The Helix Dumper is a versatile wagon and unloading system optimised for fine-grained and potentially sticky heavy bulk materials. The system has an unparalleled discharge rate of up to 25,000 tonnes per hour.

The Helix Dumper is a versatile system that is suitable for rock, pellets and concentrate. The rounded shape of the body,creates optimal conditions for efficient discharge of even the most tough-flowing and sticky concentrate material that are unsuitable for bottom discharge.

Currently, there is no technology that can match the productivity of the Helix Dumper when it comes to unloading heavy fine-grained bulk goods at a high discharge rate. In comparison, bottom dump systems operate at a fast rate but can’t handle sticky materials, and rotary car dumpers are slow and expensive compared to the rolling discharge solution of the Helix Dumper.

The Helix Dumper system and its components is tested and proven in a demanding subarctic climate in the Arctic region of Scandinavia.

Award winning, simple and effective design

The principle behind the award-winning unloading technology is simple but ingenious: When the Helix Dumper enters the unloading area, a wheel at the top of the wagon makes contact with the spiral-shaped rigid guide that constitutes the unloading station. As the wheel travels along the path of the guide, the chassis remains on the rails while the body of the wagon is rotated 148 degrees to dump its load.

Kiruna Wagon’s Helix Dumper offers a completely new technology for the unloading of fine-grained minerals and as awarded the Swedish Steel Prize 2017. Read more about the award here.

Low-cost unloading station: No moving parts – no electricity

The Helix Dumper’s discharge process is powered by the locomotive’s forward motion – the unloading station has no moving or motorised parts and requires no additional power supply. Kiruna Wagon delivers both the wagons and the unloading system, which is a robust and low-cost solution that requires minimal maintenance.

If the future brings increases in production, the system can easily be scaled up with one or more additional unloading station. Thanks to its limited construction depth and lack of electric motors, the Helix Dumper unloading station requires a smaller initial investment than, for example, rotary car dumpers.

HD in brief



Average Annual Wagon Speed (AAWS) is a key performance indicator of modern wagon fleets. Our BD built for LKAB moves at 17.5 km/h and our new-generation BD for Rana Gruber at 25.7 km/h. Download our AAWS sheet to compare our numbers with those of your own fleet.

Wagon specifications example HD 30/12
Unloading capacity 25,000 tonnes/h
Max axle load 30 tonnes
Line load 12 tonnes
Number of axles 4
Wagon length 10,300 mm
Gauge 1435 mm
Tare weight 22.4 tonnes
Loading volume 45 m³
Length between bogie centres 6744 mm
Wheel base 1778 mm
Coupler height 1040 mm
Working temperature -40 to +60 °C
Discharge angle 60˚
Unloading station specifications
Unloading capacity 25,000 tonnes/h
Required positioning accuracy
Working temperature −40 to +60˚C
Electrical power required
Loading gauge All common
All wagon types can be customised to fit your logistics preconditions. Such as axle loads, length, volume, loading profile, AAR, TSI, etc.


Since 2018, Helix Dumpers from Kiruna Wagon have provided an efficient and safe solution for Kaunis Iron’s transport operations between Pitkäjärvi in Sweden and the Port of Narvik in Norway. Each train carries approximately 2 900 tonnes of iron ore concentrate.