Page "KW-37" Paragraph 9

Typically, fleet units utilizing the KWR-37 units were outfitted with two devices for operational redundancy ; that is, should one unit fail, the other one would already be online and patches via a high level, 60-milliamp patch panel would quickly be changed around so that the current offline unit could be changed over to online status at a moment's notice, and the goal here was to ensure that there was no interruption of message traffic.

Since the KWR-37 units were aged and worn, sometimes the circuit cards inside had to be reseated with a rubber mallet which helped ensure the cards were reseated properly.

Other problems with the KWR-37's were related to the startup times.

Fleet Radiomen, and those stationed in the shore transmitting stations, had to listen to an HF signal for coordinated universal time.

Radiomen called this broadcast the " time tick ," which gave them a sharp tone, signalling them to press the restart button so that the unit could then start up for " new day " or otherwise known as " HJ's " by the Radiomen.

This took place after the new day's crypto keylist card was properly inserted into the " crib " or the card reader by securing it onto pins and then firmly closing the card access door and then locking it with a key.

Once the unit ( s ) were restarted, the key was placed back in the safe using two-person integrity ( TPI ) which was stringently enforced following the Walker spy investigation.

In the early nineties when the KWR-37 units were retired from the navy and replaced by the more reliable and modern KWR-46's, fleet Radiomen breathed a sigh of relief because the KWR-37 units were often unreliable and would occasionally fall out of synchronization timing, resulting in a loss of broadcast messages from the various fleet channels.