiM?rel=0" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe></div>

<p>&nbsp;</p>


When operating in harsh arctic conditions, reliability plays a really critical role. A reliable vessel is a safe and cost-effective vessel.

Predictive maintenance in arctic shipping

<p class="article__lead-paragraph" paraeid="{428a417f-181e-4b54-b8a8-cc6f0b4f0eda}{250}" paraid="1596792740"><em>The revolutionary icebreaking rescue vessel Baltika, developed by Aker Arctic and propelled by Steerprop, is the first vessel ever built with an asymmetric hull design that allows it to break ice ahead, astern and sideways. Because of this capability, this relatively small icebreaker is able to open a much wider channel in ice than other icebreakers of similar size. Steerprop was a natural choice for delivering a propulsion system to match the tough requirements set by both the Baltika&rsquo;s versatile operations and the harsh, arctic environment.</em></p>

<p class="MsoBodyTextCxSpFirst">The Baltika is a true multipurpose vessel, designed for icebreaking operations in harbors and adjacent waters. Because of the asymmetric hull design this relatively small icebreaker can break ice ahead, astern and sideways and is able to open a wide enough channel in ice even for large merchant ships. In addition, the vessel can be used for towing of vessels and floating facilities in an emergency, extinguishing external fires and performing various rescue operations. The vessel is also fitted with a sophisticated built-in oil recovery system. In case of oil spill, the vertical side of the asymmetric hull moves oil floating on the surface to a built-in skimmer as the vessel moves obliquely (sideways) through the oil.</p>

<p class="MsoBodyTextCxSpMiddle">Baltika was built by Arctech Helsinki Shipyard in co-operation with Shipyard Yantar JSC based on Aker Arctic&rsquo;s oblique icebreaker design, Aker ARC 100.</p>

<p class="MsoBodyTextCxSpMiddle">Because of the sophisticated multipurpose operations of this vessel, the demands on the propulsion system were high. The azimuth thrusters would need to match the critical requirements for outstanding performance and maneuverability - not only would they need to push the vessel nearly sideways both in rough seas and through thick ice, but they would also need to make the vessel turn around almost on the spot. This was a challenge Steerprop was more than confident to take on, and today the Baltika is propelled by three SP 60 PULL 2.5 MW Steerprop Azimuth Propulsors, two in the stern and one in the bow of the vessel, a solution that was successfully tested and verified in 2015.</p>

<p class="MsoBodyTextCxSpMiddle">In March 2015, Baltika departed from Murmansk and sailed to the Kara Sea to carry out full-scale ice trials, where the vessel&rsquo;s icebreaking performance was verified and its full operational capabilities were demonstrated. The testing program included performance tests in two distinct ice thicknesses in ahead and astern directions as well as in the oblique icebreaking mode. Various other operational tests were also included to verify the maneuverability and operational capabilities of the vessels.</p>

<div class="article__embed-code"><iframe width="560" height="315" src="https://www.youtube.com/embed/zwe0MHRaqhA?rel=0" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe></div>

<p class="MsoBodyTextCxSpMiddle">The results of the tests proved to be outstanding. Although the ice conditions in the Gulf of Ob were on the upper end of the vessel&rsquo;s designed icebreaking capability, the Baltika exceeded the required performance targets and expectations with a clear margin. The vessel could break 1.2 metre level ice in continuous motion when proceeding bow first and could achieve a speed exceeding 3 knots when moving astern.</p>

<p class="MsoBodyTextCxSpMiddle">The oblique mode, which had never been tested in real operations before, worked extremely well during the extensive tests on the Kara Sea. In fact, the dynamic positioning system, developed by Navis Engineering, made oblique operations surprisingly simple and straight-forward. In the port of Sabetta, the Baltika demonstrated excellent maneuverability and rubble clearing capability. The vessel also demonstrated its ability to penetrate heavily compressed ice ridges without ramming them.</p>

<blockquote>
<p class="MsoBodyTextCxSpLast">&ldquo;Baltika&rsquo;s voyage to the Gulf of Ob proves the exceptional operational capability of the oblique icebreaker concept in very difficult ice conditions,&rdquo; Head of Ship Design Mika Hovilainen of Aker Arctic says.</p>
</blockquote>

<p class="MsoBodyTextCxSpLast">&ldquo;The vessel could operate in ice conditions that exceeded the design criteria used as the basis of the vessel concept. The Baltika could carry out the same operations as conventional icebreakers with just half of the propulsion power as well as perform maneuvers which are not possible for any other vessel currently in service,&rdquo; he continues.</p>

<h3 class="article__heading--h3">Quick facts</h3>

<ul>
	<li>The Baltika is owned by the Federal Agency for Maritime and River Transport of Russia (Rosmorrechflot), and operated by the Russian Maritime Emergency Rescue Service (FGI Gosmorsspassluzhba).<br />
	&nbsp;</li>
	<li>Baltika is 76.4 metres (251 ft) long overall and 72.1 metres (237 ft) at the waterline, and has a maximum beam of 20.5 metres (67 ft). Her draught at design waterline is 6.3 metres (21 ft) and the corresponding deadweight tonnage 1,150 tons. The diesel-electric power plant consists of three W&auml;rtsil&auml; 9L26 generating sets with a combined output of 9 MW.<br />
	&nbsp;</li>
	<li>The ship is classified by the Russian Maritime Register of Shipping. Her ice class, Icebreaker 6, requires the vessel to be capable of operating in level ice with a thickness of 1 metre (3.3 ft) in a continuous motion and strengthened for navigation in non-Arctic waters where ice can be up to 1.5 metres (5 ft) thick.<br />
	&nbsp;</li>
	<li>The vessel is capable of moving in 1-metre (3.3 ft) level ice at 3 knots (5.6 km/h; 3.5 mph) in both ahead and astern directions. When operating in oblique mode, she can open a 50-metre (160 ft) channel in 60-centimetre (2.0 ft) ice. In open water, the service speed of the vessel is 14 knots (26 km/h; 16 mph) and operational range 4,500 nautical miles (8,300 km; 5,200 mi).</li>
</ul>


The revolutionary icebreaking rescue vessel Baltika, developed by Aker Arctic and propelled by Steerprop, is the first vessel ever built with an asymmetric hull design that allows it to break ice ahead, astern and sideways. 

The icebreaking rescue vessel Baltika – a new standard for maneuverability

<p class="article__lead-paragraph" paraeid="{3d48510b-c5f7-4c22-85a9-7694f7f229bf}{251}" paraid="1029831154"><em>When Eidesvik Offshore ASA and Subsea 7, in collaboration with Ulstein, set out to build the most sophisticated offshore vessel in Norway, the owners&rsquo; expectations on the performance of the vessel were high. The Seven Viking was designed to operate in the cold and harsh, but delicate conditions of the North Seas, and it was clear that the crew would need to carry out numerous different operations on the vessel, safely and efficiently - even in rough seas.</em></p>

<p>This exceptional IMR (inspection, maintenance &amp; repair) vessel, Seven Viking, was commissioned in January 2013, and included numerous advanced technologies incorporated into the vessel. It was not surprising the vessel, that sets a new standard for comfort, safety and efficiency, has received many maritime awards since its commissioning.</p>

<p>The high expectations on the vessel&rsquo;s performance naturally meant that the choice of suppliers was crucial. Suppliers needed to rise up to the challenge to deliver their very best technology, all the parts needed to come together to form the most sophisticated offshore vessel built in Norway at that time. &ldquo;We always have great expectations for suppliers, in particular those chosen for essential equipment such as propulsors,&rdquo; says Arve Nilsen, Technical Manager and Head of Procurement for Eidesvik. This project was no exception.</p>

<p>The Seven Viking vessel combines the environmental friendliness of modern technology, such as CRP (contra-rotating propellers) azimuth propulsion, with the toughness of DNV ICE-C ice-classiffication. The choice of Steerprop for the delivery of the main propulsion units for the Seven Viking was a natural result of matching our experience and technology to the operational needs of the vessel. The vessel is equipped with three SP 35 CRP propulsors that combine a robust, durable construction with the high fuel efficiency of CRP technology.</p>

<p paraeid="{2d3f04a1-e889-44ea-b4d9-e2116748d6d9}{216}" paraid="488117192">In operation, the propulsors have proven to be easy to operate. They respond quickly to steering commands and provide good feedback during operations. They are also extremely efficient in keeping a steady position during Dynamic Positioning operations.</p>

<blockquote>
<p paraeid="{2d3f04a1-e889-44ea-b4d9-e2116748d6d9}{252}" paraid="483094838">&ldquo;So far we are very satisfied with the performance of&nbsp;the propulsors&rdquo; Mr Nilsen concludes.</p>
</blockquote>

<p>However, the customers&rsquo; expectations on Steerprop&rsquo;s delivery did not stop there. High expectations were also set on commissioning and service performance, and at Steerprop we take our commitment seriously. We understand our customers&rsquo; needs and we always set out to perform at our very best, every step of the way. Throughout the periods of delivery, commissioning and service, our service personnel are co-operative, result-oriented and ready to go beyond the call of duty when necessary.</p>

<p>To further add value to our customer&rsquo;s operations throughout the lifetime of the vessel, we installed the Steerprop Care Plus condition monitoring service on the vessel in 2019. The monitoring work is handled by our engineers who follow the machinery trends and detect and notify the crew in advance of any deviation that could affect the propulsion system. By taking this proactive approach, costly breakdowns can be avoided.</p>

<p paraeid="{502831ee-bc8e-4f48-9f13-ef4a47ce880e}{19}" paraid="673496358">Steerprop Care Plus monitors the complete propulsion system, including vibration along with signals and alarms from the control system, using advanced techniques based on AI and machine learning. This offers shipowners the highest possible reliability, based on enhanced predictability, safety and productivity.</p>

<h3 class="article__heading--h3">Quick facts</h3>

<p>The Seven Viking is jointly owned by Eidesvik Offshore ASA and Subsea 7. The vessel&rsquo;s technical and operational management is with Eidesvik Offshore ASA. In early 2013, the Seven Viking was chartered by Statoil to serve in the oil fields of the North Sea.</p>

<p>At the beginning of 2019, Seven Viking was converted from a conventional to a hybrid vessel. The vessel is presently on a long term charter on Norwegian Sector for Subsea 7 with Equnior as end client.<br />
<br />
The Seven Viking is equipped with three SP 35 CRP propulsors from Steerprop for its main propulsion.</p>

<table border="0" cellpadding="3" cellspacing="1" style="width:100%">
	<tbody>
		<tr>
			<td><strong>Vessel type:</strong></td>
			<td>IMR Vessel</td>
		</tr>
		<tr>
			<td><strong>Classification:</strong></td>
			<td>
			<p paraeid="{502831ee-bc8e-4f48-9f13-ef4a47ce880e}{157}" paraid="716232307">DNVGL 1A1</p>
			</td>
		</tr>
		<tr>
			<td><strong>Built by:</strong></td>
			<td>Ulstein AS of Norway</td>
		</tr>
		<tr>
			<td><strong>Owner:</strong></td>
			<td>Eidesvik Offshore ASA</td>
		</tr>
		<tr>
			<td><strong>Main propulsion:</strong></td>
			<td>3 x SP 35 CRP</td>
		</tr>
		<tr>
			<td><strong>Power per unit:</strong></td>
			<td>3 000 kW</td>
		</tr>
		<tr>
			<td><strong>Ice-Classification:</strong></td>
			<td>DNV ICE-C</td>
		</tr>
	</tbody>
</table>

<p>&nbsp;</p>

<p><strong>Watch a video about the Seven Viking IMR vessel on Ulstein&rsquo;s YouTube channel:</strong>&nbsp;<a href="https://youtu.be/SMmiHB2Qa9M" target="_blank">https://youtu.be/SMmiHB2Qa9M</a></p>


IMR Vessel Seven Viking was designed to operate in the cold and harsh, but delicate conditions of the North Seas - safely and efficiently.

The Seven Viking - the most sophisticated offshore vessel built in Norway 

<p class="article__lead-paragraph" paraeid="{6640b1d0-f6dc-420b-b96a-0c55e0a40dc5}{229}" paraid="637552774">When designing and dimensioning propulsors for optimal performance and fuel efficiency in arctic operations, it is crucial to understand how ice loads affect the vessel and the propulsor. It is also important to understand the requirements of each ice class. We at Steerprop have substantial experience and expertise in developing propulsion solutions for arctic operations, in fact, every third icebreaker in operation around the world relies on Steerprop technology.</p>

<p>How to best dimension every propulsor depends on the requirements of each ice class. To ensure the best results when designing each propulsor, it is important to check all classification requirements for that vessel. The ice class rules for Arctic Vessels in most class societies follow the IACS Unified Requirements for Polar Ships, with PC 1 being the hardest ice and PC 7 being the weakest &ndash; old ice is, in general, harder than new.</p>

<p paraeid="{1ca7a70a-75bb-451f-8ba8-d6e118333d1e}{80}" paraid="955040348">The nature of the ice, and how much pressure is required to break through, affects the load, so it is vital to understand how ice load affects the propulsor under the water. The class rules dictate how to dimension the housing to break through different ice load magnitudes. For example, the longitudinal load is factored differently than the transversal load, which is more critical with respect to the propulsor design. Still, both must account for the load of a consolidated ice sheet that slides down the hull and impacts the propulsor. Especially with azimuth thrusters, the transversal load can play a major role. Still, all directional ice loads and magnitudes need to be considered as they hit the propulsor from different sides while the vessel cuts through ice.</p>

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<p paraeid="{1ca7a70a-75bb-451f-8ba8-d6e118333d1e}{122}" paraid="1843996550">When dimensioning arctic propulsors, we at Steerprop analyze the impact of ice loads on the slewing ring dimensioning &ndash; the hull attachment inside the ship&rsquo;s hull, with bolts dimensioned to provide the strength of the housing that withstands the ice loads.</p>
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<p>Ice loads also need to be considered when choosing how and in which material the propulsion units should be manufactured. For most ice classes, we recommend stainless steel propellers, but bronze propellers are also available for lighter ice classes. Blade scantlings are calculated according to class rules. The entire propeller can be delivered as a monoblock or built with blades bolted on. In the latter alternative, it is considerably easier to replace a single blade underwater at sea rather than changing an entire propeller.</p>

<p>Pushing and pulling have traditionally been the preferred propulsor type for arctic operations, but recently Steerprop&rsquo;s contra-rotating propulsion (CRP) technology has been gaining traction with Arctic expedition cruise vessels, as the CRP technology combines a robust, durable construction with high fuel efficiency. In addition, electric steering combined with CRP results in smooth operations and outstanding maneuverability. The CRP solution is also silent, it limits propeller noise by having two separate propellers, each with a lower loading, which helps prevent cavitation and lowers both onboard noise and underwater radiated noise.</p>

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<p>Furthermore, our pollution-free sealing solution for the severe vibration conditions caused by operating in ice has proven effective through experience.</p>

<p>Each ice class affects not only the final propeller design and configuration but also its power transmission gear design and steering. Steerprop uses a unique gear transmission design with the proper and effective load-carrying contact area and pattern that can maintain the safety margin for any unexpected load.</p>

<p>Every Steerprop propulsor also comes with high-quality roller bearings for the very best performance. To maintain consistent quality, we have worked with only two or three top-flight bearing manufacturers over the years.</p>

<p>The most important outcome is to be able to ensure that the vessel can handle even unexpected loads and safely make it through the ice, even if the propulsor is damaged. That&rsquo;s why we use computerized ice simulations to take the entire line into consideration, including the torsional vibrations from the whole system. We provide our complete analysis of the forces to the ship design house or the shipyard in order for them to further calculate the hull strength needed.</p>

<p paraeid="{d6516871-ad4a-4564-b376-74bf5995bb76}{33}" paraid="1407330074">Ultimately, the classification societies set the rules. But it is up to us to calculate, simulate and formulate how much tension and deformation would be allowable at each point in the propulsor for a safe and efficient voyage above and beyond the rules, in the actual arctic marine environment.</p>

<h2 class="article__heading--h2">Author</h2>

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<p><em><strong>Hannu Jukola</strong>, Senior Sales Manager at Steerprop, graduated as a Naval Architect with a specialization in hydrodynamics, from the Helsinki University of Technology in 1990.</em></p>

<p><em>Hannu joined Steerprop in the year 2000. His responsibilities at Steerprop Ltd. have included hydrodynamics and propeller design, sales in Nordic countries as well as managing R&amp;D programs related to development of high power CRP propulsors for passenger and ice going vessels.</em></p>
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When designing and dimensioning propulsors for optimal performance and fuel efficiency in arctic operations, it is crucial to understand how ice loads affect the vessel and the propulsor. It is also important to understand the requirements of each ice class.

Basic dimensioning principles for arctic propulsors

<p class="article__lead-paragraph" paraeid="{5a160690-e752-4325-94d2-d96c10af27a9}{244}" paraid="1142537577"><em>We at Steerprop come from a culture of curiosity for our customers&rsquo; business and of applying our enthusiasm, experience and innovation to improve it. Our culture is built on working for a purpose, on designing and delivering solutions that have a real impact and make a real difference. This resolve to perform&nbsp;has always guided the ingenious minds of the Steerprop R&amp;D department.</em></p>

<p paraeid="{2762ac1f-02ff-4c77-b509-7f9e771c795d}{47}" paraid="121277023">We provide our customers with superior propulsion units with outstanding efficiency, exceptional reliability and the lowest lifecycle costs on the market. Our gear design specialists, technical analysts and hydrodynamists are all working hard toward this end.</p>

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<p paraeid="{2762ac1f-02ff-4c77-b509-7f9e771c795d}{73}" paraid="713311675">With our high-quality propeller designs we improve propulsion efficiency, we also constantly work on lowering mechanical losses and optimizing the shapes of underwater parts. The equation is easy - more efficient propulsion units means lower fuel consumption and better returns for our customers!</p>
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<p>The reliability of our propulsion units is essential. They are used on vessels involved in very critical operations, such as ice management, on icebreakers, oil platforms, wind farm maintenance vessels and cruise vessels, where any interruption can cause huge losses. To maximize the reliability of the propulsion units, our technical department needs to consider the challenging conditions in both open and icy waters in their calculations. For example, different kinds of load cases need to be considered and propulsor tooth contact patterns need to be designed to be ideal for every specific condition and situation.</p>

<p>To ensure lowest lifecycle costs, we have developed Steerprop Care, our condition monitoring service, which enables us to support our customers in their operations and ensure operational quality throughout the lifetime of the vessel. For example, by monitoring the life of the propulsor unit&rsquo;s power transmission line, unnecessary downtime and maintenance can be avoided and both time and money can be saved. Steerprop Care turns unplanned disturbances into planned service.</p>

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<h2 class="article__heading--h2">Close cooperation to achieve the very best</h2>

<p>To be able to add true value to our customers&rsquo; business, we are always open to new ideas and developments. This requires close cooperation with our component suppliers and manufacturers, listening to their research projects, being curious and continuously learning more.</p>

<p>The maritime industry also presents new challenges. When customers ask eg. for larger propulsors, it calls for complex considerations when it comes to material properties and manufacturability. By working in close cooperation with the world&rsquo;s leading component manufacturers, we can meet these industry challenges. For example, cooperation with companies that specialize in gears has helped us to achieve the proper hardening depths for gear sets. In this way, we can shape the lower body and get even greater results in efficiency.</p>

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<p paraeid="{6a60d794-6206-468b-8fb7-78f1aa9991f8}{52}" paraid="337738946">Only the best is good enough for us. We do not make any compromises when it comes to reliability. As we are determined to create even more efficient propulsion systems for the market, we concentrate on optimizing the shape of underwater parts to minimize flow resistance and take greater advantages of the contra-rotating propellers. In our optimization studies, we use model tests and CFD calculations.</p>
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<p>As part of our commitment to developing propulsion technology that improve overall efficiency, we have developed the contra-rotating propulsion (CRP) technology ECO product line. The whole propulsor is pressure lubricated to lower mechanical losses compared with the commonly used oil bath lubrication technology. To ensure the reliability of the propulsion units, they are subject to comprehensive factory tests where the functionality of the system is tested and verified.</p>

<p>Another big development is our Steerprop LM unit, which uses an integrated permanent magnet (PM) motor that offers much better efficiency compared to a traditional induction electric motor. Moreover, by replacing our upper gear with an LM motor, we get more room in the ship for other components and we can avoid upper gear excitations in the ship hull, which is especially important for cruise vessels.</p>

<h2 class="article__heading--h2">Teamwork all the way</h2>

<p>Resolving the challenges in the market and delivering on our promise is not a one-person process or project. To succeed in performing the very best solutions for our customers, it is important to be surrounded by visionaries and brilliant individuals that work together for a common goal.</p>

<p>Steerprop&rsquo;s R&amp;D department has highly motivated in-house experts from many different fields. Along with external specialists, we work closely together to produce outstanding propulsion solutions. We do our very best every day, bringing skills from mechanical design and analyzing, hydraulics, hydrodynamics, materials, and sealing systems to create superior products to meet our customers&rsquo; needs.</p>

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<p paraeid="{6a60d794-6206-468b-8fb7-78f1aa9991f8}{206}" paraid="1661520049">In this way, we can fulfill our customers&rsquo; demands for more efficient and more reliable propulsion systems with the best lifecycle costs on the market.</p>
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<h2 class="article__heading--h2"><br />
Author</h2>

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<p><strong>Janne Martikainen</strong><br />
<em>Manager, Product Management</em></p>

<p><em>Janne holds a M.Sc. in Mechanical Engineering from Aalto University and joined<br />
Steerprop in 2013. He is responsible for the development of the Steerprop product portfolio, engineering for R&amp;D as well as project deliveries. His main focus is to continuously improve design practices, in order for Steerprop to be able to create the most customer driven, reliable and flexible products on the market.</em></p>
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Our culture is built on working for a purpose, on designing and delivering solutions that have a real impact and make a real difference. This resolve to perform has always guided the ingenious minds of the Steerprop R&D department.

Propulsion innovations that challenge the industry

Steerprop is a leading designer and manufacturer of azimuth propulsion systems for the most demanding applications and toughest conditions.
Our culture is built on working for a purpose, on designing and delivering solutions that have a real impact and make a real difference.


Propulsion innovations that challenge the industry

Ice-going vessels put their trust in CRP thrust

The icebreaking rescue vessel Baltika – a new standard for maneuverability

Steerprop Services: Supporting customers by maximising the uptime of propulsion assets

Steerprop Stories

Steerprop Services: Supporting customers by maximising the uptime of propulsion assets

Steerprop References

Retrofit installation of the improved Steerprop Control System puts you back in control

Ice-going vessels put their trust in CRP thrust

Shifting focus to ship-scale CFD in the marine industry

More efficient, sustainable and cost-effective operations in the Finnish Archipelago

Focusing on minimizing underwater radiated noise

Predictive maintenance in arctic shipping

The icebreaking rescue vessel Baltika – a new standard for maneuverability

The Seven Viking - the most sophisticated offshore vessel built in Norway

Basic dimensioning principles for arctic propulsors

Propulsion innovations that challenge the industry