Mercury vapor rectifier

Mercury vapor rectifier

Foto av museumsgjenstand, kvikksølvdamplikeretter med kolbe av glass
Foto: Jaroslav Bogomolov / Museum Nord

This mercury vapor rectifier in 220V 3-phase semi-bridge coupling that gave 60A direct current is from shunter locomotive Ska 205 on the Ofotbanen. One of the sides of the mercury vapor rectifier is broken, and it is black on the inside in several places.

Two shunter locomotives arrived in Narvik in 1936 from Trondheim with D/S Trondhjem. The locomotives were supplied by Norsk elektrisk & Brown Boweri, NEBB. The shunter locomotives were stationed at Narvik station. They were used for the shunting of the passenger and conductor wagons in the ore trains.

The shunter locomotive were electrically powered by two large battery packs, and the technology developed at the time was state-of-the-art for its time. The system was built on the principle of simple speed regulation by adjusting the voltage of the motors across a power resistor, via a turning roller.

Svarthvitt historisk foto av akkumulatortraktor på Narvik Stasjon
NSB Ska 205 shunter locomotive at Narvik Stasjon. Foto: Narvik kommunale fotosamling / Museum Nord

With the shunter locomotives, a mercury vapour rectifier was supplied in 220V 3-phase semi-bridge coupling that provided 60A direct current. The product was BBC Gleichrichter GmbH Berlin. It was located in a separate charging station at Narvik station. The glass flask for the mercury vapour rectifier is now in the exhibition at Narvik Museum.

The district had two such shunter locomotives, No. 1 and No. 2. After the Cf wagons were removed from the ore trains, the tractors were used, among other things, to change car wagons from the crossbar to departing passenger trains.

Svarthvitt foto historisk, skiftetraktor på ofotbanen
Foto: Trygve Romsloe, Narvik kommunale fotosamling / Museum Nord

See the mercury vapor rectifier at work

Video from The Edmonton Power Historical Foundation Museum


The mercury vapour rectifier is part of this week’s object 2024 – a collaboration project between Museum Nord, Árran Lule Sami Center, Helgeland Museum, Nordland Museum and Narvik War Museum. Read more about this week’s object here.

Read more about the Ofotbanen railway


The story of Hundalen by the Ofotbanen railway – the place that was strategically located for the upcoming construction road from Rombaksbotn

Life in Rombaksbotn

The community in Rombaksbotn was established when the second attempt to build the Ofotbanen railway started.

Opening of the Ofotbanen railway

On 15 November 1902, the Norwegian Ofotbanen railway was connected to the Swedish Malmbanan on the National Border. The following summer there was a tablecloth for a feast dinner and a royal visit.

Electrification of the Ofotbanen railway

Electrification of the Ofoten Line – In 1923, the Ofoten Line switched from steam locomotives to electrically powered locomotives.