Engine Order Telegraphs (EOTs) are used to send a signal from the bridge to the engine room with instructions about speed and direction (ahead or astern). Each is unique and one of a kind.

As the lifespan of large ships become shorter with advancing technology, instruments used onboard continue to be updated which means far fewer are made with costly materials such as bronze or brass.  These will be ever  more challenging for us to source - and more expensive to procure.