Wagon with opening roof

They are a large category of rail vehicle, predominantly used for the transport of hygroscopic bulk commodities such as cement, plaster, lime, potash and grain.

The last large batch of lidded wagons was procured by the East German Deutsche Reichsbahn in 1958.

The latter could be loaded and unloaded vertically by crane, the sliding roof enabling half the available length of the wagon floor to be available at one time.

For example, the wagons could be loaded at a port directly from the ship by crane; at their destination they could then be unloaded through the side doors.

In the 1970s it became clear that the movable roof was only rarely used for palettised goods whilst, for larger, awkward loads, swing-roof wagons (see below) were better suited.

For transporting heavier, even more awkward and moisture-sensitive goods the DB has, since 1964, four-axled wagons with movable roofs.

Many Td wagons are exclusively used for the transport of foodstuffs and therefore bear the index letter g. In addition there are special types for specific purposes, for example those with low-level apertures for gravity discharging (Class T…oo…).