Why there are locks and how they work

A lock is a device used for raising and lowering boatsships and other watercraft between stretches of water of different levels on river and canal waterways. The distinguishing feature of a lock is a fixed chamber in which the water level can be varied; whereas in a caisson lock, a boat lift, or on a canal inclined plane, it is the chamber itself (usually then called a caisson) that rises and falls.

Locks are used to make a river more easily navigable, or to allow a canal to cross land that is not level. Later canals used more and larger locks to allow a more direct route to be taken.

A lock is a part of a navigable waterway system that makes a water “channel” deep enough for vessels to use. The lock controls pool depths, for example in a lock and dam system across a waterway.

The lock is a place where boats that travel up or down a river or canal can be moved to the next higher or lower level. Locks are built in places where the level of the water in the river or canal suddenly changes. This may be because of a waterfall there, or because a dam or a weir has been built, or because some other thing is in the way. The lock is like a big chamber with gates at each end. They have lock gears which empty or fill the chamber with water. Locks help a river to be more easily navigable (easier for boats to travel up and down), or for canals to be built across country that is not level.

If a boat that is traveling downstream (in the same direction that the water is flowing) arrives at a lock, this is what happens:

  • The boat waits until the lock is full of water. If a boat going the other way has just come out of the lock, the water level will be right and the gates will be open. This will save time.
  • The entrance gates (if shut) are opened and the boat sails in.
  • The entrance gates are closed.
  • A valve is opened, and water flows out of the chamber so that the boat goes down.
  • When the water is at the level of the next bit of river, the exit gates are opened and the boat sails out.

If a boat that is traveling upstream (in the opposite direction to the water flow), the opposite happens:

  • The boat waits until the water level is low. If a boat going the other way has just come out of the lock, the water level will be right and the gates will be open.
  • The entrance gates (if shut) are opened and the boat sails in.
  • The entrance gates are closed.
  • A valve is opened, and water pours into the chamber so that the boat goes up.
  • When the water is at the level of the next bit of river, the exit gates are opened and the boat sails out.

The whole process of going through a lock may take about 15 to 20 minutes, depending on whether the boat has to wait. Some locks can take several boats at once, and the first one to enter may have to wait until other boats arrive.

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River portion of the trip is running to an end soon. Mobile bay on the horizon…

River portion of the trip is running to an end soon. Mobile bay on the horizon. With that said, here is another small collection of mostly the Tom Bigby. Today we turned over 1000 NM cruised in just 15 days. For a boat this age and speed i’d say we are doing well and still seeing the country. #missmarianne





 

Bobbies Fish Camp to Mobile Bay

Bobbies Fish Camp to Mobile Bay

Posted by Albert Bartkus on Sunday, November 12, 2017

Like a fireman, ready to go.

Posted by Albert Bartkus on Sunday, November 12, 2017

At Bobby's Fish Camp

Posted by Albert Bartkus on Sunday, November 12, 2017

Posted by Albert Bartkus on Sunday, November 12, 2017

Posted by Albert Bartkus on Sunday, November 12, 2017

Posted by Albert Bartkus on Sunday, November 12, 2017

Posted by Albert Bartkus on Sunday, November 12, 2017

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Looks more like I need a F1 race car track and not for a boat. 90 mile run today…

Looks more like I need a F1 race car track and not for a boat. 90 mile run today. #missmarianne

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White Epes Cliffs on the Ten Tom

One of Alabama’s most underrated natural wonders is the White Cliffs of Epes, stretching for approximately one mile, this group of historic cliffs is made from layers of the Selma Chalk Formation. Over time, this natural wonder has become more and more exposed due to the rushing river water. Today, it stands about 30 feet above water.

Tennessee Tombigbee Waterway

The Tennessee–Tombigbee Waterway (popularly known as the Tenn-Tom) is a 234-mile (377 km) man-made waterway that extends from the Tennessee River to the junction of the Black WarriorTombigbee River system near Demopolis, Alabama, United States. The Tennessee–Tombigbee Waterway links commercial navigation from the nation’s midsection to the Gulf of Mexico. The major features of the waterway are ten locks and dams, a 175-foot-deep (53 m) cut between the Tombigbee River watershed and the Tennessee River watershed, and 234 miles (377 km) of navigation channels. The ten locks are 9 by 110 by 600 feet (2.7 m × 33.5 m × 182.9 m), the same dimension as the locks on the Mississippi above Lock and Dam 26 at Alton, Illinois. Under construction for twelve years by the U.S. Army Corps of Engineers, the Tennessee–Tombigbee Waterway was completed in December 1984 at a total cost of nearly $2 billion.

The Tenn-Tom encompasses 17 public ports and terminals, 110,000 acres (450 km2) of land, and another 88,000 acres (360 km2) managed by state conservation agencies for wildlife habitat preservation and recreational use.  

Image result for tennessee tombigbee

 

Pickwick Locks Timelapse on the Tenn Tom with #MissMarianne – Great Loop travels

http://lifeofacaptain.com – Pickwick Locks Timelapse #MissMarianne on the Tennessee River, headed to the TenTom. Our friends from Chicago caught up with us .

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Here are a few more images from the last couple of days.

Here are a few more images from the last couple of days. Seems we are getting deeper into the wild and ridding the industry and commercial scenery. #missmarianne





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#sunset at Midway Marina on the Tombigbee River #MissMarianne #greatloop

#sunset at Midway Marina on the Tombigbee River #MissMarianne #greatloop http://www.lifeofacaptain.com

Midway Marina

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Whitten Lock and Dam #MissMarianne #greatloop #yachtlife

Whitten Lock and Dam #MissMarianne #greatloop #yachtlife http://www.lifeofacaptain.com

Jamie Whitten Lock Mile 412 Tenn-Tom

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