Locks

 

Watching another ship exit before we started our upstream trip

Until the 1960s, Portugal’s Douro River was populated with sizable and treacherous rapids.  Five dams with locks were constructed during that and the next decade.  The locks made the river much more navigable.

Satellite screenshot of a cruise ship in the lock

 I had no idea how exciting the ten trips (the cruise went out and back) through locks would be. 

Thirty Centimeters clearance on each side

Douro River cruise ships are built as large as can fit in the locks.  There’s about a foot of clearance on each side of the ship (especially exciting when viewed from the stateroom veranda), and some traverses require that the sunshade and bridge roof on the top deck be lowered to fit.  

One bridge, at least, required that the crew measure the clearance with a stick.

Sailing into the trash compactor

Giant door behind us beginning to close

Coming upstream, we pull into a chamber reminiscent of the trash compactor scene in Star Wars: A New hope and watch the massive doors close behind us. 

Gravity feeds water and floats us up to the new river level.  The tallest lock had 115 feet elevation change. Once we’d reached the proper level, a door dropped vertically, and off we went.

Just before the bathtub drained on the way down

 

Of course, the procedure was reversed during the downriver part of our journey.