75 years propeller - We take you on a journey through 75 years of propeller history

1948 - Hard to believe! We have been manufacturing our ship propellers in Waren (Müritz) for 75 years.

In 1948 the production of ship propellers was required to build up the shipbuilding industry in the GDR. The picture shows the first propellers. At that time, they had a raw casting weight of 3 to 4 tons and a diameter of 3 meters. The second picture shows us the building at that time with the old company name.

1949 - Rising production figures, increasing demands on quality - skilled personnel are needed.

Already in 1949, Sigfried Piarowski was commissioned to organize apprenticeship training. In the period from 1948 to 1951, there was even a company vocational school where formers, electricians, locksmiths, toolmakers and model carpenters were trained.
Even today, apprenticeship at MMG is still very important to qualify our future skilled workers. Currently, about 10 apprentices are learning the professions of machining mechanic, industrial mechanic, foundry mechanic and metal technology specialist in different apprenticeship years.

1952 - Did you know what was produced before the propeller?

The VEB Gießerei und Eisenwerk Waren produced common household appliances from aluminum alloys. The first picture shows the processing of a frying pan at that time. Due to the demands for copper alloy castings, the production of household appliances was completely stopped in 1952.
In 2020, the production was resumed with aluminum alloys - the whole with a production possibility of up to 70 tons.

Welcome to the years 1954 to 1956.

The interest of the GDR's mechanical and plant engineering industry lay in ever larger and more sophisticated foundries. In order to make these wishes come true, investments were made in a new foundry hall - the South Hall.

This made it possible to cast propellers with a diameter of 6.5 meters and a finished mass of 25 tons in the required quality.

Almost 75 years later, the former South Hall is surrounded by even larger halls and is still used as a foundry today.

Since 1970, the metal casting plant has steadily developed into a medium-sized business

Due to ever increasing demands on the quality and size of the propeller, the necessary skilled personnel also had to be provided. At that time, the metal casting plant employed up to 400 people, including about 40 apprentices.

Nowadays, the quality and size requirements have increased further. MMG has a global presence. In addition, MMG continues the tradition of that time and consolidates its position on the world market through continuous improvements. Mecklenburger Metallguss currently employs more than 200 people, including about 10 apprentices.

In 1971, fixed pitch propellers were built for the fast freighters "Karl Marx" and "Friedrich Engels".

These fixed pitch propellers had an operating weight of more than 40 tons and exceeded the capacity of the hangar at the time. The fast freighters were the fastest on the waters in the GDR at that time.

The world's heaviest propeller was produced in 2006 for the Emma Maersk. Weighing 131 tons and with a diameter of almost 10 meters.

However, this has since been replaced by a more efficient and slender propeller.

After casting, the propeller could only be removed from its mold and cleaned.

Until 1975, the fixed propellers were sold as blanks and could not be further machined. At that time, they were mainly finished by the shipyards in Rostock and Wismar. From that point forward, they could be machined in the newly built propeller machining shop.

For more than 50 years now, the MMG has taken over the finished machining and thus no longer delivers blanks.

For even better machining of the fixed pitch propellers a milling machine was installed in 1976.

The milling machine came directly from Japan and was only the second machine of its kind. The programming at that time was still done via punched tape.

Today's special milling machine increases productivity and enables the highest precision in the machining of the propellers.

In the years from 1970 to 1990, MMG supplied high-quality products.

During this time, it manufactured about 2500 different products for about 400 customers with about 350 employees. The main products were large castings, medium castings, centrifugal castings and small castings made of copper alloys.

Even then, the main product was the fixed pitch propeller with a maximum diameter of 6.3 meters and a maximum delivery weight of 25 tons. Today, the fixed pitch propeller measures up to 11.6 meters in diameter and weighs up to 160 tons.

Today, MMG continues to set the standard in terms of design, size, quality and efficiency. Our product range is constantly evolving. In 2020, for example, additive manufacturing was launched with an XXL printer for model production and an automated welding robot.

Arrived in the 2000s.

The international acquisition made it clear that propellers with a delivery weight of over 100 tons represented a gap in the market and that demand was growing. MMG accepted the challenges and risks and decided to build a new, larger foundry hall. The 1000 m² hall was equipped with 2 crane bridges with a lifting capacity of 160 tons each. In addition, another melting furnace with a melting capacity of 80 tons was added. This furnace is the largest medium-frequency melting furnace for copper alloys ever built worldwide. With it, MMG made the breakthrough to become the global market leader.

Today, we are still setting new standards. We have one of the world's largest melting capacities for aluminum and copper alloys. In the most efficient induction furnaces, we cast with the highest homogeneity of the melt.

In 1983, the first computer was put into operation at MMG.

VEB Kombinat Robotron was the largest computer manufacturer in the GDR. The word Robotron was composed of the terms robotics and electronics. In 2006, Computational Fluid Dynamics (CFD) methods were introduced to optimize hydrodynamic components. Similarly, casting simulation methods were used to improve component quality. This enabled the efficiency of the propellers to be optimized and underwater noise to be reduced.

To achieve the best possible result, the ship, rudder and propeller can be simulated as a whole.

As a result of the numerous investments made in recent years, a record was set for the first time in 2008.

Almost 200 large fixed pitch propellers were cast within one year. This high number of units required great efforts and many overtime hours in order to ensure on-time delivery in the corresponding quality. Today, more than 100 propellers still leave the factory every year. However, the delivery weight has not changed significantly, as the size and thus the weight has increased compared to 2008. MMG is constantly researching new technologies and methods to make the propellers even more efficient.

The further development of the plant was hampered by the intersecting federal highway in the direction of Teterow.

Clearly visible in the first picture. After much planning, the groundbreaking ceremony for the relocation of the Teterow road was celebrated in 2008 in the presence of prominent guests. Two years later, in May 2010, the bypass was completed. From now on, a completely new layout of the site was possible. Due to the ever increasing propellers, the internal space conditions and the entire logistics of the production chain became more and more complicated. The relocation of the road made it possible to build new halls and thus eliminate the last weak points in production.

The repair of propellers on site became more and more in demand.

This also opened up a new field of business for MMG. By increasing capacity and labor productivity in MMG's propeller grinding shop, it was possible to spare a few selected grinders from production and qualify them as fitters abroad. Long dock layovers and significant costs to customers are avoided by on-site repairs.
Even today, fast repairs are still being made to propellers, increasingly by outside contractors. Approximately 40 damage cases are processed annually.

To check the shaft contact and thus the required quality, the test was carried out with the original shaft at that time.

If this was not available, an female gauge was used. A major challenge arose in 2007 during the shaft contact test with the largest and heaviest propeller in the world. Here, the lack of capacity in MMG's halls became apparent. In 2012, this procedure was replaced by the Virtual Contact Test (VCT) for the sake of simplicity. This test ensures that the propellers can be replaced within a docking interval. In this process, the hub bore is measured to an accuracy of one hundredth of a millimeter while still in the MMG factory and compared with the design data of the existing shaft. VCT is recognized and certified by all renowned classification societies. This means that the propeller is delivered ready for assembly and the classic blueprint test can be completely replaced - both for redesign programs and for new ships.

Small cap. Big effect.

In 2013, our innovative propeller cap energy saving cap (MMG-ESCAP) was produced for the first time. With this propeller cap, shipowners can increase the efficiency of their marine propulsion systems by up to 3 %. In addition, the MMG-ESCAP features a sophisticated fin design that de-spins the hub vortex while reducing torque loss. This propeller cap is not only suitable for new construction of high-performance marine propellers, but also makes existing ships significantly more efficient. In addition, compared to previous propeller cap, it optimizes flow conditions and reduces cavitation at the rudder, thus increasing service life.

Did you know? This year we celebrate 10 years of retrofit!

In 2013, one of our propellers was refitted for the first time. MMG Retrofit Propellers offer additional potential to reduce fuel costs and CO2 emissions. To date, over 400 existing retrofit propellers have already saved more than 13.8 million tons of CO2 emissions. Replacing the old ship's propeller with a retrofit propeller matched to the new operating profile significantly increases efficiency and, in conjunction with a propeller cap, reduces fuel consumption. Up to 14% fuel savings are possible in conjunction with the MMG Escap mentioned last week.

Automation plays a central role in increasing the competitiveness of companies.

Traditionally, depth reference drilling was carried out in a time-consuming manner using a hand drill.
Especially for large structures, there is the challenge to manufacture in an automated way. Through a research project with the Fraunhofer Institute, the robot has already been put to use in our halls.
To implement the optimized propeller design, several state-of-the-art 5-axis milling and boring machines are available for machining. They are dimensioned to meet all current and future requirements for the size, shape and weight of propellers. In addition, they guarantee maximum precision. This means that even the most complex designs can be realized.

From casting to delivery

- the world's largest continuous production line for ship propellers. All this is possible at our site in Waren an der Müritz. The hall, which is over 400 meters long, has 22 molding stations, including the world's largest induction melting furnace.