Previous posts about our Scotland trip can be found here.
Our barge Fingal of Caledonia embarked from Inverness and traveled to Banavie near Fort William to the southwest. This video gives some perspective for that journey.
Lake | Loch | Lock
Loch (/ˈlɒx/) is the Irish and Scottish Gaelic word for a lake or for a sea inlet. In English and Hiberno-English, the anglicised spelling lough is commonly found in place names, pronounced the same way as loch. In Scottish English, ‘loch’ is always used. Some lochs could also be called firths, fjords, estuaries, straits or bays.
A lock is a device used for raising and lowering boats, ships and other watercraft between stretches of water of different levels on river and canal waterways.
Caledonian Canal and Lock System
Three lochs are aligned end to end along the route. The largest and most well known is Loch Ness at the northeast end of the route near Inverness. Loch Lochy is situated at the southwest near Banavie. Between them is the much smaller Loch Oich. The Caledonian Canal connects them and allows boats to access them from the North Sea and the Atlantic Ocean. Rivers also connect the lochs. The rivers are not navigable by larger vessels. The canal parallels the rivers.
The elevations of the three lochs are different. Loch Oich is the highest and most inland at 106 ft above sea level. Loch Lochy has an elevation of 94 ft above sea level. Loch Ness is 52 ft above sea level. Ample precipitation inland maintains the loch levels. Because of the differences in elevation, a system of locks raises or lowers vessels to allow them passage. From the Inverness end, there are 14 locks to allow vessels passage to and from Loch Oich the highest elevation. From the end near Fort William, there are 15 locks to allow vessels passage to and from Loch Oich.
Three places have multiple locks arranged end to end. There are 4 in a group near Inverness. There are 5 in a group at Fort Augustus. And there are 8 at Banavie. This last large group is known as Neptune’s Staircase. Passage through it can take more than 90 minutes. Operations can be challenging when the holiday season brings many pleasure boats to the canal. Our barge barely fit its length into the locks. Our width also limited the vessels that could join us in the lock.
How Locks Work
A lock can raise or lower a vessel depending on the desired direction of travel. Below are two series of graphics provided by Wikipedia User Cmglee illustrating the step by step process to raise and lower a vessel in a lock.
In the past, lock gates and valves were operated by a team of men at a rotating device called a capstan. Sturdy lengths of wood were inserted into the four white square holes so the men could push it around to turn the mechanism. Seven turns were needed to open or close a gate.
Today, the lock gates and valves are operated by hydraulics. One person can control the gates and valves from a console next to the lock chamber. In the past, a busy lock might have several men assigned to operate the gates and valves. Below is one of the hydraulic control panels.
Passage by Fingal
On the third day of our voyage we approached the set of five locks at Fort Augustus at the end of Loch Ness. The video shows our very slow and deliberate approach into the system of locks. Next, we see Fingal within the first lock being readied to be raised. The crew tied the barge and moved the small craft out of the way. The third part shows the water pouring into the chamber. The crew is busy adjusting the ropes to keep Fingal snug to the side. Finally, the water level is the same as the next lock chamber. The gate is opened for us to proceed. The whole process starts over to secure the barge and prepare for being raised in the next chamber.
One of my favorite images I found in researching this post is a map published in 1848. I include a link to it if you are interested. It is a large file over 2 megabytes. On a computer screen, it can be view full-sized showing some amazing details of the canal system. In the lower right corner:
Ordered by The House of Commons to be Printed 29th August 1848.