The Lower Mississippi River Water Trail

Paddling Through a Lock and Dam

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?

Canoes & kayaks may lock any pleasure craft through the locks on the McClellan-Kerr Arkansas River Navigation System.  Stand Up Paddleboards have been excluded from the list and will be required to portage.  Hopefully this exclusion will change in the future.

 

Steer your vessel 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. 

Canoes & kayaks 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 (Canoes & Kayaks)

 

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!

 

For more information got to the US Army Corps Little Rock District site:

http://www.swl.usace.army.mil/navigation/lock.html