The Ville class "pup" tug Listerville moved the fenders originally (see a previous post) perhaps to be used to protect CCGS Hudson during the recent severe sou'easterly winds.
Glenside is one of three "Glen" class tugs based at HMC Dockyard in Halifax (there are two more at Esquimalt on the Pacific coast). Built in 1977-79 they are 1750 bhp (Ruston-Paxman) 19 tonne Bollard Pull Voith-Schneider tugs, and were quite revolutionary for their time. Despite their great agility and ability to move within the tight confines of HMC Dockyard, they are under-powered by today's standards and obviously are getting old and parts are hard to source.
Late last year the Department of Defense and the government procurement agency issued a Request for Information to "solicit feedback from industry" for replacement of these tugs. It was not a invitation for bids, since there is no funding in place yet, but more of a sounding out of those interested in building new tugs. I have detailed some of the particulars here before, but essentially the navy wants two new tugs in Halifax and two in Esquimalt, and they are to be more or less off-the- shelf commercial designs.
Canadian Navy tugs come under the direction of the Queen's Harbour Master (QHM) and and have civilian crews. The Master Attendant in the QHM is responsible for their daily operation.
When the current Glen tugs were planned, it was recognized by the QHM that work in HMC Dockyard had some unique characteristics due to the narrow cambers between the finger piers. The operators studied tugs in many other locations, including the Alcan tugs at Port Alfred, some of the earliest V-S tugs in Canada. Voith-Schneider tugs, with their ability to change thrust direction without having to re-orient hull direction, were ideal for the Dockyard work, but I believe it was a bit of hard sell to convince the top brass that the higher cost was justified. Perhaps that is why the horsepower is so low.
Things have changed since those days however, with larger naval vessels in service and more to come. There are also many more options such as ROtor tugs (three thrusters), more sophisticated Azimuthing drives, including controllable pitch props, and more efficient V-S. It will be interesting to see what comes out of the RFI, which closed February 28.