Looks like an accident 'bout to happen at the locks! While the main chamber is down for maintenance, boats have to use the smaller chamber. They have to do what is called a "double lockage" meaning they have to cut the first three strings of barges, lock them through, then lock the next two strings with the boat on the second. What looks like turmoil here, in reality, is the Sandy Drake, background, holding the first three strings of the tow pushed by the A. N. Prentice while the Prentice is now facing up to recouple her tow. This is the "buddy system" now used by towing companies when having to double lock on the Ohio River. They take turns assisting lockages, usually six tows up then six tows down. The Enid Dibert is tied off on the lock wall awaiting to "turn a boat" meaning she's waiting on another boat to lock through and she'll take that tow on up river while the other boat takes the hopper barges loaded with coal back down river. For modeling realism notice that a lot more coal can be loaded in a hopper than gravel ( shown in the Prentice tow) because gravel is much heavier than coal.
HOW MUCH DOES A TOWBOAT TOW?
A jumbo hopper barge 195' X 35' can carry 1500 tons. That is equivalent to 15 jumbo hopper rail cars or 60 semi dump trucks. A 15 barge tow carries 22,500 tons equivalent to 2 1/4 100 car trains or 900 semi dump trucks. Lengthwise a 15 barge tow is 1/4 mile long, 2 1/4 unit trains are 2 3/4 miles long, semi trucks spaced 150' apart equal 3 miles long.
Line-haul boats travel the rivers 24 hours a day, 365 days a year. Crews usually work 30 days on and 30 days off. Some companies work 20 days on and 15 days off. Working hours for the crew is divided into six hour shifts. The shifts are as follows;
6:00 AM to 12:00 PM and 6:00 PM to 12:00 AM
12:00 PM to 6:00 PM and 12:00 AM to 6:00 AM
For local towing companies men usually work twelve hour days, four days a week
TYPES OF TOWBOATS
There are many types of workboats on the rivers today. I have categorized them into four groups, utility boats, harbor boats, trip boats, and line haul boats.
Utility boats range from 18' in length to over 50'. They perform specialized tasks such as crew boats, supply boats, tenders, bow boats, and truckables. Crew boats are used to transport personnel from boat to shore, boat to boat, or to barge fleets. They are also used as inspection boats in harbors to check barges for "leakers" and check the lines to be sure the fleet is secure. Supply boats deliver goods to the larger boats or to work barges. Grocery delivery boats are in this class. Tenders usually work in a specified area like a dam or a "mother ship" such as a dredge. A bow boat is used at the head of a tow for maneuvering. They can be piloted from a command station in the mother vessel's pilot house. Truckables are vessels that can be disassembled and placed onto trucks to be transported overland to remote locations.
Harbor boats are vessels you'll find all up and down the river. They range from 24' in length to over 60'. Their job is to assist in making and breaking tows for line haul boats, shifting barges around for drop off points along the route, and dropping off or picking up barges at terminals. Some harbor boats don't have a galley on board and the crew has to bring their lunch with them. That's where they get the name "lunch bucket" boats. Day boats are called such for they have no sleeping quarters.
Trip boats range from 55' in length up to 120'. They are called trip boats for they make trips of three to five weeks and return to their home port. Their horsepower rate from 850hp, for the small boats, to 3000hp for the larger boats. They push an average of fifteen barges, except for the ones below 1000hp, they usually push no more than nine. The smaller boats have galleys and sleeping quarters for a crew of four to nine people. The larger boats have quarters for nine to fourteen people.
Line haul boats
Cooperative Enterprise photo courtesy of Barry Griffith
Line haul boats range from 120' in length to 200'. Horsepower for these vessels range from 3500hp to 10,500hp. They run 24 hours a day 365 days a year. The only time you'll see one of these docked is when they're in for repairs and/or maintenance. The largest towboat to date was built in 1993 for the Corps of Engineers, called m/v MISSISSIPPI V, it is 241' long by 58' wide and is 7000hp.
A typical fifteen barge tow, the maximum amount of regulations on the Upper Miss., the Illinois, the Ohio, and the Tennessee Rivers, would be built with three rakes abreast facing forward leading each string, and three abreast facing rearward at the stern of each string if loaded. At the first, second, and third (or break) couplings, its anything goes, depending what you have to work with (squares or rakes). At the fourth (or steering) coupling, loaded rakes face rearward. When possible, two loaded rakes are placed back to back (box ends together) making a unit. A regulation box may also be put between these making a three piece unit. In the winter, rakes are placed nose to nose to make an ice coupling across all three strings at the break coupling. This is so that when you break the tow for lockage, the ice will not hinder facing the second cut (six barges and the boat) to the first cut (the nine barges that have already been locked through). With square (box) ends, the ice keeps the cuts from touching (about 1 to 2 feet apart) and even if it can be wired together, its not a safe coupling.
Ever wondered how locks work on the river
Locks use the law of gravity to raise and lower the water level. No pumps are used except to pump out debris from behind the gates. As you can see in the animation, valves are opened to allow water to rush in and equalize itself with it's upper level, gates are opened and the tow pulls into the chamber. The upper gates are closed and the valves are turned off and the other valves are opened to allow the water to equalize itself with the lower level. Then the lower gates are opened and the tow goes on it's merry way.