The five tower railcars of the series 704, delivered between 1977 and 1978, were developed as successors to the series 701/702 based on the railcar series 627.0/628.0. These two-engine vehicles could reach speeds of 140 km/h and still achieve 100 km/h with a trailing load on a 5 ‰ gradient. This allowed them to quickly arrive at the job site, and due to their excellent technical equipment, they were versatile in their deployment. They were often seen operating alongside overhead line construction vehicles or additional equipment cars. Throughout their over 30 years of service, they frequently changed the depots where they were stationed, depending on the workload and duration of major construction projects in the rail network, enabling rapid deployment from various locations across Germany. Initially, the crew was often affected by engine exhaust fumes, leading to the installation of new, lower-emission engines in the 704s in 1986. Additionally, exhaust pipes were routed along the left and right sides of the roof, allowing for remote-controlled diversion of exhaust gases depending on wind and air conditions. As it soon became impossible to procure spare parts after the retirement of the series 627.0 and 628.0, the tower railcars were decommissioned by 2012 and collected in Cottbus. They remained there for several years for sale but found no buyers. The last operational vehicle was the 704 002-5, which was transferred from its last depot in Ludwigshafen to Karlsruhe and then to Cottbus in January 2012. Unfortunately, all five tower railcars were dismantled, and none have been preserved for museum purposes. Our model was delivered on April 11, 1978, as the fourth vehicle of the series 704 to the depot in Osnabrück, where it remained until November 1986. It was then relocated to the depot in Würzburg, where it stayed until its retirement, after a brief stint at the depot in Nürnberg 2 from February 2004 to August 2006.