No. 21 Dredger, Morwell
No. 21 Dredger is historically significant as it was the first bucket wheel excavator to be used at the Morwell open cut. The Morwell open cut was a new major open cut project developed by the SECV with work starting on site in 1949. No 21 Dredger had a long period of service in the mine and worked between October 1955 and August 1992. It was used to excavate overburden and to supply brown coal to the Yallourn power station, and later to the Morwell power station and briquette factory, and Hazelwood Power Station.
No. 21 Dredger is technically significant as an example of the earliest design of Bucket Wheel Excavators used in the Latrobe Valley. It is representative of the first generation of German built Bucket Wheel Excavators used by the SECV, the design of which originated in German brown coal mines in the mid-1930s. No. 21 Dredger was one of the earliest uses of German continuous mining techniques and technology to be applied outside of Germany.
No. 21 Dredger is technically significant as the only example of the pre-war design surviving in the Latrobe Valley. Ordered in 1950, this machine is largely based on pre-war excavator technology. It provides a direct comparison with later post-war bucket wheel excavator designs.
This machine is fitted with a bucket wheel boom which features a crowding or thrusting movement where the bucket wheel can be moved relative to the slewing axis. This feature is largely associated with the pre-war or first stage of bucket wheel excavator development and was no longer applied to new machines by the mid-1950s. By this time, post-war excavators had greatly increased in size, and were not fitted with the crowd feature, instead the bucket wheel to slewing axis length was fixed. This greatly simplified the design of the conveyors, transfer points, and deleted the requirements for an additional conveyor, moving counterweights and a thrust drive.
Engineering Heritage Recognition Program
| Marker Type | Engineering Heritage Marker (EHM) |
| Award Date | 9 October 2016 |
| Heritage Significance | No. 21 Dredger was the first bucket wheel excavator to be used in the Morwell open cut mine. It is significant for its rarity as the only surviving bucket wheel excavator from the first generation with a crowd (thrust) mechanism and for its potential to yield information about the design of the first generation of bucket wheel excavators. |
| Nomination Document | Available here. |
| Ceremony Booklet Ceremony Report |
Not Available. |
| Plaque/Interpretation Panel | Available here. |
