It was the third type of Norwegian electric locomotive with bogies, after the NSB El 7 and NSB El 9.

They were manufactured by Norsk Elektrisk & Brown Boveri (NEBB) and Thune mekaniske verksted.

The b-series had minor modifications such as a windshield consisting of two large windows instead of four small ones.

Between 1982 and 1983 three El 11s were upgraded for use on the steep Flåmsbana branch line.

There are four preserved engines, two by the Norwegian Railway Club for use on special trains, and two by the Norwegian Railway Museum in Hamar.