Greyhound

Tom Hanks does it again.

This was an incredible thriller that kept me on edge for an hour and a half.

If you are a history buff like me, I suggest listening to the Hardcore History: Addendum podcast between Dan Carlin and Tom Hanks. It gave insights that I would have misunderstood or altogether missed in watching the movie blind.

If you are unable or unwilling to listen but want to watch the movie, below are three interesting takeaways.

1. The “Conn”

Throughout the movie, Tom Hanks tells his crew, “I have the conn.”

Quite simply:

One of the most important principles of ship handling is that there be no ambiguity as to who is controlling the movements of the ship. One person gives orders to the ship’s engine, rudder, lines, and ground tackle. This person is said to have the “conn.”— James Alden Barber, 2005, “Introduction”, The Naval Shiphandler’s Guide, p. 8.

2. U-Boat Speed

While a U-boat is capable of maintaining the same speed as a convoy, say 14 knots, they can only do so on the surface. Once a U-boat dives, they slow to 6 knots. While minimally important to understand the movie, this fascinated me and made sense why the U-boats often travel on the surface and how they are often spotted. This brings me to the last point.

3. U-Boat Power

U-boats were diesel powered. In order to dive, they had batteries which would be charged when the boat was on the surface or at periscope depth. Therefore, they needed to come back to the surface in order to “breath” and recharge their batteries. This is another reason subs regularly resurface.