From Minneapolis on to the Gulf, tows are a fact of life on the river. A tow is an array of cargo barges lashed together with cables and pushed by a specialized ship called a towboat (aka tugboat or pushboat): http://en.wikipedia.org/wiki/Pusher_(boat)
Between Minneapolis and St. Louis, where they must transit locks, tow arrays get no larger than 3 barges wide by 5 barges long (3 x 5). On the lower river, we passed tows that were 6 x 7 arrays. Since a barge is commonly 35 feet wide by 195 feet long, a 6 x 7 tow is 210 feet wide and almost 1400 feet long, not including the towboat. A typical fully loaded barge displaces 1500 tons, thus a 6 x 7 tow displaces 63,000 tons, which is greater than the WW2 battleship Missouri. These things are big and you and your tiny boat share the river with them. Anybody paddling the river should read John McPhee’s Uncommon Carriers to get a better understanding of the tows and how they work.
Tows are intimidating but actually not too difficult to live with. First, they are slow; 11 mph is about the maximum speed traveling downriver and they are a lot slower going up. Second, at normal water levels, tows stay in the channel. Tow movements are generally extremely predictable as it takes a long time to make a turn; they don’t dart around on the river. If you carry a marine radio, you can listen in on the pilot’s conversations. When one tow needs to pass another, either in opposite directions or in the same direction, much discussion ensues about who passes whom where and how. Often a tow will slow down or stop to let a faster one pass, as there are limited places on the river where passing is even possible. If you have a radio, you can even inform the tows that you are in the area. Use channel 13 and know your position before you go on the air.
Sharing the river with tows requires you to be aware of a few things. Most importantly, don’t get in their way, and don’t paddle in conditions where you might capsize in the navigation channel. Capsizing near a tow is well described in this report. Tows cannot maneuver or stop quickly and if you are too close to them, the pilot probably cannot see you. If they run you over, they may not even be aware of it. Cross the river in places with long views both upstream and downstream to ensure that there are no tows approaching. If you behave appropriately, you will not get run over.
Tows create wakes as they pass. The first wake comes off the front corners of the leading barges and is usually not very big or turbulent. There will then be a hiatus before the wake from the screws of the towboat arrives. These wakes can be large and very turbulent, particularly from tows going upriver where they have to push against the current. Keep in mind that a large towboat has three screws and 11,000 horsepower turning them. Finally, the wakes and turbulence will reflect off of the riverbanks and create random chop, particularly where the banks are steep and have been armored with rocks by the Army Corps of Engineers.
We found two things that helped a lot in dealing with wakes. First, it is best to pass tows on the inside of a bend in the river. The inside of a bend is likely to be shallower, less steep, much less likely to be armored, and the current is slower. The tows will be close to the outside of a bend as that is where the channel will be. On the inside bend you will be further away, the screw wake will be directed away from you, not toward you, and there will be much less reflective turbulence. This strategy requires crossing and re-crossing the river as it snakes its way south, but we found it made life much easier when passing tows.
If you can't get away from a closely passing tow, you can find shelter by paddling into a shoreline eddy, the larger the better. The eddy line, the point in the river where upstream and downstream currents pass each other, will absorb almost all the wake turbulence from a passing tow. If you are in the eddy, you will experience very little to no turbulence. Fortunately, eddies are common features along the riverbank, so if you see a tow coming and you are on the outside bend, you will usually be able to find one prior to the arrival of tow’s wake. Sometimes, however, we were exposed directly to tow wakes at relatively close range and were always able to ride them out without issue. So, pay attention, stay out of their way, respect them, and you shouldn’t have any problems with tows.
The turbulence caused by a single distant tow was rarely substantial. However, because tows can only pass each other in certain sections of the river, they often wait for periods so they are in the right place relative to the other tows, and they may stack up. We would often go for a couple hours seeing no tows, and then have five or six tows pass in an hour. Our most congested area had nine tows in 90 minutes. When there are tows holding position while a string of oncoming tows passes, the combination of all their wakes bouncing off the riverbank can get fairly intense.
There are also smaller towboats operating around docks. These are used to construct tows and move individual barges from here to there. Their movements are less predictable than the large tows, but the pilots have reasonably good visibility of the river. On several occasions, the pilots obviously saw us coming and waited for us the clear the area before proceeding with their duties.
Between Minneapolis and St. Louis, the Army Corps of Engineers has constructed 29 sets of locks and dams. The most northerly lock, Upper St. Anthony Falls in Minneapolis, is scheduled to be decommissioned in the spring of 2015. Operations hours of the Lower St. Anthony Lock may be reduced as well. As of this writing, the portage options are unclear and are still be discussed by various interest groups. The Mississippi River Paddlers Facebook group should be a good source of current information. The Corps closes the Upper and Lower St. Anthony Falls and Lock 1 during period of high flows. This requires finding alternative means for getting around several miles of river. Currently there is no designated portage route from St. Anthony Falls to below Lock 1; however, there is a local portage service operated by the Paddle Taxi.
You must either transit a lock or portage around it. At many locks, portaging would be difficult or impossible as there is frequently no place near the lock to take out or put in and the lock complexes can be more than ½ mile long. By studying maps and satellite images, it might be possible to plan to portage (some, many, all?) locks by using side channels. If you try to plan this, remember that both maps and satellite images may not match the water level when you are at the lock, so what may look possible on paper may be difficult or impossible in reality. For example, a spillway may be a viable portage at low water, but be a dangerous place at high water. The vast majority of paddlers use the locks. There are three exceptions described at the end of this section.
The locks were constructed because the Army Corps of Engineers built dams to maintain enough water depth for shipping and still have to allow for boats to transit the dams. The neat thing about the locks is since they were constructed with public money, use of them is free, and available to any type of craft using the river. Kayaks and canoes have the same rights to passage as tows and private powerboats. There is a pecking order and commercial traffic has priority over recreational traffic, which sometimes can mean a long wait to use a lock. It can take a tow between one and two hours to transit a lock, so if one arrives just before you do, you are in for a long delay. On our trip we had mostly good fortune with the locks and only had to wait for more than half an hour on a few occasions, while we had many “drive-thru” transits with no wait at all.
To use a lock, you paddle up to the end of the “long wall”, which is a concrete structure extending many hundreds of feet out from the lock gates, and pull a marked cord announcing your desire to make a transit. With luck, the lock staff will be able to see you and come out and let you know what the situation is. A far better solution is to carry a marine radio (use channel 14, except for Lock Mel Price, Lock 26, that uses 12) and contact the lock when you are 10 to 15 minutes out. “Lock XX, this is downbound canoe. We are 15 minutes out from the long wall and request passage. What is the current status for a transit?” The lock-master will respond and let you know whether there is a wait or not, how long the wait might be, or if you are lucky will say: “Downbound canoe, this is Lock XX, we'll have it ready for you when you get here.”
After approaching the lock, you find a place to hang out near the end of the long wall where you can see the signal light. Depending on the winds, this may not be as simple as it sounds. When the lock is ready to receive you, the light will turn green. You paddle in through the open upstream gates and usually a lock staff member will direct you to a particular point they want you to be and drop you a line to hold onto. There may be other recreational craft in the lock with you, but you will not share it with tows. After everyone is stable, the upstream gates are closed, the water level is slowly lowered to match that of the downstream river, and the downstream gates are then opened. When the lockmaster is satisfied that all is well, he will sound a loud horn signaling that it is now safe to let go of the line and paddle out. Do so and get out of the way of the downstream lock entrance as quickly as possible.
Do not tie off on the line or you may be dumped out of your boat and it will be left dangling as the water drops. Although in some locks the water level only changes by a foot or so, in others the drop is as much as fifty feet. If a tow is exiting a lock as you arrive, do not approach the long wall until the tow is completely clear of it. The tow can generate massive waves in the narrow confines near the long wall that could easily swamp your boat.
We found the lock staffs, civilian employees of the Army Corps of Engineers, to generally be very friendly, interested in our journey and helpful. On three occasions staff members actually used their own vehicles to portage us around locks that had long delays due to the presence of tows. They helped us get our canoe out of the water, transported us to an appropriate put in, and helped us get back on the water. Nice people.
There are three locks where there are easy options to transiting the main lock. At Lock 14, there is, on river right, a back channel through a marina which leads to a small auxiliary lock. Since the auxiliary lock only transits small craft, you will not be delayed by tows. It is worth using this option. At Lock 15, there is a back channel on river left that goes around Rock Island. Once in the channel, you will pass smaller Sylvan Island and soon see a dam. There is an easy and short portage river left before you reach the dam: climb up a short set of rocky steps and follow a marked trail around the dam. After the portage, a short paddle brings you back to the main river downstream from Lock 15. Given how much river traffic there is in this area, we chose to take the portage route rather than risk a long delay.
Finally, at Lock 27, the last on the river, there is a better way downriver than transiting the lock. The difficulty at Lock 27 is that to approach it, you must first paddle an 8-mile long rock-lined man-made channel. There is no shelter here from tows, which will be very close to you due to the narrow width of the channel. If you stay in the river instead, there is single obstacle: the Chain of Rocks. This is a partially natural and partially man made rocky barrier that stretches across the entire river. At normal water levels we have been told it is runnable by those who know the route, but should NOT be attempted by those who don’t. There is, however, on river left, a very easy and very short portage around this barrier. We choose to go this way and as the river was running high when we were there, the Chain was submerged and we just paddled over it without incident. Even if you must portage, we believe that you are much better off doing so than transiting Lock 27.
We generally enjoyed using the locks. It added variety to the trip, frequently being the only boat in these huge structures was really cool, the staffs were great, and it felt like we were really taking part in the way the river works.
South of Minneapolis, the main channel is marked with buoys. Looking downstream, the river right side of the channel is marked with green flat-topped buoys called “cans” and the river left side of the channel is marked with red conical topped buoys called “nuns”. These can be very useful because the tows are going to stay in the channel and the buoys identify it.
However, when the river floods, as it did during our trip, it uproots many of the buoys and drops them where it pleases. Usually this is on the riverbanks, where we saw large numbers of stranded nuns and cans. However, sometimes the river just shuffles the buoys around so they now mark what is definitely not the channel. The tows know where the channel is anyway, but the paddler probably doesn’t. We have no idea how long it takes the Coast Guard to replace and realign errant buoys after a flood. Be cautious about assuming that all of the buoys are in the right places.
In high water, buoys can also “rabbit”. The current forces them underwater and they disappear for varying periods of time, only to unexpectedly pop back up to the surface. Since these things weight about 800 pounds, getting hit by a rabbiting buoy is not a good idea. Pay attention to what is going on around you.