River Gravel was mixed with cement to form
the lockwalls at the Old Locks like Lock and Dam #50.
Many a lockman will tell you it is almost impossble
to drill a hole in the river gravel lock walls.
Lock and Dam 50
(Before 1929)
The first Federal improvements
for navigation on the Ohio River came in 1824 with the removal of snags
and sandbars. These measures were effective, but they were only temporary—new
sandbars would appear after every flood. They also provided no relief against
low water, which stopped navigation almost every year. The construction
of a dam with a stable pool and a lock bypassing the dam would have ended
problems caused by low water, but the shippers who needed the full width
of the river for maneuvering were opposed to a dam.
A compromise solution was a movable
dam that could be raised in times of low water to create a pool and lowered
when the flow was adequate for navigation. The dams finally built had a
series of Chanoine wickets, invented by Frenchman Jacques Chanoine, extending
across the river. A system of 50 movable dams was built on the Ohio River
between 1879 and 1929, making the Ohio navigable for its entire length
at all times.
The Lock walls at Lock 50 were raised up 2 more feet during it's lifetime. The Lock is flat (even elevation) in this photo and it stayed that way for quite a long time. Sometime later in it's life wickets 2 foot longer than the originals were put in the dam as was raising the lock walls two feet.