Presque Isle Tug Question

[drydock]

The attached picture from the Fleet Photo section I think shows exactly what is being discussed about the navigation wings.

[Guest]

From a contact onboard the Presque Isle, the bridge wings are bolted on and designed to be removed by a crane. The running lights and other wires are disconnectable.

[Guest]

I noticed in very early photographs in my collection of the Presque Isle tug/barge combination that the tug had two small enclosures on the edges of what I would call "bridge wings." These appear to have been deleted early in the vessel's career and replaced with standard bridge wings without enclosures. In some of the pictures on this site the tug is shown operating away from the barge without these structures attached. Are they removed to facilitate passage through the Welland Canal when the tug went to Port Weller for survey? Were they installed to be removed? I ask because in the pictures of the tug without the wings, there appear to be no torch cutting marks on the white paint of the cabins.