How to Lock-Thru a Large Dam


This information was written by my friend and fellow boater, Capt. Ken Bloomfield.  Ken provided this information as part of a boating forum and several times has traveled the Corp. of Engineers locks between the head waters of the Tennessee River and Mobile Bay.  This distance of 800 miles has 19 locks with the largest having a lift of 94 feet. Each lock is quite an experience.



Living here on the TVA portion of the Heartland river system, and having boated here for 17 years, I can assure you that the lockmasters monitor VHF and they normally proceed that way.  There are several published sites by the Corps (one given below), but here is a cribbed version of the normal procedure in these parts.  (By the way, there is a small pull cord for very small boats at the end of the lock with instruction sign, but for all "cruisers on up" the customary procedure is):


1.  Hail the Lockmaster on channel 16 at or near the approach point of the lock.  (Some of them get annoyed if you call too early and will tersely remind you to call them when you are at the approach point.  They have been "burned" too many times by somebody who radios in and says "I am 10 minutes away" and 30 minutes later they are not yet in sight).


2.  The lockmaster will then respond (maybe not immediately if he is on his little scooter traversing his lock, so don't get too excited) with instruction to switch to a working channel, channel xx (where xx is most often channel 14, but in some area where locks are close together may be another frequency such as channel 13).


3.  Once you are on the working channel he instructed you to switch to, he usually will ask you what you want.  You of course respond that you are pleasure vessel such-and-such downstream at (wherever you are, perhaps approach point) and wish to lock up (as an example, obviously could be down).


4.  I have never in many years of boating here heard any cruiser use horn signals, although they are permissible.  In fact, if you want the "chapter and verse" edition, go here for the PDF for  official (You may need to copy this and paste in your browser, as it may not act as alink) In this you will specifically find reference to the use of whistle signals, but also the permission (and encouragement) to use VHF.  This USACE document, and not my missive, is the "official procedure", but frankly a bit daunting for many.


5.  If the lockmaster has to drop the lock for you entailing releasing water, he will normally sound a siren type horn to warn the striped-bass fishermen to expect a sudden rush of water (often shoots sideways out of the lock wall towards the dam).  Fishermen in John boats, etc. are normally swarming like bees at the outflow of the generators or spillways, as this seems to be a great place for stripers.  (This gives them a chance to prepare/get out of the line of fire of the release water.)


6.  When the lockmaster has the lock ready for you, the doors will open(down or up), the light on the lock will turn from red to green (may have an intermediate amber) AND he will normally (but not always) sound a horn and often (but not always) tell you on the working channel "bring her on in and take pin #??" meaning to proceed into the lock and what pin (bollard) to take.  This is important to obey, as there may be "stuck" pins and you surely don't want to be tied to one when the water starts rising (or falling in a downlock).  Bear in mind that if there are several boats waiting for the lock transit that the lockmaster will say who goes in and in what order,normally large boats first.


7.  You enter, go to the pin (bollard) he instructed you to, tie up and then immediately thereafter radio him on the working channel that "Such-and-such is secure".  (If you look behind you, you will likely see the doors are already well on the way to closing.)  It is also customary to shut your engine down so as not to asphyxiate every other boat in the lock. 


8.  During all of this, it is the law that all deck-hands wear life-jackets. While I have seen exceptions, often the lockmaster will not start filling the lock until this is the case, and will say as much on the working channel to the offending boat.


9.  When you are finally up, the doors will open (or in at least one case drop down out of sight) and you will be given one horn when you are permitted to leave.  REMAIN tied to the bollard till you have this horn, and then leave.  If there are several boats, the lockmaster may say who leaves in what order.  There is no need to blow the horn, but it is customary to thank the lockmaster for the lift and wish him a good day.



The "landward lock" and the "riverward lock" are easy to remember.  There are often two parallel locks at many dams.  There is normally a "main lock" and an "auxiliary" lock (which is usually an older smaller lock).  In every case that I know, both locks will be towards one side of the dam (either right descending bank or left descending bank, may be either).  Here the two locks will be nestled side by side, and the one closest to the land is the "landward lock" and the one closest to the middle of the river is the "riverward lock".  Nothing more complicated.



By the way, the use of VHF also holds true for the bridges on the rivers, and I believe that horn signals in some cases might not work, as sometimes the actual bridge operator is many miles away and monitors and controls the bridge remotely.  He would be unlikely to hear a horn signal.  I have never had the case where one would not respond when hailed on either 16 or 13.


Ken Bloomfield