Drydock, Dam, Locks and Trunnion Bridge in Port Carling, ON

Big Lock and Drydock: (Satellite)

Dam and Little Lock: (Satellite)

Muskoka Steamships & Discovery Centre posted five photos with the comment: "The RMS Segwun and Wenonah II will be heading to dry dock at the Port Carling locks this Fall! The ships will undergo inspections and important maintenance during this time before heading back to Gravenhurst for the winter. Get your cruise tickets now to enjoy a ride on these beautiful ships at www.realmuskoka.com. Check out the photos from our previous dry dock that took place in 2016."

Janey Anderson shared with the comment: "Love to get up to Port Carling this winter to see these beautiful boats in drydock!!"

Bill Thomson: I worked that drydock painting the inside of a sewage tank isn't alot of fun.

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Dean Oldham commented on the above post

The Segwun is a steam powered cruise ship. It is nice to see the owners are taking such good care of it. Doug Ramey provided a couple of photos in the comments on the above post.

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When I first looked for a drydock, I could not find one. Instead I found a big (near the top) and a little (near the bottom by the dam) lock.

Satellite

Using the fourth photo above, I confirmed that the big lock is used as the drydock. 

Street View, Nov 2022

4 of 17 photos posted by Janey Anderson with the comment: "The RMS (Royal Mail Ship) SEGWUN is the oldest operating steam driven vessel in North America, built in 1887 in Clyde, Scotland as the "Nipissing" to cruise the Muskoka Lakes."

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Janey Anderson posted

BOW WOW

Took a little drive out to Port Carling today to experience the amazing Autumn colours and see the RMS SEGWUN in lock/dry dock.

Oct. 21/23 

The RMS (Royal Mail Ship) SEGWUN is the oldest operating steam driven vessel in North America, built in 1887 in Clyde, Scotland as the "Nipissing" to cruise the Muskoka Lakes.

Ed Wilson: Best engineering job I ever had.

I engineered on her for a season to get some steam time. Two compound engines and a scotch boiler that was still coal fired.

Bill Jr Salton posted two photos with the comment: "Every 5 years the old Segwun, and her replica sister Wennonah II arrive in Port Carling, ON for drydocking ahead of their winter slumber. The lock is drained and becomes a makeshift drydock for the necessary inspections and/or repairs. So great to finally see this in person! Note, the lock is close enough to the main road lift bridge that the drone camera wouldnt fit the entire boat in one frame from that level, so 2 photos were stitched together to show a full vessel 😉"

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Note that the bridge from which the above street view was taken is a trunnion drawbridge that pivots on the south side.

Peter G, Aug 2023

The elevation difference between Lakes Rosseau and Muskoka is not big, but it was big enough to create a rapids on the Indian River that hindered navigation between the two lakes. So in 1871, a lock was built. After WWI, there were more than 6,000 vessels a year and wait times over an hour. So the little locks were built to handle pleasure boats and relieve the pressure on the big lock. Today, electric gates allow boats to pass through in just 10 minutes so the little locks "have receded into the background." [MuskokaRegion] Why is "little locks" plural? I see three gates in this street view. But the lift height is not enough to justify a double lock. Looking at the satellite image, I see two boats in the little lock and four in the big lock.

Street View, Sep 2018

The MuskokaRegion article makes a big deal that the little lock wasn't built until after WWI. But this source indicates that it was built when the dam was built.

The Canadian Canal Society web site shows the dimensions as follows:

Small Lock (at the dam) built 1873, 83' x 12' (25.3 m x 3.7 m). GPS 45E07'07.59"N 79E34'35.17"W
Large Lock (On a separate channel) built 1874, 175' x 33' (53.3 m x 10 m). GPS 45E07'12.33"N 79E34'37.28"W
Mnimum depth for both locks is 8.5' (2.6 m) and lift is 4' (1.2 m).

[AmericanCanalSociety]

2:35 video @ 0:58

This source agrees that both the big and little locks were constructed at the same time. Work began in 1869.

Boaters have to pay a fee to use the big lock, but they can lock themselves through the small lock. [muskoka]

One reason it did not occur to me that the big lock was the drydock until I studied the photos was that a drydock normally has a nearby building for machine and fabrication shops and supplies. And they have concrete surfaced sides that can hold cranes. Now I realize that any lock that has bulkheads so that it can be dewatered for maintenance can be used as a drydock if you don't need support facilities.