A Schwartzkopff-Eckhardt II bogie (Schwartzkopff-Eckhardt-II-Lenkgestell or Schwartzkopff-Eckhardt-Gestell) is a mechanical device to improve the curve running of steam locomotives.

The Schwartzkopff-Eckhardt II bogie is a further refinement of the Krauss-Helmholtz bogie

Krauss-Helmholtz bogie

A Krauss-Helmholtz bogie is a mechanism used on a steam locomotive, where a carrying axle is connected to a coupled axle via a lever such that when the carrying axle swings to the side on going round a curve, it causes the coupled axle to move sideways in the opposite direction...

, whereby two coupled axles and the carrying axle are combined within the bogie

Bogie

A bogie is a wheeled wagon or trolley. In mechanics terms, a bogie is a chassis or framework carrying wheels, attached to a vehicle. It can be fixed in place, as on a cargo truck, mounted on a swivel, as on a railway carriage/car or locomotive, or sprung as in the suspension of a caterpillar...

. The carrying axle steers the second coupled axle via a long shaft and this also moves the first coupled axle via a Beugniot lever

Beugniot lever

The Beugniot lever is a mechanical device used on a number of locomotives to improve curve running. It was named after its inventor Edouard Beugniot....

. This bogie is used on the DRG Class 84

DRG Class 84

The German DRG Class 84s were standard goods train tank locomotives with the Deutsche Reichsbahn. A total of twelve engines were placed into service by the Reichsbahn between 1935 and 1937. The machines were given operating numbers 84 001–012...

. Whether DR Class 99.23-24

DR Class 99.23-24

The engines of DR Class 99.23 are metre gauge steam locomotives, that were procured by the Deutsche Reichsbahn in East Germany from 1954 to 1956. When they entered service they had operating numbers 99 231–99 247...

 locomotives were also fitted with this arrangement is not entirely clear.

It was named after the L. Schwartzkopff

Berliner Maschinenbau

Berliner Maschinenbau AG was a German manufacturer of locomotives.The factory was founded by Louis Victor Robert Schwartzkopff on 3 October 1852 as Eisengießerei und Maschinen-Fabrik von L. Schwartzkopff in Berlin ....

locomotive factory and its chief engineer, Friedrich Wilhelm Eckhardt.