The In's and Out's

of Locking Through a

Dam By

RiverBill

Mississippi River Locks and Dams… Why ?

• To achieve a 9-foot channel in the Upper Mississippi River, the construction of a system of navigation locks and dams was authorized in 1930. Dams are built on rivers to hold back water and form deeper navigation "pools." Most pools in the United States are maintained at a constant minimum water depth of 9 feet for safe navigation. Dams allow river vessels to use a series of locks to "step" up or down the river from one water level to another.

The Corps operates the locks and dams on the Mississippi River for navigation, not flood control. The locks and dams create slack-water pools for navigation during periods of low- and moderate-level water. For each pool, there is a primary control point, where a predetermined water elevation must be kept for navigation.

Reprinted from US Army Corps of Engineers website

How a Lock Works• Lockage is completed by

using a system of valves to raise and lower the water level in the lock chamber. The filling valves are opened to allow water to enter the chamber, making it the same height as the upper pool, and the emptying valves are opened to allow water to drain out, making the chamber the same height as the lower pool. There are two sets of valves, the filling valves (located at the upper pool) and the emptying valves (located at the lower pool).

During the process, no pumps are used, the chamber is operated solely on gravity

Source USACE

How to contact Lock Master

• Signal Lock Master by using signal cords located on guide walls– Signal for lockage by using the signal cords located at the

midpoints of the upper and lower guide walls. Look for the sign "Small Craft Pull Cord To Signal For Lockage."

• Hail Lock Master on marine radio– Identify your self as a north or southbound pleasure craft

wanting to lock through– Identify boat name– Ask for approximate wait time

• Call Lock Master on cell phone– Identify your self as a north or southbound pleasure craft

wanting to lock through– Identify boat name– Ask for approximate wait time

Mississippi RiverLock & Dam Phone Numbers & Marine

Radio Channels

Lock and Dam 24, Clarksville, Missouri– 573 242-3524…… CH. 14

• Lock and Dam 25, Winfield, Missouri – 314-566-8120…… CH. 12

• Lock and Dam 26, Alton, Illinois – 618 462-1713…… CH. 14

• Lock and Dam 27, Granite City, Illinois

– 618 452-7107…… CH. 12

Safety & Equipment

• Safety– Wear life jacket

– Don’t put your body between lock wall and boat

• Equipment– Boat fenders

– Paddle or dock pole to keep boat off lock wall

Preparing to lock through

• Highly recommend using fenders between concrete lock wall and boat– Some boaters even cover bumpers in a trash bag.

Lock walls have a pretty rough surface and usually have a bit of river slime on them

• Put your fenders out before entering lock. Usually on same side of lock as lock office.

• Get a paddle or dock pole out to help keep boat off lock wall

When Do you Enter the LockLock Traffic Signals• No lights shown

– Wait & Contact Lock Master

• Red Light – Stand clear & DO NOT approach

• Yellow Light – Approach lock under full control

• Green Light – Enter lock

Entering the Lock

• Lock Master will open lock gates• Lock Master will signal when OK to enter

– Traffic signal has Green light

– Some blow a horn also

• Enter lock at no wake speed and locate mooring lines hanging along lock wall. Lock worker may also give instructions as to where to position boat along lock wall

Preparing to lock through

• Hold rope to keep boat in position– DO NOT TIE ROPE TO BOAT !

• Be aware of what’s going on around you– As water goes up or down the boats around

you may move position and get close to your boat.

Locking through

• Lock Master closes lock gates• Lock Master raises or lowers water in lock

to level of next pool• Lock Master opens lock gates• Lock Master signals when boats are

allowed to leave lock chamber, usually with a short horn blast

Full lock headed southboundPool 25 Party 2009

Leaving Lock

• Push off from lock wall, leave rope• Proceed at “No Wake” speed

Leaving the Lock

The Up’s and Down’s of Locking Through

• Some locks have special weekend hours for pleasure craft

• Sometimes you must wait in line with the tows

• When the lock is damaged or some problem arises, your stuck and have to wait.

Thanks for Locking Through

WithRiverBill