Jacob H. Douma
When the lock lift exceeds, 60 feet, then consideration should be given to constructing
double locks. For example, if the total lock lift is feet, then the designer should
determine whether it's more practical, more efficient, and more economical to have two
locks, each with a
In other words at the downstream end of the lock structure
there is a
lift and at the upstream end there is another
lift.
John Davis, who was in my branch in the Chief's Office, was the best lock designer the
Corps of Engineers ever had. Any report that had anything on the design of locks was
given to John for review. The districts always wanted model test of the locks. WES did
all the model testing on locks. John always went to the district design and WES model test
meetings. Now, the Corps has excellent manuals on the design of navigation locks and
dams. John wrote those manuals.
How much does putting a lock in a structure cause you more difficulties in design?
You've talked about the high locks, but how about the basic design and the hydraulics
of such designs?
A:
Let's take a dam, say, 40 feet high, with one lock, like those on the Ohio River. If the
dam goes all the way across the river with an ogee section and tainter gates, it would be
made of concrete. During a flood, the gates would be operated and most of the water
would go over the spillway because not much water passes through a lock.
It doesn't take much water to operate a lock. There is an intake at the upper end of the
lock to a conduit and a small lock bay that controls the water to fill the lock bay. The lock
has large vertical swing gates at the downstream end that are several feet higher than the
lift. Similar gates are at the upstream end of the lock, but they are seldom more
than half as high as the downstream gates. These lock gates are closed during flood time
so all the water goes over the spillway.
When a vessel comes to the downstream end of the lock, the downstream gates are opened
so it can enter the lock. Then the downstream gate is closed, and the lock is filled by
opening the small gate in the filling culverts. It take as much as 30 minutes to fill the lock
so the water level in the lock is the same level as the water level in the river upstream of
lock. Then the upstream lock gate is opened, and the vessel goes upstream. This
process is reversed when a vessel passes from upstream to downstream.
Q ..
kind of problems does that give the hydraulic designers?
If the head is more than about
feet and the lock filling gates are not designed correctly,
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