A number of these preserved locomotives are in operational condition.

Seven members of the D class have been preserved, although only two are in operational condition.

The mill was restored to its operational condition in the 1960s.

The unit also has yet to be tested under operational conditions.

There are no current plans to restore her to operational condition.

Four members of the class are now preserved, with one of them in operational condition.

Funds are being raised to restore the rest of her to operational condition.

None are recorded as being lost to enemy fire, but only five were in operational condition by the end of the war.

A number have survived in museums including one example that has been restored to operational condition.

Weapons and warp drive have never been tested under operational conditions.