Although fleet command saw the current tugs being effective in many roles, an anonymous request was forwarded for a "Heavy Tug", designed to push super capital ships into position when disabled. Command dismissed the request, but it did inspire ideas for a search and rescue craft based on the frigate chassis (then only represented by the prototype Torpedo frigate). The two ideas merged to become the "Heavy Tug".
It's intended role is to move station sections, Explorer Mission modules, even whole starships if they were disabled. The ship comes prepared with nearly a dozen tow cables and magnetic grapples- four of which are on extended booms that clear the sides of the vessel. The largest feature of the tug is, of course, the buffer plate at the forward part of the vessel (the hammer, as called by its crews). Layered with advanced polymers and rubbers, the buffer plate allows the frigate to make solid contact with the target vessel without causing serious trauma to the vessel being pushed. In-layed within the plate are several magnetic grapplers that allow a secured hold on the target while it is being moved. When moving a large object, standard procedure dictates that the grappler and extended hooks are deployed on the target before moving the object (in concert with standard tugs).
The heavy tug also comes equipped with a small hanger to service and store standard tugs for Rescue and Towing operations. The bow of the ship, between the pusher plates, also comes with a breaching drill that allows rescue teams to get into a disabled vessel.
At least one example was constructed by the third explorer, Teer-Gig, while it was performing support missions for the Taiidan fleet.
Another concept that seems to be overlooked in the genre. Have you considered a fleet tug version to this, based on a destroyer or cruiser hull? Nicely done!