How
does a lock work?
A lock can
be thought of as an elevator to carry a vessel up or down from one pool
to the next. The lock has massive fixed concrete sides and large movable
metal miter gates at each end which are closed to create the equivalent
of an elevator car
which carries the vessel up or down using the water enclosed in the
lock.
To move up the waterway from a lower elevation pool to a higher one,
a vessel enters the lock chamber at the lower level with the upstream
gate closed; the downstream gate closes behind the vessel after it has
entered the lock.
To raise
the level of the water in the lock and the vessel with it, water from
the upper pool is allowed to flow by gravity into the lock through valves
until it fills the lock to the same level as the upper pool. The upstream
miter gate is then swung open and the vessel moves out into the upper
pool.
To move a vessel from a higher elevation pool to a lower one, the procedure
is reversed. With the downstream gate closed, the vessel moves into
the lock chamber filled to the upper pool level, the upstream gate is
closed behind the vessel, the water is permitted to drain out of the
lock through valves, and the vessel is lowered with the level of the
water. When the level of water in the lock reaches that of the
lower pool, the downstream miter gate is opened to allow the vessel
to move out into the pool.
Contrary to what many people think, no pumps are used to fill or empty
a lock; the water simply flows by gravity. It takes about 15 minutes
to fill or empty a lock chamber.
Who
can lock through?
You may lock pleasure craft through the locks on the McClellan-Kerr
Arkansas River Navigation System. Pleasure craft includes bass/fishing
boat, ski boat, party barge, runabout, day cruiser, houseboat, personal
watercraft excluding the stand-up variety, etc.
These
guidelines are provided for your protection and to make your locking
through experience a pleasant one. Make
sure you steer your boat directly towards the lock. Do not approach
the spillway sections of the dam. Currents are strong in this area,
and your boat may be drawn into or under the gates.
Signals
Stay between red and green buoys. They mark the river's navigable channel.
Small boats
may signal that they want to lock through by using the small boat signal
located near the end of the upper and lower lock walls, or by marine
radio. First try channel 16, then work through channels 14, 13 and 12
until you get an answer from the lock operator.
Entering
the Lock
After signaling that you want to lock through, wait for the lock operator
to signal that you may enter. You should stay past the end of the lock
walls until you are signaled to enter the lock. If a large craft is
leaving the lock and is headed in your direction, stay clear of departing
craft.
Traffic
signal lights and horns guide you at the locks.
A flashing red light means: Stand Clear. DO NOT ENTER!
A flashing green light means: Enter the Lock.
The lock
operator will, in addition to the traffic lights, signal you with an
air horn.
One long blast (4 to 6 seconds) means: Enter Lock.
One short blast (1 second) means: Leave Lock.
Four or more short blasts mean: DANGER.
Locking
Through
Please carry aboard at least 50 feet of mooring line in your vessel
to lock through. You will need it during lockage to tie your craft safely
to a floating mooring bitt. Do not tie to ladders or mooring posts along
the wall. Be prepared to cast off your mooring line quickly in case
of emergency.
Make sure
there is a mooring ring or similar device on your boat to tie the mooring
line to. Use fenders to save damage to your boat and to lockwalls. Turbulent
water is created during lockage. Passengers should remain seated in
your boat. Don't leave motor of craft running during lockage. Always
wear a life jacket on deck.
The lock
operators have been given the same authority over your boat in the lock
as traffic policemen have over your car at intersections. For your own
safety, you must obey their instructions. Wait for the lock operator's
signal before untying mooring lines to leave the lock. Travel at reduced
speeds when you enter and leave the lock. Fast speeds endanger your
own boat, other craft, and the lock gates.
Order
of Locking Through
The Secretary of the Army has ordered the U.S. Army Corps of Engineers
to pass vessels through the locks in the following order:
(a.) Vessels owned by the U.S. Government
(b.) Passenger Vessels
(c.) Commercial Vessels (i.e. towboats)
(d.) Rafts
(e.) Pleasure Craft
If commercial
traffic is heavy, pleasure craft may be required to wait approximately
1 ½ hours; or may be permitted to lock through with the commercial vessels.
Safety
Reminders
Be "dam" conscious! Know your location on the river with regard
to proximity of each dam and lock.
"NO BOATING" areas have been established immediately upstream
and downstream of the Dam. These areas are hazardous for small craft
because of dangerous currents.
Do not approach the dam. Approach the lock along the bank, directly
in line with the lock, and at a reduced speed. Be sure you have an anchor
on board.
Carelessness has resulted in loss of boats and loss of lives. Be safe!