I've been working on a totally scratch-built tug for the last several months. This tug is a compilation of ideas I've gleaned from pictures, searches, and "if it looks right, it works for me." Although this isn't a build log, I thought someone may be interested in the steering system, and a couple of shots of the progress.
The steering concept isn't new for sure because several old steam tugs used chains to pull over the rudder quadrants through a steam engine mounted either behind the deck house, or in the aft end of the engine room. I didn't have the correct angle or space for a quadrant, but was able to use a yoke. The problem to over come with a yoke is the chains had to track straight fore and aft across the deck like a quadrant would allow. As the yoke turned the angle of the chains decreased dragging them across the deck side to side. The answer here was to install a couple of fairlead wheels aft of the rudder post then turn the chains around them creating a straight consistent track across the deck to the servo mounted in the engine room.
There's another winter's work in this build with the interior details, doors, windows, and deck gear, but it has been launched, and run several times. All ballasted and in running trim she weighs 47 lbs. She's 55 inches long, and 1:18 scale.

Nice!

For those unfamiliar with steering quadrants, here's one on the 1906 tug Baltimore. Hard to see, but it has two grooves, one for each chain. In this case, the chain is taken over sheeves and down below deck. Sometimes the chains go a bit farther forward and then down. Sometimes the chains run in a covered channel on deck and into the aft house (engine room). And sometimes they go in covered troughs all the way forward along the house, before going inside to connect to the wheel.

Old style ship's wheels are attached to drums with ropes or cables wound around.

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Some mid-1930's GA plans I have show a hydraulic steering system in the lazarette, so yes probably a hydraulic pump connected to the wheel.

Thank you Pat.

This seemed like a worthwhile experiment. The biggest concern was the strength of the chain in the correct scale. None of the costume jewelry chains of the required size had the tensile strength needed. I ended up getting a couple meters of stainless steel chain from Germany.

SS Master tug in the Vancouver (a lot of video on her on Youtube, ) has steam/chain steering which lets the chains out of the bulwarks aft around a turning block then run forward and back aboard in the area of the deckhouse aft.
Seguin had chain boxes across her aft deck.